Optimisation of radiological protection

Draft document: Optimisation of radiological protection
Submitted by Heinz Peter Kapteinat, VGB PowerTech
Commenting on behalf of the organisation

VGB Comment to the ICRP Foundation document “The Optimisation of Radiological Protection – Broadening the Process”, Document 42/105/05 (1) General Remark Although it is said in the document that the recommendation is not a fundamental change but an evolution of former principles, we believe that there are some aspects which at least can be interpreted as an important change. We believe that there are no reasons for a fundamental change of the optimisation principle because the RP practice has been proven to be effective. In detail the following comments should be taken into account: (2) Dose constraints The basic level of protection is provided according ICRP by the dose limits and dose constraints. ICRP stresses that dose constraints are an essential tool and proposes a set of maximum dose constraints below which the process of optimisation starts. In former recommendations dose constraints have been part and not necessarily the starting point of the optimisation process. The introduction of a set of maximum constraints makes the system more complicated without appropriate benefit. Therefore we suggest keeping the current concept of dose constraints. (3) Optimisation process There is obviously a remarkable change in the new recommendation away from quantitative (objective) assessments towards qualitative processes. It is of course a fact that any optimisation is embedded in a societal, political surrounding, that has to be taken into account e.g. by stakeholder involvement. However, we would prefer that the ICRP provides a guideline how to find an optimum which is of more objective nature. The fact that quantitative tools of optimisation as e.g. cost-benefit considerations are nearly completely out of the focus of the document and primarily qualitative factors as stakeholder involvement or safety culture are highlighted, concerns us. By this change any optimisation discussion is losing its objective scale of rating, and the answer to the question, if a situation really is an optimum, becomes a subjective issue with some arbitrariness and randomness. Especially also in qualitative processes there is a need to have objective scales, because unfortunately it is a fact that the risk perception on radiation within the population rarely is in agreement with the real risks. Some groups simply understand only a "no radiation world" as the optimum. According to the recommendation the process always goes without end towards lower doses. In reality there might be several situations where the level of the remaining dose can be considered as optimal and a further dose reduction would only mean to waste resources rather than be an “improvement”. It should be clearly stated by ICRP that the process of optimisation has endpoints so that the overall-benefit is optimized and the overall-detriment/risk is as low as reasonably achievable. There might even be situations, where a real optimisation also can lead to higher doses. The ICRP should dare to express also this fact and should not express optimisation as a pure "one way" to a permanent reduction of doses. That would mean minimisation and not optimisation. In this context the demand for BAT needs a clarification. BAT without looking on the appropriate risk-reduction connected to this technique is l’art pour l’art. (4) Optimisation endpoint A risk-oriented approach means that there will be a point where further reduction of the risks/doses is inappropriate, because they are too low to be of any concern. The propagation of a cut-off criteria or de minimis dose would be very helpful for any practical application. It is not understandable that e.g. exclusion values are derived from doses in the order of some 10µSv/a, but on the other side doses down to zero still stay in the focus of optimisation. Even when assessed with low significance a further discussion of such very low doses will unnecessarily prolong any decision process and quite often also lead to measures and efforts not really justified by radioprotection aspects. (5) Stakeholder involvement Operators and authorities are responsible for decision finding. Other stakeholders are normally not responsible and should therefore not act on the same level in the decision-making process. The involvement of stakeholders certainly is an important measure to achieve acceptance and trust. Therefore it is already widely implemented in modern societies. To satisfy the interests of stakeholders and to get a consensus might be a way to the best possible degree of acceptance, what might be a societal optimum, but that isn't necessarily the optimum concerning radioprotection. Therefore we think that it is important to express also the limits of stakeholder involvement. Stakeholder involvement does not mean that all interests of all stakeholders can be satisfied. This should be made very clear by ICRP.