The Minister for the Environment has said it is absolutely unacceptable for British Nuclear Fuels to continue to discharge radioactive waste into the Irish Sea.
Martin Cullen made the comments after a meeting with the British Energy Minister, Brian Wilson, which was described as very frank.
Mr Cullen said all discharges should end and he did not accept Mr Wilson's assertion that shutting Sellafield was 'plain daft'.
Mr Wilson earlier described the latest reports of leaks from Sellafield as nothing more than a scare story.
Referring to a report that a roof of a building at the nuclear plant was at risk of leaking, he said all matters at Sellafield were being dealt with 'in a proper way' and Britain had a bigger interest than Ireland in ensuring safety was a priority.
He characterised efforts to close the reprocessing facility at Cumbria as 'plain daft..the worst of all worlds', and therefore something which was 'not an option'.
He said he fully respected Ireland's interest in what happened at Sellafield, but called for 'common sense and balance' in discussions on the matter.
Meanwhile, Martin Cullen has asked the nuclear watchdog body, the Radiological Protection Institute of Ireland, to raise the reports of a possible leaking roof with its regulatory counterparts in Britain.
The owners of Sellafield, British Nuclear Fuels, have said there is no leak and no risk of contamination.
