Agreement on a Methodology for Deriving Environmental Assessment Criteria and their application

Transcription

1 Agreement on a Methodology for Deriving Environmental Assessment Criteria and their application (OSPAR Agreement: ) 1 Introduction 1. This agreement sets out the methodology for deriving criteria for the radiological environmental assessment of concentrations of radioactive substances in the marine environment of the OSPAR maritime area by OSPAR Contracting Parties. The agreement also describes how the criteria should be applied. 2. The practical aspects of the methodology should be reviewed and updated where necessary by Methodology 3. The methodology developed by the International Atomic Energy Agency (IAEA) for deriving the environmental assessment criteria (EAC) is set out in Reference 1 ( the IAEA Methodology ) and attached at Annex 1. The principles of the IAEA Methodology were agreed by the OSPAR Radioactive Substances Committee in 2013 subject to further testing and demonstration (see Application below). 4. The scheme used in the IAEA Methodology to assess the radiological impact on humans and non humans in an integrated manner is summarised in Figure 1. 1 English only 1 of 14 OSPAR Commission OSPAR Agreement

2 Figure 1: Scheme used by the IAEA to derive reference concentrations (taken from Reference 1) 5. In summary, the criteria are in the form of reference activity concentrations in filtered seawater (Cref) which equate to whichever is the lower of the concentrations that would give rise to: 2 of 14 OSPAR Commission OSPAR Agreement

3 a. an annual radiation dose of 1 millisievert (msv) to humans; or b. a radiation dose rate at the lower bound of the relevant Derived Consideration Reference Level (DCRL) as defined by the International Commission on Radiological Protection for key marine Reference Animals and Plants. 6. The EAC for the OSPAR indicator radionuclides are given in Table 1. Table 1: Environmental Assessment Criteria for OSPAR Indicator Radionuclides OSPAR Indicator Radionuclide Cref (Bq/l, filtered seawater) H E+05 Tc 99 Cs 137 Pu 239/240 Ra 226 Ra 228 Po 210 Pb E E E E E E E 04 Application 7. The OSPAR Radioactive Substances Committee tasked an Intersessional Correspondence Group (ICG EAC) in 2013 and 2014 with the testing and practical demonstration of the IAEA Methodology. 8. The testing and demonstration carried out by the ICG EAC is described in References 2 and 3, and attached as Annexes 2 and 3. The principal conclusions and recommendations from this work with regard to the application of the methodology are as follows. 9. The EAC in Table 1 may be used for screening purposes, as part of a suite of assessment tools, provided it is made clear that the screening assessment is applicable to OSPAR indicator radionuclides only. 10. Care should be taken when selecting the regional monitoring data for assessment. In particular, the demonstration (see Reference 3) showed that there is the potential for artificially high Limits of Detection (e.g. where they have been set on cost rather than quality grounds) to exceed EAC. 11. The Risk Quotient (RQ) for individual radionuclides shall be the ratio of the measured activity concentration to the Cref. RQ C / Cref 3 of 14 OSPAR Commission OSPAR Agreement

4 Risk Quotients may be summed over radionuclides as appropriate (j) to give the Sum of Risk Quotients (SRQ): SRQ RQ j j 12. The SRQ may be used to categorise OSPAR Radiological Assessment Status at the regional level, and to suggest potential measures, in accordance with Table 2 as agreed at RSC 2014 (Reference 4). The use of SRQ should be qualified it is based on the dose assessment for the OSPAR indicator radionuclides unless otherwise specified. 13. In the case of the SRQ falling in Category B, OSPAR may wish to use the EACs for other nonindicator radionuclides in the assessment, especially as the SRQ value approaches The EAC may be used to assess the additional concentrations of radionuclides due to discharges. 15. The OSPAR indicators and the table of categories do not replace the need for a more detailed and specific radiological assessment if the total doses to humans or biota at a specific location from a wider range of radionuclides are required. 4 of 14 OSPAR Commission OSPAR Agreement

5 Table 2: OSPAR Radiological Assessment Status Category OSPAR Radiological Assessment Status Potential measures that may be taken OSPAR Contracting Parties C SRQ > 1 B 0.1 < SRQ 1 OSPAR assessment results indicate further consideration is needed OSPAR assessment results are satisfactory should undertake, or use existing, site specific and/or detailed assessment supported by additional monitoring OSPAR Contracting Parties may consider confirming the satisfactory status by reviewing their monitoring programme especially as the SRQ value approaches 1 A SRQ 0.1 OSPAR assessment results require no further action No additional action required 5 of 14 OSPAR Commission OSPAR Agreement

6 References 1. IAEA (2013) Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC IAEA Contribution to RSC Ref. RSC 13/7/1 (Note: a minor clarification in the text was produced by IAEA in 2016 and approved by RSC 2016). 2. RSC (2014) Report on the application of the Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC. ICG EAC report to RSC Ref. RSC 14/4/1. 3. RSC (2016). Final report on the demonstration of the proposed IAEA method for Environmental Assessment Criteria. Ref. RSC 16/4/1 (Annex 2). 4. RSC (2014). RSC 2014 Summary Record, Annex 6. Table 5: Sum of Risk Quotients (SRQ) Categories for application at OSPAR regional level. 6 of 14 OSPAR Commission OSPAR Agreement

7 ANNEXES Annex 1 IAEA (2013) Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC IAEA Contribution to the Meeting of the OSPAR Radioactive Substances Committee (RSC) Ref. RSC 13/7/1. Annex 2 RSC (2014) Report on the application of the Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC. ICG EAC report to RSC Ref. 14/4/1. Annex 3 RSC (2016). Final report on the demonstration of the proposed IAEA method for Environmental Assessment Criteria. Summary of RSC 15/3/1. Ref. RSC 16/4/1 (Annex 2). 7 of 14 OSPAR Commission OSPAR Agreement

8 Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC January 2013 IAEA Contribution to the Meeting of the OSPAR Radioactive Substances Committee (RSC) The Hague (Netherlands): 5 7 February 2013 (Note: text edited by IAEA after RSC Meeting in Brussels, Belgium, Feb 2016)

9 CONTENTS 1. INTRODUCTION CHARACTERISTICS OF THE APPROACH Radiological reference criteria for protection of the public and the environment Integrating exposure scenarios for humans and flora and fauna Discussion on the human driven versus environment driven assessment approach CALCULATION OF THE REFERENCE CONCENTRATIONS Calculation scheme Estimation of reference concentrations Consideration of the protection to marine flora and fauna THE RADIOLOGICAL ENVIRONMENTAL ASSESSMENT CRITERIA FOR OSPAR (A PROPOSAL BY IAEA) Selection of the IQQ figures to define categories CONSIDERATIONS ON THE USE OF THE CATEGORIZATION SCHEME Discussion on water/sediment equilibrium assumptions SUMMARY APPENDIX I. PROCEDURE FOR DERIVING CONCENTRATIONS RELATED TO THE HUMAN DOSE LIMIT APPENDIX II. PARAMETERS USED IN THE DERIVATION OF DOSE PER UNIT CONCENTRATION VALUES APPENDIX III. PROCEDURE FOR ASSESSING DOSE RATES TO MARINE FLORA AND FAUNA REFERENCES ANNEX I. RADIONUCLIDES USED IN A TEST CASE OF THE METHODOLOY CONDUCTED BY THE IAEA REFERENCES ANNEX II. REFERENCE CRITERIA USED FOR RADIOLOGICAL PROTECTION OF THE ENVIRONMENT BY DIFFERENT AUTHORS REFERENCES CONTRIBUTORS TO DRAFTING AND REVIEW... 42

10 1. INTRODUCTION From the time when the International Atomic Energy Agency (IAEA) held the International Conference on Protection of the Environment from the Effects of Ionizing Radiation in Stockholm [1] in Sweden in 2003, the IAEA has continued to follow and actively participate in international activities related to the progress in the area of radiological protection of the environment. Since 2004 informative reports on these activities have been submitted by the IAEA to the OSPAR Radioactive Substances Committee (RSC) on a regular basis, and discussed during its annual meetings. Following the publication of relevant international authoritative references and IAEA Safety Standards, e.g., IAEA Safety Fundamentals (SF-1) [2] (2006), ICRP Publication No 103 [3] (2007), ICRP Publication No 108 [4] (2008) and the revised IAEA Basic Safety Standards (BSS) [5] (2011) the IAEA has now developed an approach to assess the radiological impact of radionuclides which may be present in the marine environment. This recent work carried out by the IAEA is intended to encompass the requirements of the London Convention 1972 and the interests of the Radioactive Substances Committee of the OSPAR Convention. The present report summarizes the assessment scheme, calculation process and methods proposed by the IAEA Secretariat to the OSPAR RSC to define radiological environmental assessment criteria in accordance with existing international standards and ICRP recommendations as mentioned above. The draft of this report was first presented during the OSPAR RSC meeting in February 2011, held at the IAEA s Marine Environment Laboratory in Monaco, and discussed during a technical meeting in Vienna organized by the IAEA with experts representing the OSPAR RSC, held in November The present proposal by the IAEA includes comments and recommendations resulting from that technical meeting A test case was run by the IAEA using data of measurements in the OSPAR region and will be presented at the RSC Meeting in La Hague, in February

11 2. CHARACTERISTICS OF THE APPROACH Both the IAEA Fundamental Safety Principles (SF-1) [2] and the revised IAEA Basic Safety Standards (BSS) [5] specify that the objective of protection of the environment is to prevent radiological effects on ecosystems and their populations of flora and fauna. Furthermore, the BSS establish that the assessment of radiological impacts on the environment should be viewed in an integrated manner with other features of the system of protection to establish the conditions applicable to a particular source and that an integrated perspective has to be adopted to ensure the sustainability of agriculture, forestry, fisheries and tourism and of the use of natural resources, now and in the future. The consideration of such resources is consistent with the position of the United Nations Environment Programme (UNEP) submitted to the IAEA during the process of development of the new BSS and with definition of pollution contained in the United Nations Convention on the Law of the Sea (UNCLOS) [6]. The proposal elaborated by the IAEA is based on the use of simple and conservative models to calculate doses from exposure to radiation of humans (representative persons) and marine flora and fauna (reference plants and animals) and the use of appropriate radiological reference criteria to define the level of safety in connection with it. The assessment methodology presented in this report, for the purpose of the OSPAR Convention, is limited to assessing radiological impacts to humans and marine flora and fauna resulting from activity concentrations observed in the marine environment in the OSPAR regions (in water and in biota). The calculations enable conclusions regarding the relation of radiological impacts to humans and biota for the same level of activity concentrations in marine waters and sediments Radiological reference criteria for protection of the public and the environment Based on the requirements of the BSS [5] and the recommendation from the ICRP in Publication 108 [4], the IAEA suggests that the following radiological reference criteria are considered within a process for assessment and evaluation concerning protection of the public and the environment from impacts of ionizing radiation, taking into account the particular exposure situation 1 : (1) With respect to humans: (a) the established annual dose limit (1 msv) for members of the public in planned exposure situations [5], and (b) the individual annual dose level (of the order of 10 µsv) 2 used to grant exemption to activities and facilities [5]; (2) With respect to flora and fauna: (a) the derived consideration reference levels (DCRL) 3 of the ICRP [4]. 1 The ICRP defined three types of exposure situations : planned, existing and accidental. Different protection principles and criteria are defined for those criteria considering their particularities. More details can be found in IAEA BSS [5] and ICRP Publication 103 [3] µsv/a is sometimes referred as a trivial dose or, more precisely, a dose level which implies a trivial radiological concern. 3 The DCRLs have been derived of for a set of 12 Reference Animals and Plants; they represent bands of doses that are associated with negligible or very little adverse radiological effects at the level of individuals which, if affecting a relatively large number of individuals, may have an impact at the level of populations of flora and fauna. 2

12 The reference criteria mentioned above in (1) and (2) were originally not proposed to develop environmental quality criteria. However, the IAEA uses these criteria in this report as a starting point to put environmental radiological impact into the context of public and flora and fauna radiation protection. The ICRP defines DCRLs as dose rates for chronic exposures derived for a set of conceptual reference animals and plants (RAPs) representative of different environments (e.g., terrestrial, aquatic) that serve as markers at which one should pause in order for the known radiation effects data to be considered alongside other relevant factors when considering managerial options. The DCRLs are grouped into bands, which span an order of magnitude, corresponding to different RAPs and considering a range of possible effects at the level of individuals which may have impact at the level of populations (from, cytogenetic and mutation effects to loss of reproductive capacity, morbidity and mortality). The bands are expressed in terms of absorbed dose rates in µgy/h units. The ICRP DCRLs [4] do not represent dose limits; they should be considered as dose ranges at which a more detailed evaluation of the situation might be warranted. For this evaluation different factors which may affect the exposure conditions should be taken into account. Such considerations might include the type of exposure situation (planned or existing), the size of area that is affected, the time period for such exposures, the fraction of a population of a species that is exposed to such dose levels, the appropriateness of the data used for the dose estimation, and the degree of precaution that is needed for the assessment. When applying these criteria at a regional level, like that represented by the North-East Atlantic, it is important to bear in mind that different radiological situations may result among different sub-regions and even within a particular sub-region in that area (e.g., the defined OSPAR regions). The North-East Atlantic has places with different radiological conditions; for example, those areas only affected by controlled discharges of radionuclides from single or a small number of sources and others with multiple sources or the legacy of radionuclides in the marine environment resulting from accidental releases or past practices, including from fallout and run-off of radionuclides. Taking into account the discussions in previous paragraphs, the IAEA suggests that for the assessment and judgment of the radiological status of the marine environment, at a regional level for the purpose of the OSPAR Convention, for humans the annual dose limit for members of the public is considered as a starting point for further considerations (e.g., 1 msv per year). The following step is to explore whether under those conditions (e.g., doses to humans below to 1 msv per year) the resulting exposures to flora and fauna are below the lower bound of the band of the DCRLs. The observation that within the North-East Atlantic different radiological situations can be found should be considered when analyzing the results of the categorization scheme proposed later in this report. The OSPAR RSC suggested that the IAEA should consider more marine species than those recommended by the ICRP [4]. Therefore, as additional species, the marine reference organism as defined within the ERICA project [7], were selected. The reference radiological criteria is presented and discussed later in this report. 3

