It is feared a small amount of radiation at the Hinkley Point A station on the Somerset coast, may have escaped but it is unlikely to have affected the coast of Wales.

Radioactive particles may have been discharged into the Bristol Channel along with cooling water following a fault in the filtering system at the station near Bridgewater.

It is thought the release amounted to less than one tenth of 1% of the total the station is allowed to release each year.

But Environment Agency planning manager Steve Chandler, says the incident is being taken seriously and that the agency is considering action against owners British Nuclear Fuels Limited.

Tests are being carried out along the shore but they have so far failed to detect increased levels of radioactivity.

Official caution

Meanwhile, Magnox Electric - owners of Wylfa power station in north Wales - have received an official caution over the discharge of non-radioactive material.

The Environment Agency issued the formal caution after ferrous sulphate got into the Irish Sea, turning the water orange.