|23 December 2004 - World Nuclear Association
Dr. Roger Clarke and Dr. Lars-Erik Holm
International Commission on Radiological Protection
SE-171 16 Stockholm
Re : WNA’s RPWG key review comments on the current ICRP proposal
Dear Dr. Clarke and Dr. Holm
The World Nuclear Association (WNA) is pleased to provide its key review comments on the ICRP’s current proposal for the evolution of the system of radiological protection.
These review comments were prepared by the WNA’s Working Group on Radiological Protection (RPWG). The RPWG is composed of well-versed RP professionals who represent a wide-range of nuclear industry sectors in various countries and who have been constructively involved in the ongoing international debate on this key topic.
Our broader WNA membership, which consists of more than 120 nuclear industry-related enterprises in more than 30 countries, was given an opportunity to contribute to these review comments.
Our prime concern still revolves around the fundamental issue of dose constraints.
At an earlier stage – in the context of the ICRP/NEA forum in April 2003 and again during the IRPA-11 conference in May 2004 – we raised the concern that acting at the international level to set numerical dose constraints at lower values than the dose limits would be inappropriate and would create important issues. Herein we explain our view again. A key example is our detailed discussion in attachment #2 of the 0.1 and 0.3 mSv/y post-ICRP60 dose constraints.
Since that earlier stage, our closer examination of the current ICRP proposal has revealed that the issue of dose constraints has even more sweeping implications than we originally thought. Indeed, the current ICRP proposal would give a fundamentally different and broader role to dose constraints than in the current system – as described in ICRP60.
We believe that the proposed re-definition of dose constraints, which would “quantify the most fundamental level of protection for workers and the public from single sources in all situations”, would disturb the key foundations of the current system of protection. Those foundations include dose limits, optimisation (or ALARA), current dose constraints that are set as part of the optimisation procedure, stakeholder involvement as an important input in the optimisation process, and the important distinction between ‘practice’ and ‘intervention’.
The ICRP proposal would broaden the scope of dose constraints to single sources in “all situations”; i.e., normal situations, accidents and emergencies, and controllable existing exposure – thus covering ‘practice’ plus ‘intervention’. This would have the practical effect of making dose constraints more restrictive than the current dose limits.
We therefore find it striking to note an insufficient discussion about the rationale for this change and its potentially far-reaching implications. We also note that the term “normal operations” is not defined. We are not convinced that this would be straightforward or that it would really contribute to clarifying the application of the RP system for practices.
The proposed changes to dose constraints, with their wide implications for the RP system, seem inconsistent with key points that the ICRP itself affirms:
o ICRP recognises the need for stability in regulatory systems at a time when “there is no major problem identified with the practical use of the present system of protection in normal situations”
o ICRP recognizes that the current system is working well and there are no indications that its ability to continue to deliver well into the future has been compromised
o Many international and national regulations “have only fairly recently implemented the 1990 Recommendations”
o New scientific data point in the direction that the overall risk from ionising radiation is slightly lower than originally thought in ICRP60
The proposed changes are also inconsistent relative to one main outcome of the ICRP/NEA forum in April 2003: i.e., the international consensus to keep dose limits unchanged; this created the obvious expectation that dose limits would be kept as a fundamental level of protection (with justification and optimisation). To us, this indicates that dose limits have not been satisfactorily integrated into the current ICRP proposal.
For such profound changes to the foundations of the RP system, we see it as essential that the key stakeholders (regulators, the nuclear industry, and others) clearly understand and comprehend the need and the case for the proposed changes. The current proposal violates this principle.
We emphasise that a wide range of key stakeholders seems to share our view about the proposed changes to the current RP system (justification, optimisation, dose limits, practices and intervention) and about the insufficient rationale for the need/case for such changes. Most of the key presentations at IRPA-11 made this point in various ways.
We also have a concern about the sequencing of the ongoing open consultation process. Because we know that several key building blocks of the RP system are upcoming in 2005 (for example, ICRP guidance on optimisation and on critical groups), we find it premature to regard our comments as “final” at this stage. Consequently, we seek further ICRP explanation as to how this future information will be integrated into the consultative process.
