Pickering Dry Storage - Commissioning and Initial Operation

Abstract

Having commissioned all individual conventional and nuclear systems, the first Dry Storage Container (DSC) was loaded with four modules of 17 year cooled irradiated fuel (366 bundles) in the Auxiliary Irradiated Fuel Bay (AIFB) on November 29, 1995. After decontamination of the outer surface, and draining of water, the DSC was transported to the Used Fuel Dry Storage Facility (UFDSF) workshop, where it was vacuum dried, and then the lid was welded on. Following successful radiography test of the lid weld, the DSC was vacuum dried again and backfilled with Helium to a pressure of 930 mbar(a). The Helium leak test showed zero leakage (allowable leak rate is 1x10^-5 cc/sec). Finally, after loose contamination checks were performed and permanent safeguards seals were applied, the DSC was placed in the UFDSF storage area on January 23, 1996. Radiation fields at contact with the DSC surface were <0.6 mrem/hr, and at the exterior surface of the storage building wall only 33 micro-rem/hr (far below the target of 250 micro-rem/hr). Therefore, the actual dose rates to general public (at the exclusion zone boundary) will be well below the design target of 1 % of the regulatory limit.