13 2.2. Integrating exposure scenarios for humans and flora and fauna In order to assess the radiological impact to the marine environment in the OSPAR region, the IAEA considers it necessary to define simple generic exposure 4 scenarios applicable to humans and marine plants and animals in an integrated manner. For this purpose, it is assumed that the human food which is considered for the dose assessment coexists in the same location with the flora and fauna used to estimate the environmental impact. Through the use of such integrated exposure scenarios, activity concentrations in the relevant environmental compartments (e.g., seawater, marine sediments, shore sediments, seafood, and marine biota) can be derived that lead to a radiological impact to humans and the marine flora and fauna below selected radiological reference criteria defining a safe situation. This activity concentration in seawater (defined as the reference concentration ) can be used as an indication of the radiological environmental status. In practice this means that a concentration of radionuclides in seawater which leads to a dose to reference persons less than 1 msv/a, and which leads a dose to reference animals and plants below the ICRP DRCLs (or other appropriate reference criteria), defines a safe radiological situation for the people and the environment Discussion on the human driven versus environment driven assessment approach The IAEA Safety Standards, specifically the revised BSS [5], established that protection of humans, the environmental media and components in the environment such as flora and fauna and resources used by humans, for the present and in the future, shall be protected in an integrated manner. To apply this concept of an integrated assessment, the IAEA propose the linkage of humans and other components in the environment, including flora and fauna, by means of defining a common generic exposure scenario. In this assessment scenario, humans are exposed through the consumption of seafood, from the external exposure due to staying on sediments in the shore and from the inhalation of sea spray. Flora and fauna which are not included in the human food chain are assumed to coexist in the same scenario, e.g., the radionuclides in the marine environment which cause an exposure to humans through food ingestion also cause exposures to flora and fauna that are not part of the human food chain. In the current approach the radiological impact to humans and to marine flora and fauna are both explicitly considered and the criteria for humans or for flora and fauna protection are used as the dominant limitation to define the quality quotient methodology, depending on which is the most exposed. This is presented in detail in the following sections. 4 The use of generic exposure scenarios in radiation protection is not a novelty and has been used in the past by the IAEA to define, for example, exemption and clearance levels for humans [5], [9 11]. 4

14 3. CALCULATION OF THE REFERENCE CONCENTRATIONS 3.1. Calculation scheme Figure 1, below, presents a schematic description of the process used by the IAEA to develop environmental assessment criteria that consider the radiological protection of the public and the environment. The process uses, as its starting point, a predefined dose level to a reference person (in this case an annual effective dose of 1 msv, see above). This dose level is used to back-calculate activity concentrations in the environment; the results of these estimation of doses to marine reference plants and animals are compared against the relevant radiological criteria. The process considers the following: (1) For a specific radionuclide, it is assumed that a reference person receives a committed effective annual dose of 1mSv per year through various exposure pathways, these being: External exposure to radionuclides deposited on the shore; Ingestion of seafood; Inadvertent ingestion of beach sediments; Inhalation of particles resuspended from beach sediments; and Inhalation of seaspray. These exposure pathways are characterized mathematically using generic models and cautious assumptions, as for example, in the selection of dilution parameters, the consideration of all combined exposure pathways and the use of conservative habit data. These assumptions can be considered conservative because their application leads to pessimistic predictions of human doses. This is considered in more detail in Appendix I. (2) Using generic assessment models, the radionuclide concentrations in filtered seawater which result in the specified dose to humans from a combination of five exposure pathways is derived (e.g., back-calculated). These radionuclide concentrations in seawater are termed concentrations related to the human dose (C DL ). (3) These C DL are used as input for the assessment of exposure to marine reference animals and plants, taking into account internal and external exposure pathways. (4) The resulting dose rates to representative marine flora and fauna are compared against the ICRP DCRLs (and other relevant criteria for those flora and fauna used in the assessment but not included in the ICRP set). (5) If a resulting dose rate for a certain radionuclide and a certain plant and animal is above the criteria, a factor RF biota is estimated and used to derive a more restrictive activity concentration based on the criteria for biota, the DCRLs (or other relevant criteria). (6) The resulting activity concentrations in marine water, including those which needed to be set more restrictive on biota protection basis, are called reference concentrations (C ref ) and can be used directly in the following steps of the assessment (for more details, see Section 4). The results of applying the procedure schematically described in Figure 1 below shows that the concentrations of radionuclides in the environment are now the key quantity for the assessments of impacts for humans and the environment in an integrated manner. The details to calculate C DL, RF biota and C ref are presented in the following section. 5

15 FIG. 1. Scheme of the process used by IAEA to consider the radiological impact to humans and marine flora and fauna in an integrated manner using a human dose reference level of 1 msv/a and the radiological reference criteria for marine flora and fauna. 6

16 3.2. Estimation of reference concentrations The generic equation to derive concentrations related to the human dose limit for a given radionuclide is specified below (equation 1): C DL, j e D DPUC = (1) j, e where: C DL,j is the concentration in (filtered) seawater related to a dose to humans selected as starting point for the calculations, for radionuclide j (Bq/m 3 ) for all exposure pathways combined; D is the annual dose for humans selected as starting point for the calculations (in units of Sv, e.g., 1E-03 Sv); and DPUC j,e is the dose per unit concentration for radionuclide j (in filtered seawater) and exposure pathway e (in units of Sv per Bq/m 3 ). As discussed before, if a concentration related to the human dose results in a dose to animals or plants higher than the appropriate DCRL, a factor RF biota considering the relation among the resulting dose to biota and the relevant reference criteria can be estimated and then the reference concentration for each radionuclide j, C ref,j, can be calculated as follows: where: RC = C C RF (2) biota C ref, j DL, j = DL, j Ebiota, j C ref,j is the reference concentration in (filtered) seawater for radionuclide j (Bq/m 3 ); RC biota = Reference criteria corresponding to the appropriate flora or fauna (microgy/h) (the ICRP DRCLs); and E biota,j is the annual average dose rate to a type of flora and fauna resulting from a concentration in seawater equal to C DL,j for a radionuclide j (microgy/h). The derivation of the DPUC is described in detail in Appendix I and the parameters used are presented in Appendix II. biota 3.3. Consideration of the protection to marine flora and fauna Dose rates to marine flora and fauna can be estimated starting from radionuclide activity concentrations in filtered seawater. A list of marine organisms used in standard methodologies has been selected based upon those recommended by the ICRP [4] and those additional ones from the ERICA project [7] after the requirements of OSPAR (through input and dialogue with OSPAR s RSC). The final list of organisms consists of the ICRP s marine Reference Animals and Plants and their life stages [4] and selected organisms used in the ERICA integrated approach [7]. The full list of organisms comprise of: 7

17 (1) ICRP reference animals and plants: Flatfish and Flatfish egg; Crab, Crab larvae and Crab egg; Brown seaweed; (2) ERICA reference organisms: Birds; Mammals; Molluscs; Polychaete (marine worms); Pelagic fish; Phytoplankton and Zooplankton The exposure to reference animals and plants and reference organisms includes internal and external pathways. External dose rates are derived from activity concentrations in the habitat of the selected marine organisms. This requires simplifying assumptions to be made concerning where biota are located in the marine environment. Three occupancy factors are used to reflect this and relate to organisms in the water column, in sediment and at the sediment water interface. These factors are multiplied by the corresponding activity concentrations in seawater and/or sediment and by external dose conversion factors to derive the external dose rate. Internal dose rates are derived from activity concentrations of dissolved radionuclides in seawater. A simple relationship using radionuclide specific distribution coefficients (K d s) and the suspended sediment concentration is used to derive dissolved activity concentrations in seawater from total activity concentrations in seawater, as is explained in more detail in Appendices I and III. Activity concentrations in the selected marine organisms are derived by multiplying these values by radionuclide specific concentration factors. These concentration factors are different to those used for the human assessment as they relate to the whole body of the organism, as opposed to the edible parts, and have been collated specifically with these considerations in mind [12 14]. Internal dose rates are derived by multiplying the radionuclide activity concentrations in biota by internal dose conversion factors. The total dose rate is simply the sum of internal and external dose rates. The details of the methods and parameters used to calculate dose rates to biota are presented in Appendix III. The calculations were performed in principle for a list of radionuclides declared of interest by OSPAR Convention. In order to test the methodology, the IAEA ran a test case including more radionuclides which may be measured in the marine environment, for instance those included in the RIFE 10 report [15]. The list with the additional radionuclides is presented in Annex I of this report and the results on the test case will be presented in the OSPAR RSC Meeting in La Hague in February The resulting dose rates were compared against ICRP DRCLs or other applicable reference criteria as applicable. The reference marine flora and fauna used to estimate dose rates, the dosimetric method, the ICRP DRCLs and the reference criteria used in the assessment method to verify the level of protection are presented in Table 1. As discussed previously, in most of the cases, the dose rates to ICRP reference animals and plants and ERICA representative organisms arising from radionuclide activity concentrations in filtered seawater that result in doses to humans of 1 msv/a are below the corresponding reference criteria. However, in a few cases the dose rates to some ICRP and ERICA biota references fall above the corresponding reference radiological criteria. The reason for this is because some radionuclides produce a relatively low radiological impact to humans through the exposure pathways considered (e.g., relatively small dose conversion factors) and thus lead to the derivation of relatively high activity concentrations, C DL s, in seawater. 8

18 TABLE 1. ICRP DRCLs AND REFERENCE CRITERIA USED TO CALCULATE THE REFERENCE CONCENTRATIONS Reference marine flora and fauna Dosimetric method ICRP DRCL (µgy/h) Used reference criteria (µgy/h) Comments Flatfish ICRP From ICRP 108 [4] Flatfish egg ICRP From ICRP 108 [4] Crab ICRP From ICRP 108 [4] Crab larvae ICRP From ICRP 108 [4] Crab egg ICRP From ICRP 108 [4] Brown seaweed ICRP From ICRP 108 [4] Bird ERICA Tool From ICRP 108 (for duck) [4] Mammal ERICA Tool From ICRP 108 (for deer) [4] Mollusc ERICA Tool From EC PROTECT (for invertebrates) [16] Polychaete ERICA Tool From ICRP (for earthworm) [4] Pelagic Fish ERICA Tool From ICRP (for trout) [4] Phytoplankton ERICA Tool - 70 From EC PROTECT (for plants) [16] Zooplankton ERICA Tool From EC PROTECT (for invertebrates) [16] The list of radionuclides and reference marine flora and fauna where this is observed is presented in Table 2. In these cases the reference activity concentrations became based on biota radiological protection Table 2 also presents the reduction factor necessary to fulfill the flora and fauna reference criteria. TABLE 2. LIST OF RADIONUCLIDES OF INTEREST FOR OSPAR FOR WHICH THE DOSE TO REFERENCE SPECIES IS ABOVE THE CORRESPONDING REFERENCE CRITERIA WHEN EXPOSED TO ACTIVITY CONCENTRATIONS LEADING TO 1 msv PER YEAR TO HUMANS AND THE ASSOCIATED FACTOR (RF biota ) ESTIMATED FROM RADIOLOGICAL CRITERIA FOR BIOTA Radionuclide Reference specie RF biota Pu-239,240 Phytoplankton 0.3 Tc-99 Brown seaweed 0.2 It is important to note that the values of dose rates above the corresponding reference levels for these limited number of radionuclides (e.g., 3) and species (e.g., 2) are only observed when using 1 msv/a to humans as a starting point. Table 3 below presents the resulting reference concentrations C ref for the radionuclides declared of interest by OSPAR. Additional radionuclides, for example, those included in [15], which were used in a test case conducted by the IAEA (to be presented during the OSPAR RSC Meeting in La Hague in February 2013), are presented in Annex I. Finally, The doses rates to reference marine flora and fauna arising from the reference concentrations C ref and the reference criteria for flora and fauna are presented below in Table 4. 9

19 TABLE 3. REFERENCE ACTIVITY CONCENTRATIONS IN SEAWATER (BQ/L, FILTERED) THAT CAUSE EXPOSURES TO HUMANS OF LESS THAN 1 msv/a AND EXPOSURES TO EXPOSURES TO BIOTA BELOW CORRESPONDING REFERENCE CRITERIA (RADIONUCLIDE AS MONITORED BY OF OSPAR CONVENTION) Radionuclide C ref (Bq/L) Artificial radionuclides Cs E+00 H-3 5.6E+05 Pu-239,240 a 2.8E-02 Ra E-02 Tc-99 a 1.8E+01 Natural radionuclides Pb E-04 Po E-04 Ra E-02 a indicates that reference criteria for biota is most restrictive. 10

20 TABLE 4. REFERENCE CRITERIA AND ANNUAL AVERAGE DOSES RATES TO MARINE FLORA AND FAUNA (µgy/h) DUE TO AN ACTIVITY CONCENTRATION IN SEAWATER EQUAL TO C ref (RADIONUCLIDES OF INTEREST OF OSPAR) Marine biota Flatfish Reference criteria (µgy/h) Radionuclide Flatfish egg Crab Crab larvae Crab egg Brown seaweed Bird Mammal Mollusc Polychaete Pelagic Fish Phytoplankton Zooplankton Dose rates to marine flora and fauna (µgy/h) Cs-137 3E+00 2E-03 3E+00 4E-02 3E+00 9E-03 3E-01 1E-01 3E+00 6E+00 5E-02 2E-03 4E-02 H-3 2E+00 2E+00 2E+00 2E+00 2E+00 7E-01 2E+00 2E+00 2E+00 2E+00 2E+00 4E+00 2E+00 Pb-210 1E-03 4E-04 9E-04 3E-03 4E-03 4E-04 4E-03 3E-03 6E-04 3E-03 7E-04 1E-06 3E-03 Po-210 4E-02 4E-02 1E-02 1E-01 1E-01 2E-03 1E-01 2E-01 1E-01 7E-02 4E-02 1E-01 1E-01 Pu-239,240 2E-02 3E-02 3E-02 4E+00 4E+00 2E+00 1E-01 8E-01 6E-01 7E-01 1E-01 7E+01 4E+00 Ra-226 2E-01 2E-01 3E-01 1E-01 2E-01 2E-01 7E-01 2E-01 2E-01 4E-01 6E-01 5E-01 1E-01 Ra-228 4E-02 6E-04 4E-02 5E-04 4E-02 8E-04 5E-03 2E-03 4E-02 8E-02 4E-03 6E-05 5E-04 Tc-99 9E-02 7E-02 2E-01 1E-01 1E-01 4E+01 3E-02 3E-02 6E+00 2E+01 3E-02 1E-03 1E-01 Note: Marked cells indicate that for that radionuclide the reference concentration was estimated from the radiological criteria for marine flora and fauna. 11

