Each station has a storage pond with a boronated water depth of some 7 metres. The pond water is circulated through filtering, cooling and water treat­ment plant with provision for the disposal of filter and resin arisings. There are two bays where the fuel is stored in compartmemed boron steel skips for up to 100 days decay before dispatch. Typically, the two sloping discharge tubes in the IFDF each connect to one bay. The fuel element/fuel bottle arrives in a reception tube which is then tilted to the vertical, so that it can be removed and handled into the ap­propriate skip by a manipulator which bridges the pond. When the skip is full it is parked, and after the decay period the skip is removed to the dispatch bay.

The 50 tonne transport flask after cleaning of road dirt and removing the lid bolts is lowered into the

Nuclear power station design

F;c. 2.112 Irradiated fuel disposal facility at Heysham 2

pond. The lid is removed for maintenance of the lid seal — The empty skip in the flask is exchanged for the dispatch skip. The lid is replaced and the flask is removed for washing, decontamination, water level adjustment, refitting of lid bolts, leak testing, etc before dispatch by road transporter to the rail head en route to Sellafield for re-processing. The Hevsham 2 arrangements are somewhat different in that the Hask is not placed in the pond, instead, the fuel skip is raised from the pond and placed in the flask. This operation takes place immediately adjacent to the pond in a shielded ceil which the flask enters on a trolley through a sliding shield door.