|A radiation protection expert group consisting of voluntary members of the Japan Atomic Energy Agency discussed the draft of ICRP new recommendations and made a set of their comments for it. It would be our pleasure if they help the ICRP develop its new recommendations.
1) Table 1: Publication 68 should be eliminated because it is quite different in kind from the others in the table.
1) We feel questions about the change of the terms, gdeterministic effecth and gstochastic effecth to new terms, because these terms have a firmly embedded use in the current system of radiation protection. Even if the terms are changed, the new term gcancer and hereditary effectsh needs to be reconsidered because it may cause some misunderstanding to the general public. The term treats equally the cancer and the hereditary effects. However, the heritable effect for human beings has not actually been observed and cannot be regarded as equal to the cancer effect. It is also proposed that the risk for heritable effect goes down.
1) We agree to maintain the current definitions, terms and units of dosimetry system under the present situation that there is no definitive improvement of the dosimetric quantities for radiation protection. We think highly of some descriptions which clearly show the applicability of the equivalent dose and effective dose.
2) The equivalent dose and effective dose are expressed with the same unit of Sv. In order to avoid confusion of these dose concepts, we suggest adding some annotating description in the text to encourage the clear distinction of these doses.
3) Paragraphs 88 and 93: Two terms, gtissue reactionh and gdeterministic effecth are mixed in the paragraphs. It should unify the expression to make it clear.
4) Paragraph 90: gIn practice the effective dose cannot be c.h should be replaced with gIn practice the equivalent dose and the effective dose cannot be measured directly in the body.h
5) Paragraph 94: This paragraph should be deleted because this content was already described in Paragraphs 88 and 89.
6) Paragraph 97, line 6: Words gpenetrabilityh and grangeh are quite similar meaning in this sentence. It would be unnecessary to include both of them.
7) Paragraph 99: In Paragraph 93, it is described that an absorbed dose (Gy) should be used to avoid tissue reactions, where high-LET radiations are involved. However, it is explaining that the protection quantities (the equivalent dose and effective dose) are used to specify exposure limits for avoiding tissue reaction in this paragraph. More explanation should be given to clarify the context of these paragraphs.
8) Paragraph 103: Title should be replaced by gPhotons, electrons and muonsh because of the content in this paragraph.
9) Paragraph 105: It cannot be said that the function (4.3) (Fig. 1) is consistent with biological and physical data because there are no biological data in high energy region.
10) Paragraph 105, last line: gneutrons andh should be deleted from gfor neutrons and protonsh, since wR for neutrons is being discussed in here.
11) Paragraph 106: Are there any places where high-energy protons dominate in practical radiation fields around high-energy accelerators?
12) Paragraph 111: It is described that, in space, the approach with the calculation of mean quality factor has to be chosen. But it will make eliminate the basis of the introduction of the radiation weighting factor. The approach with the calculation of mean quality factor should be applied when no appropriate radiation weighting factor can be applied.
13) Paragraph 113: There is no gender difference for the risk of breast and the tissue weighting factor for breast increases greatly in this draft. The scientific reasons behind the revisions of the breast weighting factor should be explained.
14) Paragraph 117, line 3 from the bottom: gMale and female computational phantomc..intake of radionuclide.h is in no need of this paragraph because it is just a prospect and should be described in Annex B.
15) Paragraph 119: The description of splitting rule can be deleted because it is described in Paragraph 114.
16) Paragraph 121: gThese quantities aim to provide an estimate or upper limit for the value of the protection quantitiesc.h is different from the description of ICRU. The operational quantities for external exposure are defined by ICRU. This sentence should be rewritten based on the ICRU document.
17) Paragraph 123: The description of dose calculation using the voxel phantoms is not appropriate in Section 4.4, where the operational quantities are explained. This description should be deleted from this paragraph.
18) Equations in the text should be consistent with those in Annex B.
1) Section 5.1: By having the broad definition of a single source, it is expected that regulatory authorities who intend introduction of dose constraint in their regulation would reconstruct their regulation system more flexibly. However, in particular for occupational exposure in planned situations, more description should be added about the important points and considerations for selection of a single source. Suggestion of ICRP's views will provide an instructive base in the introduction to regulation.
2) Paragraph 165: We recognize that gstudentsh handling radioactive materials in a controlled area belong to a category of gradiation workersh. However, such persons cannot be categorized gWorkersh because they have not employment relationship to the employer and are inapplicable under the definition in Paragraph 170. For this reason, the definition of goccupational exposureh and gworkersh should be extended.
3) Paragraph 166: It says gradiation exposures incurred at work as a result of situations that can reasonably be regarded as being the responsibility of the operating managementh. Some concrete examples should be shown in order to make this phrase easy to understand. For example, not only radiation works in controlled areas but also operation in high radon concentration atmosphere, jet service, space flight etc.
4) Paragraph 171: It says gadministrative and support staff are more similar to the general public and are treated as such.h The commission should state clearly about following points; (1) if dose constraints for those are chosen similar to the general public, (2) if they are to be constituent member of representative individual in determining dose constraint for the general public.
5) Section 5.5: For a pregnant worker, an explanation should be clearly stated, if equivalent dose of 2 mSv for an abdominal surface in Publication60 (178) was changed into additional dose of 1mSv for fetus.
