The government’s Health and Safety Executive (HSE) has refused to release information about a “specific fire scenario” at the reactors because to do so could “threaten national security”.
The revelation has prompted calls from environmentalists for the plant to be shut down as soon as possible. But its operator, British Energy, said that it was working to improve safety.
In May 2007, the HSE’s Nuclear Installations Inspectorate complained about “significant shortfalls” in British Energy’s latest review of safety at Hunterston B. It ordered an urgent investigation of a particular fire risk, but withheld any details.
The Sunday Herald made a request under freedom of information law for documents on the fire risk. In July last year, the HSE released a little information which suggested that the risk concerned “shortcomings” in the safeguards meant to prevent a "Gas Circulator Hall oil spray fire".
The HSE was then asked to review its refusal to say anything more about the problem. On Friday last week, 14 months later, the government agency responded by keeping the information under wraps.
“Putting this information into the public domain would open up access to sensitive information to those who may choose to use it for purposes that could threaten life, threaten national security, or help criminals to commit crime,” said the deputy director of the HSE’s policy group, Les Philpott.
"The information you are asking for is about safety practices at a nuclear installation that, in the wrong hands, could be used for subversive purposes. e.g. to aid a terrorist attack.”
Duncan McLaren, the chief executive of Friends of the Earth Scotland, accepted that if there was a real opportunity for terrorists, it was right to withhold information about it. “But the public would also be right to worry about why a facility with such a risk is allowed to continue operating,” he said.
“Given it's poor reliability record in recent years, Hunterston is clearly approaching the end of its useful life, and this problem should be another nail in its coffin. There should be no question of considering extending its operating life beyond 2011. If anything, it should be closed sooner.”
Friends of the Earth Scotland backed the Scottish government’s decision to phase out nuclear power in favour of renewable energy. “The likelihood of a terrorist incident at a UK nuclear facility is thankfully low, but the consequences are unthinkable,” warned McLaren.
Hunterston, which opened on the Ayrshire coast in 1976, was originally due to shut down in 2011. But last December British Energy announced a plan to keep it going until 2016, with an option to run it a further five years until 2021.
The generating capacity of the station’s two advanced gas cooled reactors has been hampered by boiler problems, which have caused shutdowns and power reductions over the last two years. Both reactors are still only operating at 70% of their full output.
“We have made a number of significant changes and plant improvements at Hunterston B”, said a spokeswoman for British Energy. “Our regulators, the Nuclear Installations Inspectorate, have been kept informed of progress, and regularly carry out inspections at our site.”
In April the UK Information Commissioner, Richard Thomas ruled that releasing details of plutonium stores at the Dounreay nuclear plant in Caithness could have a “far reaching” impact on national security.