|ARPS Comments on the ICRP Recommendations
The ICRP recommendations cover a range of important issues relevant to the philosophy underpinning, and the implementation of, radiation protection regimes. In general there has been an evolution of thinking on many of these issues, which has been part of the increased understanding of the effects of ionising radiation.
The following comments come from the Australasian Radiation Protection Society (ARPS) and mainly relate to the implementation issues, but mention is also made of the work on the scientific basis of the effects of ionising radiation. The comments from ARPS are as stated below.
1. ARPS supports the overall objectives of the recommendations as providing an appropriate standard of protection without unduly limiting beneficial applications.
2. The Society also welcomes the improved scientific understanding of the effects of radiation that is evident in the new recommendations and notes that considerable effort has occurred to translate these into a range of new radiation and tissue weighting factors, which can be applied in a straightforward way. No significant difficulty is foreseen in implementing the revised weighting factors or the risk coefficients.
3. ARPS furthers welcomes the evolutionary nature of the recommendations since it recognises that major changes would require considerable effort and investment to upgrade well established radiation protection regimes.
4. The Society notes, however, that no conclusion has been reached on the impact of the bystander effect and that no change has occurred on the conclusions on the likelihood or otherwise of adaptive response and its potential impact on the LNT hypothesis.
5. One significant proposed change is the introduction of source related dose constraints, which now hold a much more prominent place in protection of people. However we note that there are several areas where the description of the use of these constraints appears confusing and subjective. In particular, constraints are given which are higher than dose limits and which themselves incorporate the dose limits for both occupational and public exposure. Some further clarification of the relationship of dose limits to constraints is necessary.
6. In addition, the dose constraints talk about action that should be associated with them, but this is now rather subjective (from high need to low) and does not have the clarity that was previously associated with the ALARA concept.
7. Concern is also expressed by ARPS that the dose constraints, which are lower than the limits, will become de facto limits and that the approach of allowing national authorities the ability to adjust these constraints will lead to ratchetting down of the constraints and inconsistent application of them. It also runs contrary to the urgent need to ensure international consistency in application of radiation protection standards so that we arrive at a system of internationally agreed levels for waste management, transport, commodities and emergency response, which are vital to the operation of the nuclear industry.
8. ARPS also notes that the difference between practices and interventions has become blurred and considers that this issue should be further reviewed.
9. The use of collective dose in a public exposure context can be misinterpreted, particularly where small and very small exposures over large populations predict significant numbers of fatalities. Hence the discontinuing of this measure is welcome, although there still needs to be a way to distinguish levels of dose and numbers exposed for different scenarios. However collective dose was a useful concept in occupational exposure and ARPS would still propose that this be continued. The replacement by a dose matrix approach is potentially confusing and more information will be needed on how this might be implemented.
JUSTIFICATION AND OPTIMISATION
10. Justification seems to have been downgraded as a clear process and made a decision for national authorities. While ARPS recognises that dialogue between users and national authorities will always be needed, the present proposal seems to have left the process without guidelines.
11. The Society welcomes the recommendation to consult stakeholders in any decision process. This is the right approach but will need experience in applying the concept and will require better processes for communication of the range of issues, both technical and non-technical associated with the decision.
12. Optimisation is an important part of any radiation protection regime and requires consideration of a range of issues, both quantitative and qualitative. ARPS, however, considers that the ALARA procedure had much value and was becoming a sophisticated and well understood process. Its replacement is less clear in application and does not define the nature of the judgements that will need to be made. We can find no compelling reason for moving away from the established process.
13. The introduction of an emphasis on safety culture is welcomed as high awareness of safety and methods of safe working is a key defence against accidents and a method of ensuring lower exposures. However the association of safety culture only with dose reduction is too limited.
PROTECTION OF THE ENVIRONMENT
14. The move towards a process for protection of the environment is a reflection of the requirement by society to protect the environment, the evolution of thinking on radiation protection methodologies and a recognition of the need to avoid the damage that has been caused to environments through uncontrolled discharges and practices in the past. However the current status of this assessment process is not sufficiently well defined to be easily adopted and more effort will be needed to develop the scientific understanding of the method and to provide guidance in its implementation. As currently described it has the potential for over-regulation.
15. Treating the risk associated with radiation in the same way as other hazardous substances was a stated aim of previous recommendations. ARPS contends that the current recommendations have downplayed the derivation and comparison of risks from radiation exposure compared to other hazards and thus have the potential for singling out radiation as a more hazardous process. We support further work on putting radiation risks into context, particularly with other potentially carcinogenic agents, which are known not to have thresholds.
16. The radiation protection regime applies for exposures above natural background but does not recognise that this varies widely from place to place, with no discernable differences in cancer rates, and that these variations often swamp the additional exposures that are the subject of the protective actions.
ARPS welcomes the enhancements of the scientific basis for radiation protection set out in these recommendations. However it considers that the proposals for change to radiation protection regimes are premature pending work to understand how these might alter the current system of implementation. It is proposed that:
1. The ICRP should give high priority to developing guideline documents that look at the practical issues in implementation of these recommendations.
2. The published recommendations should acknowledge that there is a need for documents that will discuss how the recommendations might be implemented.
3. The IAEA should be asked to consider how these recommendations might cause a revision to the International Basic Safety Standards and the associated Safety Standards which are the basis of many national regulatory systems.
4. The goal of these additional documents should be to arrive at a simpler and easily applicable system of radiation protection that can have wide international acceptance and can be applied in an internationally consistent manner.
5. ARPS contends that there should be no major change made to the practice of radiation protection by national authorities until these guideline documents and safety standards have been issued, after review by national agencies.