Draft Safety Guide: Radiological Environmental Impact Analysis for Facilities and Activities. Gerhard Proehl

Transcription

1 Draft Safety Guide: Radiological Environmental Impact Analysis for Facilities and Activities Gerhard Proehl Waste and Environmental Safety Section International Forum for Regulatory Supervision of Legacy Sites Vienna, 23 October 2013 International Atomic Energy Agency

2 The System of Radiation Protection in the Safety Standards

3 Safety Standards Global Reference Point Safety for protecting people and the environment from harmful effects of ionizing radiation. Safety Fundamentals Safety Requirements Safety Guides 3

4 The Safety Fundamentals Basic objectives Concepts Principles for protection and safety 10/22/2015 4

5 The new Basic Safety Standards Integration of Recommendations in ICRP 103 (2007) Approval by the Board of Governors (Sept. 2011) Replaces BSS (1996)

6 Protection against radiation risks Basic requirements on radiation protection and safety Reflects a broad international consensus Co-sponsored by FAO, ILO, OECD/NEA, PAHO, WHO Establish basic requirements for General public Workers Patients Basis for legislation in many countries

7 Key issues for remediation in the BSS Guidance on site to be remediated Post-accident situations Past inappropriate practices and insufficient regulation Nuclear legacies (Nuclear test sites, inappropriate waste disposal, experimental sites Defines responsibilities Government Regulatory body Planning/implementing institutions Recommends radiological criteria Reference level for the representative person: 1-20 msv/a Requires the application of radiation protection criteria Justification, optimization, limitation Requests Involvement of interested parties Establishment of a strategy for management of radioactive waste 7

8 Three exposure situations for Public exposure Exposure situations Planned Emergency Existing Operation of facilities Accidents, Malicious acts Post-accident Residues from past, uncontrolled practices Dose limit: 1 msv/a Reference level: msv Reference level: 1-20 msv/a

9 Draft Safety Guide: Radiological Environmental Impact Assessment for Facilities and Activities

10 Objectives Application in planned exposure situations Prospective nature Assess impacts on the public and on the environment. Consideration of potential exposures (potential consequences of accidents) Radiological Environmental Impact Assessment Safety Assessment in the authorization process for facilities and activities identified in the BSS Environmental Impacts Assessment related to the evaluation of proposals prior to major decisions being taken

11 Environmental Impact Assessment Espoo Convention Environmental impact assessment means a national procedure for evaluating the likely impact of a proposed activity on the environment Impact Any effect caused by an activity on the environment including Human health and safety, Flora, fauna, soil, air, water, climate, Landscape and historical monuments or other physical structures Interaction among these factors; Effects on cultural heritage or socio-economic conditions

12 Components Radiological impacts Exposures to humans Exposures to flora and fauna Non-radiological impacts Chemical pollutants Heavy metals, organics Dust Heat Noise Hydrology Impacts on cultural heritage

13 MAIN FACTORS AFFECTING TYPE OF ASSESSMENT Factor Inventory Source term Level of expected dose Location of facility Safety characteristics of the activity or facility Interested parties involvement Element Form (chemical/physical make up) Radionuclides Quantity (both activity and mass/volume) Potential for release source term varies between normal operation and potential exposure assessments Previous similar facility or previous assessments Presence of receptor Characteristics of environment around the facility Exposure pathways Number of safety barriers and engineering features present in the design Degree of interest

14 Remediation process Monitoring (Radiological Characterization) Land use Living habits No Assessment of exposures Decision for remediation Criteria Technologies Dose to workers Acceptance Costs Yes Remediation Exit Criteria Yes ok? No

15 Safety Assessment and Environmental Impact Assessment

16 Components of an Assessment

17 Environmental transport processes Atmospheric dispersion Deposition of radioactivity to the ground Dispersion of radionuclides Surface water Ground water Exposure assessment Transfer of radioactivity to plants and animals in the food chain External exposure Inhalation

18 Comprehensive exposure analysis Internal exposure Inhalation of radioactivity in a plume Ingestion of crops, animal food products (milk, meat) Ingestion of drinking water Ingestion of aquatic food Fish, crustaceans, molluscs External exposure From radioactivity in a plume From radionuclide deposited on the ground or in building materials From radionuclides in water and sediments e.g. from swimming, staying on cont. sediments

19 Site characterization Monitoring Air Water Terrestrial and aquatic food Building material Weather/climatic conditions Hydrological conditions Rivers Lakes Population Population density and distribution Land use

20 Limitation of exposures to the public and the environment International Atomic Energy Agency

21 Limitation of public exposure dose criteria in the BSS Existing exposures Residual radioactive material from past activities, NORM, legacies Late phase of an emergency Reference level: 1-20 msv/a Planned exposures E.g. Licensing of a new nuclear installation Dose limit: 1 msv/a Emergency exposures Accident, malicious acts Reference level: msv

22 Reference levels Reference levels are given in terms of dose They are not limits, but doses that should not be exceeded Dose to be assessed for a representative person. a more highly exposed individual in the population

23 Consideration of exposures to flora and fauna ICRP Definition of a set of Reference and Animals and Plants Definitions of a set of bands of dose rates for these that indicate no or minor effects to flora and fauna Recommended in DS 427 for planned exposure situations

24 Reference Animals and Plants (ICRP)

25 ICRP: Derived Consideration Reference Levels (DCRL) D O S E R A T E mgy/d 1 mgy/d = 42 µgy/h= 0.36 y/a

26 Radiological impact to flora and fauna in existing exposure situation Exposures to flora and fauna can hardly be controlled Remediation measures may have drastic effects on populations, e.g: soil removal Optimization Exposure to flora and fauna one factor for optimization of protective actions for people Consideration should be given to reduce exposures Technical feasibility Cost and benefits are such that further efforts are warranted. May imply reduction of exposures to people as well DCRL levels to be used as the criteria for mitigating environmental exposures.

27 Components of an Assessment

28 Conclusions DS 427 provides guidance Implementing radiological environmental impact assessment as recommended in the BSS Applies in particular for planned exposure situations Some elements can be applied for existing exposure situations Comprehensive pathway analysis Site characterization Assessment of exposures Control of exposures in existing exposure situations Public: Reference levels in the range of 1-20 msv/a Flora and fauna: Exposures cannot be controlled

29 Thank you