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Submitted by Sylvain St Pierre, WNA
   Commenting on behalf of the organisation
Document The scope of radiological protection
 
We have reviewed this important ICRP draft publication and we are pleased to provide some initial feedback on behalf of the global nuclear industry.
The ICRP draft publication was issued shortly before the IAEA draft document (Working Material WM1: Scope - The Scope of Requirements for Protection and Safety) on this same topic. The latter has been submitted (but remains to be discussed) to the IAEA Radiation Safety Standard Committee (RASSC) in April 2006.
Overall, both the ICRP and IAEA documents closely examine the multiple issues and subtleties of the scope of RP regulations and requirements. This (of course) includes particular attention to the concepts of exclusion, exemption and clearance for both sources and exposures of ionizing radiation.
The two documents helped to reveal key areas in which greater consistency and coherence in the scope of RP regulations and requirements would improve the RP system. The downside of such detailed documents, which includes an in-depth reflection on the pros and cons of complex subjects, is that the documents tend to become complicated and insufficiently clear about the preferable options that should be retained. This is particularly important in the context of RP regulations where clarity and simplicity are fundamental to the good understanding, by all stakeholders, of the RP system and of its implementation.
Nevertheless, we agree that these two documents provide an important starting point for discussion of the requirements of the ICRP next recommendations and of the IAEA Basic Safety Standards (BSS) that relate to the scope of regulatory controls of radiation safety. They should have direct implications on the overall RP system in terms of contributing to improve its consistency and coherence as well as its consolidation and simplification.
Other highlights of our main review comments follow. They address first the significant improvements that can be derived for the overall RP system, and then the concepts of exclusion, exemption and clearance.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 2
Significant improvements to the overall current RP system:
1. For consistency and coherence in the coverage of risk from exposures, it is essential that the concept of exclusion, exemption and clearance for sources becomes equivalently applicable to exposures.
2. The direct consequence of this is that the current dose limits and the upper bound of the scope of exclusion, exemption and clearance (for exposures), respectively delineate the upper and lower bounds of the optimization process.
3. Within this scope for optimization, ICRP and IAEA should define the principle of dose constraints whereas local stakeholders - national/local regulators, operators, etc. - should have the necessary responsibility and flexibility to specify adequate numerical dose constraints that are optimized relative to their specific contexts.
- The meaning and basis of numerical dose constraints set at the international level is unclear - even for RP practitioners - as recently witnessed on repeated occasions in the context of RASSC deliberations. It is important to stress that there is a real risk that such numerical values could generate confusion in the public mind about what is an adequate upper bound of public health protection.
4. The consolidated framework for the RP system shown on Figure 1, which can be derived from the information contained in the two-subject ICRP and IAEA draft reports, helps visualize the essence of these improvements. The simple colour code shown in Figure 1 should facilitate a better understanding by the public of the health risk from human exposure to ionizing radiation. This framework contributes to improve the RP system consistency and coherence - e.g. in relation to the interpretations (e.g. see Annex 2 herein) given by ICRP, IAEA and the World Health Organization (WHO) on the risk from exposure to ionizing radiation. This framework also helps clarify and simplify the understanding and implementation of the RP system.
[More comments on Figure 1 are provided in Annexes 1 and 2. Annex 1 clarifies the above items 2 and 3. Annex 2 (see its item 6) further describes Figure 1.]
Concepts of exclusion, exemption and clearance
1. The extended application (beyond sources only) of these concepts to exposures is very important.
2. We note that important notions such as dichotomous control for natural radioactivity and artificial radioactivity, unamenable control and unwarranted control, the flexible interpretation of some reference exposure values (e.g. Of the order of 0.01 mSv/y), the graded approach which can allow higher exposures and concentrations, and other notions, seem in line with those given in recent IAEA publications: e.g. its Safety Guide on Application of the Concept of Exclusion, Exemption and Clearance (RS-G-1.7). We understand that all these notions equivalently apply to sources and exposures. Throughout the report though, the notions of sources and exposures and the related application of the concepts of exclusion, exemption and clearance (including the related recommendations that should be retained) should be clearer.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 3
3. Concerning sources (here in the sense of materials to be covered or not by regulations, or to be released from sites), it is important to have clearly defined and internationally-agreed activity levels (in Bequerel per kilogram: Bq kg-1, and in Bequerel per square centimetres: Bq cm-2) for bulk materials and for smaller material quantities, above which some form of appropriate regulatory control will be applied.
