Optimisation of radiological protection

Draft document: Optimisation of radiological protection
Submitted by Mr. Hosin Choi, Korean Association for Radiation Protection
Commenting on behalf of the organisation

Para. 21: The expression "... the primary principle that requires quantitative individual dose restrictions as basic levels of protection" is ambiguous. Figure 1: Those figures explaining concept of optimization are confusing. e.g. a planned situation(a practice) may increase the dose to a level under the constraint and optimization may reduce the dose to the authorized level. In the emergency situations, the concept of intervention level does not go with the proposed new system of protection. Para. 32(the list of attributes): Although the list is not exhaustive, some features might be included. e.g. trust and emotion in the category of social considerations, resources and future development in the category of technical and economic considerations. Para. 38: Meaning of the last sentence of this paragraph is not readily understandable. Para. 39: Caution is needed to avoid addiction to BAT. Experience shows that concept of proven technology, a key feature of nuclear safety, is utmost important. Para. 46: The last sentence over-stresses the risk at low level of exposure and is not necessarily the spirit of safety culture. Para. 65: It is not readily understandable, although the resulting values to be the same, to define the collective dose as "product of the arithmetic mean dose and the number of individuals in the subgroup" instead of simple "sum of individual doses in the subgroup". Para. 70: It is not clear if there are any benefits to use the term "group dose(or sub-collective dose)" instead of "collective dose". Problems of collective dose was not in its concept but in miss-use of the quantity. The word "collective" is well consistent with the quantity we are to use. Para. 72(Figure 3): The term "dose matrix" is not easily communicable due to complex meaning in the term "matrix". A more descriptive term like "dose distribution matrix" or "dose pattern matrix" is preferable. Para. 77: Because optimization is a frame of mind as stated in para. 46, it is not an easy task to enforce optimization in real world. A competent authority may promote or foster optimization through policy, guidances, dialogues, or negotiations but may face technical difficulties to enforce. In this sense, some expressions in this para. e.g. burden-of-proof and decision-to-authorize, seem over-stated. Annex A1: 1. Introduction The second para. recalls the old 3/10 concept and may mislead as if individual monitoring be needed only for category A workers. Annex A2. 3. distribution of exposures The dimensions characterizing exposures may include "internal exposure vs. external exposure" and "exposure pathways". The gender distribution of exposures may be interesting but may not be a significant dimension to be exemplified here. Figure 7: The time scale of this illustrative graph is too farfetched. What is the real meaning of radiation risk after many million years? 4. The role of operators and authorities Prefer to use "regulatory positions" instead of "regulatory requirement" for optimization. Annex A3. C) Implementation of protection actions It is understood that there are some countries or districts who require measurements and protection actions against elevated radon levels in private dwellings for sales and renting. ICRP, however, should be careful to state that they "may be mandatory" for those specific situations.