Year
2001
File Attachment
33293.PDF318.15 KB
Abstract
The 205 fuel assemblies manufactured for the SNR 300 fast breeder reactor are currently stored at different locations in Germany and abroad. Due to various reasons the fuel has to be moved to a single storage in Germany. Furthermore, 271 fuel pins of SNR 300 type and approx. 800 MOX fuel pins are to be stored at the same place. Following requirements were specified for the packaging: · licensed as type B(U) package · a high level containment for the assemblies and pins; · interim storage must not affect the type B(U) quality of the package; · transports to be carried out with the NCS security vehicle; · easy handling at current and future storage facilities; · option to load a high number of packages into a heavy interim storage cask. The ESBB (single SNR fuel assembly container) developed by NCS fulfills these requirements. It can contain a single SNR 300 fuel assembly, max. 91 SNR 300 fuel pins or 40 MOX fuel pins. The Plutonium content may be up to approx. 10 kg. The ESBB consists basically of a stainless steel tube, a welded bottom and a plug at the top side which is welded after loading. All welding seams are checked using the Helium leak tightness check method. Stainless steel parts and the welding seams connecting them define the containment. The main dimensions of the package are: length 4538 mm, diameter 159 mm, useful length 3708 mm and useful diameter 139 mm. The mass of the loaded package is approx. 340 kg. The type B(U) license for the ESBB was issued by the German competent authority in December 2000 and validated in the U.K. in July 2001. The safety expertise was based on tests with three prototypes and calculations with approved codes. Currently (September 2001), 230 ESBBs are being fabricated of which 85 are completed and approx. 50 packages are loaded and ready for transportation. This paper will provide an overview of the design of the package, the loading and handling procedures and the safety analysis and summarizes the tests results.