|Comments from the National Dose Assessment Working Group in the UK on the June 2006 draft recommendations of ICRP
The National Dose Assessment Working Group (NDAWG) from the UK commented extensively on the previous draft of the recommendations. We are pleased to note that ICRP have significantly amended the draft to take account of the many comments received. We feel that the current draft is an improvement and particularly welcome the clear statement of the ICRP's principles of justification, optimisation and limitations. The sections on the scope of the regulations and the use of dose constraints are also now adequate. We also welcome the view that the recommendations do not suggest any need for changes to protection standards based on the previous recommendations in ICRP Publication 60. NDAWG has the following specific comments on the draft recommendations.
We feel that the reasons why collective dose is not always an appropriate tool are not fully explained in paragraph 147. It would be helpful to explain that the reliability of collective dose as an indicator of total health detriment decreases where the exposures occur over long time periods, in large populations or across large geographical areas. The problem is that there may be very small risks at the individual level which – when summed over very large groups of people - may be difficult to communicate or to compare with non-radiation risks.
NDAWG notes that the dose coefficients published by ICRP are reference values for fixed model parameters and are therefore not subject to uncertainty (paragraph 152). However, NDAWG considers that it is important to have an understanding of the total uncertainty in prospective and retrospective dose assessments. We would welcome any further guidance ICRP can give on the level of uncertainty in dose coefficients so that this can be put in context with other dose assessment uncertainties.
ICRP has removed much of the detailed recommendations on the protection of the environment in the revised 2005 Recommendations. NDAWG agrees that it is probably too early to provided a detailed framework for protecting the environment. However, NDAWG supports the continued development of such a framework based on the use of Reference Animals and Plants.