|Comments on the ICRP TG report entitled "Application of the Commission''s Recommendation for the Protection of People in Emergency Exposure Situations"
The ICRP TG report has been reviewed by the working group in the Central Research Institute of Electric Power Industry (CRIEPI).
1. General comments
This report is intended to serve as a guide for the protection of people against radiation in emergency exposure situations, and is reasonable and convincing because the principle of setting different indices (effective dose, equivalent dose, and absorbed dose) as reference levels and their values in accordance with situations is described therein. However, the relationship between these reference levels and the intervention level, which was explained in the previous report (Publication 63), is unclear, and readers may be confused.
It is understandable that ''malicious uses of radioactive materials'' and ''potential satellite crash'' are considered as possible emergency exposure situations and are introduced in the plan. However, it is not appropriate to discuss the measures for the optimization for the above two situations and for accidents at nuclear facilities using the same scheme. The consideration of security is also required.
2. Specific comments
1) Compatibility with Publication 63
Rules for using the reference level, which should be set in the range of 1-20 mSv and 20-100 mSv depending on the case, should be explained as guidance with a description of the recommended intervention levels in Table 3 of Publication 63.
In Publication 63, entitled "Principles for Intervention for Protection of the Public in a Radiological Emergency," several important intervention levels are recommended; the intervention level for the administration of stable iodine and evacuation shorter than one week is 500 mSv and that for relocation is 1,000 mSv. On the other hand, in this report, the intervention level is considered as a useful tool, but the reference level is typically identified on the basis of the new ICRP recommendation (Publication 103), that is, the reference level between 1 and 20 mSv is used to judge the optimization of protection strategies in the long term after the occurrence of emergency exposure, i.e., for existing exposure situations, and that between 20 and 100 mSv is used to judge the residual dose in emergency exposure situations. The values in Publication 63 and in this report are one order of magnitude or more different, which cannot be explained by the difference between the intervention and reference levels discussed in this report only.
2) Understanding of ''malicious'' and ''satellite crash''
A measure against ''malicious events'' is to keep radiation sources under appropriate control so as to prevent their malicious use, which is considered to be quite different, in particular, from the principle of optimization in the planning phase described in 2.3.3 and 2.3.4. The difference between their principles should be described clearly and accurately.
Regarding ''malicious,'' it is stated in paragraph (36) that "The exceptions are extreme malicious incidents and some high consequence, low probability emergencies (cf. 2.3.4)". In contrast, in paragraph (92) in 2.3.4, it is stated only that "The level of detail of optimization of the response plan should be commensurate with the needs of the situation. This is a matter for national authorities to decide. In general, events with the potential to result in widespread, high levels of contamination and events that are relatively likely to occur require more detailed planning than very low probability events or events whose consequences are expected to be limited."
Moreover, a ''satellite crash'' is considered as an example in paragraph (2): "The Commission defines radiation emergency exposure situations as ''situations that may occur during the operation of a planned situation, or from a malicious act, or from any other unexpected situation and require urgent action in order to avoid or reduce undesirable consequences''." However, because ''satellite crash'' is unsuitable for the principle of optimization in the planning phase, there is no need to list such an example that may cause misunderstanding.
3) Editorial comments
p. 15 (15) l.1: "an" and "as" should be switched.
(Correct) ... the situation as an emergency...
p. 16 (16) l.10: "be" should be removed.
(Correct) ... it is not possible....
p. 42 2.4.3 (108)-(114): "2.4.3 Stakeholder involvement in planningEis left undeleted, and a sentence in (108) is repeated in (111).