While concerned about the current ICRP proposal, we do recognise topics on which there might be a need/case for improvement or evolution. Our reading of the ICRP proposal suggests three main topics:
1) Clarifying ‘intervention’ or the RP system for accidents, emergencies, and controllable existing exposure
2) Simplifying the post-ICRP60 dose constraints
3) Introducing a policy on non-human species.
On these topics, we would welcome clearer explanations, at the beginning of the ICRP proposal, about the related shortcomings of the current RP system and about how the current proposal helps to address these specific topics without unnecessarily disturbing the RP system for practices.
While expressing our concerns about the current ICRP proposal, we wish to underscore our belief in the value of the constructive ICRP-RPWG dialogue in which we have participated over the last two years. In that spirit, we are pleased to offer our suggestions (in attachment #1) on the following key issues:
o Current RP system for practices
o Dose constraints: public exposure and occupational exposure
o Optimisation or ALARA
o Natural background
o Policy on non-human species
o Exclusion, exemption and clearance
o Collective dose or dose matrix
o Critical groups
As our dialogue continues, we wish to stress the importance of achieving a clear process for addressing the proposed key changes to the current RP system. We welcomed the ICRP series of recent international events on its evolving proposals. We also welcome the ICRP’s open public consultation process. We encourage the ICRP to formalise this process still further as consultations progress. As a broad principle, we trust that the ICRP will bring forward, discuss and debate fully and transparently any major changes to the current RP system.
Should the ICRP decide to move forward on with its proposal to make profound changes to the foundations (justification, optimisation and dose limits, practices and intervention) of the current RP system, we would attach particular importance to the question of clear process. One necessity would be a realistic timetable for adequately debating these changes in a few upcoming international events (e.g., IRPA-style).
We welcome the ICRP effort to seek the views of competent RP representatives of all interested parties as the ICRP examines and seeks to improve the foundations of the current RP system. We also recognize that improved public understanding of radiation and related issues requires that the ICRP take into account the values and concerns of stakeholders outside the RP community. Respected ICRP leadership is indispensable for public trust and sustainable development.
We appreciate this opportunity to contribute to the ICRP’s open consultation process, and we look forward to working further with you in exploring ways to improve the current RP system.
Director for Environment and Radiological Protection
*** ATTACHMENT #1 ***
Summary Views about a Potential Way Forward on Key Issues
1) The current RP system for “practices” should be kept unchanged – Justification, optimisation (and dose constraints as part of the optimisation procedure) and dose limits of the current RP system should be kept intact.
2) Intervention should be kept separated from “practices” – The scope of “intervention” is complex and has been often poorly understood. Any ICRP attempts to integrate the “world” of intervention into the more simple framework on practices would unduly disturb the RP system for “practices”. We encourage the ICRP to seek new options for addressing intervention without disturbing the RP system for “practices”.
3) Dose constraints: public exposure and occupational exposure – Provided that “intervention” is excluded from the domain of application, for public exposure, the introduction of the principle of source-related dose constraints for single sources, as a complement to the current public dose limit of 1 mSv/y, seems appropriate in the context of “practices”. However, at the international level, setting numerical values for dose constraints that would parallel the public dose limit would be inappropriate.
Setting such numerical values is a matter that is best left to local stakeholders as part of their practical involvement in the optimisation process and ultimately as a means of ensuring compliance with the dose limit. Should ICRP have a role in setting numerical values for optimisation and for ensuring compliance? For occupational exposure, we believe that the principal control regime is the individual dose limit and ALARA, with source-related dose constraints having, as a principle, a secondary role at the international level in this case. Source-related dose constraints are in the context of occupational exposure more a matter for RP management at the workforce level.
For simplification and greater clarity, ICRP should present the rationale for each post-ICRP60 dose constraint and foster a debate within the international RP community. In our view, greatly reducing (if not eliminating) the 30 or so post-ICRP60 dose constraints and expressing this clearly in the ICRP proposal would help achieve more simplicity and clarity. Rolling-in such dose constraints directly or indirectly by simple references to post-ICRP60 documents in the ICRP proposal is not appropriate.
