Radiological Protection in Geological Disposal of Long-lived Solid Radioactive Waste


Draft document: Radiological Protection in Geological Disposal of Long-lived Solid Radioactive Waste
Submitted by Kathryn H Pryor, Health Physics Society
Commenting on behalf of the organisation

The Health Physics Society[i](HPS) is a professional organization whose mission is to promote excellence in the science and practice of radiation safety.  The HPS appreciates the opportunity to provide comments on the Draft Report for Consultation – Radiological Protection in Geological Disposal of Long-lived Solid Radioactive Waste.

 

The HPS has reviewed the draft ICRP report, Radiological Protection in Geological Disposal of Lon-Lived Solid Radioactive Waste, and the comments on this draft report provided by members of the National Council on Radiation Protection and Measurements (NCRP) Program Area Committee 5 (enclosed).   The HPS believes that in large measure this draft report achieves the objectives of updating and consolidating previous ICRP recommendations on solid waste disposal, and developing a report which describes how the ICRP System of Radiation Protection (described in ICRP Publication 103) can be applied in the context of geological disposal of long-lived solid radioactive waste.  The HPS encourages the report Task Group to carefully consider the NCRP PAC-5’s comments for the purposes of improving the clarity, quality, and guidance on the functional applicability of the ICRP Publication 103 recommendations to geological disposal of long-lived solid radioactive waste of this report.



[i] The Health Physics Society is a nonprofit scientific professional organization whose mission is to promote the practice of radiation safety. Since its formation in 1956, the Society has grown to approximately 5,000 scientists, physicians, engineers, lawyers, and other professionals representing academia, industry, government, national laboratories, the department of defense, and other organizations. Society activities include encouraging research in radiation science, developing standards, and disseminating radiation safety information. Society members are involved in understanding, evaluating, and controlling the potential risks from radiation relative to the benefits. Official position statements are prepared and adopted in accordance with standard policies and procedures of the Society.

Comment by S.Y. Chen

 

In general, this proposed document provides updates and consolidates previous ICRP recommendations on solid waste disposal and it applies specifically to the geological disposal of long-lived radioactive waste in light of the 2007 ICRP System of Radiological Protection described in Publication 103. In a large measure, the document has achieved its objective with by a systematic approach toward various stages of protection for the waste facility under direct oversight (short term), indirect oversight (medium term), and no oversight (long term).

 

In reviewing the document, however, I also have a number of concerns that are described as follows. These concerns are primarily surrounding the very large uncertainties for the long-term assessment and the associated clarifications regarding the proposed system particularly if it is to be incorporated into the regulatory approach.

 

  • In Section 3.1.2 (Basic ICRP principles dealing with future generation), it emphasizes that optimization principle is of primary importance and also reinforced in the new ICRP Recommendations (Paragraph 19). For this, the concept on dose and risk is largely based on today’s knowledge on radiological health risks, and that the efforts on radiological protection are to be guided entirely by the current understanding of health and environmental effects (Paragraph 20). It follows to say (Paragraph 21) that “…the assessment of the robustness of the protection system provided by the solid waste disposal in the long-term does not need precise knowledge …in the far future.” This is because, “The challenge is rather to estimate, in an optimization process, through a comparison (using dose and risk indicators) of alternative options…is acceptable in light of the level of protection accepted today.”
  •  

    There are a number of issues related to the above statements:

     

    ·         It appears to be a misnomer to consider the exposure situation under the design-basis evolution to be “planned exposure situation” under the “no oversight” conditions. Considering that such exposure would be well into hundreds of thousands years from emplacement, the exposure situations will become highly probabilistic subject to many uncertainties. Thus to consider such an exposure situation as “planned” is truly unfathomable; as it implies that the exposure can be anticipated today whereas it is not. Since after such a long time when people who may be exposure would likely not have any record of such radiation sources, thus it may resemble “existing exposure situations” rather than “planned exposure situations.” The Committee ought to provide more justification and clarification on this subject.

