[guardian] Criminal charges are to be brought against the Sellafield Nuclear power plant over a radioactive leak which went undiscovered for months, the Health and Safety Executive has said.

The facility’s owner, British Nuclear Group Sellafield Ltd, is charged with breaching conditions regarding the safe storage of radioactive materials.

The decision follows the discovery of 18,257 gallons (83 cubic metres) of radioactive liquor inside a protected area of the Thorp reprocessing plant in April last year.

Two managers were suspended after the leak of acid containing uranium and plutonium leaked from a pipe inside the shielded area of the processing plant.

The liquor leaked into a stainless steel-lined cell with 1.5m thick concrete walls and was discovered on April 19, 2005. HSE officials said there is no current evidence of any harm to workers or the public.

The facility remains closed and both managers have now been reinstated following an internal inquiry. It is thought the fluid may have been leaking for several months before it was uncovered, said a Sellafield spokeswoman. more