Any credible dose constraint value (maximum or otherwise) that is set internationally and that is practically equivalent to introducing new more stringent standards (lower values) than the dose limits should be well substantiated; its context of application should be well defined and explained; and it should be subject to open and transparent international debate with the competent and qualified representatives of concerned parties.
Basis – We seek further information and explanation about the different drivers for introducing, at the international level, any of these quantified values in the system of radiological protection. What are the supporting international studies? What evidence exists on public health grounds and in practical cases that are universally applicable worldwide?
Context of application – Any quantified dose constraints should be accompanied by a clear definition of the sources to which they are applied as well as clear explanations as to how this should be practically achieved. The proposed definition in the ICRP proposal helps little in this respect.
Knowing the source is fundamental to any values on dose constraints and almost certainly not straightforward at the level of ICRP – even for a single source. This specific information is more the domain of the local stakeholders. Conversely, once this exercise has been well executed locally, a specific numerical dose constraint is not relevant at the international level.
Defining numerical dose constraint values at the ICRP level appears paradoxical as it goes in the precise direction (e.g., responsibility of operating management, subject to the requirements of the competent national authorities) that the ICRP guidance understandably seeks to avoid (see e.g., para. 139, 162, 174 and 190).
It can be argued that a “source” that would fit the definition of “the cause of an exposure” (para. 16) could include the behaviour of the individual himself, thus getting closer to the notion of doses. This unclear distinction between the source and the person exposed to that source would introduce another level of confusion.
Conceptually, it can also be argued that accounting for all the individuals exposed to a given source (para. 130) bears similar limitations to accounting for all the sources contributing to the exposure of an individual (dose limit). The case for putting more emphasis on dose constraints than on dose limits is therefore not straightforward, especially considering that dose limits and that dose constraints as part of an optimisation process have delivered steady progress in radiological protection for over several decades.
Optimisation and stakeholder involvement – We seek further explanation as to how the introduction of these quantified values at the ICRP level would fit with the aim of making the system simpler and easier to understand by stakeholders as part of the optimisation process. We would argue that introducing, at the international level, numerical dose constraints at values that are below the values of the dose limits is not coherent with the optimisation process and inconsistent with the ICRP’s emphasis on the importance of stakeholders input as part of this process (S11).
4) Optimisation or ALARA – Both quantitative aspects and qualitative aspects (the latter including “safety culture” and “stakeholder involvement”) are integral parts of ALARA. This is already accounted for in the IAEA’s Basic Safety Standards (BSS). We therefore see no need to introduce a distinction here.
We are concerned about the implication of the ICRP proposal that ALARA may be an endless downward process; e.g., continue optimising until all parties are in agreement as a way forward, best available technology (BAT) without considerations for health risk, and 0.01 mSv/y as the minimum dose constraint which implies that ALARA at lower doses.
This suggests that, one of the fundamental aims of the recommendations (para. S2) – beneficial actions giving rise to radiation exposure, and balancing them relative to the detriments of radiation exposure – has been lost or underplayed in the ICRP proposal discussions about optimisation. We advocate that this be fully reinstated in the ICRP proposal with suitable explanatory text (para. S2 is not enough).
The lack of practical guidance about balancing beneficial actions giving rise to radiation exposure and the detriments of radiation exposure is a key shortcoming of the ICRP proposal. Protection against radiation exposure is essential but accounting for the beneficial actions is also important. Further guidance in this respect is necessary, especially when addressing optimisation.
5) Natural background – Background is background, with radon. It should continue to provide a useful perspective but the key values of the “RP system” should continue to be based on the current, well developed, and more defensible health-risk approach.
It is well known and widely accepted that natural background averages about 2.4 mSv/y on a worldwide scale, and usually ranges from about 1 to 10 mSv/y depending on the geographical location, with many local exceptions that go up to 100 mSv/y. This important perspective is factored in around the world, and is part of the comprehensive public consultation process that led to the acceptance of “practices” and their licensing.
