ALARA AND PROFESSIONAL NETWORKS - PROMOTING OPTIMISATION OF RADIATION PROTECTION

Transcription

1 ALARA AND PROFESSIONAL NETWORKS - PROMOTING OPTIMISATION OF RADIATION PROTECTION Caroline SCHIEBER IRPA RC-10, Buenos-Aires, 22 October 2008 cepn

2 Content of the presentation Foundation of optimisation of radiation protection Historical evolution From ICRP 60 to ICRP 103 Optimisation in practice Optimisation process Elements supporting the ALARA approach Role and interest of professional networking Challenges for the future 2

3 The foundation of the principle of optimisation of radiation protection 3

4 Historical evolution of the concept (1) Until the 40's, radiation protection was based on protection against the deterministic effects of ionising radiation The individual dose limit, set up well below the threshold of deterministic effects was a guaranty that such effects would not appear below the limit. During the 1940s Recognition of 'stochastic effects' Impossibility to demonstrate the existence or non-existence of a threshold for such effects Due to this uncertainty, the limit is no longer a guaranty of the absence of risk => Prudent attitude of the ICRP with the recommendation "That every effort be made to reduce exposures to all types of ionising radiation to the lowest possible level" (1955) 4

5 Historical evolution of the concept (2) To reduce exposure to the lowest possible level To keep exposure as low as practicable Pub To keep exposure as low as readily achievable economic and social consideration being taken into account Pub To keep exposure as low as reasonably achievable economic and social consideration being taken into account Pub To keep exposure as low as reasonably achievable economic and social factors being taken into account Pub

6 Historical evolution of the concept (3) ICRP 60 (1990) Need to consider in the optimisation process : "the magnitude of individual exposures, the number of people exposed and the likelihood of incurring exposures where these are not certain to be receivers Emphasis on the equity issue : optimisation may introduce inequity between one individual and the other (uneven distribution of benefits and detriments through society) => Propose the use of dose constraint for practices: a source-related value of individual dose used to limit the range of options considered into the procedure of optimisation 6

7 Historical evolution of the concept (4) ICRP 103 (2007) 'the likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable, taking into account economic and societal factors. This means that the level of protection should be the best under the prevailing circumstances, maximising the margin of benefit over harm. In order to avoid severely inequitable outcomes of this optimisation procedure, there should be restrictions on the doses or risks to individuals from a particular source (dose or risk constraints and reference levels)' 7

8 From ICRP 60 to ICRP 103 (1) ICRP 60 Practices justification, optimisation, limitation (except for medical exposures) Dose limits Individual dose constraint Interventions justification, optimisation Intervention levels 8

9 From ICRP 60 to ICRP 103 (2) The ICRP 60 approach Practices Dose limit Dose constraint Interventions "generic" optimisation Action/intervention level Optimisation 9

10 From ICRP 60 to ICRP 103 (3) ICRP 103 Planned exposure situations: situations involving the deliberate introduction and operation of sources. Justification, optimisation, limitation (except medical exposures) Dose limits, dose constraint Emergency exposure situations: situations that may occur during the operation of a planned situation, or from a malicious act, or from any other unexpected situation, and require urgent action in order to avoid or reduce undesirable consequences. Justification, optimisation Reference levels Existing exposure situations: exposure situations that already exist when a decision on control has to be taken, including prolonged exposure situations after emergencies Justification, optimisation Reference levels 10

11 From ICRP 60 to ICRP 103 (4) The ICRP 103 approach Planned exposure situations Dose limit Emergency and existing exposure situations Reference level Dose constraint Optimisation Optimisation 11

12 Levels of protection Dose Limits Dose Constraints and Reference Levels Protect individuals from public and occupational exposure from all regulated sources, in planned exposure situations from a source, in all exposure situations 12

13 Dose range proposed by ICRP 103 for dose constraints and reference levels (1) Band of constraint or reference level (ICRP 103) Greater than 20 to 100 msv Greater than 1 to 20 msv 1 msv or less Characteristics Individuals exposed by sources that are not controllable, or where actions to reduce doses would be disproportionately disruptive. Exposures are usually controlled by action on the exposure pathways. Individuals will usually receive benefit from the exposure situation but not necessarily from the exposure itself. Exposures may be controlled at source or, alternatively, by action in the exposure pathways. Individuals are exposed to a source that gives them little or no individual benefit but benefits to society in general. Exposures are usually controlled by action taken directly on the source for which radiological protection requirements can be planned in advance. 13

