Railway-carried flasks are used to transport spent fuel from
nuclear power stations in the UK and the
Sellafield spent nuclear fuel reprocessing facility. Each flask weighs more than 50 tonnes (110,000 lb), and transports usually not more than 2.5 tonnes (5,500 lb) of
spent nuclear fuel.
[2]
Over the past 35 years,
British Nuclear Fuels plc (BNFL) and its subsidiary PNTL have conducted over 14,000 cask shipments of SNF worldwide, transporting more than 9,000 tonnes of SNF over 16 million miles via road, rail, and sea without a radiological release. BNFL designed, licensed, and currently own and operate a fleet of approximately 170 casks of the Excellox design.[
citation needed] BNFL has maintained a fleet of transport casks to ship SNF for the
United Kingdom, continental
Europe, and
Japan for
reprocessing.
In the UK a series of public demonstrations were conducted[
citation needed] in which spent fuel flasks (loaded with steel bars) were subjected to simulated accident conditions. A randomly selected flask (
never used for holding used fuel) from the production line was first dropped from a tower. The flask was dropped in such a way that the weakest part of it would hit the ground first. The lid of the flask was slightly damaged but very little material escaped from the flask. A little water escaped from the flask but it was thought that in a real accident that the escape of radioactivity associated with this water would not be a threat to humans or their environment.
For a second test the same flask was fitted with a new lid, filled again with steel bars and water before a train was driven into it at high speed. The flask survived with only cosmetic damage while the train was destroyed. Although referred to as a test, the actual stresses the flask underwent were well below what they are designed to withstand, as much of the energy from the collision was absorbed by the train and in moving the flask some distance. This flask is on display at the training centre at
Heysham 1 Power Station.