Radioactive spills and breakdown revealed at British nuclear plants

Leaked report details incidents at three plants during February that were serious enough to be reported to ministers

Guardian.co.uk, Rob Edwards, Wednesday 20 April 2011

A puddle containing plutonium five times the legal safety limit leaked from
Sellafield nuclear complex in Cumbria, the report says. Photograph:
Christopher Furlong/Getty Images

There have been two spillages of radioactive waste and a breakdown in an emergency cooling system at Britain's nuclear plants in the past three months, according to a report to ministers leaked to the Guardian.

A brown puddle containing plutonium five times the legal safety limit leaked from an old ventilation duct at the Sellafield nuclear complex in Cumbria. This exposed "a number of shortfalls in the design", says the report.

Groundwater at the Torness nuclear power station near Edinburgh was contaminated with radioactive tritium (a form of hydrogen) leaking from two pipelines. At Hartlepool nuclear station on the north-east coast of England, the back-up cooling system was put out of action by a faulty valve.

All three incidents occurred in February this year and are still under investigation by the Office for Nuclear Regulation (ONR), the government's newly created nuclear safety watchdog. They were sufficiently serious to be reported to ministers under safety guidelines agreed in the wake of the Chernobyl accident in Ukraine 25 years ago.

Disclosure of the incidents could further delay the government's plans for a new programme of nuclear power stations, already being held up by a safety review prompted by the Fukushima accident in Japan. Critics will press for the incidents to be included in the review, being led by the executive head of the ONR, Mike Weightman.

The Guardian has been provided with a copy of a report on the incidents sent to ministers on 18 April by Weightman. It was circulated to the energy secretary, Chris Huhne; the business secretary, Vince Cable; the environment secretary, Caroline Spelman; the employment minister, Chris Grayling; the Scottish secretary, Michael Moore; and the Scottish first minister, Alex Salmond.

In a covering letter, Weightman says that a fourth incident involving contaminated ground at an unnamed nuclear site is still under investigation, and may be reported to ministers in the future. The criteria for reporting nuclear incidents, which takes place every three months, include leakages, breaches of safety limits and events where "safe operation may be significantly affected".

According to the ONR, the response to the incidents from the companies that run the three plants was "appropriate". The plutonium spillage at Sellafield has been cleaned up, use of the leaking pipelines at Torness was suspended, and the faulty valve at Hartlepool was fixed.

But the ONR is continuing to quiz the operators and monitor the plants, to try and make sure that similar mishaps do not occur again. A spokesman for the ONR told the Guardian that the report to ministers on the incidents is due to be posted online later today.

George Regan, the chair of the local government voice on nuclear issues, Nuclear Free Local Authorities, said that it was unusual for three incidents to be reported to ministers in one three-month period. There was only one incident in each quarter of 2010, three at Sellafield and one at Dungeness nuclear station in Kent.

"With Fukushima very much in the public's mind, we are particularly concerned to hear of a coolant incident at Hartlepool," Regan said. "We will be urgently seeking clarification from the ONR on why these incidents occurred and whether they are of any relevance to the current safety review."