For practical purposes, and to secure public understanding, there must be particular emphasis on establishing simple and common terminology that applies to materials that are not subject to regulatory control, no matter what decision route has led to that situation. Such material, which of course still contains some radioactivity, is clearly “unrestricted”. The importance of establishing a clear, simple and easily understood framework for the control of materials should therefore be a key practical outcome of this debate on the “scope”. The nuclear industry fully supports the use of the term “clearance” which we believe is generally well established and understood, although we recognize that it could be more clearly delineated.
We would like to draw your attention on the fact that the ICRP values of around 1 Bq kg-1 for alpha emitting radionuclides and of around 10 Bq kg-1 for beta and gamma emitting radionuclides are not consistent with IAEA’s Safety Guide RS-G-1.7. Given that the later reflects a wide consensus among the UN Member States on a common set of rules for adequately governing the use or disposal of bulk materials, we would strongly recommend that ICRP does not introduce new confusion on such an important topic. Instead, it would be far better that ICRP addresses this issue in due course through its co-sponsor organization role in RASSC deliberations.
We would also like to draw your attention on the WNA Working Group Position Statement (February 2006) on Removal from Regulatory Control of Material Containing Radioactivity – Exemption and Clearance. This Statement, which addresses this topic in greater detail than above, concludes our main comments about sources.
4. Concerning exposures, the rationale for addressing radioactive discharges and the context of waste management and disposal in a different manner than other common public exposures to radiation such as cosmic rays above ground, simple routine medical applications (e.g. chest x-rays) and even “practices” associated with naturally occurring radioactive materials (NORM) industry, is unclear. This discrepancy would not contribute to improve the consistency and coherence of the RP system. (See Annex 2, item 7.)
5. The radon level for exclusion in dwellings seems set at too low a level. Setting the exclusion at 40 Bq m-3 seems too low given the high natural variability of ambient radon levels. Dry or wet conditions and changes in atmospheric pressure can alone generate high variability – even on a daily basis! To be more practical, the value should be of the order of 100 to 200 Bq m-3. Again, this would unnecessarily introduce a new numerical value that is not consistent with current internationally-agreed standards and guidance.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 4
In addition to these main review comments, Annex 2 includes a series of review comments on the ICRP draft report that we have enhanced by adding references to the related IAEA draft report. Also, Annex 3 includes some review comments specific to the IAEA draft report.
We thank ICRP for this opportunity to provide review comments at this stage of the consultation. We are looking forward to the outcome in terms of an improved ICRP draft report.
We are looking forward to other opportunities for the worldwide nuclear industry to contribute its practical expertise and perspective on the ICRP deliberations.
Best Regards,
Sylvain Saint-Pierre
Director for Environment and Radiological Protection
cc. IAEA RASSC and WASSC Chairs and Secretariats, the related IAEA head personnel, and RASSC’s co-sponsor organizations.
Attachments:
Figure 1 Consolidated Framework for the RP System - Towards a More Consistent and Coherent RP System
Annex 1 Some Comments on the Consolidated Framework for the RP System (Figure 1)
Annex 2 WNA Review Comment on the two subject ICRP and IAEA documents
Annex 3 WNA Review Comments specific to the subject IAEA document
Note: The WNA Working Group Position Statement (February 2006) on Removal from Regulatory Control of Material Containing Radioactivity – Exemption and Clearance is available on the WNA website under the heading “WNA Working Group Position Statements”: see http://www.world-nuclear.org/position/index.htm.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 5
Figure 1 - Consolidated Framework for the RP System: Towards a More Consistent and Coherent RP System
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 6
ANNEX 1 – Consolidated Framework for the RP System
Some WNA Comments
As illustrated in Figure 1 herein, it is also clear that the two subject ICRP and IAEA documents should contribute to consolidating and simplifying the current RP system. The significant improvements that we can derive from them seem to be two-fold:
1. The bottom of the scope of RP regulations/requirements ranges from doses of the order of 0.01 mSv/y up to doses of the order of 0.1 mSv/y - with the caveat that exemption may allow doses up to 1 mSv/y in the context of either exposures to natural radioactivity or potential exposures with low probability of events. This bottom scope is practically put into play through the application of the concepts of exclusion, exemption and clearance. Below these dose levels, it is widely recognized that there is increasingly a need to question the value of the extra gains in protection versus the extra resources needed to achieve these gains and the broad context of common human health risk-benefits. To the extent possible, to encourage better understanding and trust by the public on the scope and credibility of RP regulations/requirements, countries should be encouraged to follow the universal agreement. A move to depart from it should be discouraged.