21 4. THE RADIOLOGICAL ENVIRONMENTAL ASSESSMENT CRITERIA FOR OSPAR (A PROPOSAL BY IAEA) As described in Section 3, the reference concentrations, C ref, are calculated in such a way that it is ensured that the radiological impact to humans and to flora and fauna are below any level of concern for these concentrations or lower values. This approach is first applied for each radionuclide independently, but in this section a method is described to assess a scenario with many radionuclides simultaneously present in a single environmental compartment. C ref for each radionuclide j in marine water obtained as described before and presented in Table 3 can be used to define environmental individual quality quotients as follows: where: QQ C m, j j = (3) Cref, j QQ j is the Quality Quotient for radionuclide j; C m,j is the measured activity concentration for radionuclide j in water, filtered, in Bq l -1 ; and C ref, j is the radionuclide reference concentration in seawater, filtered, derived individually from 1 msv to human or based on reference criteria for plants and animals (DCRLs or others) for radionuclide j (Bq L -1 ) (see Table 3). If more than one radionuclide have to be considered, an integrated quality quotient (IQQ) has to be calculated, which is defined as the summation of the individual quality quotients for all radionuclides present in the environment in a specific location (for instance, an OSPAR Region): IQQ m, j = = j C C ref, j j QQ j (4) The QQ are unitless and carries information about the dose to humans and to flora and fauna, but are not radionuclide dependent anymore. Therefore, the summation of QQ is possible and the IQQ, which can be defined as a radiological environmental assessment indicator is also unitless. This IQQ includes all the assessed radionuclides and by means of its estimation, it can be used to assess the radiological status in marine regions, in the way it is explained in Section Selection of the IQQ figures to define categories The categories proposed here are chosen in principle based on the annual doses to humans corresponding to the IQQ. Despite the fact that doses to humans are used as a starting point considering that the derived C ref also produce doses to marine flora and fauna below the relevant radiological criteria for biota, the categories define a level of protection for humans and marine flora and fauna in an integrated manner. Basically, an IQQ of 1 corresponds to an annual dose of 1 msv used as a starting point of reference, the categories are chosen in between fractions of this number. The values used to define categories of the environmental status from the radiological perspective are not used as limits and are not defined as any kind of new international 12

22 criteria, but as practical starting point levels for the purpose of the OSPAR Convention and the analysis and evaluation of its particular environmental radiological circumstances. Nevertheless, these values have some radiological meaning: 1mSv per year (IQQ = 1) is comparable to the internationally agreed dose limit for members of the public, which has been proposed and justified from the scientific and societal point of view by the ICRP and is adopted in the IAEA Safety Standards and in the regulatory frameworks of IAEA Member States worldwide. 100 µsv per year (IQQ = 0.1) is an arbitrarily selected level which corresponds approximately to the upper bound of the typical range of doses to the public due to controlled releases of radioactive materials to the environment during the normal operation of a large number of types of nuclear installations [17] (e.g., typically in the range µsv per year). 10 µsv per year (IQQ = 0.01): In the IAEA BSS, exposure levels of the order of 10 µsv/a correspond to the radiological criteria used within the IAEA Safety Standards and many national and international 5 regulations to apply the concepts of exemption of materials from the need of regulatory control and clearance of materials from any further regulatory control. With respect to flora and fauna, doses below the lower end of the band of the DCRLs defined by the ICRP (or other consistent radiological criteria used) implies no radiological concern. Based on these considerations, categories for IQQ are proposed and shown in Table 5 below. TABLE 5. INTEGRATED QUALITY QUOTIENT (IQQ) CATEGORIES, PROPOSED BY IAEA FOR OSPAR, FOR APLICATION AT A REGIONAL LEVEL Categories defined with results of the Integrated Quality Quotient Category A IQQ > 1 Category B 0.1 < IQQ 1 Radiological environmental status The radiological impact represents a concern The radiological impact needs consideration Category C 0.01 < IQQ 0.1 The radiological impact is satisfactory Category D IQQ 0.01 The radiological impact is trivial A test case consisting on an application of this categorization scheme proposed by the IAEA will be presented during the OSPAR RSC Meeting in La Hague in February µsv is one of the radiological criteria used within London Convention 1972 to authorize the dumping of materials with very low levels of activity concentrations at sea, which are considered as practically non-radioactive. 13

23 5. CONSIDERATIONS ON THE USE OF THE CATEGORIZATION SCHEME The activity concentration reference levels presented in Table 3 in Section 3, when combined as an integrated quality quotient IQQ, as defined in Section 4, and compared to 1, 0.1 and 0.01 may represent a graded level of radiological quality in the marine environment at the regional level. The use of these categories are subject to interpretation and should be set in accordance with the managerial needs, for instance, those related to the OSPAR Convention. In this report the IAEA provides some suggestions for interpretation of these categories based only upon radiological considerations: concentrations of radionuclides in the marine environment (seawater), representative of a certain region, leading to an IQQ in the lowest category D are to be understood as representing a trivial or insignificant impact. If the IQQ is in category C the condition of the marine environment from the radiological point of view can be considered satisfactory. If IQQ is in category B and close to 1, the situation needs some consideration. If IQQ is above 1, the radiological situation represents a concern. The managerial actions should be defined in the framework of the requirements by the OSPAR Convention. As an indication, categories C and D may indicate no need of additional environmental monitoring programmes to those already in place. Category B could imply the need of a slightly extended monitoring programme and, particularly when IQQ is approximating 1, the need for a more detailed assessment. Category A could imply the need to define monitoring strategies in order to make more detailed evaluations of the radiological situation. The criteria applied to define categories are those used for normal exposure situations, as defined in [3] and [5], and are generally source related (e.g, related to a particular installation considered as the source of radiation) and applied to a person representative of those more highly exposed (e.g., the representative person in the past defined as the critical group defined by the ICRP in Publications 103 and 60 [3, 18]). As discussed before, the methodology presented in this report is to be applied at a regional level. Such cases are not source related, as some regions may not only receive inputs of radioactivity from single planned operations but from many installations distributed along the region and in other regions, and the concept of representative person or critical group cannot be used straightforward to define a regional environmental status. Furthermore, some situations in OSPAR regions were affected by accidents or past practices leading to a legacy of radionuclides in the marine environment. Therefore the definitions of the categories and interpretation of the results should consider these circumstances. As an example, while in principle 1 msv per year to the representative person is acceptable for the control of a single source during normal operation (and this implies that the vast majority of the population at the regional level will receive doses much lower than that value), doses of 1 msv per year to the entire population influenced by an OSPAR region may need some consideration (as it is indicated in category B). It was mentioned before that the categorization method proposed in this report is of a regional character. The measurements of activity concentrations in the marine environment should be those representatives of a particular region, and not individual values in a single location. The OSPAR Convention has already defined regions and applicable statistical methodologies which may be used to define a representative value of activity concentrations that would be used in the process of categorization described. 14

24 5.1. Discussion on water/sediment equilibrium assumptions Steady states conditions are considered as an appropriate assumption for the assessments of radiological impacts for long term exposure scenarios. Such conditions are usually assumed when assessing or controlling the impact on the public due to radioactive discharges to the environment during normal operation of installations. It is well known that some cases exist where the assumption of equilibrium conditions between radionuclides in marine water and those in marine sediments is not correct. This is, for example, the case when releases of radioactive materials to the sea happened a long time ago and where discharges have been non-negligible. Under such conditions, the actual activity concentration of radionuclides in sediments could be higher than those levels derived from averaged seawater activity concentrations using equilibrium water/sediment distribution coefficients, for example, because the bulk of the radioactivity in the water column has long since been deposited to the bottom sediments and marine currents may have caused a continuous dilution of any remaining radionuclides in the water column. Under these conditions, the seafood and the marine flora and fauna living in or close to sediments could have higher internal activity concentrations or receive higher external doses than those estimated using equilibrium assumptions. This is a situation which may apply for some regions in OSPAR. Within the OSPAR Convention, activity concentration in marine water (C Wm ) and in marine biota (C Bm ) is measured and reported. C Bm can be used to derive activity concentrations in marine water based in the biota measurements (C Wb ), assuming equilibrium and using the relevant K d, for instance: = / (5) Under these assumptions, the derived water activity concentrations resulting from regions with non-equilibrium and sediments with high concentrations may be greater than the activity concentration measured directly in the water. These C Wb derived from measurements in biota can be used to derive IQQ in a similar way than C Wm is used (see Section 4). The two results can be used to compare the IQQs in order to define categories. Through this, some indication of the non-equilibrium status and the increased activity concentrations in the sediments can be concluded. For instance, in the regions and for the radionuclides where equilibrium conditions prevail, C Wm and C Wb may result more similar than in other regions where non-equilibrium exist and radionuclides are accumulated in the sediments. The differences in the IQQ calculated with C Wm versus those calculated with C Wb would depend on the non-equilibrium status and the contribution to the IQQ of each of the radionuclides. If the differences are large, this should be considered when interpreting the results. Examples from the Test Case run by the IAEA illustrating this issue will be presented during the OSPAR RSC Meeting in La Hague, in February

25 6. SUMMARY An approach to define an environmental (marine) radiological environmental criteria and an associated qualification scheme is proposed in the current report by the IAEA for consideration by the OSPAR Convention RSC. It is based on IAEA Safety Standards and uses ICRP recommendations and positions with regard to the issue of protection of the environment. The environmental radiological criteria are derived in terms of activity concentrations of radionuclides in seawater, based on the radiological impact to humans, resources and marine plants and animals, which are considered in an integrated manner. Activity reference concentrations C ref for each radionuclide are essentially based on human radiological protection, (e.g., the C ref is derived from dose criteria for humans) except for a few cases where the flora and fauna are not implicitly protected when exposed to such levels of activity concentrations (e.g., the resulting dose rates to certain flora and fauna are above the relevant reference criteria). In those cases, the C ref are based in the reference criteria for the relevant biota (e.g., the C ref is derived from the DCRLs). The radiological environmental status defined by the impact of multiple radionuclides which may be present in the environment, to humans and marine flora and fauna, is estimated with an integrated quality quotient defined in this report and named IQQ. The values of an IQQ of 1, 0.1 and 0.01 are used to define environmental status categories based on humans and flora and fauna radiation protection considerations. The process used to define IQQ considers both explicitly the doses to humans and the doses to marine reference flora and fauna in an integrated manner. The methodology applies cautious assumptions for the definition of exposure scenarios and model parameters. 16

26 APPENDIX I. PROCEDURE FOR DERIVING CONCENTRATIONS RELATED TO THE HUMAN DOSE LIMIT This appendix provides details on how activity concentrations in marine water of individual radionuclides are calculated from a starting point of a given dose level to humans. An annual dose of 1mSv is used as a starting point for normalized calculations for deriving radionuclide activity concentrations in (filtered) seawater. The parameters necessary to apply the methodology described in this appendix are specified in Appendix II. The generic equation to derive concentrations related to the human dose used as a starting point is given below: where: C DL D, j = (6) DPUC e C DL,j is the concentration in (filtered) seawater for radionuclide j (Bq/m 3 ) corresponding to a dose equal to the dose limit for all exposure pathways combined; D is the selected annual dose for humans (in units of Sv, e.g., 1E-03 Sv); DPUC j,e is the annual dose per unit concentration for radionuclide j (in filtered seawater) and exposure pathway e (in units of Sv per Bq/m 3 ) I.1. Calculation of dose per unit concentrations, DPUCs, based on exposure of the public to radionuclides The annual dose per unit concentration is estimated for members of the public exposed to radiation in connection with the activity concentrations in the marine environment (water, seafood, sediments on the shore and seaspray). The doses specified are committed effective doses from intakes (ingestion or inhalation) and effective doses for external exposure. Individual doses to members of the public should take account of the age of these individuals. Accordingly, parameter values used in the calculation of individual doses to members of the public corresponds to two age groups: adults and infants aged 1 to 2 years. The DPUC used in the calculation of C DL,j is that giving the highest dose. I.1.1. Exposure pathways Radionuclides are present in both sediments and seawater. They may be taken up by marine animals and plants and thus enter the human food chain. Members of the public who live in the coastal areas may be exposed to radionuclides through five main exposure pathways: External exposure to radionuclides deposited on the shore; Ingestion of seafood; Inadvertent ingestion of beach sediments; Inhalation of particles resuspended from beach sediments; and Inhalation of seaspray. j, e 17

27 I.1.2. DPUCs from external exposure to radionuclides deposited on the shore Then following approach is based in IAEA-TECDOC-1375 [11] and the updated version in preparation by IAEA [19]. The annual effective dose to members of the public from external exposure to radionuclides deposited on the shore, E ext, public (in Sv/a), can be calculated using equation (7): where: E ext, public =t public C S jdc gr j j (7) t public is the time spent by members of the public on the shore in a year (in h); DC gr (j) is the dose coefficient for ground contamination of radionuclide j (in Sv/h per Bq/m 2 ); C S (j) is the surface contamination of radionuclide j in the shore sediments (in Bq/m 2 ). The radionuclide concentration in coastal sediment is assumed to be a factor of 10 lower than that in suspended particles in the water column, C p (j). The surface contamination in the coastal sediment of radionuclide j, C S (j) (in Bq/m 2 ), is obtained from the equation (8): where: ρ S is the density of coastal sediment (in kg/m 3 ); d S is the effective thickness of coastal sediment (in m). C S j= C jρ S d S 10 (8) Since the activity concentration, by mass, in the suspended particles, C P (j) (in Bq/kg, dry weight), is obtained from the equation: where: C P j= K d jc DW j (9) K d (j) is the distribution coefficient (m 3 /kg) for radionuclide j ; C DW (j) is the activity concentration of radionuclide j in filtered seawater (Bq/m 3 ). And since C DW (j) can be considered equal to 1 Bq/m 3 for the calculation of the dose per unit concentration, DPUC, for a given radionuclide, j, equation (7) becomes: DPUC Kd( j) ρsds ( j) = tpublic DCgr( ) 10 ext, public j (10) where all terms have been defined above. The DPUC ext,public (j) for a given radionuclide j can be derived with this equation using the parameter values provided in Appendix II. I.1.3. DPUCs from ingestion of seafood The total annual effective dose from the ingestion of seafood, E ing, food, public (in Sv/a), can be calculated using equation (11): 18

