Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident


Draft document: Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident
Submitted by Kakutaro Kauchi, None
Commenting as an individual

1.With respect to the reference level for the people living in long-term contaminated areas following the emergency response (Main Points, fourth line 56, para 80, etc.):

1-1.(Line 126-128,546-552) "Stakeholder involvement" emphasized by ICRP recommendations includes setting up, reorganizing and canceling evacuation zones, formulating basic policies for the Child and Disaster Relief Support Act, etc.. However, the Japanese government arbitrarily and partially operated these ICRP recommendations, and did not adopt the reference level (selected from below 1-20 mSv per year, typical value is 1 mSv) of ICRP for existing exposure. The right of people to participate in policy making on exposure protection should be guaranteed.

1-2.(Line 114-121,para80 line826-) As the reference level for the recovery process, "the reference level should be selected within or below the band of 1 to 20 mSv per year for existing exposure situations———, and there is generally no need for the reference level to exceed 10 mSv per year. The objective of optimization of protection is a progressive reduction in exposure to levels on the order of 1 mSv per year."  But in this sentence, the term of "no need" is vague. Therefore, it should be recommended that the term of "no need" be deleted, and that the reference level generally should not exceed 10 mSv per year. And the objective of optimization of protection is a progressive reduction in exposure to the reference level of 1mSv per year.

1-3.(Para 80 Line 830-847) The Publication 111(o)(para50) states that "Past experience has demonstrated that a typical value used for constraining the optimization process in long-term post-accident situations is 1 mSv/year. National authorities may take into account the prevailing circumstances, and also take advantage of the timing of the overall rehabilitation program to adopt intermediate reference levels to improve the situation progressively."
However, the Japanese government did not adopt the above reference level adopted by the Chernobyl authorities, so the Fukushima experience seems to have eased the expression to "order" in this publication draft. It is a vague expression, and "with the objective to reduce exposure progressively to levels on the order of 1 mSv per year" (Main Points 4th,line 56, para 80, etc.) should be changed to "with the objective to reduce exposure progressively to a typical value of 1 mSv per year, a level that is close or similar to exposure situations in non-affected areas (ICRP, 2009b, Para. 50).

2.(Line 2674) Concerning a lifetime exposure dose:
2-1. For emergency and recovery process, the rough standard period of time should be recommended not to allow to use high standard period of time.
2-2. If the rough standard period of time cannot be established, it should be recommended to set a lifetime exposure dose limit.


1.復旧期の参考レベルについて(Main Points, fourth line 56, para 80, etc.):
1-1.(Line 126-128,546-552) 日本政府は、ICRP勧告を恣意的、部分的に運用し、ICRPの現存被ばく時の参考レベル(年1-20mSvの下方から選択、代表的な値は1mSv)は採用しなかった。 ICRP勧告が強調する「ステークホルダーの関与」は、避難区域設定、再編、解除、子ども・被災者支援法基本方針策定など、重要な政策の決定の際には行われなかったし、反対意見を述べても無視されている。人々が被ばく防護に関する政策決定に参加する権利を保証すべきである。

1-2. (Line 114-121,para80 line826-) 復旧期の参考レベルとして、「年1〜20mSvの範囲内またはそれ以下で参考レベルを選択すべきであり、年間1mSv オーダーへの段階的な被ばく低減を目的として、一般的に年間 10mSv を超える必要はない」としているが、この文で「必要がない」は曖昧で意味不明である。これを削除し「年間 10mSvを超えてはならない(should not)」と勧告すべきである。

1-3.(Para 80 Line 830-847) publication 111(o) (para50)にある「過去の経験では、・・・代表的な値は年1mSvである」としている。これに対して本勧告案の“levels on the order of 1 mSv per year.” に変更している。チェルノブイリの当局が採用した参考レベルを、日本政府が採用しなかったため福島の経験に基づいて表現を「程度」に緩和したように思われる。紛らわしい表現であり、 ”on the order of”(=程度) を削除し(Main Pointsの4点目56行、para 80など)、「ここに被災していない地域における被ばく状況に近いか類似したレベルである年間 1mSvの代表的な値に」(1 mSv per year, a level that is close or similar to exposure situations in non-affected areas (ICRP, 2009b, Para. 50).) に変更すべきである。


2.(Line 2674-) 生涯被ばく線量限度について:
2-1.緊急時と復旧期に関しては、時間的目安を設けていないことは、高い基準値を長期間運用することを容認することになる。
2-2.時間枠を設定できない場合は、生涯被ばく線量限度を設定するように勧告すべきである。


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