2. The current dose limits and the upper bound of the scope of exclusion, exemption and clearance (i.e. of the order of 0.1 mSv/y, with the above-mentioned caveat for doses up to 1 mSv/y), respectively delineate the upper and lower bounds of the optimization process. Within this scope for optimization, ICRP and IAEA should define the principle of dose constraints whereas local stakeholders - national/local regulators, operators, etc.) should define their numerical values. This is because local stakeholders should have the necessary responsibility and flexibility to specify optimized numerical dose constraints that address their specific contexts. The contrary (setting numerical dose constraints at the international level) is impractical for various reasons:
a. Compliance with both dose limits and optimization (including the principle of dose constraints) is legally enforceable and widely implemented.
b. Through optimization - taking into account protection, technical feasibility, and socio-economic factors - dose constraints could only with great difficulty be numerically specified at the international level in a universally applicable way.
c. Correspondingly, the meaning and basis of such dose constraints would be unclear.
d. There is a real risk that specifying numerical dose constraints at the international level would unduly contribute to ratcheting down the optimization process – a potential key issue that has been flagged up by the IAEA (IAEA WM3 report on optimization, section 4.10).
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 7
ANNEX 2 - ICRP Draft Report : The Scope of Radiological Protection Regulations
and
IAEA WM1 Draft Report: The Scope of Requirements for Protection and Safety
WNA Review Comments (Initial Input)1:
1. WNA welcomes this draft report from ICRP that primarily aims at clarifying “the principles of good governance that the application of regulatory systems for protection and safety will strike an appropriate balance between what is necessary to avoid harm, on the one hand, and the optimal use of societal resources on the other.” (para.. 5 – herein, such paragraph references relate to the ICRP draft report). The statement in Section 1.1 of the IAEA WM1 draft report is analogous: “There is an expectation, deriving from principles of good governance, that the application of regulatory systems for safety will strike an appropriate balance between what is necessary for safety on the one hand, and the preservation of societal freedoms and resources on the other.”
2. WNA agrees that it is important that these principles, which have an important bearing on the practical use of the concepts of exclusion, exemption and clearance, apply to both sources and exposures of ionizing radiation.
3. The WNA agrees that the bottom of the scope of RP regulations/requirements should start from exposures that are of the order of 0.01mSv/y and up to of the order of 0.1 mSv/y [para (k), 41, 79, 92 of the ICRP draft report and sections 4.2 and 4.4 of IAEA WM1 report] with the caveat mentioned earlier for doses up to 1 mSv/y. As indicated in IAEA WM22 (section 2.1.1) by reference to quantitative guidance on the risk-benefit trade-off, originally devised by the World Health Organisation (WHO): ‘The lowest Category of Risk was called “trivial”, corresponding to an effective dose up to 0.1 mSv, and only required a “minor” level of societal benefit such as increasing knowledge. The next Category of “minor to intermediate” Risk covering the dose range from 0.1 – 10 mSv required an intermediate to moderate societal benefit. In this range the risks “cannot readily be either accepted or used as the basis for refusal” and the benefits would typically range from increases in knowledge leading to health benefit to the cure or prevention of disease.’
It is equally important to stress that none of these two values (0.01 and 0.1 mSv/y) should be considered as precise (para. 45, 49) but rather in the full context of the main aim of the RP system: “an appropriate balance between what is necessary to avoid harm, on the one hand, and the optimal use of societal resources on the other.” (The equivalent statement in Section 1.1 of IAEA WM1 is also relevant here.) For doses that are lower than of the order of 0.01 mSv/y, it is vital that extra gains in protection are realistically and fairly assessed relative to the extra resources required to achieve these gains and the broad context of common human health risk-benefits.
