The containers in which British Nuclear Fuels transports by air material containing plutonium to Europe would not survive all air accidents, it was acknowleged this week.
BNFL plans to increase flights of mixed-oxide (MOX) fuel when a new production plant comes on stream next year.
The company has carried out free-fall tests from helicopters, whereby containers were dropped more than 520m on to concrete. `Although these containers received severe external damage, there was no loss of containment,’ said BNFL.
While the speeds reached by the containers (near terminal velocity of 96kmph) were far below the speed at which a plane could crash (over 600kmph), BNFL maintained the impact in the tests would have been greater.
Roger Cheshire, head of BNFL’s transport division, said this was because the impact in the tests was direct – in most air accidents it would be indirect.
But in a case where an aircraft flew straight into a hillside, he accepted the impact would be far greater than that of the tests.
In such an event, there would not be a nuclear explosion but there would be a risk of radioactive plutonium, which makes up about 5% of MOX fuel, being dispersed in the subsequent fire.
BNFL argues that the ceramic matrix which binds the plutonium and uranium into the fuel pellets would keep its integrity and prevent this. However, John Large, independent nuclear consultant, said `in a fierce fire the ceramics could break down’.
By Andrew Cavenagh