Review of the UK s Regulatory Framework Governing the Management of Radioactive Liquids

Transcription

1 Review of the UK s Regulatory Framework Governing the Management of Radioactive Liquids Identifying present stakeholder concerns and proposals for potential improvements

2 This work was undertaken under the Radiation Assessments Department s Quality Management System, which has been approved by Lloyd's Register Quality Assurance to the Quality Management Standard ISO 9001:2015, Approval No: ISO Report version Draft version 1.3 ii

3 Contents 1 Introduction 5 2 Concerns identified An absence of out of scope values for artificial radioactive aqueous liquids Inability of those who hold permits for radioactive waste discharges to use exemptions Definition of relevant liquids Out of scope values close to limits of detection Off-shore oil and gas facilities Miscellaneous 8 3 Proposals 9 4 References 9 iii

4 Introduction 4

5 1 Introduction The United Kingdom is reviewing its approach to regulating the management of liquid wastes, particularly those containing very low levels of radionuclides, to ensure that it is fit for purpose; reflects international standards, requirements and best practice; is underpinned by coherent policy; protects the public and environment; and does not place unnecessary burden on business or regulators. It should be made clear that this report is an interim one intended to document comments already received regarding the regulatory regime and to elicit further comments where areas of concern have not already been identified. The current version of the report records the comments that have previously been received but does not indicate whether they can or should be addressed. This report notes concerns with the current regime identified from the following sources: Responses to the BEIS consultation on Revised Requirements for Radiological Protection: Regulation of Public Exposures (BEIS et al, 2018b) and in particular those given to the specific question related to the regulatory regime for liquid waste. There were 36 responses to the consultation on this topic from both individuals and organisations. One group which provided detailed comments was the Clearance and Exemption Working Group (CEWG) which brings together a wide range of representatives of nuclear operators across the UK. Issues that the Regulators have identified through the course of their work for consideration. Feedback elicited as part of this work through direct requests [this will be updated following consultations with interested parties] 2 Concerns identified A number of key concerns have been identified and are given in this section. Some of the problems identified overlap across issues but in the interest of brevity they are only detailed once. 2.1 An absence of out of scope values for artificial radioactive aqueous liquids In the current regulations, there are no activity concentrations below which aqueous liquids containing artificial radionuclides or Naturally Occurring Radioactive Materials (NORM) used for its fertile, fissile of radioactive properties would be defined as being out of scope of the legislation. However, these values do exist for solids or relevant liquids (see Section 2.3 for the definition) and for liquids containing NORM from industrial activities. One of the key comments from the respondents to the relevant BEIS consultation is that, at present, it is not possible to have any radioactive contamination in a liquid without it being defined as radioactive. A closely-related comment received was that it is also possible to have the 5

6 Concerns identified scenario where radioactive contamination is reduced in the liquid waste to levels at or below background, but nonetheless, the liquids or water would still have to be managed as radioactive because it has arisen from an industrial process, and there are presently no out of scope criteria that could be considered or applied. Respondents also commented that they consider that some processes which are undertaken to dispose of large quantities of liquids with trivial amounts or potentially no radioactivity are highly disproportionate. They believe that in a number of cases, the environmental implications of the treatment and disposal processes could be considered to outweigh any radiation protection benefits and are also an unnecessary economic burden. Cited examples of the issue include groundwater from one site where a new nuclear reactor is being built containing very low levels of tritium as a result of migration from a nearby existing nuclear site. This has resulted in the groundwater generated during construction from dewatering activities having to be managed as radioactive waste under the site s radioactive substance regulation (RSR) permit, even though the levels of activity are very low (generally less than 10 Bq/l). 2.2 Inability of those who hold permits for radioactive waste discharges to use exemptions The current regulations do include exemptions to allow liquid wastes with very low levels of radionuclides to be discharged to water environments, but these exemptions cannot be utilised by those who hold permits in relation to radioactive waste discharges, as the legislation precludes it. The reason being that most aqueous disposals from any particular site are, to some extent, inter-related and that these discharges need to be optimised across the site as a whole. However, as stated in the BEIS guidance document on exemption (BEIS et al, 2018a), where a permit is in place, the holder can apply for those waste streams which would otherwise be exempt to be included in the existing permit. These wastes will then be subject to the conditions set out in the permit. An example given by a respondent is where liquids with trace amounts of tritium are passed through effluent treatment plants because that it is the only permitted option. The comment made is that this needlessly reduces the efficacy of the ion exchange columns by passing large volumes of minimally contaminated liquids through them (with no expectation of reducing the tritium content). Furthermore, the environmental cost of incinerating water with trace tritium and the worker doses arising in the contaminated facilities when processing trivial liquids, needs to be considered. Other examples of waste liquids containing low activity concentrations which fall under the permitting regime given by respondents were rainwater collected at nuclear sites (this was stated as currently being sent for incineration) and barrier handwashing effluents. One of the respondents contended that when the current approach to radioactive liquid wastes was introduced in 2012, the exemption provisions for aqueous liquids were deemed inapplicable to a site permitted to discharge radioactive liquids because once the liquids had been mixed they could no longer be separated. They further commented that this assumption took no account of circumstances where those waste streams are not mixed prior to discharge (e.g. waste water from nuclear power station boilers that are lightly contaminated with tritium). In these circumstances, the respondent argued that the introduction and application of out of scope levels to aqueous liquids would be appropriate. 6

