Current Handling of Transport- and Storage Flasks at German Intermediate Storage Plants – Safety Aspects

In 2010 the Recommendations for Guidelines on the 10 yearly Periodical safety assessments of Intermediate Storage Plants (ISP) for spent nuclear fuel and heat supplying radioactive waste (L 1) were published new. Hence the most unfavorable load drop situations had to be investigated. A huge number of investigations had to be done, with the risk of results which are not assessable. As this could have caused a delay on the time schedule of the necessary disposal of spent nuclear fuel from German NPP, most of the German NPP and ISP operators decided to take the alternative possibility that is given in the Guidelines of the Reactor Safety Commission (RSK) (L 2) or which is also regulated within the Atomic accident guidelines for German PWR (L 3), to design the complete Load Chain (ISP-Crane, Lifting beam and Load attaching points (LAP) of the flask) according to the increased requirements of the KTA Standards 3902 and 3905. A lot of consequent measures (e. g. Crane Reconstruction, Changes in administrative regulations) had to be done at the ISP. This paper shows the different phases of the reconstruction from the flashpoint to the approval process, the details of successful realization of the consequence measures, the involved parties and it focuses some interesting design measures of the most complex part of the load chain, the ISP-Crane.