    ·         Radiological assessment for the long-term time frame is certainly not limited to the optimization process as stated in Paragraph 21. It also has to demonstrate that the doses or risk assessed are to meet the limits as well reference levels for various conditions (as indicated in Table 1 of the draft report). Thus the assessment is used not only for comparison of options under the optimization process; they are also intended to meet the limits and constraints in various stages of operation. Thus, the philosophy on the assessment has to be further clarified as whether it is intended to opt for conservatism or realism.

    ·         The report needs to clarify how natural events (such as seismic events, in Section 4.3.3) would affect the protection issues, and how to “plan” for such events. In view of what’s happening in Fukushima, Japan and elsewhere today (i.e., estimate of probabilities and the related cascading affects are difficult to ascertain), further guidance is needed to deal with the assessment of the event probabilities and potential consequences.

     

  • Whereas it makes sense to preserve the consistency on protection by considering such elements as Representative Person (Section 5.1) and the related consideration of individual gender and age groups in the dose and risk assessment in the short term, the consideration appears to be largely academic in view of the very large uncertainties for the long term (particularly during the nom oversight situations). This is equivalent to artificially addressing the precision issue without adding any accuracy to the assessment. Likewise, the concern applies to the Protection of the Environment (Section 5.2). It is unclear how in the long term such assessment would make any sense using the Reference Animal and Plants when there are many unknowns (for example, there were discoveries of the baby mammoth in Russia Arctic from the last ice age, which was extinct about tens of thousands of years before). ICRP needs to focus on the appropriate treatment of the very large uncertainties. Too many artifacts have been introduced in the name of preserving the consistency of the framework. Instead, we need to develop appropriate surrogates for the assessment when such large uncertainties are expected.
  •  

     

    Comment by Thomas Hinton

     

    1) Lines 359-361:

     

    Comment: The sentence highlighted above is in paragraph 7, which deals with protection from chemotoxic and radiotoxic substances that might be released from a disposal facility.  It is excellent that the ICRP has noted that two types of toxic substances exist and might be released.  What is missing, however, is a statement that additional work on the interactions of these two types of contaminants is needed.  We have very little knowledge about the effects of radiation in a mixed contaminant context.  Such studies are rarely performed; instead, contaminant research is conducted as if pollutants exist in isolation.  Thus, we have little information on potential antagonistic or synergistic effects due to contaminant mixtures. Consider adding a sentence at the end of line 361, : “The optimization of this framework will require additional knowledge on the potential interactions of radiation and chemical substances when in a mixed contaminant context.”

     

     

    2) Line 448-449:

     

    Comment: This sentence contains a typo (“into”).

     

    3) Lines 1251-1253:

     

    Comment: Aren’t the default targets for environmental protect the Derived Consideration Reference Levels (DCRLs; lines 1521), and the Reference Animals and Plants are merely a means of estimating the DCRLs?  Consider rewording sentence on line 1251 to: “The default target for protection and protective actions are currently considered to be Derived Consideration Reference Levels (DCRLs) that have been described using Reference Animals and Plants within ICRP Publication 108 (para 195).”

     

    4) Important ICRP philosophy relative to environmental protection appears for the first time within the Appendix 1, rather than in the body of the report.   Appendix 1 is stated as being a summary (line 1346) and as such, should not be presenting new information.  Instead, consider adding a new paragraph to the end of the environmental section.  This would be paragraph 88 (line 1272), and could contain information brought up from Appendix 1 (lines 1562-1565; 1574-1575 and 1578-1582):

    “(88)  The Commission believes that the development of a clearer framework is required in order to assess the relationships between exposure and dose, and between dose and effect, and the consequences of such effects, for non-human species.  The Commission does not therefore propose to set any form of “dose limits” with respect to environmental protection.  Importantly, the Commission will continue to develop its environmental protection framework by gathering and interpreting data in order to provide more comprehensive advice in the future, particularly with regard to those aspects or features of different environments that are likely to be of concern under different exposure situations (ICRP Publication 103, para. 370).”

     

    5) Section that begins on line 1383:

     

    Comment:

    There is no reference to the environment in this section on optimisation. The environment should be included in the optimisation process, as was stated earlier in the report (line 198 and 199):

     

     

    6) Annexes:

    Comment: The annexes are not referenced or referred to anywhere within the main body of the report.  A brief comment as to their existence and purpose should be placed in the introduction of the report.  Annex 1 starts with the following sentence (lines 1346 and 1347)

     The purpose of this annex is to summarize the key recommendations of ICRP

    1347 relevant to waste disposal. 