1 These WNA review comments were first developed for the ICRP document and then enhanced by adding references to this IAEA document and other relevant IAEA documents.
2 IAEA WM2 draft report (March 2006) on Requirements for justification of practices and interventions – Reviewing the basic safety standards
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 8
4. The industry agrees that for the overall consistency and coherence of the RP system on the control of radiation sources and their exposures (para. 6, 131 and 133), it is important, and even essential, that countries converge towards the implementation of a universal agreement on the scope of RP regulations/requirements (para.137).
Within this agreement, it is expected that countries will regulate any sources and exposure situations that exceed the levels defined by the scope of exemption, and conversely will prevent undue burden of regulating sources and exposure situations that fall clearly within the scope of exclusion, exemption and clearance.
To the extent possible, for a better understanding and trust by the public in RP regulations/requirements and for the credibility of this agreement, countries should be encouraged to follow this universal agreement and conversely, any intent to depart from it should be discouraged.
5. The industry recognizes the current dichotomous approaches between natural and artificial exposure situations (para. 31); however, again, it is key that for the consistency and coherence of the RP system, that these two approaches converge over time.
6. The consolidated and simplified “3 bands” RP system that can be derived from the above and from the current dose limits is illustrated in Figure 1 herein. The 3 bands are as follows:
Band 1: from of the order of 0.1 mSv/y to the public dose limit of 1 mSv/y (with a provision for a maximum of 1 mSv/y averaged over 5 years),
Band 2: from the public dose limit (1 mSv/y…) to the occupational dose limit (20 mSv/y averaged over 5 years, 100 mSv in 5 years, with a provision for a maximum of 50 mSv in a single year),
Band 3: from the occupational dose limit to of the order of 100 mSv.
A simple colour code - The RP system shown on Figure 1 encompasses a simple colour code (green, yellow, orange and red) that reflects the actual knowledge of health risks from human exposure to ionizing radiation. In this respect, it is important to stress that the level of risk corresponding to the occupational dose limit and to the public dose limit differs; the dose limits include safety margins respectively of about a factor of 5 and 100 relative to the dose level from which human health radiation risk has been conclusively demonstrated by scientific evidence such as epidemiological data. The common colour system proposed here should facilitate an easier understanding by the public of the health risk from human exposure to ionizing radiation.
Compliance with both dose limits and optimization (including the principle of dose constraints) is clearly enforceable and widely implemented – This is the case all around the world. Complying only with the dose limits is not an option for operators. They must comply with both the dose limits and optimization. The “3 Bands” here clearly delineate the scope for optimization.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 9
Defining the principle of dose constraints and specifying their numerical values - It is important that ICRP and IAEA define the principle of dose constraints and that local stakeholders (national/local regulators, operators etc.) have the necessary responsibility and flexibility to specify adequate numerical dose constraints that are optimized relative to their specific contexts. The contrary (setting numerical dose constraints at the international level) is impractical for various reasons: through optimization (taking into account protection, technical feasibility, and social and economic factors), dose constraints could only be with great difficulties numerically specified at the international level in a universally applicable way. Correspondingly, the meaning and basis of such dose constraints would be unclear.
It should be borne in mind that local stakeholders use dose constraints for a wide range of situations. Sometimes dose constraints are used as “hard” limits or as softer concepts, and sometimes they are used for the control of sources (e.g. public doses from nuclear sites) or the control of activities (e.g. worker tasks).
The above clearly indicates that the case for specifying numerical dose constraints at the international level is not compelling. Moreover, there is a real risk that specifying numerical dose constraints at the international level would unduly contribute to ratcheting down the optimization process - a potential key issue that has been flagged up in the IAEA WM3 report3 (section 4.10)
For example, adopting 20 mSv/y and 1mSv/y as the maximum numerical dose constraints would de facto contribute to ratcheting down the RP requirements relative to the current dose limits as the latter include more flexible provisions. Similarly, adopting numerical dose constraints that would be lower than the current dose limits further contribute to ratcheting down the RP requirements at the international level.