14 Dose range proposed by ICRP 103 for dose constraints and reference levels (2) Band of constraint or reference level (ICRP 103) Greater than 20 to 100 msv Greater than 1 to 20 msv 1 msv or less Examples Reference level set for the highest planned residual dose from a radiological emergency Constraints set for occupational exposure in planned situations Constraints set for comforters and carers of patients treated with radiopharmaceuticals Reference level for the highest planned residual dose from radon in dwellings Reference level for existing situation resulting from accidents: between 1 and 5 msv Constraints set for public exposure in planned situations 14

15 Planned Exposure Situations Occupational exposure Constraints usually set by operator Small operators may need guidance from regulator Transient/itinerant workers need special attention Public exposure Constraints usually set by regulator About 0.3 msv in a year appropriate 15

16 Emergency Exposure Situations Optimisation recommended to and below Reference Levels The old intervention system implied optimisation to intervention levels Reference Level: An upper value of residual dose for all pathways combined The old system implied averted dose for single countermeasures Additional guidance is under preparation Existing guidance in ICRP P63 is extended, not replaced 16

17 Existing Exposure Situations Optimisation recommended to and below reference levels The 1990 system implied optimisation to intervention levels Optimisation, an iterative process This does not mean a moving target the reference level stays Step 1 Step 2 Step 3 Reference level Individual dose level 17

18 Optimisation in practice 18

19 Optimisation process A source related process to keep the magnitude of individual exposures, the number of people exposed and the likelihood of potential exposure As Low As Reasonnably Achievable, taking into account economic and societal factors An on-going, cyclical process: Evaluate exposure situation to identify the need for action Set up appropriate individual dose constraint or reference level Identify possible protection options to obtain exposures below the dose constraint Select best option under prevailing circumstances Implement the selected option Regular review of the exposure situation 19

20 Optimisation process (2) Level of effort and formalisation has to be commensurate with the level of individual and collective exposures (level of risk) Evolution from a strict consideration of "cost-benefit" decision making processes (the 'economic and social factors' being integrated in the so-called 'alpha value - monetary unit of collective exposure) to more flexible processes, integrating other considerations and based on quantitative as well as qualitative judgements 20

21 The elements supporting an ALARA approach (1) A commitment of all stakeholders, eg: Authorities Operating managers All non-exposed individuals whose action can impact the level of exposure of other individuals The exposed individuals All stakeholders involved have to know an agree with the basic assumption of radiation protection (any level of exposure can induce a risk) 21

22 The elements supporting an ALARA approach (2) Commitment of Authorities Regulations and willingness to enforce it Guidelines: balance between dialogue and control. Commitment of operating management Definition of Radiation Protection policy Set general goals, Attribute responsibilities in ALARA implementation Maintain independence of RP professionals from operation Allocate means and resources for ALARA implementation, Motivate (acknowledgment of efforts). To set up a confident ambiance between all involved parties (stakeholders). 22

23 The elements supporting an ALARA approach (3) Commitment of individuals Individual empowerment Produce and share information Vigilant attitude Adapted training to functions and responsibilities Retraining for keeping motivation Self-education and training 23

24 The elements supporting an ALARA approach (4) Decision-making and coordination structures Organise dialogue between the professional disciplines involved in an operation Favour the transparency of the optimisation process Identification of decision criteria Traceability of the decision making process Procedures, rules Clarify the responsibilities for the implementation of the optimisation process Tools Software (prediction of exposure, dose rate modelisation, ) Feed-back experience databases ALARA check-list (design, preparation, operation, feed-back,..) Decision-aiding tools 24

25 Optimisation of protection and stakeholder involvement (1) ICRP examples of stakeholder Decision maker Exposed individual or their representative Institutional and non-institutional technical support to DMP Representatives of the society (elected and NGOs) Stakeholder involvement: A proven means to achieve incorporation of values into the decision-making process improvement of the quality of decisions resolution of conflicts among competing interests building of shared understanding with both workers and the public (does not mean a consensus!) building trust in institutions 25

26 Optimisation of protection and stakeholder involvement (2) Involving concerned parties reinforce the safety culture Introduce flexibility in the management of radiological risk Stakeholders may be particularly helpful for Identification of the attributes of exposure situations Identification of protective actions Stakeholders involvement does not imply that the operating management/the authorities do not have the responsibility for the 'final decision' with respect to the adequacy of protection solutions 26

27 ALARA in summary A behaviour and a frame of mind A questioning attitude of 'individuals': Have I done all I reasonably can to reduce individual doses and the number of people exposed? A necessity usually to work collectively to be able to answer to that question 27

28 Role and interest of professional networks in promoting and implementing optimisation of radiation protection 28

29 Different kind of 'professional' networks (1) National, Regional, International level Various fields: industrial, medical, nuclear, Authorities, professionals, members of the public, elected people, 29

