Optimisation of radiological protection

Draft document: Optimisation of radiological protection
Submitted by Shigeo UCHIDA, Radiation Safety Research Center National Institute of Radiological Sciences
Commenting on behalf of the organisation

Optimisation document is reviewed by Health Physics and Environment (Technical Division in Atomic Energy Society of Japan) Chairperson: Shigeo UCHIDA General Comment The five foundation documents provide no replies to the numerous comments(200 reports)@submitted in response to the previous yearfs consultation (no replies are given in these documents). The ICRP should provide answers in a specific form, not in the form of the five foundation documents, at least to numerous common comments such as constraints and the concept of intervention. Holding an international conference to give an explanation about the results of the consultation for comments is crucial. The ICRP should make clear what parts of the documents have been changed and what parts are left unchanged in relation to the previous recommendations; and documents otherwise things will get mixed up. Specific Comments 1-1. Title Endpoint to optimization for exclusion and exemption 1-2. Text (p7 at the end of the 1st paragraph) gExclusion or Exemption levels should not, defacto, be considered as relevant endpoints to optimisation.h (p25 Paragraphi56j) gThe exclusion levels, as defined in the 2005 Recommendations, should not be considered as a relevant endpoint to optimisation.h It can be seen from these descriptions that 1) endpoint to optimization should be higher than exemption level or exclusion level in ICRP 2005 draft report. On the contrary, it can be also understood that 2) this guidance requires the further optimization to achieve an annual individual dose lower than the exemption level or the exclusion level. If the meanings of these descriptions are above 1), it can be recognized from the sentence just before the description. If they are 2), it would be required to reduce the annual dose to lower than the exemption level or the exclusion level. Since this is not consistent with past ICRP recommendations, the descriptions of gExclusion or Exemption levels should not, defacto, be considered as relevant endpoints to optimisationh and gThe exclusion levels, as defined in the 2005 Recommendations, should not be considered as a relevant endpoint to optimizationh should be deleted. 1-3. Reason (ICRP 1990 recommendation, paragraph 287) gThere are two grounds for exempting a source or an environmental situation from regulatory control. One is that the source gives rise to small individual doses and small collective doses in both normal and accident conditions. The other is that no reasonable control procedures can achieve significant reductions in individual and collective doses.h (ICRP 2005 draft report, paragraph 24) gThere are many sources for which the resulting levels of annual effective dose are very low, or for which the combination of dose and difficulty of applying control are such that the Commission considers that the sources can legitimately be excluded completely from the scope of its Recommendations.h (ICRP 2005 draft report, paragraph 26) gIn order to avoid excessive regulatory procedures provisions can be made for granting exemptions in cases where it is clear that further controls are unnecessary. The regulatory act of assessing the situation and granting an exemption is, in itself, a form of authorization and the material that is exempted remains subject to the system of protection, although without further regulatory control.h These descriptions indicates that it is not reasonable to control any sources lower than exemption level or exclusion level. It is not absolutely consistent with the past ICRP recommendationfs design to require further optimization to achieve lower individual dose than the exemption level or the exclusion level. 2-1 Title. Figure 6 in Appendix A2 2-2 Text The figure 6 and a sentence gFigure 6 provides a simple graphical representation of these examples.h just before the figure in Appendix A2 should be deleted. 2-3. Reason In the paragraph after the Fig. 6, there are descriptions of gThe Commission feels that our current state of knowledge, and our ability to model populations and exposure pathways can appropriately contribute to decision-making for exposures predicted to occur over a time period covering a few generations. Beyond such time frames, the Commission recommends that predicted doses should not play a major part in decision-making processes.h This is not consistent with especially the right side example in Fig.6. To emphasis the example against the ICRP recommendations may lead to occur some confusion.