|Comments from the OECD Nuclear Energy Agency On the Latest ICRP Draft Recommendations
As part of its ongoing co-operation with the ICRP, the OECD Nuclear Energy Agency, (NEA) has organised a series of meetings and conferences designed to provide stakeholder input to the process of developing new ICRP general recommendations. The latest version of these recommendations, known as RP06, was made available in June 2006 for general comment. The NEA provided the draft to its standing technical committees (in the areas of radiation protection and public health, CRPPH, radioactive waste management, RWMC, regulatory activities, CNRA, nuclear safety, CSNI, nuclear development, NDC, nuclear science, NSC, and nuclear law NLC), soliciting constructive comments. In addition, two large stakeholder conferences, in Asia (Tokyo, 5 – 6 July) and North America (Washington D.C., 28 – 29 August) have been organised, and three Expert Group meetings have been held to discuss, in detail, the draft (Tokyo, 7 July, Washington D. C., 30 August, and Paris, 6 – 8 September). In addition, the NEA will hold, in collaboration with the ICRP, the 3rd NEA/ICRP Forum on the Evolution of the System of Radiological Protection, in Prague, 24 – 25 October, to hold detailed stakeholder discussions of the latest ICRP expression of principles and recommendations.
As a result of these activities, the NEA’s Expert Group on the Implications of ICRP Recommendations (EGIR) met for three days in Paris (as noted above) to analyse RP06 in detail. The result of the EGIR’s assessment includes both these general suggestions for the Commission to consider, as well as a series of specific additions and deletions (listed in Track Change Mode in Word) to the RP06 text itself. The objective of all these comments and suggestions is to assist the Commission in improving its recommendations to better meet the implementational needs of policy makers, regulators, and practitioners in radiological protection.
In addition to the suggestions agreed to during this meeting, the EGIR took into account the work performed by the two satellite EGIR meetings in Tokyo and Washington, D.C., the results of the Tokyo and Washington conferences, and all the comments sent to the NEA by its standing technical committee members. As such, these suggestions represent broadly the collective views of the NEA’s member country policy makers, regulators and practitioners.
In preface to these comments, the EGIR would like to thank the ICRP for its openness, and for its willingness to actively engage in stakeholder discussions regarding the nature and quality of its recommendations.
Based on extensive collection of viewpoints throughout the NEA membership, the EGIR broadly feels that this draft, while still in need of substantial editing, contains good, solid, soundly based principles and recommendations that can be of use to regulatory organisations and RP practitioners alike. The concept of a dose constraint as a value above which one plans not to go, and below which one optimises in all situations seems solid (although needs to be consistently presented in this fashion). It should be noted, however, that the EGIR does not view dose constraints as the fundamental level of protection. The use of some sort of non-regulatory, numerical benchmark, to gauge the level of achievement against all that is needed when implementing optimised protective actions during Emergency and Existing situations, also seems to be a possible use for the value chosen for the constraint in these situations. The focus of the recommendation on optimisation as the key to exposure management in justified situations, although in need of some reinforcement, is also welcomed.
Thus, on behalf of the CRPPH Expert Group on the Implications of ICRP Recommendations (EGIR), I transmit to you the following comments:
1. General comments: (See Below and Web Link: http://www.nea.fr/download/icrp-comments/)
• from the EGIR meeting
• from the North American EGIR Satellite Meeting
• from the Asian EGIR Satellite Meeting
2. Detailed, Track-Change-Mode suggestions from the EGIR to the body of the RP06 recommendations (see Web Link: http://www.nea.fr/download/icrp-comments/)
3. Detailed, Track-Change-Mode suggestions from the EGIR to the RP06 Glossary (See Web Link: http://www.nea.fr/download/icrp-comments/)
4. Annex: Comments received by the NEA from its constituency (See Web Link: http://home.nea.fr/download/icrp-comments/)
• From Sweden: Bo Lindell, Björn Cedervall
• From the UK: NIREX
• From Spain: Maria-Jesus Munoz
• From Germany: BfS, BMU
• From France: Jean-Claude Barescut
• From Switzerland
• From PAHO
CRPPH Scientific Secretariat
OECD Nuclear Energy Agency
General Comments from the CRPPH Expert Group on the Implications of ICRP Recommendations (EGIR) Paris, 6 – 8 September 2006
While the EGIR came to broad agreement on the comments presented here, the specific views of individual Group members sometimes differed considerably from the majority view. To address this, all the specific comments on RP06 that were received by the Secretariat prior to the EGIR meeting are attached here in annex. Group members were also encouraged to submit their comments independently of the EGIR directly to the ICRP.