30 Different kind of 'professional' networks (2) Professional societies eg: medical physicists, industrial radiography, RP societies, Associations/NGO eg: Patients association eg: GMF- Group of EU Municipalities with Nuclear Facilities eg: Local Liaison Committees eg: ANCLI (French National Association of Local Commission of Information) Dedicated network (one sector or multi-sectorial) eg: Occupational RP (ISOE for RP in nuclear power plants) eg: ALARA Networks (all sectors), eg EAN, RECAN, ARAN,.. eg: Authority networks (ERPAN) 30

31 Activities / tools of such networks Directory of contact persons Web site Newsletters Discussion Forum Workshops / congresses Working groups Centralisation of documentation Production of specific guidelines Participation to decision-making processes. 31

32 Interests (1) Members sharing the same objectives Particular benefit for isolated professionals Creation of individual relationships Sharing of experience Identification of 'good practices' Creation of knowledge 32

33 Interests (2) Training Benchmarking Harmonisation of practices Spreading a professional culture RP culture but also sharing issues of other professionals For a better understanding and better collaboration eg: RP professionals working with patient association to spread RP culture or with agriculture professionals for preparation of post-accident situations 33

34 Difficulties of networking Resources Financial resources "Human" resources (time to be spent in participating in activities of the network/association) How to sustain motivation? How to renew activities? How to reach new members? 34

35 The European ALARA Network (EAN) 1996 : EAN Founded and sponsored by EC (DG Research / DG Environment) Self-sustainable since : 8 20 countries are represented by at least one person. (13 in the Steering Committee) Coordination : CEPN (France) - HPA (UK) 35

36 EAN Objectives To maintain and develop competences in radiation protection, with special emphasis on ALARA for all types of exposures - occupational, public, patients - in routine operations as well as emergency situations To contribute to the harmonisation of radiation protection policies and practices, particularly concerning ALARA, at regulatory and operational levels To cover all types of practices within the different sectors (nuclear industry, other industries, medical, research, transport, etc ) To cover radiation protection themes relevant to all sectors (e.g. waste management), as well as themes specific to one or more sector(s) (e.g. industrial radiography) 36

37 EAN Activities (1) 10 Workshops (700 participants) Decommissioning, NORMs, internal exposures, risks management, industrial radiography, medical sector and radiopharmaceuticals, site rehabilitation, inspection & control, waste management 37

38 EAN Activities (1) 10 Workshops ~ 100 topical recommendations to: EU, ICRP, IAEA, National Authorities, Operators, Workers trainers, etc. 21 ALARA Newsletters (2 issues/year) 1,000s addressees 1 Website & its Forum 10,000s/y downloads 38

39 EAN Activities (2) Collaboration agreements signed with professional societies: EFNDT (Non Destructive Testing) ESR (Radiology) EFRS (Radiography) EFoMP (Medical Physics) Co-operation with other existing networks: ISOE (Information System of Occupational Exposure) RECAN (Regional European & Central Asia ALARA Network) 39

40 EAN Challenges - Development of Networking To involve various types of stakeholders which are not yet well represented in EAN: operators, workers, NGOs, Unions, citizens, etc. To help in launching other international ALARA networks in Africa, South Pacific, South America... and to collaborate with them afterwards. To become a place where differences and divergences between stakeholders can be discussed and compromises and consensuses worked out. To become an active and recognised interlocutor in risk management decision processes, influencing international rules and regulations on the basis of the experiences sharing as well as the promotion of good practices and lessons learned from incidents and accidents. 40

41 Information System on Occupational Exposures (ISOE) Created in 1992 by the Nuclear Energy Agency of OECD Joint secretariat with IAEA Members: Nuclear power plant utilities (71 utilities in 29 countries) RP and/or Safety authorities (24 countries) Objectives: to provide a forum for radiation protection professionals from nuclear electricity utilities and national regulatory authorities worldwide to share dose reduction information, operational experience and information to improve the optimisation of radiological protection at nuclear power plants. 41

42 ISOE products International database on occupational exposures in NPPs Collective doses (annual outage, job) since 1992 from more than 300 NPPs Possibilities to extract data for trend and benchmarking analysis Regional and international symposia North America, Europe, Asia Web site Forum of discussion Availability of database for members Various RP documents Organisation of experience sharing visits between utilities 42

43 Challenges for the future 43

44 In view of optimisation of radiation protection Foster optimisation in some fields Optimisation for medical exposures (patients and workers) Optimisation for emergency situations Optimisation for workers exposed to NORMs Optimisation for public and workers in existing exposure situations Need to identify the stakeholders / professionals in each field In some fields, need to create new networks Create links and cooperation between networks/societies of RP professionals and other professional networks 44