MAINTENANCE OF UF6 TRANSPORT CYLINDERS IN COGEMA PIERRELATTE

Uranium hexafluoride (UF6) cylinders are used world-wide to transport natural UF6 or reprocessed UF6. To ensure fuD security of these transports, this type of package is periodically maintained in AMC, the Cylinder Maintenance Facility at COGEMA!Pierrelatte. The main purpose of the AMC, commissioned in the early 80's, is the maintenance and regulatory hydraulic testing of30\" and 48\" cylinders, essentially the JOBs and 48Ys. During the past 10 years, more than 13,000 cylinders of these types have been washed and hydraulically re-tested in this facility on behalf of utilities, fuel manufacturers, enrichers and transporters, both French and foreign. Besides the packages having contained UF6 from natural uranium, this unit is specially equipped to process cylinders ofUF6 from reprocessing, thereby contnl>uting to the mastery of the reprocessed uranium recycling process by the COGEMA Group. All the work is done in aecordance with written instructions in procedures and operating instructions. These documents permit the facility to be operated in compliance with the safety regulations. They list the operations to be performed on the cylinders, are under Quality Assurance and guarantee conformity of the operations with the ANSI N-14-1 regulations and USEC65 1 recommendations. This document reviews the various maintenance steps of a cylinder : incoming package inspections, washing - shot blasting I painting - five-year hydraulic testing - drying - wall thickness control - valve tightness tests- as well as inspection procedures.