     

    A similar statement of purpose is missing in Annex 2 and 3, and would be appreciated by many readers.

     

     

    Comment by E. Vincent Holahan, Ph.D.

     

     

    Page 9, line 322:  The comment that radioactivity will decrease with time is very simplistic.  Some EPA calculations anticipate that the radiation exposure risk from a geological repository could peak tens of thousands of years into the future due to the decay of certain isotopes.  Should the background section address this issue or not?

     

    Page 21, lines 801-805:  Comment.  The Commission may wish to review and reconsider the risk constraint for occupational workers.  The Commission recommends a generic risk constraint of 2x10-4 per year which is similar to the probability of fatal cancer associated with an average occupational annual dose of 5 mSv.  The average occupational annual dose in the US is 1.1 to 1.2 mSv per year (NCRP Report 160) and these values are fairly stable for the years 2003 to 2006.  In addition, the fatal injury rate for US workers was 3.5 x 10-5 per year in 2009 (Bureau of Labor Statistics), a factor of almost 10 lower.  So why do we think 0.5 mSv should be the basis for the generic risk constraint for occupational workers?

     

    Page 32, lines 1262-1270:  Delete.

    Reason:  Unsure what the value of this paragraph is to the document.  The undisturbed geological repository does not contribute to a change in the biosphere.  In most instances, a change in the biosphere may have significant impacts on the flora and fauna (e.g., glaciations), but no impact on the repository.

     

    Page 35, lines 1366-1370:  Revise to read “Justification:  Any decision that alters the exposure situation should do more good than harm.  It is the process of determining whether a planned activity involving radiation is, overall, beneficial, i.e. whether the benefits to individuals and to society from introducing or continuing the activity outweigh the harm (including radiation detriment) resulting from the activity.”

    Reason:  The second sentence of the current version is confusing and could be confused with optimization.  Reducing existing exposure and reducing risk of potential exposure is more closely associated with the optimization of protection, not justification of a practice.

     

    Page 37, lines 1472-1478:  Delete.

    Reason:  The term collective dose is not used in the text of the document nor is it referenced elsewhere in the other annexes.

     

    Page 44-45, lines 1784-1799:  Delete.

    Reason:  The information duplicates the text in lines 1537 to 1548.  Conversely, delete lines 1537 to 1548 and refer to the text in annex 2 by reference.

     

    Page 45, line 1804:  Agree with previous comments about an editorial review.  For example, it is “design-basis” not “desing-basis”.

     

     

     

    Comment by Ruth E. McBurney, CHP

     

    General Comment:  The document provides a “broad brush” of concepts for consideration in radiation protection from high-level waste disposal in geologic repositories.  Even though the Scope states that “The report does not describe the disposal safety assessment in detail..,” some additional detail would have been beneficial.  For example, the assessment of such a facility for an extended period of time (10,000 years or more) should also address the potential for and consequences of climate change. 

    Lines 712-720:  The phraseology of this paragraph regarding the possible changes in regulatory standards after the period of control has ended is vague and confusing.  Some edits to clarify the intent of the paragraph would be beneficial.

     

     

    Comment by Bruce Napier

     

    I have no major problems with the draft ICRP report.  This report will be useful to most of the world, which is not all organized as we are in the US…

    In this respect I am going to disagree with Andy Wallo – I think that it is acceptable and reasonable to suggest that biota doses be included.  This is being done in US Environmental Impact Statements for other nuclear facilities, and for completeness and public acceptance, I think that it would be reasonable to include a short analysis showing (rather than simply stipulating – that just doesn’t work in today’s world) that there is no impact, and the ICRP approach provides a framework for doing that.

    I also noticed that the annexes are not specifically called out in the main text.  There are several places that a simple “(see Annex 2)” or something like that would help the discussions, particularly when definitions or advanced concepts are introduced.  This would help respond to comments like the one about “is risk a product of probability and detriment?” – which is explicitly explained on lines 1777-1778.