Concerning public doses from significant sources of exposures, local stakeholders (national/local regulators, operators, etc.) should have the flexibility to specify whatever numerical sub-limits or dose constraints appropriate to each specific context on the grounds of ensuring compliance with both the dose limits and the optimization principle, taking into account protection, technical feasibility, socio-economic factors etc.. For this purpose, it can easily be argued that the range of applicability from 1 mSv/y down to about 0.1 mSv/y (upper range of exemption: inclusive of the graded approach) is sufficiently narrow. Moreover, because it is the potentially most exposed public group of individuals (commonly referred to as the “critical group”) under assessment here, it is self-evident that the public in general is automatically provided a much more stringent level of protection that is actually necessary.
The context of waste management or prolonged exposure, for which the apparent link (based on ICRP and IAEA) between a dose constraint of 0.3 mSv/y (and even of 0.1 mSv/y!) and the case of multiple sources is not evident, illustrates this key issue of setting, at the international level, numerical dose constraints that are lower than the public dose limit of 1 mSv/y. It would rather appear that the value of 0.3 mSv/y was
3 IAEA WM3 draft report (March 2006) on Requirements for optimization of protection – Reviewing the basic safety standards.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 10
simply selected as it corresponds to a level of risk of about 10-5 (see the DS354 draft, section 2.12; IAEA WM1report, sections 2.3 and 3.2; ICRP77 para.44 and 48a; ICRP81 para.55). Based on the IAEA WM1 report (section 4.2), it should be emphasized here that this risk level corresponds to the level of which “few people would commit their own resources to reduce an annual risk of death”. The logic of such dose constraints is unclear because it would leave only an extremely narrow band for the local stakeholders to specify optimized numerical dose constraints below 0.3 mSv/y (and even 0.1 mSv/y) – with the value of 0.1 mSv/y already corresponding to the upper bound of exemption when accounting for the graded approach!
In summary, the consolidated and simplified RP system that can be derived from the ICRP and IAEA draft reports and the current dose limits is as follows:
Above “Band 3”, it is clear that drastic measures are necessary to ensure that such exposures are avoided or if they occur, are lowered substantially.
“Band 1 to 3” delineates the scope for optimization (including the principle of dose constraints) with the current dose limits as the numerical upper bounds of the optimization process. The principle of dose constraints should be defined at the international level by ICRP and IAEA whereas the local stakeholders should specify the numerical dose constraints that are adequate to their specific contexts.
Below “Band 1” and down to of the order of 0.01 mSv/y is the scope of exclusion, exemption and clearance. Within this dose range (and even more for lower doses), there is a need to increasingly question extra gains in protection versus the extra resources needed to achieve these gains within the broader context of common human health risks-benefits.
7. Things like radioactive discharges and the context of waste management and disposal should also be viewed in the context of other common public exposures to radiation such as:
a. Cosmic rays above ground: not only air crew members and frequent travellers (e.g. 100 transatlantic return trips each year are not uncommon for a single individual) can accumulate doses of the order of 10 mSv/y, but also infrequent travellers (e.g. one transatlantic return trip) can also easily receive doses of the order of 0.1 mSv/y.
b. Simple routine medical applications such as chest x-rays: also contribute about 0.1 mSv per event.
c. “Practices” associated with the naturally occurring radioactive materials (NORM) industry: can contribute up to about 0.3 mSv/y (para. 48). It is stressed that exemption is suggested for these practices.
Furthermore, for both items “a” and “b”, it is clear that the benefits from these two very common activities far outweigh any loss in protection. It can also be argued that these exposures are controllable. For example, air ticket holders are required to board an airplane; air miles are tracked on an individual basis. So the possibility of controlling
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 11
exposures exists. Similarly, access to x-rays can be more controlled. The reality is that at such low level of incremental exposures, society has deemed it inappropriate to give particular consideration to protection against these sources because of the benefits that it gains; and out of consideration for freedom of choice.
Similarly, the benefits that nuclear energy provides, as one of the few available large-scale sources of clean and safe energy that is much needed in this century and beyond as part of a balanced energy mix, clearly outweigh its minuscule and local environmental impact on the public. This must be compared to the multiple prevailing and threatening commonplace environmental stressors: e.g. air pollution-causing climate change, chemical pollution, urban development, agriculture, fisheries, and excesses that substantially impact the global environment. Whether radiation effects on animals and plants are one of these prevailing factors remains to be seen! It is not difficult to see that regulators and operators do have the responsibility and duty to make balanced and rational decisions in regulating environmental matters and in implementing environmental measures in their fullest context.
