Documents reveal hidden fears over Britain's nuclear plants

Unexplained cracks in reactor cores increase likelihood of accident, say government inspectors John Vidal and Ian SampleWednesday July 5, 2006The Guardian Revelations of safety concerns at Britain's AGR power stations come at a crucial time for the nuclear industry, with results of the government's energy review due in the next fortnight. Photograph: Martin Argles
Government nuclear inspectors have raised serious questions over the safety of Britain's ageing atomic power stations, some of which have developed major cracks in their reactor cores, documents reveal today.
The safety assessments, obtained under Freedom of Information legislation, show the Nuclear Safety Directorate (NSD) has issued warnings over the deterioration of reactor cores at Hinkley Point B in Somerset and other British nuclear plants. The directorate also criticises British Energy, which operates 13 advanced gas-cooled nuclear reactors including Hinkley.

According to the papers, the company does not know the extent of the damage to the reactor cores, cannot monitor their deterioration and does not fully understand why cracking has occurred. They reveal that in June last year, the NSD said it was faced with "significant regulatory issues ... for all operating AGR reactors".
The NSD's most recent safety assessment of Hinkley, completed in April, warns that its continued operation is likely to increase the risk of an accident. While the NSD says it does not believe that there is any immediate radiation danger to the public, it says there is a possibility of serious faults developing that would force the long term or permanent closure of other nuclear plants of the same design.
"While I do not believe that a large release [of radiation] is a likely scenario, some lesser event ... is, I believe, inevitable at some stage if a vigilant precautionary approach is not adopted. There is an an increased likelihood of increased risk should we agree to continued operation," says the inspector.
The documents show the NSD wants more frequent and more probing inspections of the reactor cores at all Britain's AGR plants. These inspections require the reactors to be shut down for weeks. The premature closing of any nuclear power plant could throw Britain's electricity supplies into chaos. Closure of Hinkley Point would be likely to lead to closure of at least three other nuclear stations built at the same time, which are also known to be suffering from cracks in their cores.
Cracks in the graphite brick cores of ageing reactors have been observed for some time but until now there has been little public knowledge of the extent of the problem. British Energy warned in 2004 that its Hinkley Point B, Hunterston B, Heysham 2 and Torness plants might not be able to be extend their 30-year lives because of cracked bricks, but it gave few details of the extent of the problem.
British Energy is keen to extend the life of its AGR reactors but the papers, obtained by Greenpeace via Stop Hinkley, a local nuclear watchdog group, suggest that unless British Energy improves safety checks, the plants might have to be closed.
The revelations come at a critical point, with the government's energy review expected to be published in the next two weeks and both Tony Blair and Gordon Brown having indicated that a new generation of nuclear power is needed. Yesterday the prime minister told the Commons liaison committee that he had altered his position in favour of nuclear power since the last white paper on energy policy in 2003. "I'll be totally honest with you, I've changed my mind," he said.
However, John Large, an independent nuclear engineer who has advised the government and who reviewed the FoI papers for Greenpeace yesterday said it was "gambling with public safety" to allow Hinkley Point to continue operating. Calling for other AGR stations to be closed, he said: "The reactors should be immediately shut down and remain so until a robust nuclear safety case free of uncertainties has been established".
He accused the NSD of being reluctant to call for the closure of Hinkley Point because of the Mr Blair's stated intention to review nuclear power. "What nuclear installations inspector is going to close a plant down at such a politically critical time?", he asked.
In the papers from June 2005, an inspector concludes of Britain's AGR power stations: "I judge that there is significant uncertainty in the likelihood and consequences for the core safety functionality posed by ... core damage. The assessor needs to assume worst case consequences of ... core damage unless the licensee is able to provide robust arguments."
In a 2004 assessment, the inspector complains about the "lack of clarity" by British Energy, "continued uncertainty" in the prediction of behaviour in reactor cores, and the "lack of progress" made by British Energy in addressing issues in all AGR reactors.
British Energy said yesterday it had provided new evidence to the NSD. "If the health and safety executive [the government body that oversees the NSD] were not confident in the safety of the reactor cores we would not allow the reactors to operate. The assessment report was part of the ongoing regulatory process ... The Nuclear Safety Directorate is monitoring closely British Energy's work on graphite and, where necessary, is influencing the scope and extent of the reactor core inspections that the company carries out.
"British Energy has also been working on methods to monitor the cores whilst the reactors are in service. This will provide added re-assurance on the condition of the cores."
Stephen Tindale , executive director of Greenpeace said: "These documents show the incompetence of the government and British Energy who have known about these cracks yet have refused to do anything about it."
Problem sites
Hinkley Point B, Somerset (switched on 1976)Known to have core damage
Hartlepool, Cleveland (1983)Known to have core damage
Hunterston B, Ayrshire (1976)Known to have core damage
Heysham 1, Lancashire (1983)Known to have core damage
Dungeness, Kent (1983)Documents hint that core damage found
Torness, East Lothian (1988)Documents hint that core damage foundRelated articles04.07.2006: I've changed my mind on nuclear power, admits Blair28.06.2006: The lights will go out if we avoid the nuclear option, says Darling14.06.2006: Carbon pricing to encourage new nuclear power stations10.06.2006: Chirac agrees to share expertise as Blair pushes case for nuclear power stations09.06.2006: Tories refuse to give guarantees to nuclear power industry08.06.2006: Gorbachev puts anti-nuclear case to Blair29.05.2006: Blair adviser calls for more nuclear powerSpecial reportsGreen politics Home affairsNuclear industry