Introduction of New Flasks for High Burnup Spent Fuel

Abstract

New flasks have been designed to transport the high burnup spent fuels now becoming available from the world's nuclear power stations. Two versions have been designed: Excellox 6 for 5 metre PWR fuels and Excellox 7 with increased neutron shielding for 4·5 metre PWR and BWR fuels arising in Japan. The designs of these flasks have been finalised; Excellox 6 has been approved and validated as a Type B(U)F package and the first two have been manufactured and are now in routine service, with a third at an advanced stage of manufacture. The Excellox 7 design is ready for manufacture when service requirements for it have been settled. An account is given of the final adjustments to the design in the course of manufacture, the main steps and tests in the manufacturing process and the commissioning tests at the reprocessing and reactor sites. The entry of the flasks into service is reviewed.