Tánaiste Simon Coveney said the Government has been following "with concern" reports that the UK proposes to use the Mourne mountains as a storage area for nuclear waste.
He will discuss the issue with Northern Secretary Karen Bradley when he meets her later this week.
Green Party leader Eamon Ryan said he understood that the Scottish Assembly ruled out such "deep geological storage of nuclear waste" there but that the Northern Ireland Assembly had agreed.
Raising the issue in the Dáil, Mr Ryan said it was not clear “what the parties in government in Northern Ireland have agreed or why they did so”.
But he asked “what if anything is the Government doing about this”.
Independent Louth TD Peter Fitzpatrick said reports that the UK was considering dumping hazardous waste in the Mourne mountains were “spreading fear” rapidly in the border county.
Mr Fitzpatrick said he hoped it was not happening because the North had had no government for the past two years. He said the Northern Secretary and civil servants were keeping departments in operation and were looking for more power.
“We had Sellafield for years and the last thing we want is to have hazardous waste in the Mountains of Mourne.”
Concerns
Mr Coveney said he took on board the concerns of TDs who raised the issue and “we need more details on it”, which he would discuss with Ms Bradley.
Last week Newry, Mourne and Down District Council, unanimously passed a motion opposing locating any nuclear waste facility in the local area.
It follows a report by a UK state-owned company Radioactive Waste Management stating that an area of granite bedrock near Newry stretching from Slieve Gullion to the Mourne mountains might be suitable for a geological disposal facility.
Newry is one of five areas in the North and 45 in the UK under consideration for the waste including an area between Omagh and Cookstown, Co Tyrone; a location between Belfast and Larne; areas near Coleraine, Co Derry and Ballymoney and Ballycastle in Co Antrim.