    There are quite a few various spelling errors that I have not mentioned because I assume a competent editor will eventually review the manuscript.

    The word “radiation” is probably missing after the word ‘ionizing’ in this section:

    463 Safety of Radioactive Waste Management details the long-term aspects of the safety

    464 objectives for disposal by requiring to meet the principle that “…individuals, society

    465 and the environment are protected from harmful effects of ionising, now and in the

    466 future, in such a way that the needs and aspirations of the present generation are

    467 met without compromising the ability of future generations to meet their needs and

    468 aspirations”

     

     

     

    Comment by Carl J. Paperiello, Ph.D.

     

    Background

     

    I based my review on this document on my previous experiences with the licensing of a high level waste repository at Yucca Mt. in the United States.  This project is apparently terminated by the Department of Energy (DOE).  However, there is an extensive body of experience with the development of regulations and the evaluation of the performance (i.e. probabilistic performance assessment) for this site which was conducted for a considerable number of years.  Furthermore, the outcome of litigation not withstanding,  a recent NRC report, NUREG-2107, August 2011, indicates that the site could have met the dose performance criteria in the US regulations than those proposed in the ICRP document.

    The basic performance criteria for this site is described in US Nuclear Regulatory Commission regulations at Title 10 Code of Federal Regulations Part 63.  Specific requirement for Post-Closure are found in Subpart L to that regulation.  These regulations prescribe individual dose limits of 0.15 mSv/year for the first 10,000 years and 1 mSv/year for the period after 10,000 years, but within the period of geological stability.  These dose limits include human intrusion.  The rule prescribes a stylized procedure for evaluating human intrusion by drilling using current US drilling methods.  There are also separate groundwater protection standards for the first 10,000 years.

    This area of the US in which Yucca Mountain is currently very arid and has been such for the past 1000 years.  It was somewhat less arid during the first millennium of the Common Era.  It is also a region that has experienced igneous activity and seismic activity in the past several million years.  The regulations address both of these issues.  Regulations require addressing the consequences of climate change. 

    Comments

    Line 321-323 … radioactivity will decrease with time.

    This is true only for separated high level waste from reprocessing.  In the case where spent fuel for an LWR is disposed of without reprocessing, there will be an in growth of uranium daughters.  After several hundred thousand years, these daughters are sufficiently high to require evaluation.  This point is important because the ICRP document appears to have an underlying premise that at some distant point the waste decays to levels approaching background.

    Lines 921- 938  ….For the severe natural disruptive events not taken into account in the design-basis evolution. 

    The document does not specify what events are to be considered design basis and which ones considered “severe natural disruptive events not taken into account in the design-basis evolution.”  If this is based on probability, this should be specified.  Further, it is not clear that these “severe natural disruptive events” are known or unknown.  If they are not known with a certain degree of quantification it is not clear how one could model them in a performance assessment.  If they are known, why are they not in the design basis?

    Line 279 and 1004:  “No Oversight” Period

    The ICRP document does not specify how long this period is.  The US rule specifies “during the period of geological stability.”  The ICRP document appears to assume that at some point the waste decays to a level that the dose criteria could be met with any scenario so there is an indefinite period of performance assessment.  The current US evaluation by both the DOE and the NRC are 1 million years.

    Line 1528: Risk Constraint

    Is Risk  the probability per year of an unattended event multiplied by the dose consequence of the event?  Lines 1533 and 1534 imply this but Lines 1534 and 1535 imply the risk constraint is just the dose constraint.  Other places in the document “risk constraint” is used and it is not clear whether it is a risk related dose value or a probabilistic dose (dose consequence of scenario X probability of scenario).   In US performance assessment it is the latter.  It is also given with a mean value and a range.

     

     

    Comment by Frank L. Parker

    I have to assume that this document will be read by people interested in waste disposal and who are not familiar with the many documents of the ICRP and their detailed information on radiological protection. Having listened to such people for many years I am familiar with some of their misunderstanding of the ICRP process and its recommendations. In general, I think this is an excellent document but it would have greater impact if it were more specific for the additional audience it will have.

                                                                Detailed Comments

     L. 199 “Optimization of protection is the central element…”  Not so, instead use justification, limitation and optimization!

