Mr Maclean said it was nonsense to suggest that the leak - which he described as seriousbut 'well within safety limits' - was responsible for massive contamination of the food chain.
But he confirmed that the ministry, which takes the lead on food policy, was involved in the investigation with Her Majesty's Inspectorate of Pollution and Her Majesty's Nuclear Installations Inspectorate.
The incident occurred on Friday when the plant was being visited by Jack Cunningham, the shadow Foreign Secretary and local Labour MP, with Lewis Moonie, a Labour front bench colleague. Mr Cunningham, the MP for Copeland, said it was unacceptable that one-quarter of the annual authorisation of radio nucleids was discharged in a 24- hour period as a result of the leak.
Criticising a 'totally unacceptable series of events', Mr Cunningham said they had not been informed that excessive discharges had taken place. Mr Maclean said that was 'a rather extraordinary discourtesy'.
The leak was embarrassing for BNFL, which is seeking approval for the Thorp nuclear reprocessing plant at the coastal site. Mr Maclean said he was concerned about the reporting time to HMIP and to the NII. Although it is believed the leak started on Thursday, they were not told until 4pm on Friday.
In his statement to the Commons at the request of Mr Cunningham, Mr Maclean said only a small amount of radioactive material had escaped.Reuse content