THE ageing Hinkley Point A nuclear power station was this week facing prosecution after an investigation into radiation which leaked into the sea for up to four months.

Environment Agency officials concluded solid radioactive particles had been escaping from a cooling pond into the Bristol Channel.

They began a probe in September after a faulty filter was discovered on an outflow from a pond used to cool the station's spent nuclear fuel rods.

Agency spokesman Bridget Norris said: "It is our opinion that solid particles did escape, and we are currently considering prosecution.

"At the moment, we are gathering evidence and taking formal witness statements from those involved."

Any prosecution would be expected to look at the way the radiation leaked, rather than the quantity of material involved.

Alleged degradation of the cooling pond filter could indicate problems with plant maintenance at the 34-year-old station, which has two of the oldest Magnox reactors in the country.

Station owner British Nuclear Fuels estimated the quantity of material which possibly leaked was up to one gigabecquerel of solid caesium 137 equivalent.

Hinkley A has authorisation to discharge up to 1,500 gigabecquerels a year, but only in liquid form.

BNFL spokesman Jason Impey said: "The fuel route in question is now being put back into service with the Environment Agency's say-so.

"We will carry on co-operating fully and are awaiting the agency's decision."

The latest radiation scare for Hinkley A came just four days after completion of repair work which had kept the station's two reactors closed for five months.

One reactor was re-started in September, but the second was still out of action this week while regular maintenance was carried out on top of the emergency repairs.

The repairs were ordered after it was discovered some work on the reactor boilers during the station's construction in 1965 was faulty.

Any prosecution would be the second in four years for Hinkley A, which was taken to court in 1995 by Her Majesty's Inspectorate of Pollution after two tons of radioactive gas escaped from corroded pipes in two incidents three weeks apart.

On that occasion, the station's then-owner Nuclear Electric was handed a £22,000 bill in fines and court costs.