Year
1992
Abstract
Since 1986, a Sealing Technique has been studied and tested by JRC-Ispra at the plant of Sellafield, aimed at the Safeguarguarding of Spent Fuel Containers. In this technique a special \" Sea 1 ing - B o l t \" is used to replace one of the bolts which close the lid of these special BNFL containers called \"MultiElement Bottle\" (MEB). The Sealing-Bolts (SB) can be easily installed on a MEB and verified underwater thanks to adequate tools and an Ultrasonics/Electronics portable instruments. In mid 1990, a Field-Test involving at least 50 SBs was decided and Ispra was committed to manufacture the SBs and to provide the necessary tools, reading equipment and staff for the demonstration exercises, whereas BNFL had to arrange for a staff support on site and MEBs handling as requested for the performance of the exercises. Between November 1990 and February 1992, in occasion of 11 exercises on site and 3 in Ispra, 53 MEBs could be sealed in a Transfer Bay of which 36 were successfully reverified a f t e r their transportation into the new THORP Storage Pond, during the last exercise. By using new tools, 10 SBs could be properly \"broken\" for demonstration purposes and 5 were removed. This Field-Test was completed to the satisfaction of EURATOM and IAEA inspectors and a complete set of equipment has been left on site for future routine use.