Minister for the Environment Dick Roche has said he has received assurances from the British government that a shipment of plutonium from Sellafield will not enter Irish territorial waters on its way to France.
The Atlantic Osprey, owned by the British Nuclear Group is due to pass along the east coast of Ireland through the Irish Sea in the next couple of days.
The ship is bringing 1.25 tonnes of Mixed Oxide (MOX) fuel containing about 90kg of plutonium from Sellafield to Cherbourg. The shipment will then be transported the Beznau nuclear plant in Switzerland.
Mr Roche said today the Government has repeatedly raised its concerns with Britain over the transportation of nuclear waste and fuels through the Irish Sea. These concerns relate to safety, security and environmental risk from an accident or incident.
"Utilising the voluntary, confidential, advance, notification arrangements which have been in place for a number of years now, 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," the Minister insisted today.
"Nevertheless, the Irish Coast Guard are monitoring the situation."
Green Party leader Trevor Sargent claimed this morning the single-engined, single-hulled ship was inadequate for the task, lacking security aspects considered prerequisites for the shipment of such materials.
"While plutonium shipments through the Irish Sea are unacceptable, this one appears to be especially dangerous. This shipment is an affront to the health and economic well-being of the Irish people," he added.
He said he is concerned that the ship, which does not have a navy escort, could be targeted by "those with malicious intent".
Labour Party nuclear safety spokesman Emmet Stagg this afternoon called on Mr Roche to deny the ship passage through the Irish Sea.
"The plutonium fuel on board is highly dangerous and should the ship encounter any accident the consequences for the east coast would be catastrophic," he said.
He also raised the prospect of a possible terrorist attack. "This is a matter of real concern at a time when vessels carrying nuclear materials are potential targets. One shudders to think of the damage to life and to the environment that would cause."