Vacuum drying of advanced gas reactor fuel

The UK will shortly cease reprocessing spent advanced gas reactor (AGR) fuel in favour of direct disposal, however since a permanent geological disposal facility is not envisaged as being available until 2075 interim storage will be required. The initial intention is to continue wet storage but it is possible that this may not be viable for as long as is hoped. Dry storage is commonly used worldwide for the interim storage of zirconium clad spent nuclear fuel however AGR fuel is stainless steel (SS) clad and as such a new safety case will be required to ensure that fuel can be adequately and safely dried.

A rig has been designed to allow a comparison of the two main drying techniques in use; vacuum drying and flowed gas drying. This paper looks primarily at the design and development of the rig. Some of the initial data is presented to indicate how the rig was developed as a result of early results and is followed by some of the later test data to illustrate the improvements made.