|Comments for ICRP draft Recommendations
The Federation of Electric Power Companies (Japan)
i‚PjDose constraint for public
Although it might be rational that the dose constraint should be applied to
the public who is not monitored an individual dose, if the figure less than the dose limit 1mSv/y is adopted as the dose constraint, the situation will be the same as the dose limit decreasing. By introducing the dose constraint, arguments based on misunderstanding might occur among general people that the standard of radiation became still severer. From this reason, giving serious consideration regarding such a negative response is needed.
i‚QjDose constraint for workers
On the other hand, the individual sum total dose can be managed appropriately even if workers work at plural facilities since their doses are always monitored. Especially in Japan, the individual sum total dose is managed mostly in the nation wide, therefore introduction of the dose constraint doesnft have a merit and only causes confusion.
Moreover, when the dose constraint 20mSv/y (or less) is introduced, the dose in a certain plant, even though the dose limit 50mSv/y still remains, will be restricted to 20mSv/y (or less). If individual dose will be limited excessively the collective dose will increase because of loss of flexibility on planning work and worker arrangement.
In 2003 fiscal year TEPCO inspected pipe cracking of their plants PLR systems extensively. At that time they expected many workers exceeding 20mSv/y. It was not legal problem because the dose limit was 50mSv/y, but they made every effort not to exceed 20mSv/y that was in-house target in their company. As a result, there were no workers who exceeded the target, but they had to make unreasonable efforts to achieve that. For example, they gathered many workers from thermal power stations or chemical plants to replace workers being close to 20mSv/y, and increased number of workers then veteran workers worked only for essential steps. Moreover they newly appointed an assistant for supervisor and the supervisor directed the work from the low radiation area.
Of course it needed a lot of cost and there were another fear that working inexperienced workers cause degradation of quality and efficiency of their work, and lead to increasing total collective doses. It needed big efforts even if 20mSv/y was in-house target. If the dose constraint is adopted as the regulation, the flexibility of work will be lost because the new target that is less than 20mSv/y has to be set to prevent exceeding the regulation.
Publication60 recommended the dose limit of 100mSv/5y that has a flexibility to satisfy the lifetime dose 1Sv. The dose constraint 20mSv/y (or less) doesnft have flexibility and it is inconsistent with the thought of Publication60. To have flexibility and good quality, itfs appropriate to use the present dose limits system.
Judging from these points, there is no necessity for applying the dose constraint to workers in Japan. But some countries have intention to introduce that, so the conditions by which they can judge whether they apply that or not according to the situation of their countries should be specified in the recommendations.
Specifically, the following sentence should be inserted at the last of (164) second paragraph.
"However it doesnft need to apply the dose constraint to workers in the situation where there is appropriate individual monitoring of exposure at every facilities, and where there is the system by which all figures are summed precisely and we can check having not exceeded the dose limits"
‚QDThe object of the radiation protection
For sustainable development of the earth, utilization of nuclear is indispensable and the benefit obtained is inestimable. Meanwhile, by applying a LNT hypothesis to very low dose, ICRP gives the unnecessary feeling of fear to radiation to general people noting that the effects for the health, i.e. cancer etc., could occur also by trivial quantity of radiation exposure, and it has checked smooth nuclear development. As suggested by investigation research in high background radiation areas, ICRP should also examine excluding the radiation level of about several mSv/y from the object of radiation protection that is the same level as natural radiation and cannot be distinguished from other risk factors and cannot also be detected radiation influences.
‚RDThe protection of the environment
When considering the influence of the radiation to living things, ICRP should use realistic parameters and premises for the study to avoid excessive regulations. Moreover we would like ICRP to have a balanced discussion such as comparison examination with other risk factors, i.e. chemical substances etc.