6) Section 5.6: There is a discussion that the total of constraints is restricted to below the dose limit. For example, the public in the area surrounded by several nuclear facilities, and the workers who work in many nuclear facilities. Although we recognize that such application of constraint is not practical and appropriate , additional explanation is desired about this point.
7) Section 5.7: The new concept of radiation protection system should be visually illustrated to facilitate the understanding of relation between all categories of exposure on three situations and the principles of radiation protection.
8) Paragraph 187: What does the phrase gthose situations which are determined by the regulatorh mean? Do gthose situationsh indicate gplanned situationsh simply?
9) Section 5.7.2: It should be described who has the responsibility for the justification for the exposure of caregivers and supporters. It seems that the justification for the exposure of caregivers and supporters is similar to that for patients. It should be clarified.
10) Section 5.8: Relationships between all categories of exposure on three situations and dose constraint should be visually illustrated to facilitate the understanding.
11) Paragraph 201: Since there is the phrase gtaking account of the Commissionfs guidanceh at the last sentence, it seems that the Commission will provide further policy guidance for dose constraints. We expect the Commission to publish it.
12) Paragraph 205 and Table 4: It should be explained more why the second band for the dose constraints is set from 1 to 20 mSv. Furthermore, the examples of the Paragraph 205, gsheltering and iodine prophylaxish, should be added to Table 4.
13) Paragraph 211: The application methods and requirements of dose constraints and optimization using the constraints should be more clearly described for occupational exposure in planned situations. According to this draft, the requirements of dose constraints for occupational exposure seem to be as follows: (1) not to create inequity, (2) to apply to a single source, (3) to use as a starting point in the optimization process, (4) to establish for the type of occupation, and (5) to give as an annual dose. The optimization using dose constraints that meet all these requirements will be limited to the following occupation: uranium mining, x-ray diagnostic and so on, of which works are simple and predetermined through a year. However, in the nuclear power plants and research institutes, the workers may be exposed to many radiation sources and be involved in various types of radiation work. In these cases, the application of optimization using dose constraints seems to be impractical or impossible.
14) Paragraph 225: gSection 10h in the last phrase should be corrected as gChapter 11h
15) Table 4: Table 4 in page 61 should be Table 5. In the caption of the table, g(effective dose in a year)h should be g(effective dose)h. It is inappropriate to use gin a yearh for acute exposures.
16) Paragraph 242: It should be shown what gits guidanceh in line 5 indicate.
1) We agree that the clear definitions of medical exposure and the related personnel are described in this draft. It is very useful that recommendations for medical exposure, which have been described in some publications after Publication 60, are integrated into this draft.
1) About Exemption: In the draft recommendations, the system of radiological protection applies to all natural sources and exposures. But some natural sources (or situations) are excluded from the radiological protection regulations on the basis of the proposed level in the recommendations, and are exempted from the regulations according to the level that national regulators set up. It seems that such concept for the radiological protection against natural sources can be widely accepted by national regulators. However, no criterion to fix the exemption level and situation is shown in the draft. In order to avoid confusion, the Commission should publish a guideline concerning method to fix the exemption level and situation.
2) About Exclusion: It is necessary to explain how the commission derived the value of 1000 Bq/kg for the uranium series etc. The recommended values are numerically the same as the exclusion level of IAEA RS-G-1.7. The IAEA document describes that the values have been selected on the basis of consideration of the upper end of the worldwide distribution activity concentrations in soil provided by UNSCEAR. In addition, the document describes that doses to individuals as a consequence of these activity concentrations would be unlikely to exceed about 1 mSv in a year. The ICRP should also explain the rationale of the exclusion level in the draft.
1) This chapter seems to be written by arranging the corresponding statements in Publication 64, 76, 77 and 81. However, there is no description of specific application method to the practice of radiological protection. The guideline including examples of actual calculation methods and estimation of risk for the potential exposure will be hoped for in the future.
2) Section 8.5: It is necessary to classify the exposures with malicious intent in three proposed situations, and to explain the concept of radiological protection for the occupational and public exposures in each situation.
3) Paragraph 326: It is necessary to delete ge.g., of the order of thousands of mSvh, because it is not appropriate to use gSvh at the dose level that the deterministic effect are almost certain to occur.
4) Paragraph 328: It is necessary to describe "Occupational dose limit admitted internationally" concretely. If the limit admitted internationally means the dose limits recommended by ICRP, it is necessary to describe like that.
1) Paragraphs 338 and 339: According to Paragraphs 338 and 339, the intervention levels given in Publications 60 and 63 are regarded as dose constraints of 100 mSv. It is necessary to describe the reason to change the limitation value for the immediate and urgent remedial work (0.5 Sv) in Publication 60 and the evacuation level (500 mSv) and relocation one (1000 mSv) in Publication 63.
1) This chapter only describes the background and the direction to develop the system of radiation protection of the environment in the future. There seems no need to set this chapter because no concrete recommendations are included in the text. If this chapter is left, the Commission should describe what should we do at present concerning the protection of the environment under the circumstances that each country advances an original program for the environment.
1) New ICRP recommendations need to be written in an easy description rather than in a noble style so as to understand easily and accurately for non-English speakers. It is a good way to use some figures especially for the complicated concept.
2) It would be helpful to show more explanation in the forms of the contrast table to summarize the changes between Publication 60 and this recommendation especially in the terminology.