7 There was a request that the environment agencies should consider including an exempt aqueous discharges clause within the permit templates. 2.3 Definition of relevant liquids There are out of scope values for solids that can be applied to non-aqueous and some aqueous liquids which have hazardous properties which prevent them from being discharged to water environments. These liquids are defined as relevant liquids. In the legislation the exact definition of a relevant liquid is: 1) a non-aqueous liquid (for example mercury and oil), or 2) a liquid classified (or would be so classified in the absence of its radioactivity) under Council Regulation No. 1272/2008) as having any of the following hazard classes and hazard categories (as defined in that Regulation): (i) acute toxicity: categories 1, 2 or 3 (ii) skin corrosion/irritation: category 1 corrosive, subcategories: 1A, 1B or 1C or (iii) hazardous to the aquatic environment: acute category 1 or chronic categories 1 or 2 Respondents commented that a liquid should be defined as a relevant liquid if, due to its nonradiological hazardous properties, is sent off site for treatment, use and/or disposal at an appropriate facility where it is not disposed to a potential drinking water source route. Examples given of such liquid wastes included those termed as grey water and machinery coolants. A number of suggestions of definitions of the term grey water were supplied in response to the BEIS consultation. However, subsequent investigations did not find any formal or widely accepted definition in the documents that could be accessed. Some of the suggested documents were not available due to their classification but on further discussion it was agreed that they were unlikely to help. 2.4 Out of scope values close to limits of detection One respondent commented that the out of scope values were too low given that the analytical laboratories struggle to analyse down to them. They argued that if it is not possible to measure down to the out of scope values then it is unclear how the present regulatory regime could be sensibly applied. 2.5 Off-shore oil and gas facilities The oil and gas industry generates some of the most significant quantities of liquid NORM wastes. The majority of this waste stream arises offshore and installations are permitted to discharge the waste waters produced directly to sea or where suitable facilities exist to reinject back into the seabed or hydrocarbon bearing formation. Some liquid waste streams contain concentrations of oil that prevent such disposal at sea and these must be sent to shore for treatment. Respondents to the UK NORM strategy data collection process (DECC 7

8 Concerns identified et al, 2014) indicated that onshore disposal of water produced from oil and gas installations was becoming a problem because of a lack of permitted onshore wastewater treatment facilities. The UK NORM strategy (DECC et al, 2014) also noted that there is some evidence that onshore treatment and disposal of produced water is becoming an issue for some industries (particularly oil and gas production) who generate NORM waste which cannot be classed as exempt radioactive waste. Respondents from the oil and gas industry have also commented that they believe that the definition of relevant liquid could be usefully revised to include produced water from offshore oil and gas installations containing hydrocarbons and entrained solid material. The presence of hydrocarbons and entrained solid material means that the waste cannot be disposed of to the environment (i.e. it cannot be discharged to river or sewer and so will be processed in isolation from drinking water pathways). Respondents commented that other pollution control legislation regulates discharges from oil and gas facilities and there is a perception of overregulation in this area given that that assessments supporting the permits show that the radiation doses to those likely to be the most highly exposed are estimated to be of the order of a few µsv y -1. Another issue identified was that NORM wastes produced during oil and gas production tend to contain organic hydrocarbons and inorganic heavy metals such as cadmium and, particularly, mercury. Respondents commented that due to the limited availability of permitted UK sites able to process these liquids and the fact that other European countries have not classified such liquids as radioactive waste, there is greater availability of appropriate disposal routes outside the UK. However, in order to utilise such routes, a respondent has commented that transfrontier shipment formalities need to be navigated and permit changes are often required. It should be noted that The Transfrontier Shipment of Radioactive Waste and Spent Fuel Regulations (UK Parliament, 2008) do not apply to NORM waste from industrial activities, but the respondents to the consultation may mean generally waste export regulations. 2.6 Miscellaneous A number of other comments were also made. Expansion of Table 6 Schedule 3 to include embalming fluid where persons have undergone treatments involving radioactive materials Addition of a weekly activity limit of aqueous liquid radioactive waste which is to contains uranium or thorium or prepared compound of uranium or thorium which can be exempted from regulations. Currently the exemption states that 0.5 kg of uranium or thorium per year can be disposed as aqueous liquid waste. Requirement for offshore oil and gas installation to hold an Oil Pollution Prevention and Control (OPPC) permit as well as a radioactive substances permit. Amendment of the limits for relevant liquids to those used for the exemption of VLLW solid waste. 8

