‘No risk’ to public from N-plant leak at Sizewell

PUBLISHED: 11:03 17 September 2011 | UPDATED: 11:09 17 September 2011

The Sizewell A site, which closed in 2006 and is now being defuelled.  Pic Wendy Turner.

The Sizewell A site, which closed in 2006 and is now being defuelled. Pic Wendy Turner.


INVESTIGATIONS have been launched into a leak of radioactive water at the Sizewell A Nuclear Power Station – but bosses have insisted there was no risk to people or the environment.

Magnox, which owns the decommissioned station, informed regulators that water was founding leaking from a cracked flow meter in the site’s active effluent treatment plant (AETP) earlier this month.

The leakage, which amounted to about 13.3 cubic metres, was spotted during routine checks and the plant was shut down before early warning alarms were sounded.

The leaking water was captured by a secondary container over a period of four-and-a-half hours.

Bosses are carrying out an investigation into the incident but said that radioactivity in the spilt liquid was “very low” and did not pose a risk.

They also insisted major safety improvements made after a more serious leak in 2007 had remained effective.

The damaged meter forms part of a section of the system which returns treated water to the used fuel storage pond.

Tim Watkins, site director of Sizewell A, has written to members of the Sizewell Stakeholder Group – which was set up to manage the flow of information about the nuclear site – to inform them of the incident. The plant stopped generating electricity in 2006 after 40 years and is in the process of defuelling.

He said: “Our physical safety defences performed exactly as expected. All the treated water except a small amount which remained on the floor in the AETP was captured by the system and there was no impact on personnel or the environment.

“We are currently carrying out our own investigations to identify any lessons to be learned from this event.

“Both the Office for Nuclear Regulation and the Environment Agency have been informed. Inspectors from both organisations have declared their intention to carry out their own investigations and we will support them in doing so.”

In 2007, as much as 40,000 gallons of radioactive water spilled out of a 15ft-long split in a pipe at the station, some leaking into the North Sea, but alarms did not sound in the main control room.

Mr Watkins said this incident led to “a complete review and overhaul” of the plant’s design and safety systems.

He added the latest spillage did not mean those improvements had not been effective as the drop in water levels in the pond caused by the leak had not been enough to trigger alarms.

A spokesman for the Office for Nuclear Regulation (ONR) said: “ONR is satisfied that there was no radiological release and that the risk to the safety of employees or the public was negligible. ONR inspectors have since attended the site and established that the plant is in a safe condition and that appropriate immediate actions have been taken. Magnox has initiated its own investigation and ONR will monitor its progress, as well as continue to make its own inquiries.”

An Environmment Agency spokeswoman said: “We take the failure of maintenance of equipment by a nuclear site operator as a serious matter.

“There was no impact on the environment from this incident but we must ensure lessons are learnt to prevent any repetition.”

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