    L.224-228 “The scientific basis for dose and risk assessments at very long times into the future then becomes questionable and the strict application of numerical criteria may be inappropriate. Hence, the annual dose constraint of 0.3 mSv in a year is to be used for the sake of comparison of options rather than as means of assessing health detriment.” Though this statement is clear to the professionals in the field, it is still not accepted in many other disciplines-I assume they are unaware of this statement. Their understanding would be complete if an example could be given such as “It is inappropriate and inaccurate to state in the millionth year, the dose should be limited to 0.3 mSv.”

    L. 270-273 “(j) ICRP recommends that dose or risk estimates derived from these exposure assessments should not be regarded as direct measures of health effects beyond  timescales of around several hundred years into the future. Rather, they represent indicators of the protection afforded by the geological disposal system.” Though this statement is clear to the professionals in the field, it is still not accepted in many other disciplines-I assume they are unaware of this statement. Their understanding would be complete if an example could be given such as “It is inappropriate and inaccurate to state after several hundred years that the dose should be limited to to a fixed number.”

    L. 380-389 “(10) In the case of geological disposal, the occupational exposure of workers and the exposure of the public are managed in accordance with the ICRP system of  protection. The main protection issue dealt with in this report concerns exposures that may or may not occur in the far future. Any corresponding estimates of doses to individuals and populations will have growing associated uncertainties as a function of time due to incomplete knowledge of the future disposal system behaviour, of geological and biospheric conditions, and of human habits and characteristics. Furthermore, due to the long timescales, verification that protection is being achieved cannot be expected in the same manner as for current discharges since knowledge of the disposal facility may eventually be lost and oversight may be absent.” The highlighted words are all qualitative and could mean very different things to different people. Should be more specific.

     

    L. 319-328 “The goal of a geological disposal facility is to achieve the isolation and  containment of the waste and to protect humans and the environment for time scales  that are comparable with geological changes. At great distance from the surface, such changes are particularly slow and, at the same time, radioactivity will decrease  with time. Additionally, if a site is chosen in an area with no known natural resources, the potential for human intrusion will be limited. Finally, a properly chosen geological  formation would assure stable chemical conditions for the waste. Further, it would  attenuate and slow down any releases of radionuclides. In this context „distance‟ can  imply horizontal or vertical distance as, for example the case of a disposal facility  sited deep within a mountain.” The highlighted words are all qualitative and could mean very different things to different people. Should be more specific.

     

    L. 750-752 “Waste management and disposal operations are an integral part of the practice generating the waste. It is wrong to regard them as a free standing practice that needs its own justification.“ Important insight-needs to be highlighted.

    L. 1472-1478 “ICRP Publication 103, para. 159: For the purpose of optimisation of radiological protection, predominantly in the context of occupational exposure, the Commission has introduced collective dose quantities (ICRP Publication 26). These quantities  take account of the exposure of all individuals in a group over a given time period or  during a given operation executed by this group in designated areas. Collective effective dose is not intended as a tool for epidemiological studies, and it is inappropriate to use it in risk projections.” Though this statement is clear to the professionals in the field, it is still not accepted in many other disciplines-I assume they are unaware of this statement. The understanding would be complete if an example could be given such as it is inappropriate and inaccurate to state “There will be 40,000 deaths from Chernobyl due to the collective dose multiplied by the deaths per dose incurred.”

    L. 1556-1580 “It also  recognises that these objectives may be met in different ways, that ionising may be  only a minor consideration – depending on the environmental exposure situation and that a sense of proportion is necessary in trying to achieve them (ICRP 1559 Publication 103, para. 361).”Important insight-needs to be highlighted.

     

    Comment by Chris Whipple

     

    Line 712: “The cessation of direct oversight of the site will not occur before tens to hundreds of years after the start of operations. It is not possible to specify the criteria that will be used by the people making decisions at that time.”

     

    Comment: It is hard to think of tens to hundreds of years as the far distant future or to think that criteria for decision-making will be so different from those used today. It is important to distinguish between the cessation of direct regulatory oversight versus the period of applicability of regulatory standards. The phrase “not possible to specify the criteria” in the above confuses the two.