Given the above, at very low doses, whether there are individual benefits or societal benefits associated with the exposures should be a secondary matter.
On this basis, although clearance may not be applicable for radioactive discharges, the concept of exemption remains relevant, in particular for doses in the range of 0.01 to 0.1 mSv/y. Specifying numerical dose constraints internationally at 0.3 and even 0.1 mSv/y seems awkward for both radioactive discharges and for the context of waste management and disposal. This is because such dose constraints values are barely above the dose levels for exemption, thus barely leaving sufficient room for local stakeholders to define numerical dose constraints that are optimized to their own contexts.
8. The radon level for exclusion in dwellings seems set at too low a level. Setting the exclusion at 40 Bq m-3 seems too low given the high natural variability of ambient radon levels. Dry or wet conditions and changes in atmospheric pressure can alone generate high variability – even on a daily basis! To be more practical, the value should be of the order of 100 to 200 Bq m-3.
9. From a policy viewpoint, the coverage of the important topics of recycling and re-use (para. 128) is disproportionally light. It is important to address the four key environmental principles (Reduce waste or contamination at source, Recover, Recycle, Re-use - commonly referred as the 4 Rs) for both matters (lands, buildings, materials and even wastes) and “people” (re-deployment of workforce and local re-development). Disposal should be the last resort measure.
As for any large industry and manufacturing activity, there are today high social expectations for the sustainable use of resources. Of course, safety is paramount but understandably, societal expectations go beyond protection alone and extend to the domain of the re-use of both material and human resources.
WNA Review Comments on ICRP Draft Report – June 13, 2006 Page 12
ANNEX 3 IAEA WM1 Draft Report – The Scope of Requirements for Protection and Safety
WNA Review Comments (Initial Input):
1. Section 2.3 - RP requirements – quantitative characteristics: We wonder what the basis is for the statement: “…with the implication that the acceptable boundary for individual practices may be lower: a typical value in use is 0.3 mSv/y”. We would argue that this is not consistent and coherent with the intent of not ratcheting down the optimization process (IAEA WM3, section 4.10) and with the scope of exclusion, exemption and clearance (i.e. from of the order of 0.01 mSv/y up to 0.1 mSv/y). See also our WNA Draft Review Comments 3 and 6.
2. Similarly, Figure 4 (b) seems awkward. In particular, we wonder what a “region of dose constraints” means? Setting the “region of optimization” at 0.1 mSv/y is also irrelevant. Optimization applies from 1 mSv/y and down to lower doses until it reaches the scope of exclusion, exemption and clearance. The contrary would be awkward. In section 2.6, Figure 5b contains the same shortcomings. Stating that the dose limit is set at 20 mSv/y (bottom of Figure 5b) is also incorrect and indicative of a ratcheting down approach.
3. Section 3.2 – Exclusion of exposure below a specified regulatory threshold: Until transparent and objective evidence for the basis and practical relevance of the numerical dose constraints (0.1 and 0.3 mSv/y) specified in ICRP82 are provided, we cannot favourably support the related guidance. This is because regulators and operators have the important responsibility and duty to clearly understand the basis of all standards. The current state of affairs on this key issue is that such evidence remains to be seen. Sometimes the value of 0.3 mSv/y is reported as to corresponding to a risk level of 10-5 and sometimes it is reported as relevant to cases of multiple sources. We are seeking international studies of relevant practical cases that would support that such numerical dose constraints are universally applicable. By definition, this is a key prerequisite to any robust international consensus.
4. Section 4.4 – Exemption after an optimization assessment: It is noted that with the graded approach defined in RS-G-1.7 for exemption, the corresponding dose level can, in principle, go up to of the order of 0.1 mSv/y (and even up to 1 mSv/y).
5. Section 6.1 – Exclusion: In the context of air travel, it seems incorrect to state that exposure to cosmic rays above ground level is unamenable to control. Access to air flight is controllable. Given the magnitude of the doses for both air crews and public passengers, proposing the exclusion of these exposures seems highly questionable. The RP system should be more coherent for all forms of public exposures (See also our WNA Main Review Comments, Annex 2, item 7.)