1. General: New Recommendations
• The EGIR is very pleased to have the opportunity to comment extensively on the draft recommendations, and was pleased to learn that a new draft will be developed taking into account the comments that the ICRP will receive.
• The EGIR suggests that there is no need to rush the finalisation of the new recommendations. Their importance, and the fact that in their current state they require significant re-writing before publication, suggest that the time necessary to appropriately finalise the recommendations should be taken. Sufficient time should also be allowed for substantive comments on the next draft recommendations.
• There is a need for the new ICRP recommendations to be a stand-alone document as much as possible. While they must be sufficiently explanatory to be understandable (i.e. importing more detailed explinations on specific topics from foundation documents), they must also refer to foundation and other documents where more detailed information would be available.
• The new recommendations should be concise, clear and as much as possible scientifically based, and should present principles and frameworks, not regulatory guidance.
• The ICRP should clearly explain how its recommendations, in particular the use of effective dose as well as collective, should be used to prospectively and retrospectively assess risks.
• The statement in paragraph 34, that the system “applies to all radiation sources and radiation exposures for any source, regardless of its size and origin.” is very strongly supported. This needs, however, to be consistently applied throughout the document. The description of exclusion and exemption, in particular, should be carefully reviewed in this light.
2. Collective Dose
• The advice from the ICRP that collective dose cannot be used to estimate risk for retrospective studies needs a clear, concise rationale as a justification for this statement.
• The ICRP should better articulate any restrictions it sees on the use of collective dose, particularly on doses in the far future, and very small doses. Criteria are preferred rather than numerical guidance. For example, it could be suggested to adapt collective dose criteria to best fit the decision-making needs of the case at hand, i.e. to consider, or not, very small doses, or to consider, or not, far future doses depending on the protection decision being made.
• The EGIR recognises that the protection of future generations is essential, but it is not clear how the ICRP would recommend using collective dose in this context (paragraphs 57, 231).
• The “matrix” approach, which is still present in the Foundation Document, should be explained and guidance should be provided
3. Dose Constraints and Dose Limits
• The EGIR understands a Dose Constraint to be a level of exposure that one plans NOT to exceed, and below which optimisation of protection is performed.
• The EGIR recognises that dose constraints can be useful tools in the broad process of optimisation, however they must first be clearly and consistently explained. The ICRP needs to more clearly express the rationale for dose constraints being elevated to such an important position in the new recommendations. Dose constraints should not be described as the fundamental level of protection.
• Most of the text on dose constraints should be consolidated in a single section as far as possible.
• Constraints and optimisation are the key elements of the new recommendations. The use of constraints, particularly for Existing and Emergency Situations, should be more clearly explained because the current text is confusing and inconsistent. Some suggested changes have been proposed to assist in correcting this confusion.
• The statement that all previously recommended values can now be regarded as constraints is problematic (or in fact incorrect) given the emerging understanding of constraints (i.e. Intervention Levels are not constraints, Action Levels are not constraints). This statement, if kept, should be better explained.
• The relationship between dose constraints and dose limits needs to be clearly articulated. Dose limits are the “fundamental” tool for protection in planned situations. The place of constraints in the system needs to be explained.
• If constraints are only prospective tools, the ICRP should recommend what to use for a “benchmark” to retrospectively assess the quality of protection that has been implemented in Existing and Emergency Situations. The EGIR felt that pre-established dose-constraints could serve as retrospective guidelines for the implementation of optimisation.
• The EGIR agreed that the selection of numerical values for dose limits is a very judgemental, social decision and needs to be explained in some fashion by the Commission – similarly to what was done in Publication 60 (paragraphs 122 – 125; paragraphs 147 – 178; paragraphs 188 - 194). The Commission should try again to clearly and succinctly explain the rationale behind the selection of numerical dose limits. This text could be placed in a general introduction section describing the general rationale for selecting numerical values of dose limits or dose constraints.
• The relationship between constraints and the well-established use of collective dose for the optimisation of protection of workers in the nuclear industry should be explained.
