Sizewell Q&A: the expert's view
Updated on 11 June 2009
Channel 4 News speaks to nuclear engineer, John Large, who explains the significance of the Sizewell A accident.
Q: How serious was this incident?
A: The real fear comes with what could have happened if the leak hadn’t been spotted – just 12 hours later the coolant water would have completely run out.
That would have led to 60 tonnes of nuclear fuel catching fire. So it is the potential for what could have happened that is the major concern here.
With a subsequent fire there would have been a nuclear plume that could have stretched from the Suffolk coast right up to north Norfolk. Certainly, it would have been on the same scale as Windscale.
Q: What problems did the discharge into the sea cause?
A: The accident discharged about 1 per cent of their annual discharge in just 45 minutes; in reality 5 per cent of their annual discharge.
The problem is that if it is discharged by unauthorised means it picks up muck and other materials that will float on top of the sea as contaminated waste – this can wash up on beaches and affect fishermen in the area.
Q: Who is in charge of monitoring this sort of thing?
A: The Nuclear Installations Inspectorate (NII) and the Environment Agency (EA) are duty bound to investigate and take whatever action is required.
This can range from a minor directive, to prosecution under criminal law.
Basically, the EA is responsible for the material that goes into the marine environment, the NII for the rest. In this instance, the NII wrote up a damning report but did not move to prosecute “because its resources were stretched”.
Q: The site has been closed down, what happens now?
A: The site has been shut down but the nuclear fuel is still there – it means there is radioactive fuel on the site now. The reactors were actually closed before the accident.
The same situation remains, if the fuel is allowed to heat up – the coolant escapes – then it can catch fire. It is so volatile; it can catch fire at room temperature.
