The British government today moved to assure Irish authorities a cargo vessel carrying nuclear fuel en route from Sellafield to France will not enter Irish waters.
Amid calls for the shipment to be stopped, Minister for the Environment Dick Roche said Britain was under no illusions that the vessel was barred from our territorial seas.
Mr Roche said he had raised a number of concerns with UK authorities.
"These concerns relate to safety, security and environmental risk from an accident or incident," the minister said.
The ship, the Atlantic Osprey, is understood to be preparing to carry 1.25 tonnes of mixed oxide or MOX fuel, which contains about 90kg of plutonium, to Cherbourg within the next few days.
The Green Party, the Labour Party and Sinn Féin all urged the minister to block the cargo.
Mr Roche said: "The Government secured an assurance from the UK that the MOX Fuel shipment would not enter Irish territorial waters and that the shipment is governed by a stringent system of regulation established in line with internationally agreed standards and recommendations.
"Nevertheless, the Irish Coast Guard are monitoring the situation."
Mr Roche said the Government's concerns in relation to nuclear shipments are regularly and repeatedly conveyed to the British government at ministerial and official level.
"The continuing concerns of the Irish Government in relation to the transportation of nuclear waste and fuels through the Irish Sea have been made known to the UK authorities," he said.
"The United Kingdom Government is under no illusions as to Irish Government policy on such shipments. They are aware that these shipments cannot enter Irish waters.
"In this regard, I can also promise the Irish people that I will continue to voice their concerns about the marine shipments of nuclear material at every possible forum."
Sellafield's MOX Plant utilises plutonium, separated during reprocessing of spent fuel for foreign customers at Sellafield, and returns it in the form of fuel for use in nuclear reactors.
Mr Roche said the MOX Plant is inextricably linked with the operation of THORP with all that this entails in relation to marine radioactive discharges to the Irish Sea.
"These concerns, regrettably, are regularly reinforced by the poor ongoing safety record at the Sellafield complex and more recently by the serious incident at the THORP Plant in April 2005," he said.
"The Irish Government will continue to use every diplomatic, political and legal route available to bring about the safe and orderly closure of the Sellafield plant."