28 E ing, food, public = kh B k j C EB j, kdc ing j (11) where: H B (k) is the annual human consumption of seafood k (in kg); DC ing (j) is the dose coefficient for ingestion of radionuclide j (in Sv/Bq); C EB (j,k) is the concentration of radionuclide j in the edible fraction of seafood k (in Bq/kg, fresh weight) as calculated using equation (12) below. Since radionuclide concentrations in marine biota k are obtained from the concentrations in the dissolved phase in seawater, C DW (j), multiplied by the appropriate concentration factors (CFs): where: C EB j,k=cfj,kc DW j (12) C EB (j,k) is the activity concentration of radionuclide j in the edible fraction of marine biota k (in Bq/kg, fresh weight); CF(j,k) is the concentration factor of radionuclide j in marine biota k (in m 3 /kg). And since C DW (j) can be considered equal to 1 Bq/m 3 for the calculation of the dose per unit concentration, DPUC, for a given radionuclide, j, equation (11) becomes: where all terms have been defined above. DPUCing, food,public(j) = HB(k)CF(j,k)DCing(j) (13) k The DPUC ing,food,public (j) can be derived with this equation using the parameter values provided in Appendix II. I.1.4. DPUCs from inadvertent ingestion of beach sediments The annual dose from inadvertent ingestion of shore sediments, E ing, shore, public (in Sv/a), can be calculated using equation (14): where: E ing shore, public = t public H shore C Sj ρ S L B DC ing j j (14) H shore is the hourly ingestion rate of beach sediment by humans (in kg/h). The radionuclide concentration in the ingested material is derived from the surface contamination of the sediment on the shore, C S, from equation (8) divided by the thickness L B of the sediment layer and the sediment density, ρ s. Ingestion rates of shore sediments are usually given as hourly rates. The quantity of beach sediments ingested in a year is the product of the ingestion rate, H shore (in kg/h), and the annual time spent on the shore, t public (in h) given in Appendix II. In a similar way to that explained above in deriving DPUCs for a given radionuclide j from external exposure to radionuclides deposited on the shore (Section I.1.2), an expression for 19

29 C S (j) (and thereafter C P (j)) assuming C DW (j) = 1 Bq/m 3 can be substituted into equation (14) to derive the following equation: where all terms have been defined above. Kd(j)ds DPUCing, shore,public(j) = tpublichshore DCing(j) (15) 10L The DPUC ing,shore,public (j) can be derived with this equation using the parameter values provided in Appendix II. I.1.5. Doses from inhalation of particles resuspended from beach sediments The dose from inhalation of resuspended beach sediments, E inh, shore, public (in Sv/a) can be calculated using equation (16): where: E inh shore, public = t public R inh, public DL shore C P jdc inh j j (16) R inh, public is the annual inhalation rate of members of the public (in m 3 /h); DL shore is the dust loading factor for beach sediments (in kg/m 3 ); DC inh (j) is the dose coefficient for inhalation for radionuclide j (in Sv/Bq). The annual occupancy of people on the shore, t public (in h) is taken to be the same as the value used in the calculation of doses due to external exposure (Appendix II). Since C P (j) can be expressed by equation (9) and C DW (j) equals 1 Bq/m 3 when calculating the DPUC for a given radionuclide j for inhalation of particles resuspended from beach sediments, the following equation can be defined: DPUCinh, shore,public(j) = tpublicrinh,publicdlshore Kd(j)DCinh(j) (17) where all terms have been defined above. The DPUC inh,shore,public (j) can be derived with this equation using the parameter values provided in Appendix II. I.1.6. Doses from inhalation of seaspray The annual dose to members of the public from inhalation of airborne sea spray on the shore, E inh,spray,public (in Sv/a), can be calculated using equation (18): where: E inh,s pray, public = t public R inh, public C spray ρ w C W jdc inh j j (18) C spray is the concentration of sea spray in the air (in kg/m 3 ); ρ W is the density of seawater (in kg/m 3 ) an approximate value of 1000 kg/m 3 can be used; C W (j) is the concentration of radionuclide j in seawater (in Bq/m 3 ). B 20

30 The annual occupancy of people on the beach, t public (in h), is taken to be the same as the value used in the calculation of doses due to external exposure. The inhalation rate, R inh, public (in m 3 /h) and the dose coefficient for inhalation, DC inh (j) (in Sv/Bq), are the same as those used to calculate doses due to the inhalation of resuspended sediments. Since the total (activity) concentration in seawater, C W (j) (in Bq/m 3 ), is given by: where: S is the suspended sediment concentration (kg/m 3 ), C W j=1+k d j SC DW j (19) And since C DW (j) can be considered equal to 1 Bq/m 3 for the calculation of the dose per unit concentration, DPUC, for a given radionuclide, j,, the following equation can be derived: DPUC Cspray (j) = tpublic Rinh,public ( 1 Kd(j)S) DCinh(j) (20) ρ inh, spray,public + W The DPUC inh,spray,public (j) can be derived with this equation using the parameter values provided in Appendix II. I.2. Conservative nature of the procedure The generic screening procedure and the selection of default parameter values (see Appendix II) are based on conservative assumptions in order to avoid overestimating the activity concentrations in seawater characterizing Radiological Environmental Assessment Criteria. Conservatism is achieved through the use of cautious assumptions about the nature and magnitude of pathways leading to human exposure. For example, the values selected for the habit data (rates of ingestion of seafood, inhalation of resuspended sediment and sea spray, shore occupancy) are at the upper end of the range of realistic values and have been chosen to maximize the potential doses received by these individuals. By combining a large set of exposure pathways to derive Radiological Environmental Assessment Criteria, the resultant seawater concentrations might also be considered highly protective in the sense that it is pessimistic to assume that all 5 exposure pathways would apply to the small group of individuals. 21

31 APPENDIX II. PARAMETERS USED IN THE DERIVATION OF DOSE PER UNIT CONCENTRATION VALUES This appendix describes the parameters required to perform the calculations in Appendix I and provides generic values for them. Then data and assumptions are similar to those in IAEA-TECDOC-1375 [11] and the updated version in preparation by IAEA [19]. For element or radionuclide dependent parameters, values are provided for a number of radionuclides identified as relevant in the context of OSPAR Convention and an extended list of radionuclides. All generic values and data used in this appendix are given in Table 6 to 10. For the parameters that relate to individual doses to members of the public, values for adults and infants aged 1 to 2 years are provided (see Table 7). II.1. Inclusion of progeny Progeny that have been included with the respective parent radionuclide in the derivation of DPUCs are presented in Table 6. Notes to the table provide an explanation of the considerations adopted to select the progeny. II.2. Parameters and default values II.2.1. Parameters related to radionuclides or elements II Radioactive decay constants, λ(j) Radioactive decay constants are presented in Table 7 and were calculated using half-lives of the radionuclides taken from ICRP Publication No. 38 [20]. II Sediment distribution coefficients, Kd(j) K d s are used to calculate the partitioning of radionuclide concentration between seawater and sediments. K d values in m 3 /kg for selected elements are provided in Table 8. They were derived from the values reported in [21]. II Concentration factors for marine biota, CF(j,k) Element specific concentration factors are used to calculate the activity concentration of radionuclides in marine biota, in this case seafood for the human assessment, from the activity concentration in the seawater. For the purpose of the procedure described in Appendix I the types of edible marine biota included in the assessment are fish, crustaceans and molluscs. Recommended values are taken from [21] and are provided in Table 8. II.2.2. Dose coefficients for external and internal irradiation II Dose coefficients for external irradiation on the shore, DFgr(j) Values for dose coefficients for external irradiation from radionuclides deposited on the shore are provided in Table 7. They relate to a surface contamination and are therefore given in Sv/a per Bq/m 2. The effective doses are based on equivalent doses from US EPA Federal Guidance Report No. 12 [22] and recalculated according to ICRP Publication 60 [18]. These values are based on the conservative assumption that the radionuclides that are washed ashore will be deposited mainly on the surface of the beach. 22

32 II Dose coefficients for ingestion, DCing(j), and inhalation, DCinh(j) Dose coefficients for ingestion and inhalation for adults and infants (age 1 to 2 years) are provided in Table 7. They are taken from the IAEA Basic Safety Standards [5]. II.2.3. Parameters related to physical characteristics of sediments and seaspray II Thickness of sediment boundary layer, LB The layer of sediment at the bottom of a hypothetical water column is used to calculate the concentration of radionuclides dissolved in the water. The value adopted in compartmental models for the assessment of radiological consequences of routine radioactive discharges into North European waters is 0.1 m [23]. A more conservative assumption in this procedure is to assume that the thickness of the sediment boundary layer is small. Therefore, the sediment layer is reduced to 0.01 m (see Table 9). II Suspended sediment load in the water column, S The suspended sediment load in the water column is necessary to calculate the activity concentration in seawater and suspended sediments. Suspended sediment loads in North European waters range are given in [23]. A generic value of kg/m 3 has been used (see Table 9). II Bulk density in suspended sediments, ρ S, and in boundary layer sediments, ρ B The bulk density of sediments is necessary to calculate the concentration of radionuclides in coastal sediments from the concentration in seawater. For the purpose of the procedure described in Appendix I a generic value of kg/m 3 may be used for both densities (see Table 9). II Effective thickness of coastal sediment, d S The effective thickness of coastal sediment is necessary to calculate the radioactivity concentration on the shore from the concentration in the water. A generic value of 0.1 m may be used (see Table 9). Selection of this value assumes that 1% of the material placed at the site washes up on the shore. This value is similar to values used in compartmental models for the assessment of the radiological consequences of routine radioactive discharges into the North European waters [23]. II Concentration of seaspray in the air, C spray A generic value of 0.01 kg/m 3 is used for the concentration of airborne seaspray (marine aerosols) [24] (see Table 9). II Dust loading factor on shore, DL shore A generic value of kg/m 3 is used for the dust loading factor on the shore is used [24, 25] (see Table 9). 23

33 II.2.4. Habit data for calculation of individual doses II Time of exposure of members of the public on the shore, t public A time per year spent by members of the public on the shore of 1600 h for adults and 1000 h for infants is used [26] (see Table 10). II Inhalation rate, R inh, public A generic inhalation rate of 0.92 m 3 /h for adult members of the public and 0.22 m3/h for infant members of the public should is used [27] (see Table 10). II Ingestion rates of seafood, H B (k) Consumption rates for fish H B (fish) (34 kg/a), molluscs H B (moll) (11 kg/a) and crustaceans H B (crust) (12 kg/a) for adults have been proposed by OSPAR (presented in Table A3.3 in Annex 3 of the OSPAR RSC Second Periodic Evaluation 2007 [28]). These values have been used in all calculations pertaining to ingestion doses (see Table 10). Dose per unit activity concentration coefficients are reported in Table 7. For infants aged 1 to 2 years, an annual consumption rate of 25 kg/a of fish has been used, while no consumption of shellfish is included [28] (see Table 10). II Ingestion rate of beach sediment, H shore For adults a value of kg/h is used for ingestion of beach sediments [20, 21]. For infants an ingestion rate of beach sediments of kg/a [29] is used (see Table 10). 24

34 TABLE 6. LIST OF PROGENCY INCLUDED IN THE ESTIMATION OF THE DOSES TO HUMANS WITH THEIR PARENT RADIONUCLIDES IN THE ASSESSMENT 6 Radionuclide Progeny Ce-144 Pr-144 Cs-137 Ba-137m Np-237 a Pa-233 Pb-210 Bi-210, Po-210 Pu-241 a Am-241 (0.03) Ra-224 Rn-220, Po-216, Pb-212, Bi-212, Tl-208 (0.36), Po-212 (0.64) Ra-226 Rn-222, Po-218, Pb-214, Bi-214, Po-214, Pb-210, Bi-210, Po-210 Ru-103 Rh-103m Ru-106 Rh-106 Sb-125 Te-125m (0.23) Sn-113 In-113m Sr-90 Y-90 Th-228 Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 (0.36), Po-212 (0.64) Th-230 Ra-226, Rn-222, Po-218, Pb-214, Bi-214, Po-214, Pb-210, Bi-210, Po-210 Th-232 b Ra-228, Ac-228, Th-228, Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 (0.36), Po-212 (0.64) U-235 c Th-231, Pa-231, Th-227, Ac-227, Fr-223 (0.01), Ra-223, Rn-219, Po-215, Pb-211, Bi-211, Tl-207 U-238 Th-234, Pa-234m, Pa-234 (0.002), U-234, Th-230, Ra-226, Rn-222, Po-218, Pb-214, Bi-214, Po-214, Pb-210, Bi-210, Po-210 Zr-95 Nb-95 a For Np-237 and Pu-241, only a fraction of the entire decay series has been included because the remaining progeny in the decay chain cannot build up to give any significant activity or dose contribution. b No subchains have been provided for Th-232 as the chain reaches equilibrium within a few decades. c No subchains have been provided for U-235, as the activity of U-235 is only a few percent to the activity of U 238 and therefore, the contribution of all progeny can always be included. 6 Unless explicitly provided in the table (value in brackets next to the progeny), weighting factors are equal to 1. The value in brackets following a progeny are the ratio of maximum daughter specific activity to initial parent specific activity. correspond to the branching ratio for the parent decay to that specific daughter nuclide. 25

35 TABLE 7. RADIOACTIVE DECAY CONSTANTS AND EFFECTIVE DOSE COEFFICIENTS FOR EXTERNAL AND INTERNAL IRRADIATION Radionuclide External dose Internal dose coefficients (Sv/Bq) Radioactive coefficients Ingestion Inhalation decay constant Surface deposit Infants Infants (1/a) (Sv/a per Bq/m 2 Adults Adult ) (1-2 years (1-2 years) Ag-110m Am Ca Ce Ce Cl Cm Cm Cm Co Co Co Cr Cs Cs Fe Fe H Hg I I I Ir Mn Na Nb Np Pb Pm Po Pu Pu Pu Pu Pu Ra Ra Ra Ru Ru S Sb Sb Se Sn Sr Sr Sr Tc Th Th Th Tl U U Zn Zr

36 TABLE 8. MARINE SEDIMENT DISTRIBUTION COEFFICIENTS (M 3 /KG) AND CONCENTRATION FACTORS (M 3 /KG) FOR EDIBLE MARINE FISH AND SHELLFISH Element Sediment distribution Concentration factor (Bq kg -1 f.w. per Bq m -3 ) coefficient (m 3 /kg) Fish Crustaceans Molluscs Ag Am Ca Ce Cl Cm Co Cr Cs Fe H Hg I Ir Mn Na Nb Np Pb Pm Po Pu Ra Ru S Sb Se Sn Sr Tc Th Tl U Zn Zr TABLE 9. GENERIC VALUES FOR PARAMETERS USED IN THE CALCULATION OF RADIONUCLIDE CONCENTRATIONS IN ENVIRONMENTAL MATERIALS Parameter Symbol Value Thickness of boundary sediment layer in box (m) L B Effective sediment thickness (m) d S Bulk sediment density (kg/m 3 ) ρ S, ρ B Suspended sediment concentration (kg/m 3 ) S Seaspray concentration in air (kg/m 3 ) C spray Dust loading factor on shore DL shore TABLE 10. GENERIC VALUES OF PARAMETERS USED IN THE CALCULATION OF INDIVIDUAL DOSES Parameter Symbol Adult Infant (1 to 2 years) Occupancy on sediments on shore (h/a) t public Breathing rate (m 3 /a) R inh, public Ingestion rate of fish (kg/a) H B (fish) Ingestion rate of crustaceans (kg/a) H B (crust) Ingestion rate of mollusc (kg/a) H B (moll) Ingestion rate of sediment on beach (kg/h) H shore