We are puzzled by the proposal to exclude radon from natural background and the related provisions (e.g. para. 31). Para. 157 leaves the impression that radon is controllable everywhere and that it is only a matter of indoor environment. This view is inappropriate.
Radon is also a matter of outdoor environment for which the level of control is much more limited; nor is it straightforward to control in an indoor environment. Should the need/case for a common system of protection for humans and non-human species ultimately become relevant, it is very unlikely that radon in habitat of animals and plants will be offered the same level of control as in homes and workplaces.
If the contribution from radon is excluded, the world average natural background becomes 1 mSv/y. Current ICRP discussions seem to indicate that some connection is to be drawn between this level and the allowable public dose. But the fact that this “without radon” level is roughly the same as the current public dose limit of 1 mSv/y is purely coincidental and has no scientific significance regarding the question of the adequacy of the public dose limit. Assessment of the public dose limit must continue to be guided by the question of whether it poses a significant health risk. This principle also applies to non-human species should the need/case for a common system of radiological protection ultimately become relevant.
It is important to keep the system flexible in view of potential future health risk evidence that may trigger changes to the key values of protection (e.g., dose limits for humans and dose-rate guidance values for non-human species). Irrespective of background, lower values may become appropriate should the risk from radiation be higher and vice-versa. The health risk assessment approach is fit for both human and non-human species.
Associating “exposure levels” and the “need for action” is difficult to understand and comprehend, especially for levels within the range of natural background and for levels well below the current dose limit for the public. We also question the need for action for doses that are less than about 0.01 mSv/y.
These messages would contribute to augmenting public fear about any man-made sources of radiation. They also appear inconsistent in view of para. 31, which states that “it is incremental risk (not in isolation of natural background) that is of interest for decision-makers”. Associating “exposure levels” and the “need for action” is not sound.
6) Policy on non-human species – We welcome the introduction of a policy that revolves around the radiological protection of animals and plants at the population level (or an higher organisation level). In this respect, paragraphs 246 and 247 are key.
We welcome the early development of a framework for assessing radiation effects in non-human species – with the expectation that such a system would primarily aim at establishing the links (robust scientific foundations) between effects at the individual level and the corresponding effects at the species level in terms of frequency of effects that are relevant to this latter level. However, as this early development is less about the policy itself than about the how to implement the policy, we are not convinced that the ICRP proposal is the suitable place to address this matter at this time.
Concerning subsequent steps (e.g., a framework, a common approach/system, new standards, and any related control matters) that go clearly beyond the introduction of a policy, we firmly believe that this is premature and should not be included in the ICRP proposal. It would raise confusion and be misleading. We stress that one key outcome of the June 2004 IAEA meeting on a draft international action plan for the development of such an assessment framework is the international consensus that the need/case for any subsequent steps has not yet been made.
We emphasise that the need/case for ICRP to focus on the individual level appears weak, and we therefore seek further clarification and explanation. Most current regulatory regimes aim directly or indirectly at the protection of animals and plants at the species level. (Even efforts to protect individual rare or endangered animals and plants are aimed at protecting the remaining population of a species.) We ask this: How, on a practical level, could the current widespread legal and regulatory structure possibly be adapted to a new protection policy and assessment framework not designed for the protection of species or populations?
The technical difficulties and challenges for the development of the assessment framework (e.g., linking dose-response at the individual level and population effects level) should not be the driver of the ICRP policy on non-human species. Para. 247 is key in this respect.
7) Exclusion, exemption and clearance – We welcome the ICRP approach that leads to concentrations below which current practices would no longer be subject to the requirements of the RP system. As part of optimisation, provisions for higher concentrations in the context of exemption and clearance levels would represent an important improvement. This is another practical area where balancing beneficial actions giving rise to radiation exposure and the detriments of radiation exposure are particularly important. Further guidance would be welcome here. We would also welcome further consistency between ICRP and the IAEA in the field of exclusion, exemption and clearance.
