Current handling of transport and storage flasks at German intermediate storage plants – safety aspects

Abstract

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 were published in a new edition. Hence, the most unfavourable load drop situations had to be investigated. A huge number of investigations had to be done, with the risk of results that are not assessable. As this could have caused a delay on the time schedule of the necessary disposal of spent nuclear fuel from German nuclear power plants (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) or which is also regulated within the atomic accident guidelines for German PWR, 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. Many consequent measures (e.g. crane reconstruction, changes in administrative regulations) had to be implemented at the ISP. This paper describes the different phases of the reconstruction from the flashpoint to the approval process, the details of successful realisation of the consequence measures and the involved parties, and it focuses some interesting design measures of the most complex part of the load chain, the ISP crane.

Keywords:

• Intermediate waste storage
• Storage flasks
• Safety assessment
• Regulation and guidelines