37 APPENDIX III. PROCEDURE FOR ASSESSING DOSE RATES TO MARINE FLORA AND FAUNA This appendix provides the generic procedure applied in deriving doses for marine biota from the activity concentrations in seawater. The parameters necessary to apply the methodology are also discussed or presented in this appendix and in Appendix II. III.1. Marine flora and fauna included in the procedure The methodology described in this appendix has been developed to assess radiation dose rates to a suite of marine organisms. The list includes marine ICRP Reference Animals and Plants (RAPs), and their life stages as defined by ICRP [3], and other representative organisms selected to expand the coverage of the assessment and with relevant exposure parameters having been defined elsewhere [7]. The selected organisms were Flatfish [3]; Flatfish egg [3]; Crab [3]; Crab larvae [3]; Crab egg [3]; Brown seaweed [3]; Birds [7]; Mammals [7]; Molluscs [7]; Polychaete (worms) [7]; Pelagic fish [7]; Phytoplankton [7]; Zooplankton [7]; Absorbed dose rates (in units of µgy/h) are calculated taking into account internal and external exposures. Dose rates from internally incorporated alpha-emitting radionuclides are modified by a radiation weighting factor, to take account of the greater effectiveness of this radiation-type to give rise to radiation-induced effects. III.2. Calculation of doses rates to marine flora and fauna III.2.1. Exposure pathways Radionuclides released into the marine environment partition between a fraction which is dissolved and a fraction that becomes adsorbed to sediments. Radionuclides are thus present in both sediments and seawater and may lead to irradiation of marine animals and plants by the following exposure pathways: External exposure to radionuclides present in bottom sediments and in the seawater; Internal exposure to radionuclides incorporated within the organism (caculated with conmcentration ratios). 28

38 III.2.2. Calculation of radionuclide concentrations in marine flora and fauna Filtered, seawater concentrations, C Dw (j), expressed in units of Bq/l are used to estimate the derived radiological environmental assessment criteria defined by IAEA. Radionuclide concentrations in marine biota (RAP or representative organism) k are then obtained from these values multiplied by the appropriate concentration factors (CFs): where: C B j,k = CRj,k $ %&' ( ) (21) C B (j,k) is the activity concentration of radionuclide j in marine biota (Reference Animal or Plant) k (in Bq/kg, fresh weight); CR(j,k) is the concentration ratio of radionuclide j in marine biota (Reference Animal or Plant) k (Bq/kg fresh weight per Bq/kg seawater); and ρ w is the density of seawater (1000 kg/m 3 ). The concentration factors applied here differ from those used in the assessment of activity concentrations in marine biota for human dose assessments, which relate to the transfer of radionuclides to the parts of the organism included in the human diet [23]. The concentration factors for biota dose rate assessments pertain to the whole body of the organism thus accounting for radionuclide accumulation in body organs not forming part of the human diet. The concentration factors are obtained from the ICRP guidance [12] and reference. [13]. The values are presented in Table 12 and 13 III.2.3. Dose rates from external exposure to radionuclides in the water column The dose rates to the RAPs (i.e., flatfish, crab and brown seaweed) from external exposure from radionuclides in the seawater and in sediments deposited on the sea floor, E ext,biota (in µgy/h), can be calculated using equation (22): where: E ext, RAP =,-. C W j ρ w C P j0dcf ext j,k (22) ν w is the Occupancy factor in the water column (dimensionless); C W (j) is the total activity concentration of radionuclide (j) in seawater (Bq/m 3 ); C P (j) is the activity concentration of radionuclide (j) in sediment (which is assumed to be equal to the activity concentration in suspended particles, Bq/kg, dry weight); DCF Ext (k,j) is the dose conversion factor for external exposure of marine biota (Reference Animal or Plant) k and radionuclide j (in µgy/h per Bq/kg); and C P, the radionuclide concentration in sediment is calculated using equation (9) in Appendix I. As explained in Appendix I, the total (activity) concentration in seawater, C W (j) (in Bq/m 3 ), is related to the filtered seawater concentrations by the equation: where: C W j=1+k d j SC DW j (23) K d (j) is the distribution coefficient (m 3 /kg) for radionuclide j ; and C DW (j) is the activity concentration of radionuclide j in filtered seawater (Bq/m 3 ). 29

39 The dose conversion factors (DCF) for external exposure for each of the marine reference plants and animals mentioned before are taken from ICRP Publication No. 108 [4] and from ERICA methodology [7]. The DCFs were derived by assuming a simplified ellipsoid geometry and that the aquatic organisms are submerged in an infinite water medium, as outlined in more detail in ICRP Publication No. 108 [4]. DCF are not presented in this report but can be found elsewhere in [4] and [7]. Occupancy factors need to be assigned to each of the marine biota considered in the calculations. For pelagic organisms such as phytoplankton, ν w equals 1 and the external dose is entirely derived from CW, the total activity in seawater (Bq/m 3 ). Conversely, for sediment dwelling organisms, such as polychaete worm, ν w equals 0 and the dose is entirely derived from CP(j), the total activity of radionuclide j in sediment (Bq/m 3 ). For organisms at the sediment water interface, such as flatfish, ν w = 0.5 and the dose is derived from both seawater and deposited sediment. Occupancy factors for each of the organism groups are provided in Table 11. III.2.4. Dose rates to biota from internal exposure to radionuclides The dose rates to the marine organisms from internal exposure to radionuclides incorporated within the organism, E Int,biota can be calculated using equation (24): where: ( k, j) DCF ( k j) f ( j) 3 E int, biota = CB int, m wr, m (24) m= 1 C B (j,k) is the total concentration of radionuclide j in the marine biota k (in Bq/kg, fresh weight) as calculated using equation (21); DCF Int (k,j) is the dose conversion coefficient for marine biota k and radionuclide j (in µgy/h per Bq/kg); f m (j) is the fraction of the DCF associated with the specific type of radiation (f 1 alpha particles and spontaneous fragments); and w R,m is the weighting factor for the fraction of the DCF associated with the specific type of radiation (10 for alpha particles, 1 for others). The dose conversion factors (DCF) for internal exposure and the fractions of the values associated with the following types of radiation: alpha particles and spontaneous fragments (f 1 ); low-energy (< 10 kev) electrons and beta particles (f 2 ) and from photons and highenergy electrons (f 3 ) are available in ICRP Publication No. 108 [4] and from ERICA methodology [7]. The DCF for internal exposure from alpha emitters are modified by a radiation-weighting factor of 10. III.2.5. Total dose rate The total dose rates to each organism E org (in µgy/h) may be estimated as the sum of the dose contributions calculated using equations (22) and (24). E Biota EExt, biota+ EInt, biota = (25) 30

40 TABLE 11. OCCUPANCY FACTOR IN THE WATER COLUMN FOR EACH OF THE MARINE ORGANISMS CONSIDERED Organism νw = Occupancy factor in the water column Flatfish 0.5 Crab 0.5 Seaweed 1 Flatfish egg 1 Crab larvae 1 Crab egg 0.5 Bird 1 Mammal 1 Mollusc 0.5 Polychaete 0 Pelagic fish 1 Phytoplankton 1 Zooplankton 1 TABLE 12. CONCENTRATION RATIO (CR) VALUES (IN UNITS OF BQ/KG F.W. PER BQ/KG) FOR ADULT MARINE REFERENCE ANIMAL AND PLANTS [10, 12, 14] Element Flatfish Crab Brown seaweed Ag Am Ca Ce Cl Cm Co Cr Cs Fe 1 x 10 3 (a) 5 x 10 4 (a) 1 x 10 5 (a) H Hg 3 x 10 4 (b) 2 x 10 4 (a) 2 x 10 4 (b) I Ir Mn Na 1 x 10 0 (b) 7 x 10-2 (b) 5 x 10-1 (b) Nb Np Pb Pm 3 x 10 2 (b) 4 x 10 3 (b) 3 x 10 3 (b) Po Pu Ra Ru S Sb Se Sn 5 x 10 5 (b) 5 x 10 5 (b) 2 x 10 5 (b) Sr Tc Th Tl 5 x 10 3 (b) 1 x 10 3 (b) 1 x 10 3 (b) U Zn Zr (a) IAEA (in press) [14]; (b) IAEA (2004) [10]. 31

41 TABLE 13. CONCENTRATION RATIO (CR) VALUES (IN UNITS OF BQ/KG F.W. PER BQ/KG) FOR LIFE STAGES OF MARINE REFERENCE ANIMAL AND PLANTS* Element Flatfish egg Crab egg Crab larvae Ag Am Ca Ce Cl Cm Co Cr Cs Fe H Hg I Ir Mn Na Nb Np Pb Pm Po Pu Ra Ru S Sb Se Sn Sr Tc Th Tl U Zn Zr *Values have been derived using direct empirical data or the guidance [12]. 32

42 TABLE 14. CONCENTRATION RATIO (CR) VALUES (IN UNITS OF BQ/KG F.W. PER BQ/KG) FOR ADULT MARINE REPRESENTATIVE ORGANISMS [13] Element Birds Mammals Molluscs Polychaete Pelagic Phyto- Zoo- (worms) Fish Plankton plankton Ag Am Ca Ce Cl Cm Co Cr Cs Fe H Hg I Ir Mn Na Nb Np Pb Pm Po Pu Ra Ru S Sb Se Sn Sr Tc Th Tl U Zn Zr

43 REFERENCES [1] INTERNATIONAL ATOMIC ENERGY AGENCY, UNITED NATIONS SCIENTIFIC COMMITTEE ON THE EFFECTS OF ATOMIC RADIATION, EUROPEAN COMMISSION, INTERNATIONAL UNION OF RADIOECOLOGY, Proceedings of the International Conference on the Protection of the Environment from the Effects of Ionizing Radiation, Stockholm 2003, IAEA CN-109, IAEA, Vienna (2003). [2] ENVIRONMENT AGENCY EUROPEAN COMMISSION, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANIZATION, INTERNATIONAL MARITIME ORGANIZATION, NUCLEAR ENERGY AGENCY/ORGANIZATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT, PAN AMERICAN HEALTH ORGANIZATION, UNITED NATIONS ENVIRONMENT PROGRAMME, WORLD HEALTH ORGANIZATION, Fundamental Safety Principles, Safety Standards Series No. SF-1, IAEA, Vienna (2006). [3] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann. ICRP 37 (2-4) (2007) [4] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, Environmental Protection - the Concept and Use of Reference Animals and Plants. ICRP Publication 108. Ann. ICRP 38 (4-6) (2008). [5] INTERNATIONAL ATOMIC ENERGY AGENCY, General Safety Requirements (GSR) Part 3: Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, Vienna (2011). [6] United Nations Convention on the Law of the Sea (UNCLOS) (1973). [7] BROWN, J.E., ALFONSO, B., AVILA, R., BERESFORD, N.A., COPPLESTONE, D., PRÖHL, G., ULANOVSKY A., The ERICA Tool, Journal of Environmental Radioactivity 99, Issue 9, (2008) [8] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, ICRP Environmental Protection: Transfer parameters 7 for Reference Animals and Plants, Draft 2011 (in preparation). [9] FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL ATOMIC ENERGY AGENC, INTERNATIONAL LABOUR ORGANIZATION, NUCLEAR ENERGY AGENCY/ORGANIZATION FOR ECONOMIC CO- OPERATION AND DEVELOPMENT, PAN AMERICAN HEALTH ORGANIZATION, WORLD HEALTH ORGANIZATION, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115, IAEA, Vienna (1996). [10] INTERNATIONAL ATOMIC ENERGY AGENCY, Application of the Concepts of Exclusion, Exemption and Clearance Safety Guide, IAEA Safety Standards Series No. RS-G-1.7, IAEA, Vienna (2004). [11] INTERNATIONAL ATOMIC ENERGY AGENCY, Determining the Suitability of Materials for Disposal at Sea Under the London Convention 1972: A Radiological Assessment Procedure, IAEA-TECDOC-1375, IAEA Vienna (2003). [12] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, Environmental Protection: Transfer Parameters for Reference Animals and Plants, ICRP Publication 114. Ann. ICRP 39 (6) (2009) 34

44 [13] HOSSEINI, A., THØRRING, H., BROWN, J.E., SAXÉN, R., ILUS E., Transfer of radionuclides in aquatic ecosystems Default concentration ratios for aquatic biota in the Erica Tool, Journal of Environmental Radioactivity, Volume 99, Issue 9 (2008) [14] INTERNATIONAL ATOMIC ENERGY AGENCY, Handbook of parameter values for the prediction of radionuclide transfer to wildlife, Technical Reports Series, IAEA, Vienna (in preparation). [15] ENVIRONMENT AGENCY, FOOD STANDARDS AGENCY, NORTHERN IRELAND ENVIRONMENT AGENCY, SCOTTISH ENVIRONMENT PROTECTION AGENCY, Radioactivity in Food and the Environment 2010 (RIFE 16), Bristol, London, Belfast and Stirling (2011). [16] EUROPEAN COMMISSION, PROTECT Deliverable 5, Numerical benchmarks for protecting biota from radiation in the environment: proposed levels, underlying reasoning and recommendations. Andersson, P., Beaugelin-Seiller, K., Beresford, N.A., Copplestone, D., Della Vedova, C., Garnier-Laplace, J., Howard,B.J., Howe, P., Oughton, D.H., Wells, C., Whitehouse, P. (2008). [17] UNITED NATIONS SCIENTIFIC COMMITTEE ON THE EFFECTS OF ATOMIC RADIATION, Sources and Effects of Ionizing Radiation, UNSCEAR Report 2008, Vol. II, Annex B (2010). [18] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, 1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60 Ann. ICRP 21 (1 3) (1991) [19] INTERNATIONAL ATOMIC ENERGY AGENCY, Determining the Suitability of Materials for Disposal at Sea under the London Convention and London Protocol: A Radiological Assessment Procedure, 2013 Edition, including an assessment procedure for protection of people and the environment, IAEA TECDOC, IAEA, Vienna (in preparation). [20] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, Radionuclide Transformations - Energy and Intensity of Emissions, ICRP Publication 38, Ann. ICRP (1983). [21] INTERNATIONAL ATOMIC ENERGY AGENCY, Sediment Distribution Coefficients And Concentration Factors For Biota In The Marine Environment, IAEA Technical Report Series No. 422, IAEA, Vienna (2004). [22] ECKERMAN, K.F, RYMAN, J.C., External Exposure to Radionuclides in Air, Water and Soil, Federal Guidance Report No. 12, US Environmental Protection Agency, Washington, DC (1993). [23] SIMMONDS, J.R., LAWSON, G., MAYALL, A., Methodology for Assessing the Radiological Consequences of Routine Releases of Radionuclides to the Environment, EUR , European Commission, Luxembourg (1995). [24] INTERNATIONAL ATOMIC ENERGY AGENCY, Definition and Recommendations for the Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matter, 1972, 1986 Edition, Safety Series No. 78, IAEA, Vienna (1986). [25] WILKINS, B.T., SIMMONDS, J.R., AND COOPER J.R., An assessment of the present and future implications of radioactive contamination of the Irish Sea Coastal Region of Cumbria, NRPB-R267, National Radiological Protection Board, HMSO, London (1994). [26] INTERNATIONAL ATOMIC ENERGY AGENCY, Generic Models for Use in Assessing the Impact of Discharges of Radioactive Substances to the Environment, Safety Reports Series No. 19, IAEA, Vienna (2001). 35

