|These comments are provided on behalf of the Nuclear Energy Institute (NEI). NEI is the U.S. nuclear energy industry’s policy organization. NEI is a member of the World Nuclear Association Working Group on Radiological Protection (WNA-RPWG) and participated in the development of the WNA-RPWG comments submitted to the ICRP on 23 December 2004 regarding the draft ICRP Recommendations. The following additional comments are intended to reinforce supplement the WNA-RPWG submittal.
The current ICRP framework for radiological protection has proven to be effective and has supported safe uses of nuclear technologies that benefit every aspect of our lives, such as generating electricity in a manner that helps reduce global warming, diagnosing and treating disease, developing new medicines, enhancing food safety and abundance, creating fresh water supplies, fighting crime and terrorism, protecting the environment, and improving public safety. Any major revision to the existing ICRP radiological protection framework should be undertaken with great care and should arise from an expectation of substantively improving radiation safety without compromising the vast contributions made by nuclear technologies to our quality of life. The rationale for proposed changes should be compelling and clearly justified, for example, in terms of reflecting new scientific developments, solving defined problems, and/or reducing unnecessary complexity or cost.
The draft ICRP recommendations include some proposals that entail significant changes to the existing radiological protection framework, yet they lack a compelling rationale or clear justification. Some of the proposals will undoubtedly lead to increased complexity and cost if carried out in national regulations, while at the same time, it is not apparent how they will produce a substantive improvement to the protection of people or the environment. By ICRP’s own account, much of the supporting information needed to better understand and evaluate the proposals is still under development or has only recently been made available for review in the form of “foundation documents.”
We view the draft recommendations as a work-in progress, rather than as near-final product. We commend the ICRP for making the full set of draft recommendations available at this stage of development to allow for early engagement by a very broad range of stakeholders –ostensibly, at a time when proposed concepts and methods remain open to discussion and debate. We support ICRP in its plans to publish a series of draft foundation documents for review and comment and to reflect the feedback into a revised version of the draft recommendations, as well as in finalizing the foundation documents. We strongly encourage ICRP to then make the revised draft recommendations, along with the final editions of the foundation documents, available on its web site for an additional period of consultation, so that stakeholders can provide comments based on a more complete understanding of the ICRP proposals.
Some significant updates to the scientific basis for radiological protection are expected to be published in the near future and, to the extent practical, should be reflected by the ICRP within the final version of its general recommendations. Among these are expected reports from the Radiation Effects Research Foundation (RERF), National Research Council Committee VII on the Biological Effects of Ionizing Radiation (BEIR VII), International Agency on Research on Cancer (IARC) international study of radiation workers, and the next major report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). In particular, the ICRP should use such information to better clarify its explanation of how it has addresses the “challenges associated with information on cellular adaptive responses, the relative abundance of spontaneously arising and low dose-induced DNA damage and the existence of the post-irradiation cellular phenomena of induced genomic instability and bystander signaling.”
Dose Constraints and Dose Limits:
The rationale presented by the ICRP for several significant changes to the general system of protection is unclear and unconvincing –in particular, in regard to the application of dose limits and dose constraints.
In the draft recommendations, the ICRP has essentially reversed the roles of dose limit and dose constraint, as previously described in ICRP Publication 60 and following ICRP reports. Dose constraints are now defined as the “fundamental level of protection.” If implemented in regulation as proposed in the draft recommendations, dose constraints will become the limits on dose, which will reflect more restrictive values than are currently employed.
This is contrary to ICRP’s conclusion that overall risk has not increased (in fact, it has slightly decreased) and that the ICRP’s present dose limits continue to be valid. Further, this unjustified reduction in limitation on dose will create significant additional burden on regulators and operators (in terms of cost and complexity) without any foreseeable benefit to the health and safety of workers or the public –due primarily to the practical need to maintain a margin between actual dose and a mandatory constraint to prevent a “statutory offence.”
In effect, occupational dose from a source of exposure would be strictly limited to some value less than 20 mSv per year and public dose would be limited to less than 0.3 mSv per year. The flexibility contained within the current dose limits of 100 mSv, averaged over 5 years, not to exceed 50 mSv in a year (Occupational) and 1 mSv per year from all man-made sources (Public) would be lost. The adverse impacts arising from the ICRP proposal on dose constraints will be particularly acute for situations where workers transition between multiple facilities during the course of a work-year (e.g., within the nuclear power industry) and facilities where multiple sources are routinely employed that potentially result in the incidental exposure of specific groups (e.g., practitioners, patients, and students at medical-teaching-research facilities).
We strongly urge that dose limits be reinstated as the fundamental level of protection with dose constraints remaining as an important tool supporting optimization.
Protection of the Environment:
We welcome ICRP’s initiative in pursuing a science-based approach and methodology for addressing the “conceptual gap” in the current ICRP radiological protection framework. We continue to believe that the current system for the radiological protection of human is, in fact, protective of non-human species in the environment. This belief arises from the stringency and robustness of the regulations and operational controls for releases, as well as the documented results of the programs for monitoring the environs. We encourage ICRP to maintain focus on what is needed to satisfactorily resolve the defined problem without creating an unnecessarily burdensome and complex new framework.
In addition, the scope and level of detail of the information presented in the draft recommendations is seen as premature and inappropriate for the eventual general recommendations document that this draft will become. Much of the discussion is speculative and anticipatory and it represents more of a progress report and work plan, rather than a practical set of recommendations. We suggest that the final document reflect the actual current published recommendations of the ICRP (e.g., as expected in pending reports), as they exist at the time at the time of publication.