     

    976 (58) For longer time periods, in case oversight has disappeared, the occurrence of human intrusion cannot be totally ruled out. Therefore, the consequences of one or more plausible stylised intrusion scenarios should be considered by the decision maker to evaluate the resilience of the disposal facility to potential inadvertent intrusion. Any estimates of the magnitude of intrusion risks are by necessity dependent on assumptions that are made about future human behavior. Since no scientific basis exists for predicting the nature or probability of future human actions, the Commission continues to consider not appropriate to include the probabilities of such events in a quantitative performance assessment that is to be compared with dose or risk constraints (Publication 81). If recognized at the time an intrusion occurs, it would be treated as an emergency exposure situation or an existing exposure situation depending on the severity of the related disturbance.

     

    988 (59) The Commission wishes to emphasise that the dose criteria specified in  Publication 81 for human intrusion only apply to near surface disposal. In case of geological disposal, intrusion means that many of the barriers which were considered in the optimization of protection for the disposal facility have been by-passed. Since a future society may be unaware of the radiation risk associated with such events, any protective actions required should be considered during the development of the disposal system. Therefore the dose or risk constraints recommended by the Commission for the application of the optimization of protection in geological disposal do not apply to inadvertent human intrusion.

     

    Item 58 (line 976) ends with “If recognized at the time an intrusion occurs, it would be treated as an emergency exposure situation or an existing exposure situation depending on the severity of the related disturbance.” This seems to mean that if doses are higher than allowed by applicable dose limits, then emergency dose limits will apply. The last line of item 59 (line 988) seems to take an opposite position: “If recognized at the time an intrusion occurs, it would be treated as an emergency exposure situation or an existing exposure situation depending on the severity of the related disturbance.” The logic of item 59 seems to be a stretch to me. I understand the logic to be that in the far future, society is unaware of the repository and its risk, so that passive protective features need to be part of the design. But if those passive features are by-passed, dose limits do not apply. I do not follow the “therefore” in the last sentence. This suggests that if the passive design features do not work, that is okay.

     

    Section 4.4 Optimisation and Best Available Techniques

     

    What is meant by optimization would be helped by some examples; the principles are clear but their application is not. It would also be helpful to discuss how optimization is compatible with best available techniques.

     

     

    Comment by Andrew Wallo

     

    General Comments:

    The ICRP does an excellent job in identifying issues and difficulties associated with establishing and implementing requirements and programs to provide for protection of the public when disposing of waste that will be hazardous far into the future.  The authors are to be congratulated for their efforts; however, too much emphasis may have been placed on maintaining consistency with processes used to provide protection during the operations of normal practices rather then giving due consideration to different approaches that might be warranted because of the unique factors affecting long-term geologic disposal.  This report, in some places, strains to force fit existing radiation protection principles and radiation protection procedures and processes developed largely for operation activities or practices.  The ICRP should consider more significant changes to address radiation protection needs unique to geological disposal.  For example the use of annual dose limits and constraints is useful for operational facilities and practices but the use of lifetime dose criteria may be more appropriate for applications where the concern is chronic exposure over long periods.   The recommendation that age specific annual doses be computed for events hypothesized to occur a thousand years or more in the future will add little to support making a decision about whether the performance of a geological disposal facility will be acceptable.

     Throughout the report, the ICRP seems to be straying outside of radiation protection space and into regulatory and project management space.  This is fine to the extent this is done to illustrate how the ICRP principles and recommendations should be implemented,  but the ICRP should make it clear that these illustrations are not radiation protection recommendations but simply illustrations to help explain how their recommendations can be integrated into regulation and management functions.  Project management and regulatory recommendations should be left to the operators and the regulators – ICRP should not give the appearance of foreclosing on their implementation of alternative approaches.   For example figure 1 on page 15 and the similar figure in the executive summary should be titled something like “Illustration of possible Disposal Facility life phases and relevant analysis process.”  Other examples are noted in the specific comments below (e.g., comment for Page 5, paragraph (d).

