Updating of the investigation and assessment of the activity-related radiation exposure in facilities according to AtG, on-site interim storage facilities for radioactive waste and non-nuclear facilities according to StrlSchV and RöV. Technical final report

In the context of the project 3615S22301 task related occupational exposure in nuclear facilities according to AtG, in on-site storage facilities for radioactive waste and spent fuel and non-nuclear facilities according to StrlSchV and RöV were assessed and eval-uated. This report summarized the work performed within the project; detailed results have been documented in reports dedicated to the special work field to be addressed. The results of the project show that the total collective exposure of the plants in opera-tion have stabilized on a low level, where the total annual collective exposure show significant changes from one year to the next. These changes are inter alia due to out-age-free years on the one hand and high back-fitting activities on the other. Due to the 13th amendment of the Atomic Energy Act in the year 2011 in consequence of the Fu-kushima-accident, eight plants were finally shut down; their total annual collective ex-posure shows an additional significant reduction. But independently, the total occupa-tional exposure of the staff has decreased within the last years; this is reflected by the trend in time of the mean personnel doses as well as of the distribution of the unit-related individual doses of the involved personnel. The trend of the dose distribution is significant for utility personnel, but is also visible for contracted personnel. Dismantling of NPPs under decommissioning can be carried out with low annual collec-tive doses compared to the doses during operation. The performance of a full system decontamination, which is routinely done in recent years before the beginning of dis-mantling works leads to a further reduction. The total annual collective dose of all NPPs under decommissioning show a decreasing trend, but the annual value is strongly in-fluenced by the progress of the individual dismantling work in the different decommis-sioning projects. With respect to the occupational exposure in the fuel cycle facilities, which are consid-ered in the project, their individual annual collective doses are of the order of up to several 10 Pers.mSv/a. Accordingly, they are far beyond the annual collective dose of the nuclear power plants in operation. As part of the analysis of dedicated tasks within this project, the mean task related dose rate has proven to be an excellent tool to compare the radiological work condi-tions of different NPPs and to identify radiological sensitive areas of work as well as of areas of potential improvement and optimization. The results support the knowledge on the different situations in the individual nuclear power plants, which are also reflected in the dose rates measured at dedicated measuring point. Within the last years it turns out that – in particular for nuclear power plants under decommissioning – the collection of task related exposure data becomes difficult. This is, as due to optimized planning and conduct of individual decommissioning measures opportunities for detailed dosim-etry of individual task becomes more limited. Practice shows, that such detailed dosim-etry result in a significant higher effort and higher costs. In the international comparison, regarding the average collective dose for PWR, the German plants rank up to 2011 in the upper third of the bandwidth of the PWR-plants of important nuclear energy producing countries. In this field it must be kept in mind that the average dose in Germany was dominated by a few older plants, namely those DWR of generation 2, with higher collective dose. The shutdown of these plants in 2011 shifted the average collective dose to lower values. For BWR-plants, the average collective dose of German plants is in the lower third of the distribution of average col-lective exposures on the international scene.