2005 ICRP Recommendation

Draft document: 2005 ICRP Recommendation
Submitted by Werner Zeller, Swiss authorities responsible for radiological protection
Commenting on behalf of the organisation

ICRP Draft Recommendations 2005 Comments from Switzerland Preamble The document submitted for consultation was studied by the Swiss authorities responsible for radiological protection. The objective of the new recommendations ¡V to clarify the situation and to simplify the concepts involved ¡V has not been achieved by the recommendations submitted for consultation, and the new recommendations tend to worsen rather than improve radiological protection. The competent Swiss authorities and the Swiss Federal Commission for Radiological Protection and Monitoring of Radioactivity in the Environment therefore propose to reject publication of the recommendations in their current form. Following alternatives are proposed: either to engage a complete revision of Recommendation 1990 or to publish the most important modifications, particularly concerning WT and WR in a supplement of publication 60. The main arguments underpinning this position are listed below: Arguments against the proposal 1. The recommendations do not really contain any new proposals in terms of radiological protection strategy; the 1977 recommendations (Publication 26) and the 1990 recommendations (Publication 60), in contrast, presented new material. The introduction of minor elements (such as changing the wR or wT factors) does not affect the strategy itself and does not justify the publication of new recommendations. 2. The proposal does not represent the ¡§recommendations of the ICRP¡¨ by itself. Constant reference is made to Publication 60, which retains its validity. A proposal of this kind is highly unsatisfactory for the individuals responsible for implementing it. 3. In the view of the Swiss authorities, the most important modification proposed is the reduction of genetic risk. Yet this change is neither presented clearly nor justified extensively. The method of modifying in a relatively arbitrary fashion (for example, only the first two generations are used) the factors used to estimate genetic risk will unsettle professionals already perturbed by the current discussions (which are questioning the LNT hypothesis, promoting the concept of hormesis, etc.). If the genetic risk is estimated to be four times lower than has been assumed up to now, in-depth scientific justification for this new estimate must be provided. 4. The problem of levels involving very low doses which are at the limit of negligible is a delicate one, and a well-argued and exhaustive recommendation would have been welcomed. It should have dealt with all the aspects involved: the de minimis dose, link with the justification, the special case of trivial applications, strategy for exemption, exclusion and clearance, activity limit in goods, and the possible distinction between natural and artificial sources. The mere introduction of exclusion limits which are weakly argued and in which potassium-40 plays such a prominent role with no real justification falls far short of meeting our expectations. 5. Abandoning the three-pronged system of justification, optimization and limitation of individual doses, or at least mounting a hidden attack on this system, is a completely inadequate approach to the problem. Even if the excessively mechanical application of the first two principles (for example by introducing the factor ƒÑ) has not been successful in the past, the Swiss authorities still believe that they constitute a solid and rational basis for protecting man and the environment. It should be noted in passing that the question of defence that a government could put forward to justify a decision concerning radiological protection is a delicate one at the moment. As far as optimization is concerned, an aspect which is now deemed to be complementary, the unilateral criticism of the concept of collective dose is inadequate since this concept remains an effective tool when applied to a well-defined population. 6. While the modification of the values of wR and wT does not present a problem to the extent that this modification is justified in a serious manner, the prospect of having the names of the dosimetric parameters and their unit changed makes a laughing stock of the radiological protection community (the concepts are being changed constantly, and in fact faster than they can be established in practice), and this should not be pursued at any cost unless the gains are likely to be major; this is not the case here. 7. There is a major contradiction between the way the nominal probability coefficients for stochastic effects are stated with two decimal places and the arguments put forward for choosing the factor DDREF (no good reason to change). The answer should be either to abandon the DDREF, which cannot be expressed in figures, or to accept a value containing a high degree of uncertainty; in the latter case the decimal places in Table 6 should be eliminated, and the risk for both the population and occupational exposure would then be 5 % per Sv. 8. The concept of dose constraint (source-related limit) is an old one which is useful in terms of application. It has been used in particular in the Swiss legislation. It is a derived quantity, with the primary quantities being the dose limits. There is little sense in putting the concepts of dose constraints and dose limits on the same level since that will only cause confusion. 9. It is unfortunate that the new recommendations have not been used to eliminate the limit on the effective dose of 50 mSv in any single year, with the further provision that the limit on the effective dose should be 20 mSv averaged over five years. The experience gained since the limit was reduced from 50 mSv/year to 20 mSv/year in 1990 should have been sufficient to allow the reserve, which was perhaps necessary at the time to ensure a smooth transition, to be eliminated. We feel that here the Commission has missed a good opportunity to move things forward. Moreover, justifying the limit with a risk-based approach is more convincing than an approach based on a relationship with the natural background radiation. 10. As far as protecting the environment is concerned, we welcome the Commission¡¦s act of faith and its willingness to become involved in this aspect. However, beyond announcing the Commission¡¦s intentions, the recommendations do not contain any concrete proposals capable of guiding the way radiological protection is implemented. Here too, the radiological protection community expects a clear strategy that takes into account the concept of sustainable development and established principles for the management of waste in the environment. In this context, it would have been good to see some comments on the limits of the principle of dilution and on the necessity for taking leave of the delivered dose as the sole deciding criterion and moving towards a more global concept of unjustified pollution. To finish on a more positive note, we would like to express our great appreciation of Chapter 9 on medical applications.