    The ICRP should include more discussion about the importance to knowledge transfer and maintenance functions far into the future.  In the longer term, it is only the knowledge of the disposal system and why this generation created it that will help future generations take appropriate actions to either maintain it and avoid inadvertent intrusion or take other actions they deem appropriate based on their assessment of the risks and benefits.  The National Academy of Public Administration (NAPA) in the June 1997 report “Deciding for the Future: Balancing Risks, Costs, and Benefits Fairly Across Generations” noted in discussing the “Chain of Obligation Principle” :

     

    “We recognize the existence of a “rolling present,” where the future becomes the present. Like the “chain of obligation” of parents to their children, there is a similar chain from one generation to the next. This principle allows for incremental decision making. According to this strategy, the current generation should provide the next succeeding generation the skills, resources, and opportunities to cope with any problems the current generation bequeaths.” 

     

    The ICRP needs more emphasis on records and knowledge transfer to ensure future generations can make informed decision regarding disposal sites created by this generation.

     

    Specific Comments:

    Page 5, paragraph (d), lines 194 to 202.  The paragraph staes:  “These ICRP recommendations describe the radiological concepts and criteria that ought to be used by both the designer and/or operator of the facility and the regulator…Optimisation of protection is the central element of the step-wise construction and implementation of a geological disposal facility. It has to cover all elements of the system, including the societal component, in an integrated way. Important aspects of optimisation of protection must occur prior to waste emplacement, largely during the siting and design phase.”   This should be revised to reflect the fact that the regulator in developing standards for HLW disposal may choose to address optimization as part of the development of the standard such that the designer and operator of the facility need only comply with the requirements of the standard as has been done in the United States. Although the statement above recognizes the regulator, it goes on to imply the designer and operator must apply the ALARA process – if the regulator decides to implement Optimization through the standard that should be acceptable as well.  The ICRP should avoid dictating how the governments insure implementation the principles are met and focus on the radiation protection.

    Page 6, paragraph (e):  several sentences in this paragraph appear inconsistent.  The sentence beginning on line 214 indicates the 0.3 mSv per year dose constraint should be used without weighting of doses in the far future. Suggesting it is a performance objective for the disposal system far into the future. They then go on to correctly recognize the flaws in using dose constraints beyond a few hundred years including the fact that the detriment may no longer be important to society and appropriately concluding that the value of using numeric criteria far into the future is questionable.   They finally conclude that the 0.3 mSv in a year value is only useful for comparing alternatives not as a means of assessing health impacts.  This leaves the reader confused.  The ICRP should be very clear that they are not recommending the use of 0.3 mSv in a year as a performance objective for the site far into the future (e.g., beyond 1000 years).  Paragraph (j) on page 7 seems to support such a position but again falls short of clearing stating that comparison of quantitative dose estimates to numeric performance objectives in the far future for compliance purposes is not appropriate.

    Page 8, Table:  This table furthers the implication that the numeric criteria (0.3 mSv in a year) should be employed as a performance objective far into the future by applying footnote 2 to the no oversight column.  For this column it should be recognized that application of this numeric criteria beyond a thousand or so years as a performance objective for compliance is not appropriate.  Note for here and elsewhere, please clarify that the risk constraint is equal to the Probability of the event times the public health risk from the associated hypothetical exposure.

    Page 13, paragraph (16), line 465.  The Joint Convention does not require or obligate signatures to meet the subject principle.  Furthermore, I do not agree that the subject principle is consistent with the ICRP Publication 77 stated recommendation.  The IAEA statement is a thoughtful and clear statement that indicates an expectation that the need of both the present and future generations need to be considered and address fairly.  The ICRP statement on the other hand is a simplistic statement that can be interpreted to imply radiation protection requirements applicable to present day persons are appropriate to apply to generations far into the future which for the reasons stated throughout this report (see paragraph (e) and elsewhere) is not appropriate.  In assessing how radiation principles should be applied to future generations far into the future, the ICRP should review the recommendations in the previously reference NAPA study which included the following intergenerational protection principles:

    Trustee Principle - Every generation has obligations as trustee to protect the interests of future generations.

    Sustainability Principle - No generation should deprive future generations of the opportunity for a quality of life comparable to its own.