45 [27] INTERNATIONAL COMISSION ON RADIOLOGICAL PROTECTION, General Principles for the Radiation Protection of Workers, 1st Edition, ICRP Publication 75, Annals of the ICRP Volume 27/1, Elsevier (1997). [28] OSPAR COMMISSION, Radioactive Substances Committee Second Periodic Evaluation of Progress towards the Objective of the OSPAR Radioactive Substances Strategy, Publication Number 338/2007 (2007). [29] NATIONAL RADIOLOGICAL PROTECTION BOARD, Generalized derived constraints for radioisotopes of strontium, ruthenium, iodine, caesium, plutonium, americium, and curium, Documents of the NRPB Vol. 11, No. 2, HMSO, London (2000). 36

46 ANNEX I. RADIONUCLIDES USED IN A TEST CASE OF THE METHODOLOY CONDUCTED BY THE IAEA Table I-1 presents the factors, RF biota, estimated as described in Section 3, for the radionuclides of interest for OSPAR (marked in grey) and additional radionuclides which may be observed in marine environment [I-1] which were used by IAEA in a test case (that will be presented in the RSC Meeting in La Hague in February 2013). It is important to note that the values of dose rates above the corresponding reference levels for these limited number of radionuclides (e.g., 12) and species (e.g., 5) are mainly observed when using 1 msv/a to humans as a starting point. For a starting point of 100 µsv/a the list is substantially reduced (1 species: phytoplankton; 1 radionuclide: Cm-242) and for 10 µsv/a no species or radionuclides are observed in this situation. Table I-2 below presents the activity concentration reference (C ref ) as defined in Section 3for the radionuclides of interest for OSPAR (marked in grey) and for additional radionuclides used by IAEA to run a test case (the results of the test case to be presented in RSC Meeting in La Hague, February 2012). TABLE I-1. REFERENCE ACTIVITY CONCENTRATIONS IN SEAWATER (BQ/L, FILTERED) THAT CAUSE EXPOSURES TO HUMANS OF LESS THAN 1 msv/a AND EXPOSURES TO EXPOSURES TO BIOTA BELOW CORRESPONDING REFERENCE CRITERIA. RADIONUCLIDEs AS MONITORED BY OF OSPAR CONVENTION (marked in grey) AND ADDTIONAL Radionuclide Reference specie RF biota Am-241 Phytoplankton 0.6 Cm-242 Mammal 0.6 Phytoplankton 0.1 Cm-243 Phytoplankton 0.6 Cm-244 Phytoplankton 0.3 Pu-238 Phytoplankton 0.3 Pu-239,240 Phytoplankton 0.3 Pu-242 Phytoplankton 0.3 Bird 0.3 Ra-224 Mammal 0.9 Sr-85 Mammal 0.2 Sr-89 Mammal 0.3 Tc-99 Brown seaweed ap

47 TABLE I-2. RADIONUCLIDE OF INTEREST OF OSPAR AND ADDITIONAL RADIONUCLIDES, REFERENCE ACTIVITY CONCENTRATIONS IN SEAWATER (BQ/L, FILTERED) DERIVED INDIVIDUALLY FROM 1 MSV TO HUMAN AND VERIFYING DOSES TO BIOTA BELOW CORRESPONDING REFERENCE CRITERIA Radionuclide C ref Artificial radionuclides Ag-110m 8.5E-02 Am-241 a 1.4E-02 Ce E-02 Cm-242 a 9.4E-03 Cm-244 a 1.0E-02 Co E-02 Cs E+00 Cs E+00 H-3 5.6E+05 I E+01 Nb E-02 Np E+00 Pm E+00 Pu-238 a 2.6E-02 Pu-239,240 a 2.8E-02 Pu E+00 Ra E-02 Ru E-01 Sb E+00 Sr E+01 Tc-99 a 1.8E+01 Zr E-03 Natural radionuclides Pb E-04 Po E-04 Ra E-02 a indicates that reference criteria for biota is most restrictive. 38

48 .TABLE I-3. REFERENCE CRITERIA AND ANNUAL AVERAGE DOSES RATES TO MARINE FLORA AND FAUNA (µgy/h) DUE TO AN ACTIVITY CONCENTRATION IN SEAWATER EQUAL TO C ref (RADIONUCLIDES OF INTEREST OF OSPAR AND ADDITIONAL) Marine biota Reference criteria (µgy/h) Flatfish Flatfish egg Crab Crab larvae Crab egg Brown seaweed Bird Mammal Mollusc Polychaete Pelagic Fish Phytoplankton Zooplankton Radionuclide Dose rates to marine flora and fauna (µgy/h) Ag-110m 7E-01 5E-03 5E+00 1E-02 7E-01 1E-02 5E-01 1E+00 8E-01 2E+00 1E-01 1E-04 1E-02 Am-241 3E-01 1E-02 4E-01 2E+00 2E+00 4E-02 7E-02 7E-02 3E+00 4E+00 9E-02 7E+01 2E+00 C-14 Ce-144 3E+00 1E-04 2E+00 3E-02 7E+00 9E-03 2E-03 2E-03 5E+00 1E+01 3E-03 1E-04 3E-02 Cm-242 7E-02 6E-02 2E-01 3E+00 3E+00 3E+00 5E-02 5E-01 8E+00 5E-01 3E-02 7E+01 3E+00 Cm-244 6E-02 6E-02 2E-01 3E+00 3E+00 3E+00 5E-02 5E-01 8E+00 5E-01 3E-02 7E+01 3E+00 Co-60 3E+00 3E-04 3E+00 3E-03 3E+00 1E-03 2E-03 2E-03 3E+00 7E+00 2E-02 5E-05 3E-03 Cs-134 3E+00 2E-03 3E+00 1E-02 3E+00 4E-03 1E-01 8E-02 3E+00 6E+00 2E-02 2E-03 1E-02 Cs-137 3E+00 2E-03 3E+00 4E-02 3E+00 9E-03 3E-01 1E-01 3E+00 6E+00 5E-02 2E-03 4E-02 H-3 2E+00 2E+00 2E+00 2E+00 2E+00 7E-01 2E+00 2E+00 2E+00 2E+00 2E+00 4E+00 2E+00 I-129 1E-02 7E-03 8E-03 2E+00 2E+00 1E+00 7E-04 7E-04 3E+00 3E-02 3E-03 1E-03 2E+00 Nb-95 3E+00 4E-05 3E+00 1E-02 3E+00 9E-05 2E-04 6E-04 3E+00 7E+00 2E-04 3E-05 1E-02 Np-237 6E-01 6E-01 3E+00 5E-01 5E-01 1E+00 1E-01 1E-02 7E+00 1E+01 3E-02 4E+00 5E-01 Pb-210 1E-03 4E-04 9E-04 3E-03 4E-03 4E-04 4E-03 3E-03 6E-04 3E-03 7E-04 1E-06 3E-03 Pm-147 2E-01 5E-02 9E-01 7E-01 1E+00 5E-01 5E-02 5E-02 2E+00 3E+00 5E-02 1E+01 7E-01 Po-210 4E-02 4E-02 1E-02 1E-01 1E-01 2E-03 1E-01 2E-01 1E-01 7E-02 4E-02 1E-01 1E-01 Pu-238 2E-02 3E-02 3E-02 4E+00 4E+00 2E+00 1E-01 8E-01 6E-01 7E-01 1E-01 7E+01 4E+00 Pu-239,240 2E-02 3E-02 3E-02 4E+00 4E+00 2E+00 1E-01 8E-01 6E-01 7E-01 1E-01 7E+01 4E+00 Pu-241 5E-04 6E-04 8E-04 7E-02 7E-02 4E-02 2E-03 1E-02 1E-02 1E-02 2E-03 2E-01 7E-02 Ra-226 2E-01 2E-01 3E-01 1E-01 2E-01 2E-01 7E-01 2E-01 2E-01 4E-01 6E-01 5E-01 1E-01 Ra-228 4E-02 6E-04 4E-02 5E-04 4E-02 8E-04 5E-03 2E-03 4E-02 8E-02 4E-03 6E-05 5E-04 Ru-106 3E+00 2E-03 3E+00 4E+00 2E+01 1E-01 2E-02 2E-02 5E+00 1E+01 1E-02 8E-04 5E+00 Sb-125 1E+00 1E-01 1E+00 2E-01 1E+00 4E-01 1E-01 2E-01 1E+00 3E+00 9E-02 1E-03 2E-01 Sr-90 3E-01 2E-02 7E-02 7E-01 1E+00 9E-01 5E-01 2E+00 3E+00 5E-02 4E-01 3E-02 7E-01 Tc-99 9E-02 7E-02 2E-01 1E-01 1E-01 4E+01 3E-02 3E-02 6E+00 2E+01 3E-02 1E-03 1E-01 Zr-95 2E+00 1E-05 1E+00 4E-03 2E+00 2E-04 7E-05 1E-04 2E+00 3E+00 4E-05 1E-05 4E-03 Note: Marked radionuclides corresponds to those declared of interest of OSPAR. Marked cells indicate that for that radionuclide the reference was estimated from the radiological criteria for marine flora and fauna. 39

49 REFERENCES [I-1] ENVIRONMENT AGENCY, FOOD STANDARDS AGENCY, NORTHERN IRELAND ENVIRONMENT AGENCY, SCOTTISH ENVIRONMENT PROTECTION AGENCY, Radioactivity in Food and the Environment 2010 (RIFE 16), Bristol, London, Belfast and Stirling (2011). 40

50 ANNEX II. REFERENCE CRITERIA USED FOR RADIOLOGICAL PROTECTION OF THE ENVIRONMENT BY DIFFERENT AUTHORS Table II-1 below presents for illustration reference criteria used for radiological protection of the environment by different authors. Marked values correspond to those proposed by IAEA to be used within OSPAR according to discussions in the main text. TABLE II-1. DOSE RATES PROPOSED BY VARIOUS AUTHORS RELEVANT FOR RADIOLOGICAL PROTECTION OF FLORA AND FAUNA NCRP IAEA UNSCEAR Environment Canada, ERICA EC Protect [II-1] ICRP (low end DCRL) µgy h -1 Terrestrial Plants Pine tree 4 Wild grass 40 Animals Invertebrates 200 Bee 400 Earthworm 400 Birds Duck 4 Mammals 100 Deer 4 Rat 4 Aquatic Freshwater organisms Algae 100 Macrophytes 100 Benthic invertebrates Frog 4 Fish 20 Trout 40 Marine organisms Crab 400 Flatfish 40 Brown seaweed 40 Deep ocean organisms Note: the underlined flora and fauna are those used as indicators of the radiation exposure conditions for the OSPAR assessment approach being proposed by IAEA. The meaning and intended use of the values differ. Data compiled under EC PROTECT project. REFERENCES [II-2] EUROPEAN COMMISSION, PROTECT Deliverable 5, Numerical benchmarks for protecting biota from radiation in the environment: proposed levels, underlying reasoning and recommendations. Andersson, P., Beaugelin-Seiller, K., Beresford, N.A., Copplestone, D., Della Vedova, C., Garnier-Laplace, J., Howard,B.J., Howe, P., Oughton, D.H., Wells, C., Whitehouse, P. (2008). 41 APP

51 CONTRIBUTORS TO DRAFTING AND REVIEW IAEA staff and consultants who assisted to develop the IAEA proposal Bonchuk, I. Brown, J. Bossio, M Cabianca, T. Kliaus, V. Proehl, G. Telleria, D. Van Der Wolf, J. Ukrainian Radiation Protection Institute, Ukraine Norwegian Radiation Protection Authority, Norway Autoridad Regulatoria Nuclear, Argentina Health Protection Agency, United Kingdom Republican Scientific-Practical Centre of Hygiene, Republic of Belarus International Atomic Energy Agency International Atomic Energy Agency International Atomic Energy Agency (intern) Participants nominated by OSPAR RSC to attend the Consultants Meeting to elaborate on the IAEA s proposal for environmental radiological quality criteria for the OSPAR Convention (November 2011, IAEA Headquarters, Vienna) Andersson, P. Engeler, C. Fiévet, B. Goud, R. Gwynn, J. Hemidy, P.-Y. Kelleher, K. Leonard, K. Swedish Radiation Safety Authority, Sweden Rijkswaterstaat Centre for Water Management, Netherlands Institut de Radioprotection et de Sureté Nucléaire, France Rijkswaterstaat Centre for Water Management, Netherlands Norwegian Radiation Protection Authority, Norway Électricité De France, France Radiological Protection Institute of Ireland, Republic of Ireland Centre for Environment, Fisheries & Aquaculture Science, United Kingdom Rodriguez Lucas, L. OSPAR Commission, United Kingdom Saint-Pierre, S. World Nuclear Association, United Kingdom 42