9 3 Proposals Some proposals were given in responses to the BEIS consultation and they are summarised below. Calculation of out of scope and exemption values for specific sites and disposal routes Respondents have contended that it should be possible to calculate site-specific out of scope values based on the demonstration that any discharges would result in doses to the public of less than 10 µsv y -1. In addition, it was also argued that values could be calculated for different generic disposal routes such as discharge to sea (or other tidal waters), discharge to freshwater, discharge to sewer etc. Amend conditional exemption criteria to unlimited volumes of aqueous waste to be discharged to coastal waters In the HPA-CRCE-005 report (Ewers and Mobbs, 2010) the exemption levels in terms of activity concentration (Bq l -1 ) were calculated. The report indicated that that exempt levels for disposal of aqueous liquids were based on a volume limit of 3000 m 3 y -1. The report states that discharges to coastal waters would give rise to lower doses because of the additional dilution and hence there is no need for restrictions on the volume of water containing the activity concentrations that can be disposed of to coastal waters based on radiological protection criteria. However, at the time the DECC Exemption Order Review team decided to include a volume limit to rivers and seas in order to take account of other factors such as meeting OSPAR requirements. It is proposed that the removal of this volume limit for discharges to coastal waters be considered. Introduce out of scope values for artificial radioactive liquids There was a request that out of scope values for artificial radioactive liquids should be calculated particularly for one or two specific radionuclides e.g. 3 H. Review the list of specified radionuclides which can be disposed of under the conditional exemption of 100 Bq ml -1 to sewer Currently this exemption allows the maximum annual disposal activity of 1 x 10 8 Bq for the sum of: 3 H, 11 C, 14 C, 18 F, 32 P, 33 P, 35 S, 45 Ca, 51 Cr, 55 Fe, 67 Ga, 89 Sr, 90 Y, 99m Tc, 111 In, 123 I, 125 I, 131 I, 153 Sm and 201 Tl and 1 x 10 6 Bq for the sum of all other radionuclides. Given developments in the use of radionuclides in medical treatments and research it is proposed that this list is reviewed. PHE s Medical Exposures Group has suggested that based on the IPEM advice note (IPEM, 2018) the following radionuclides could be also considered: 68 Ge, 75 Se, 124 I, 169 Er, 177 Lu, 186 Re and 188 Re 4 References BEIS, Defra, Welsh Government and DAERA (NI) (2018a). Scope of and exemptions from the radioactive substances legislation in England, Wales and Northern Ireland. Department for Business, Energy & Industrial Strategy, London. BEIS, Scottish Government, Welsh Government and DAERA (NI) (2018b). Response to the consultation on revised requirements for radiological protection: regulation of public exposures 9

10 References and the justification of practices: Transposition of the Basic Safety Standards Directive (2013/59/EURATOM). London. DECC, Welsh Government, Northern Ireland DoE and Scottish Government (2014). Strategy for the management of Naturally Occurring Radioactive Material (NORM) waste in the United Kingdom. Ewers LW and Mobbs SF (2010). Derivation of Liquid Exclusion or Exemption Levels to Support the RSA93 Exemption Order Review. Health Protection Agency, Chilton, UK, HPA-CRCE-005. IPEM (2018). Advice Notice: Excretion Factors: the percentage of administered radioactivity released to sewer for routinely used radiopharmaceuticals. [Online] Available at [accessed] UK Parliament (2008). Atomic Energy and Radioactive Substances: The Transfrontier Shipment of Radioactive Waste and Spent Fuel Regulations (No. 3087) 10