    Chain of Obligation Principle - Each generation’s primary obligation is to provide for the needs of the living and succeeding generations. Near-term concrete hazards have priority over long-term hypothetical hazards.

    Precautionary Principle - Actions that pose a realistic threat of irreversible harm or catastrophic consequences should not be pursued unless there is some compelling countervailing need to benefit either current or future generations.

     

    Page 14, Paragraph 20, line 509 - 512:  The statement that the direction of change cannot be predicted is questionable.  Given the last few hundred years or so of evidence seems to clearly support a conclusion that although there maybe sporadic  ups and down the direction will be positive.  Suggest revising to read something like:  “…Likewise, the ability to cure or mitigate induced health effects may change in the future.  It is not possible to make any prediction regarding the magnitude of the change but the direction of these changes are likely to be positive.”  Given that, it is not clear how ICRP can conclude that using the current understanding of health effects as the basis for decisions affecting the distant future will necessarily not cause more harm than good.   What is the justification for spending sparse resources today to protect against numeric dose constraints to hypothetical persons 1000s of years into the future.

    Page 31, Paragraph (83), lines 1215 to 1228:  This is an unnecessary requirement that will not aid in the decision-making process and should be revised to recommend a single dose calculation that is representative of all age groups over their lifetimes.   Before making recommendations that increase the burden and costs of analyses, the ICRP should evaluate data quality objectives of the analysis.  The purpose of modeling doses hundreds and thousands of year into the future is to assess the performance of the disposal system and as the report indicates is not to try to predict or assess future health impacts to individuals a thousand years hence!   Given that goal, what value is it to the decision maker to see dose calculations for infants, children and adults?  Given the magnitude of uncertainty in long-term projections of site performance, the uncertainty of the dose estimates and associated dose factors and even the actual risk in the future associated with estimated doses, requiring detailed age specific analyses is simply unnecessary – it in no way will contribute to the decision-making process.  As also noted in the report the estimates are stylized hypothetical  representations of what might happen.  The assessments comparing alternatives far into the future need only assess doses to a single representative person.  Furthermore, because the goal is to provide protection from long-term chronic exposure it would be far more useful, as noted, in lines 1226 to 1228 to assess lifetime doses or risk – one must seriously question the value of using annual dose constraints for this analysis and applying them to multiple age groups.  Although annual dose limits and constraints are an essential tool in regulating normal practices and operations, they are not necessary for assessing the performance of a geologic disposal system.

    Page 32, Section 5.2, beginning on line 1230:  This section seems totally unneeded.  To suggest that disposal in a geological repository poses sufficient risk to ecosystems such that analyses using publication 108 data sets is warranted is not a responsible use of our resources.  There may be some potential for environmental impacts associated with the physical effects in the construction and operation of the surface facilities.  As observed in paragraph (85) these will be assessed as part of the environmental assessment process and are not radiological protection issues.  Although surface disposal of radioactive waste can conceivably produce a radiological effect that might impact the biota, review of assessment conducted to date have not been indicative of any long-term significant impact so given the extreme isolation provided by geological disposal, ICRP should recommend that such analyses are unnecessary.  In paragraph (87) the report expresses concerns associated with biosphere changes.  Over the time periods involved the biosphere changes will occur whether the repository exists or it does not exist.  The impacts on the biota and the environment from these biosphere changes will be far more significant than any associated with the repository.

    Page 35, line 1388:  The last sentence  in this paragraph should be moved to be the first sentence in the next paragraph (Application of Dose Limits) as it is really talking about dose limitation under which Optimization works.  Also over the years we have seemed to develop descriptions of the three principles of protection that never seem to address their interrelationship or overall goal.  Many years ago I recall a presentation that described them as follows:  Justification basically ensures that public welfare is considered in the use of radioactive materials – before approving their use for a specific action it must be determined that there is a net benefit.  Optimization is a process by which we ensure those uses are conducted in a manner that has the most benefit or least detriment to society that is reasonable to achieve – it focuses on society as oppose to individuals.  Dose limitation is intended to protect the individual – it ensures that no individual or group of individuals will be put to a disproportion risk to benefit society.   The three work together to ensure practices employing radiation are overall beneficial without causing undue burdens or risk to society or specific individuals. 


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