52 Annex 2 Report on the application of the Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by the RSC 1 1. Introduction 1. The International Atomic Energy Agency (IAEA) has proposed a methodology for radiological environmental assessment, and associated criteria, for the OSPAR Convention [1]. This methodology was presented to the Radioactive Substances Committee (RSC) in February 2013 (RSC 2013) along with the results of a case study based on OSPAR Region 6 (Irish Sea Sellafield). Generally speaking, the approach uses simple, generally conservative, models to calculate doses from exposure to radionuclides present in the marine environment for both humans and non human species. The principles of the methodology were agreed at the RSC 2013 but questions were raised about how it would be applied, the underpinning dose criteria and whether there might be any unintended consequences resulting from its application. 2. The RSC recognised the need to evaluate the potential application of the methodology. Consequently, the RSC set up an Intersessional Correspondence Group (ICG) on Environmental Assessment Criteria (EAC) to take this review forward. Specifically, the aim of the ICG was to clarify matters arising from the potential application of the proposed IAEA method and explore technical issues of relevance to OSPAR. In particular it should consider: i) a suitable starting point upon which the assessment is based; ii) iii) iv) suitable assessment categories; suitable category descriptions; suitable non human dose reference criteria. 3. This report outlines the ICG EAC s evaluation of its application of the methodology in the OSPAR context and makes recommendations for its testing, implementation and minor modifications. The ICG s work was carried out by correspondence and included a workshop in London in July The assessment methodology provides a screening or generic assessment tool for use by OSPAR RSC. The methodology incorporates current state of the art tools and knowledge of radiation protection for both humans and wildlife. However, while the understanding of radiation effects on humans is relatively well established, the understanding of effects upon biota is, in contrast, a more developing area and this should be taken into account as part of a review of the methodology after 5 10 years. The assessment methodology incorporates standard assumptions used widely in the radiation protection community and therefore is well grounded for the purposes of RSC. Importantly the methodology may allow the identification of where further impact studies may be justified. 5. Although the methodology was originally designed with OSPAR in mind it may potentially be applied to any marine environment. Therefore it should be made clear that the assessments and associated recommended management actions relate specifically to the OSPAR context. 1 ICG EAC report to RSC Ref. 14/4/1. OSPAR Commission 1 of 10 RSC 14/4/1 E

53 6. The ICG agrees with the RSC that the overall approach is adequate, however the ICG concluded that the following issues associated with application be subject to detailed testing. 2. Issues to be tested 2.1 Assumption of equilibrium between seawater and sediment 7. The principal reference criteria are the lowest radioactivity concentrations in seawater that would give rise to a dose of 1 msv per year to humans or to exposure at the lower bound of the relevant Derived Consideration Reference Level (DCRL) for key marine non human species. In common with many radiological assessment models the method assumes that the activity concentrations in sediment and seawater are in equilibrium; this is considered to be reasonable approximation for radiation dose assessment purposes. The assumption of equilibrium takes into account the potential contribution from the remobilisation of radionuclides from sediment as well as from discharges. However, it should be recognised that in areas which have received higher historic discharges that have built up in the sediment or in areas that are receiving new sources of discharge, the concentrations in sediment may differ from those inferred by the concentration in seawater at that location this is discussed in section 5.1 of reference [1]. 8. Sediments often display localised variations in concentrations resulting in a wide variation of biota exposures but which may have a limited impact on the population of the species in the region as a whole. The use of seawater concentrations as the principal reference criteria is therefore considered appropriate because they are likely to be the most representative environmental indicator at the OSPAR regional level. These aspects, however, should be further evaluated by testing the methodology and its application fully within the OSPAR regions particularly to evaluate whether the assessment adequately reflects the fact that there may be a build up of contaminated sediments at radioactivity concentrations greater than that implied by equilibrium with seawater. 2.2 Spatial and temporal averaging 9. The OSPAR monitoring regions defined in the monitoring agreement for radioactive substances [2] (the monitoring regions ) have been selected for the purpose of data gathering, modelling, carrying out trend assessment against baselines, and in some cases where there is a limited number of sources discharging to a region, the regional area selected is large, for practical purposes. Regional averaging can lead to smoothing of intra regional variations. 10. The effect of spatial averaging is therefore an important topic for testing. The testing should look at varying the scale of the spatial averaging and its effects on the results. 11. In common with many radiological assessment tools the methodology uses temporal averaging, which is a well established approach for environmental exposures which are often long term and low level. The use of annual averaging is appropriate because all of the modelling assumptions used are based on annual rates (e.g. annual consumption rates) and the exposure rates are assumed to be uniform over time. 2.3 Representative non human species 12. The impact on the marine ecosystem as a whole is represented by the exposure of a representative set of marine organisms. The representative species include the Reference Animals and Plants (RAPs) recommended by ICRP for the marine environment and, at the request of OSPAR RSC, ERICA marine reference organisms [3]. If the application of the methodology indicates that the environmental assessment criteria are challenged then more detailed assessments of particular species may be needed and the resulting doses could be higher or lower than those estimated using the generic methodology. Additional species could be added to the standard list but this requires valid scientific information on the dosimetry, transfer factors and on the relationship between dose and effect for those species. 13. The ICRP Publication 108 [4] explains that RAPs were chosen on the basis of the availability of good quality radiobiology and effects data, and because they are typical and widespread flora and fauna of particular ecosystems. RAPs are not intended to represent all the species in an ecosystem, they are intended to be used as reliable indicators of the health of an ecosystem as a whole. The ICRP, and IAEA OSPAR Commission 2 of 10 RSC 14/4/1 E

54 through their forthcoming IAEA Safety Guide on Radiological Environmental Impact Assessment, both stress that reference criteria for other reference animals and plants can be derived if necessary provided that good quality data are available. 14. In conclusion, for the purposes of a generic or screening assessment of this kind, the use of the ICRP RAPs combined with the ERICA marine reference organisms provides a good coverage of the species likely to be typical of the marine ecosystems found in the OSPAR regions. 2.4 Radionuclides 15. The methodology has been applied initially to eight radionuclides for which OSPAR monitoring data are generally available. These were: tritium, technetium 99, caesium 137, lead 210, polonium 210, plutonium 239/240, radium 226 and radium 228. However, not all of these radionuclides are monitored in seawater at every location in every OSPAR monitoring region. Certain radionuclides are also monitored in fish, molluscs and seaweed at some locations. 16. An analysis of a longer list of radionuclides measured in the marine environment as part of the UK s Radioactivity in Food and the Environment monitoring programme (RIFE) in 2010 was also carried out as part of the initial testing of the methodology conducted by IAEA [1]. 17. The ICG recommends that further testing be carried out to determine the proportion of the impact covered by the standard list of indicator radionuclides and to determine whether the majority of the radiological impact is accounted for. This may also identify any gaps in monitoring data that may need to be addressed and help determine the minimum set of data required to give a meaningful indication of the overall radiological status of each region. 2.5 Radiation dose basis 18. The reference seawater concentrations are derived using a human dose criterion ( the starting point ) of 1 msv per year, or the lower bound of the Derived Consideration Reference Levels (DCRLs) for biota, whichever is the more limiting. While there are potential alternatives for the underpinning dose criteria, such as dose constraints set at a fraction of the public dose limit (e.g. 300 µsv), or thresholds such as the 10 µsv used as the basis for exemption values, the ICG support the approach taken for the following reasons: If a lower value were used for the human dose criterion (e.g. a dose constraint), this is likely to make humans the most restrictive receptor in all cases but it also, by definition, applies to single sources whereas the assessment required by OSPAR is for all discharges into a given OSPAR region. Similarly using a value such as of the order of 10 µsv/y (the basis for international exemption levels and also in use in for determining the suitability of materials for disposal at sea under the London Convention and London Protocol [5]) would be inappropriate for evaluating impacts resulting from authorized discharges, this being the interest of OSPAR. 19. The dosimetric approaches used to define the reference concentrations for humans have been based on typically conservative, but not unrealistic, dose assessment calculations that consider the principal pathways of exposure for humans. The method described in IAEA TECDOC 1375 [5] was used for the calculations with different, generally cautious, ingestion rates for sea foods (e.g. those defined by OSPAR RSC based on Marina II studies). The exposure pathways are also consistent with those identified for use in the London Convention (TECDOC 1375 and its update) [5]. The other habit and occupancy data used are also consistent with those used in the London Convention, and other habit data typically used for the assessment of the radiological impact of discharges from nuclear installations, for example those used in the UK. 20. The exposure pathways considered in the methodology are: external exposure to radionuclides deposited on the shore; ingestion of seafood; inadvertent ingestion of beach sediments; inhalation of particles resuspended from beach sediments; and inhalation of sea spray. The methodology does not include all minor pathways, for example the exposure due to immersion in seawater and external exposure OSPAR Commission 3 of 10 RSC 14/4/1 E

55 to water borne radionuclides e.g. while in boats. These examples and similar pathways omitted from the methodology are normally assumed to be very minor contributors to overall dose [6]. 21. The lower end of the band of the DCRLs defined for the ICRP RAPs has been used to derive the biota criteria. The purpose of the RAPs is to relate exposure to dose and dose to effects for that type of organism. In this way, it allows the numerical criteria to be defined for different wildlife groups that can be applied to other similar and related species. ICRP have used the RAPs specifically for this purpose when defining the DCRL. 22. The DCRLs are considered to be a band of dose rate within which there is likely to be some chance of deleterious effects of ionising radiation occurring to individuals of that type of Reference Animal or Plant, derived from a knowledge of defined expected biological effects for that type of organism that, when considered together with other relevant information, can be used as a point of reference to optimise the level of effort expended on environmental protection, dependent upon the overall management objectives and the exposure situation [4]. 23. The application of the DCRLs to determine the reference criteria is in line with the approach outlined in the latest draft of the ICRP report Protection of the Environment under Different Exposure Situations [7]. The final draft report outlines how, for planned exposure situations, you might expect to use the bottom of the DCRL band (as is done within the assessment methodology) as you would want to avoid situations where some form of deleterious effect(s) may occur (i.e. at dose rates within the DCRL band). Consequently the derivation of the environmental assessment criteria is in line with the use of the ICRP DCRLs. As a point of reference for different wildlife groups, the DCRLs are also applicable to other examples of wildlife. So for example, it is reasonable to assume that the ICRP RAPs for mammals (rat and deer) will be reasonable analogues for other mammals that are not specifically included in the ICRP RAPs. Again the proposed methodology is consistent with the anticipated interpretation and application of the DCRLs. 24. Where the criteria used in the proposed methodology have been derived from sources other than the DCRLs, e.g. those for phytoplankton, zooplankton and molluscs, these have been taken from other major reviews of biological effects and should be cautious or highly protective [8]. 25. In conclusion, the reference criteria based on the lower bound of the DCRL band or from other sources are likely to be conservative. 2.6 The use of individual doses 26. The methodology focuses on the radiological impact on individual humans and organisms as an index of radiological quality rather than collective or population impacts. The collective dose concept for humans should only be used prospectively as an input into the optimisation of waste management decisions [9], and is therefore not appropriate for retrospective assessments of the kind required in the OSPAR context. 27. The impact on populations is an important consideration for non human species, however if all the individuals in an OSPAR region are exposed below the bottom of the relevant DCRL band the effects at the population level should be negligible. 2.7 The degree of conservatism 28. The use of a conservative, yet realistic, approach is in line with international radiological assessment guidance. For example, ICRP advises that prospective assessments should be conservative to account for uncertainty about the future, but at the same time as realistic as possible to avoid gross overestimation. The input data for retrospective assessments are generally more certain and therefore the assessment can often be made more realistic than for prospective assessments. However, retrospective assessments for OSPAR need to balance conservatism and realism because of the uncertainties associated with a regional generic screening assessment. 29. The dose criteria adopted are considered to be conservative. The reference concentrations are based on a dose reference of 1 msv per year for humans (equivalent to the public dose limit for planned OSPAR Commission 4 of 10 RSC 14/4/1 E

56 exposures) and dose rates at the lower end of the DCRL bands, which are both considered low levels of exposure. The model parameters are also generally conservative, although the effect of using parameters in the non human species assessment that are derived instead of being based on empirical data is unknown. The conservatism associated with the assessment of impacts on humans is generally better known. 30. Overall, it is expected that the proposed methodology will provide generally cautious reference criteria rather than highly conservative ones. However, it is important to understand and document the degree of conservatism. During testing of the assessment methodology, it is recommended that the level of conservatism be established for biota in particular. 2.8 The protection of ecosystem goods and services 31. The OSPAR NE Atlantic Environment Strategy [10] states: The OSPAR Commission s vision is a clean, healthy and biologically diverse North East Atlantic Ocean, used sustainably. To this end, the OSPAR Commission s activities under this Strategy will be guided by the application of the Ecosystem Approach which is the comprehensive integrated management of human activities based on the best available scientific knowledge about the ecosystem and its dynamics, in order to identify and take action on influences which are critical to the health of the marine ecosystems, thereby achieving sustainable use of ecosystem goods and services and maintenance of ecosystem integrity 2. The OSPAR Commission will implement the Ecosystem Approach taking account of its role within the wider political and legal frameworks. 32. The health of marine ecosystems and their sustainable use are therefore key underpinning drivers for OSPAR s strategies. The OSPAR Radioactive Substances Strategy contributes to the OSPAR vision by aiming to reduce human input of radioactive substances into the marine environment to such an extent that it is not adding significantly to existing levels of radioactivity in the marine environment. 33. The assessment methodology provides an indication of the radiological impact on biota and on humans, and hence provides an indication of ecosystem health. However, the sustainability of ecosystem goods and services (e.g. food, amenity/tourism, seawater), may be affected by factors unrelated to the actual radiological risk, for example the perception of tainted goods or services may also be a factor and this may need to be taken into account on a case by case basis. 2.9 Assessment categories and their descriptions 34. The IAEA has suggested four assessment result categories [1]. There were a number of questions raised at RSC 2013 related to the terminology used when describing the radiological environmental status and what the associated management actions might be. The ICG has also considered the use of colour coding used for categories. 35. For consistency in communication the ICG considered changing some of the terminology. For example, the terms Quality Quotient and Integrated Quality Quotient are described in reference [1]. However, the terms Risk Quotient and Sum of Risk Quotients are more commonly used in ecotoxicology and in the ERICA tool. Given that OSPAR also deals with other hazardous substances and the multitude of terms that are in use, it is recommended that terms are consistent across the risk assessments and that internationally recognised terms are used where appropriate. 36. A modified list of three categories and descriptors is proposed for use in the table below. 2 As defined by the Statement on the Ecosystem Approach to the Management of Human Activities Towards an Ecosystem Approach to the Management of Human Activities adopted in 2003 by the Joint Ministerial Meeting of the Helsinki and OSPAR Commissions. OSPAR Commission 5 of 10 RSC 14/4/1 E

57 Category OSPAR Radiological Assessment Status Potential measures that may be taken Additional monitoring may be considered along with more site specific and/or detailed C SRQ > 1 B 0.1 < SRQ 1 OSPAR assessment results indicate further consideration is needed OSPAR assessment results are satisfactory assessment where such assessments are not already available. This should consider aspects such as sources of the radionuclides and background levels etc Slightly extend monitoring programme (especially if closer to 1) A SRQ 0.1 OSPAR assessment results require no further action No additional action required Note: SRQ = Sum of Risk Quotients the ratio of measured concentration to reference concentration summed across radionuclides this is equivalent to the Integrated Quality Quotient described in reference [1]. 37. The OSPAR Commission s strategic objective with regard to radioactive substances is to: prevent pollution of the OSPAR maritime area from ionising radiation through progressive and substantial reductions of discharges, emissions and losses of radioactive substances, with the ultimate aim of concentrations in the environment near background values for naturally occurring radioactive substances and close to zero for artificial radioactive substances. In achieving this objective the following issues should, inter alia, be taken into account: a. radiological impacts on man and biota; b. legitimate uses of the sea; c. technical feasibility. The radiological impacts on man and biota should therefore be taken into account in an assessment of whether environmental concentrations of radionuclides are close to zero. The ICG tasked with developing a test, or tests, for determining whether concentrations are close to zero above historic or natural background levels may wish to consider the proposed environmental assessment methodology as a tool for taking into account radiological impacts on man and biota. 3. Conclusions and recommendations OSPAR Commission 6 of 10 RSC 14/4/1 E