4. Exclusion and Exemption
• The EGIR agreed that the ICRP should not provide specific numerical guidance for the criteria that it recommends for exclusion and exemption decision making.
• In particular, the generic exemption levels for foodstuffs, imported from CODEX, are intended for use in a one-year post-accidental situation, and are not applicable for use as generic exemption levels.
• The Commission should expand on the types of criteria that it feels should be taken into account when making exclusion and exemption level decisions for artificial and natural radionuclides.
• Although the EGIR neither endorses nor refutes the use of the Clearance concept, the EGIR agreed that the Commission should explain why the concept of Clearance, which is widely used, has not been adopted. It could also be noted that the CRPPH, in its document on Regulatory Authorisation, points out that the concepts of Exclusion, Exemption and Clearance are not necessary for regulatory decision making.
• Optimisation remains as a key principle of the new recommendations, but is not well explained in a concise manner for all types of situations.
• The focus of the document’s text on optimisations and constraints tends to overlook the other aspects of optimisation that are also worth describing
• Uncertainties arise in many aspects in relation to the new recommendations, but are not well explained. (ex. Section 3.2.3)
• Uncertainty need not always be “mathematical” but also includes judgement.
• The numbers in table 2 are not well explained (rounding, DDREF, lethality of cancer, etc.)
7. Scientific Information
• Recognising that detailed information is presented in Annex A and B, the EGIR suggests that there is a need for the Commission to better explain, in the body of the recommendations, the rationale for gender and age averaging (e.g. averaging for breast cancer risks), and to explain why that this does not result in systematic underestimation of risk to major parts of the population.
• The Commission’s truncation of hereditary risk at the second generation needs to be very well explained and substantiated.
8. Natural Sources: Chapter 7
• The chapter should explain why numerical criteria are not expressed as dose, but rather as concentrations.
• The discussion of action levels and intervention levels in this chapter suggests that these can now be termed constraints. This does not seem appropriate in that constraints are upper values below which optimisation is performed, while action levels are levels that cause action only if exceeded. The text should be clarified
• The EGIR agreed that the ICRP should not provide numerical criteria for exemption and exclusion of natural radionuclides (paragraph 295, 296).
• Current studies indicate that there is a statistically significant increase in risk starting at radon concentrations of on the order of 100 Bq/m3 for dwellings. Recommended constraints for radon are far above this. This is a unique situation in that other dose limitation criteria have been selected well below where statistically significant effects can be seen. The Commission should comment on this situation.
• There is nothing in this chapter discussing air crew exposures. The Commission’s views should be expressed on this important issue. The Commission’s document on scope (and previously in Publication 75), which addresses these issues, should be consistent with what the Commission includes in its principal recommendations.
9. Potential Exposures: Chapter 8
• This chapter does not clearly distinguish between potential exposures from uncertain accidents, and from possible exposures in the far future from waste repositories. This distinction should be more clearly made
• The Commission seems to mistakenly equate safety culture and optimisation (paragraph 322).
• Sections 8.2, 8.5 and 8.6 are about exposure prevention and mitigation, but not about potential exposure. These sections are important but are not well placed in the chapter on potential exposure. These should be moved to another part of the recommendation.
10. Emergency and Existing Situations: Chapter 9
• Statements referring to emergency and existing situations are scattered throughout the recommendations, and are somewhat inconsistent. The Commission should consolidate its treatment of these important subjects.
• It is not clear from the text whether dose constraints in emergency situations refer to individual countermeasures (i.e. sheltering, evacuation), or to the overall residual dose resulting after the implementation of all countermeasures. The EGIR recommends the latter, however Table 4 refers to a constraint for evacuation, i.e. for a single countermeasure – this should be corrected.
11. Environmental Protection: Chapter 10
• This is an important and new area for the ICRP. Although the Commission does say that it will review its previous statement on the protection of man being sufficiently protective of the environment, this draft makes no actual recommendations with regard to the radiological protection of non-human biota. The EGIR could not agree on whether the appropriate focus on this topic should be achieved by slightly expanding paragraphs 19 and 20 and deleting Chapter 10, or by simply consolidating and focusing Chapter 10.
• The Commission should provide some discussion of how reference plants and animals could be used in the broader framework for the radiological protection of ecosystems.