8) Collective dose or dose matrix – We welcome the statements in para. 198 and 200 that limit the scope of collective dose. We recognise the value of disaggregating the collective dose results, provided that this procedure also includes a lower bound cut-off dose level – by analogy with the concept of exclusion, exemption and clearance.
9) Critical groups – It is striking to note the changes in the definition of some factors that are considered for critical groups. Para. 172 states that “the critical group may, however, include some individuals with extreme or unusual habits and should be selected such that all relevant habits are taken into account”. This change is inadequate and would represent a major shift in comparison to the current policy.
10) Terminology – The need/case for replacing the following terms does not seem compelling:
o the term ‘deterministic effects’ by the term ‘tissue reactions’
o the term ‘ stochastic effects’ by the term ‘cancer and heritable disease’.
*** ATTACHMENT #2 ***
The post-ICRP60 dose constrains of 0.1 and 0.3 mSv/y:
A key practical example that provides perspective on our comments
Let us examine more closely the practical case of the proposed maximum dose constraint of 0.3 mSv/y that ICRP is proposing for normal situations with multiple dominant sources (para. 164) and of the related and even more stringent maximum dose constraint of 0.1 mSv/y. The latter seems indirectly included by reference (S29) to ICRP77, 81 and 82. All of these values are related to the disposal of radioactive waste.
Basis – We emphasise that a simple reference to ICRP77, 81 and 82 does not do the job. When examining ICRP77 (para. 48), which introduces the value of 0.3 mSv/y, we note the apparent absence of international studies that would support such a value and of related analyses and discussions. As a basis, ICRP77 appears to refer only to a “review of the doses to critical groups in England and Wales (Robinson et al., 1994)”. Without further evidence on public health grounds and further analysis of practical cases that would be universally applicable across the world, we question the relevance of bringing such values into the international system of radiological protection. ICRP81 and 82 go further in that direction without apparent further international basis. Among other things, ICRP82 (para. ‘k’ and 132) introduces the value of 0.1 mSv/y for the prolonged component of the exposure. The apparent shortcomings in international basis for this value seem similar to those for the value of 0.3 mSv/y.
Among other issues, there is a real concern that lower dose constraints (1 mSv/y) for effluent discharges may later set an unrealistic expectation that can bear huge implications for the transport of spent nuclear fuel (SNF) and high level waste (HLW) and for their disposal in deep geological repositories. Continuing to set dose constraints on the basis of health-risk considerations is very important.
Context of application – What is meant precisely by “source” is not straightforward and is fundamental. Most of the discussions about “sources” in, for example, ICRP77 (e.g. para. 42 and 44) and ICRP82 (para. 2 and 11) are about the general concepts and lack supporting discussions and analyses (with suitable references) of the specific cases that would help explain the international relevance of these values and their context of application. This type of information, necessary for an open and transparent international debate of the matter, is notably missing.
The need for open and transparent international debate – We emphasise that practically none of the 30 or so post-ICRP60 dose constraints (including the introduction of the 0.3 and 0.1 mSv/y values) has been truly debated internationally with the competent and qualified representatives of the concerned parties. We recognize that ICRP60 was subject to such a debate, and we would expect that any important post-ICRP60 matters deserve the same attention. We point out that even if some values (below 1 mSv/y) may have been used as dose constraints in some jurisdictions for various specific reasons, this does not make the case to extrapolate them to the international scene.
The conclusion that arises from this key practical example is that the status of the 0.1 and 0.3 mSv/y dose constraints (and likely also the remaining 30 or so post-ICRP60 dose constraints) has not yet been openly and transparently debated internationally. The post-ICRP60 dose constraints appear more relevant to the former ICRP’s “DAD” philosophy (Decide, Announce, Defend) than to the more recent ICRP’s “MUM” philosophy (Meet, Understand, Modify). MUM is now internationally understood as essential to the ICRP’s approach with regard to any proposed important changes and should be the operative theme in current international discussions and debates.