58 38. The ICG has explored technical issues arising from the application of the proposed assessment methodology of relevance to OSPAR. It has considered the suitability of the dose criteria for both humans and non human biota, and the assessment categories and their descriptions. 39. In summary, the ICG concludes that the assessment methodology is a sound, and generally conservative, basis for radiological assessment in the OSPAR context which may be used as a generic assessment and/or screening tool to indicate whether further detailed studies may be necessary. 40. Recommendation 1: The ICG recommends that the RSC considers whether the assessment methodology might be adopted for use in OSPAR periodic reviews following appropriate modification of sections 4 and 5 of reference [1] as detailed in this report, and following full testing in Recommendation 2: The ICG recommends that the methodology should be tested for all OSPAR regions as defined in the Monitoring Agreement for Radioactive Substances [2] (the monitoring regions ) in 2014 and a report submitted to RSC The testing should include: a. The effects of regional averaging a test case may be used to compare results at a local (intra regional) level with those for a full monitoring region. b. The effects of any differences in the data available between regions, for example, resulting from an uneven distribution of monitoring locations between regions. c. The management of results at limit of detection (LoD) or the absence of data. d. The effects of potential changes over time in the number and location of monitoring points within regions. e. Presentation and communication of results, for example where a large inter regional variation is produced which is affected by the size of the region and/or other factors linked to the monitoring data. f. The assumption of equilibrium conditions between the activity concentrations in the water column and in sediment, for example where there is localised build up of radioactivity in sediment. The proportion of the impact assessed by the methodology and the available data should be determined. The monitoring data are likely to be available only for a small set of indicator radionuclides for both manmade and naturally occurring species, therefore we need to determine the extent to which the most radiologically significant radionuclides are accounted for. This is particularly important in the context of non human species exposure in the case of humans, existing assessment studies may be referred to. The level of conservatism within the methodology should be established and, for the non human species assessment, that a sensitivity analysis of the key parameters be undertaken. The key parameters that are driving the assessment should be considered in the context of all available information to assess whether the values are appropriate, fit for purpose and/or generally conservative based on expert judgement. OSPAR Commission 7 of 10 RSC 14/4/1 E

59 42. Recommendation 3: The ICG developing tests for determination of close to zero concentrations above historic levels should consider the use of the assessment methodology as a way of taking radiological impacts into account. 43. Recommendation 4: The methodology and its input data should be reviewed after 5 10 years in view of the developing nature of environmental radiation protection. 4. References 1. IAEA, Definition of Radiological Environmental Assessment Criteria for the OSPAR Convention: A Proposal by the IAEA for consideration by RSC. January RSC 13/7/1 E. 2. Agreement on a Monitoring Programme for Concentrations of Radioactive Substances in the Marine Environment. (Reference number: , 2011 Revision). 3. Beresford N A, Brown J, Copplestone D, Garnier Laplace j, Howard B J, Larsson, C M, Oughton D, Prohl G, and Zinger I D ERICA: An integrated approach to the assessment and management of environmental risks from ionising radiation. Deliverable of the ERICA project. Swedish Radiation Protection Auhtority, Stockholm. 4. International Commission on Radiological Protection. Environmental Protection the Concept and Use of Reference of Reference Animals and Plants. ICRP Publication 108. Ann. ICRP 38 (4 6) (2008). 5. International Atomic Energy Agency. Determining the suitability of materials for disposal at sea under the London Convention 1972: A radiological assessment procedure, IAEA TECDOC 1375, IAEA Vienna (2003) and 2013 edition (in prep). 6. Jones K.A., Walsh C., Bexon A., Simmonds J.R., Jones A.L., Harvey M., Artmann A. and Martens R. (2006) Guidance on the Assessment of Radiation Doses to Members of the Public due to the Operation of Nuclear Installations under Normal Conditions. Health Protection Agency Report HPA RPD International Commission on Radiological Protection. Protection of the Environment under Different Exposure Situations. ICRP Publication 124 (in prep). 8. PROTECT project Andersson, P., Garnier Laplace, J., Beresford, N.A., Copplestone, D., Howard, B.J., Howe, P., Oughton, D., Whitehouse, P Protection of the environment from ionising radiation in a regulatory context (PROTECT): proposed numerical benchmark values. J. Environ. Radioact., 100, International Atomic Energy Agency. General safety requirements (GSR) Part 3: Radiation protection and safety of radiation sources: International Basic Safety Standards, Vienna (2011). 10. OSPAR Commission,The NE Atlantic Environment Strategy. OSPAR Agreement OSPAR Commission 8 of 10 RSC 14/4/1 E

60 ANNEX 2 General Comments France The following comments have been made by France on the final draft of the report. The proportion of total impact The ICG has suggested that further testing be carried out to determine the proportion of the impact covered by the standard list of indicator radionuclides and to determine whether the majority of the radiological impact is accounted for. France commented that: No, this is beyond the objective of OSPAR strategy. However, such tests might be helpful for Environmental Impact Assessment of specific facility and Contracting Parties might be invited to consider the methodology and to test its consistency for their specific application. Comments were also provided on the summation of quotients for individual radionuclides and also the scope of any testing to look at the effects of spatial averaging: QQ and IQQ France would like to emphasize the distinction between the use of a Quality Quotient QQ j, calculated for a single radionuclide, and the Integrated Quality Quotient, which is supposed to combine the impact of all radionuclides contributing to the dose to man and biota. It is important to note that to assess progress towards OSPAR objective on concentration of radioactive substances, QSR 2010 focused on concentrations of indicator radionuclides. The concept of QQ j is consistent with this approach and France suggests testing this concept with this actual set of radionuclides (137Cs, 99Tc, Pu, ), where concentration data are available. Conversely, France considers that the use of IQQ in RSC raises a number of difficult questions to solve and would not be useful to appraise whether the strategy has been delivered. It is to be noted that total alpha activity and total beta activity have been used in QSR 2010 to assess progress towards OSPAR objective on discharges of radioactive substances but not on concentrations. A few problems are listed below: It is not feasible to measure the concentration of all discharged nuclides in the OSPAR zone of the marine environment. No real integrated dose can therefore be assessed. Moreover, many concentrations are less than the detection limit. OSPAR Commission 9 of 10 RSC 14/4/1 E

61 If modelling discharges dispersion was considered as an alternative to measured concentration in seawater, many further questions would raise (issues of suitable models, validation of results, uncertainties ). In summary, without challenging the concept of IQQ in any way, France considered that its use in OSPAR does not help the RSC to demonstrate the progress towards RSS but may severely impair the progress of its work. Spatial averaging The assessment methodology provides an assessment tool for use by OSPAR RSC. It relates specifically to OSPAR context and it may therefore be not appropriate in other contexts. The methodology should therefore not be used for special scales other than the OSPAR monitoring regions. In the OSPAR context the effect of spatial averaging should concentrate on the 5 OSPAR Regions versus the 15 OSPAR RSC zones. OSPAR Commission 10 of 10 RSC 14/4/1 E

62 Annex 3 Final report on the demonstration of the proposed IAEA methodology for deriving Environmental Assessment Criteria 1 Introduction 1. The strategic objective of the OSPAR North East Atlantic Environment Strategy with regard to radioactive substances is to prevent pollution of the OSPAR maritime area from ionising radiation through progressive and substantial reductions of discharges, emissions and losses of radioactive substances, with the ultimate aim of concentrations in the environment near background values for naturally occurring radioactive substances and close to zero for artificial radioactive substances. In achieving this objective the following issues should, inter alia, be taken into account: i) Radiological impacts on man and biota; ii) iii) Legitimate uses of the sea; Technical feasibility. 2. The Radioactive Substances Strategy will be implemented progressively by making every endeavour, through appropriate actions and measures to ensure that by the year 2020 discharges, emissions and losses of radioactive substances are reduced to levels where the additional concentrations in the marine environment above historic levels, resulting from such discharges, emissions and losses, are close to zero. 3. The OSPAR Radioactive Substances Committee (RSC) set up an Intersessional Correspondence Group (ICG) on Environmental Assessment Criteria (ICG EAC) to assess the potential application of such criteria in OSPAR assessments. 4. The derivation of environmental assessment criteria (EAC) for OSPAR purposes follows a methodology proposed by the International Atomic Energy Agency (IAEA) (IAEA (2011)). The methodology was refined and tested using a case study based on Region 6 (Irish Sea Sellafield)2 following an IAEA/OSPAR workshop (IAEA 2013). In 2013, RSC endorsed the principles of the methodology and following further testing by the ICG EAC in 2014, RSC 2015 agreed to recommend the use of EAC in future OSPAR assessments as part of a suite of assessments tools. 2 Environmental Assessment Criteria 5. The IAEA methodology is used to calculate reference radioactivity concentrations in seawater that correspond to reference levels of radiation exposure of humans and wildlife and the most restrictive concentration taken as the EAC. The reference levels of radiation exposure used to derive the reference concentrations were the established dose limit for humans of 1mSv/y (IAEA (2014)) and the lower bound of the appropriate range of the International Commission on Radiological Protection s (ICRP) Derived Consideration Reference Levels (DCRLs) (ICRP 2008) for the Reference Animals and Plants (RAPs). In the majority of cases the reference concentrations derived on the basis of human exposure were the most restrictive. 3 Demonstration of the Methodology 2 Data on environmental concentrations are reported to OSPAR for 15 monitoring areas that generally represent subdivisions of the five designated regions of the OSPAR maritime area. See Figure 1. 8 of 14 OSPAR Commission OSPAR Agreement

63 6. In 2014, ICG EAC examined a number of issues raised by RSC regarding the practical application of the methodology in the OSPAR context. This report summarises and updates the progress report of the demonstration of the methodology tabled at RSC 2015 (RSC (2015)), in light of the comments made at RSC 2015 and further comments from the ICG EAC. 3.1 Demonstration of EAC for OSPAR monitoring regions 7. The Environmental Assessment Criteria (EAC) were compared to the measured concentrations of OSPAR indicator radionuclides for each of the OSPAR monitoring regions shown in Figure Monitoring data issues 8. The assumption of equilibrium between sediment and seawater concentrations, spatial averaging issues and the variation in the datasets underpinning the derivation of the EACs were considered. 9. Using three selected regions, i.e. Region 1 (Wider Atlantic, Bay of Biscay/Golfe de Gascogne, Iberian Waters and the Western Approaches), Region 4 (Irish Sea, Republic of Ireland) and Region 6 (Irish Sea, Sellafield), spatial and temporal averaging of OSPAR data was considered to determine the variability of concentrations and how these compared with the EAC. 10. A short literature review of the role of historical discharges and environmental sinks in contributing to seawater concentrations of radionuclides was conducted. The remobilisation of radionuclides from contaminated sediments is well documented and has been the subject of many studies in areas within, for example, Region 6 (Irish Sea, Sellafield) and these were the focus of the review. 3.3 Relative impacts of the OSPAR indicator radionuclides 11. To investigate the relative impact of OSPAR indicator radionuclides when compared with the longer list of radionuclides which may be detected in the OSPAR regions, estimates of dose rates to biota for the measured OSPAR radionuclides and monitoring data from the Radioactivity in Food and the Environment (RIFE) report (Environment Agency et al (2014)) were compared. For this purpose the ERICA tool (Brown et al (2008)) was used, which is compatible with the ICRP methodology (ICRP 2008) used by IAEA to define the EAC. Region 6 (Irish Sea, Sellafield) was used for the comparison as it has a relatively large dataset. The percentage contribution of the OSPAR radionuclides to the total dose from the wider set of radionuclides was assessed for the years 2008 to A review of the contribution of OSPAR indicator radionuclides to doses to humans in the vicinity of Sellafield was also carried out. 3.4 Sensitivity and uncertainty 12. A particular area of sensitivity in the assessments of doses to non human species is the concentration ratio representing the equilibrium ratio of radionuclide concentration in the tissue of organism to that in its external environment. A limited exercise was carried out to explore the probability distributions attached to concentration ratios and their effect on the calculated dose rates. 9 of 14 OSPAR Commission OSPAR Agreement

64 Region 1. Wider Atlantic Region 2. Cap de la Hague Channel Region 3. Channel East Region 4. Irish Sea (Rep. of Ireland) Region 5. Irish Sea (Northern Ireland) Region 6. Irish Sea (Sellafield) Region 7. Scottish waters (Dounreay) Region 8. North Sea South (Belgian and Dutch coast) Region 9. German Bight Region 10. North Sea (NW, SE and Central) Region 11. North Sea (Skagerrak) Region 12. Kattegat Region 13. Norwegian Coastal Current Region 14. Barents Sea Region 15. Norwegian, Greenland Seas and Icelandic waters Figure 1: The OSPAR monitoring regions for RSC purposes 4 Summary of results 13. This section summarises the key results and conclusions. 4.1 Demonstration of EAC for OSPAR monitoring regions and data issues 14. The OSPAR Monitoring Agreement specifies that monitoring of eight indicator radionuclides (Cs 137, Pu 239/240, H 3, Tc 99, Ra 226, Ra 228, Po 210 and Pb 210) in seawater and biota should be carried out where possible. The OSPAR Monitoring dataset is comprehensive, however this work demonstrated that a full comparison of seawater concentrations against the EAC was not possible for all indicator radionuclides for all years in all regions. For the majority of regions, data were available for the four artificial radionuclides but were not always available for the whole of the 5 year period studied ( ). The number of data entries per radionuclide for each region varied greatly as did the proportion of limit of detection (LoD) values which varied between 0 and 100% of the seawater concentrations. 15. The EAC values were not exceeded by measurements of artificial radionuclides in any region over the 5 year period studied. However, the quoted LoD for Pu 239/240 in in Region 8 exceeded the EAC. 16. There were a few cases where the LoD (or in three cases the actual measurement) of naturally occurring radionuclides exceeded the EAC (i.e. radium isotopes in Region 8 for the years and Po 210 in regions 14 and 15 for the year 2012). However, this does not include the subtraction of natural background levels which could account for all, or a significant fraction, of the measured concentrations. 10 of 14 OSPAR Commission OSPAR Agreement