12. Implementation of the Commission’s Recommendations: Chapter 11
• This chapter seems to be more a summary of standards from other organisations, such as the IAEA, rather than a description of key implementation aspects. As such, this chapter should be significantly condensed to a few paragraphs at most.
• Some key points, such as the discussion of stakeholder involvement, the problems related to legislation that is too prescriptive, the delegation of some regulatory functions (e.g. in section 11.1.1), should be kept.
• This section needs significant editing.
General Comments from the Japanese EGIR Satellite meeting Tokyo, 7 July 2006
1. Relationship between ICRP and other international organizations
• The role of the ICRP in the development of RP principles, particularly with respect to the roles of other organisations, such as the IAEA, UNSCEAR and NEA/OECD, should be clarified. This should be included in the historical section of the document.
2. Dose limit and dose constraint
• There are several places in section 4.3.2 that seem to be inconsistent with table 5 where dose limits are expressed. This should be reviewed.
• Key questions to be resolved: who sets dose constraints? What is meant by dose constraints being the most fundamental level of protection? What is the relationship between dose limits and dose constraints in practice?
3. Structure of the recommendations
• There could be a matrix approach to explain the structure of the main recommendations (e.g. exposure situations, exposure types) as recommended by the JHPS in its presentation in the 3rd Asian Meeting.
• The structure of the chapters of the recommendation should be reviewed (with the above comments in mind).
• The content of Chapter 5, which describes the generic system, should also reflect this structure.
• The description of protection against natural radiation exposures needs to be much more detailed in Section 7. If it is difficult, we request a separate ICRP document on this subject.
4. Terminology and expression
• There is a problem in translating endeavour and effort (e.g. see paragraph 25), both of which are very similar, and the difference between the two is not clear. This makes translation difficult. This applies to other ambiguous words. The full document should be screened for these problems
• There is perhaps value to the replacement of stochastic and deterministic, particularly because stochastic can be taken to imply no threshold, and this may or may not be biologically true. So if the new terms can avoid this implication then they improve the situation. The question of whether tissue reaction is always negative (tissue reactions can be seen as adverse or not) should be addressed – maybe use the term adverse tissue reaction. Consider the use of the term tissue damage. Acute reactions to radiation (vomiting for example) are not tissue reactions, but systemic reactions. So the use of tissue reactions is not necessarily all-encompassing.
• Cancer and hereditary effects can be seen to give equal weight to each, when in fact hereditary effects are much less significant. Whatever the words chosen, clarity and appropriate balance need to be assured.
• The use of equivalent dose and effective dose, both using the unit Sv, is confusing. The ICRP should assure that the meaning of criteria expressed in Sv is explicitly clear each time this unit is used.
• This same argument also applies to the use of absorbed dose modified by RBE (see paragraph 93), which uses the Gy for both absorbed dose and RBE modified absorbed dose. Clarity is needed.
• There are several places where the same contents are described (e.g. paragraphs 114 and 119). This should be reviewed.
General Comments from the North American EGIR Satellite Meeting Washington D.C., 30 August 2006
• The structure of the document should describe how the system of protection, particularly the application of constraints, is intended to be applied in Planned, Existing and Emergency situations.
2. Dose Constraints
• The concept of constraints does not seem to bring any value added to radiological protection that is applied in well-managed planned activities. Current good practice could be described as a process of constrained optimization, but is generally described as the application of ALARA. This is particularly true of occupational exposures.
• The result of the optimization process can be a “band of doses” within which operational RP will be agreed to be acceptable (ALARA). An Action Level can be set just above this band to represent an operational constraint above which some action is almost always required, and below which operational optimization continues to be performed.
• The most fundamental level of protection in planned situations is the Dose Limit, not the Dose Constraint.
3. Emergency and Existing Situations
• In Emergency and Existing situations, particularly where public Dose Limits are not applicable, the system should focus on justification and optimization. In these situations, the Constraint represents a planning guideline that is used as a benchmark against which the results of protective actions can be checked to see if, under the circumstances being considered, planned protective actions are adequate. These are planning guidelines, and do not represent regulatory boundaries.
• To the extent practicable, exposure of workers responding to Emergency situations should be managed as planned occupational exposures. Emergency situation dose limits will generally be applied, however exceptional exposures may be authorized in exceptional circumstances, for example life-saving or critical infrastructure protection.
• The management of Existing situations is a planned activity, and occupational exposures are therefore to be controlled as such.