WASHINGTON, Aug. 5 Kyodo - The U.S. government plans to ship weapons-grade plutonium from disassembled Russian nuclear arms from the United States to France for reprocessing, but the vessels will not be escorted by warships, according to U.S. Energy Department documents obtained by Kyodo News on Thursday.

Anti-nuclear groups have expressed opposition and concern that the two vessels transporting 140 kilograms of high-purity plutonium across the Atlantic Ocean could be targeted by terrorists, even though they are armed.

The plutonium to be shipped to France sometime this month can easily be used to make more than 30 atomic bombs, according to nuclear experts.

Under the Energy Department plan, the powdered plutonium, which is kept at Los Alamos National Laboratory in Los Alamos, New Mexico, will be shipped from the Charleston Naval Complex in South Carolina to France. The reprocessed fuel will be shipped back to the United States.

The two ships will guard each other during the voyage across the Atlantic, but will not be escorted by warships, according to the Energy Department plan.

Sources familiar with the shipment plan say the ships expected to be used are the Pacific Teal and the Pacific Pintail, which are involved in shipping reprocessed nuclear fuel from Europe to Japan.

The lack of military escort has raised concerns the ships could be hijacked, especially amid threats of terrorist attacks during the Olympic Games in Athens around the same period.

The Energy Department documents, however, say the method of mutual protection between the two cargo ships has satisfactory defense capability.

The U.S. Nuclear Regulatory Commission gave the green light in June for shipping the plutonium to France.

Under a treaty between the United States and Russia, plutonium from disassembled nuclear weapons is to be reprocessed into plutonium-uranium mixed oxide fuel, also known as MOX fuel, and consumed at nuclear power plants.

However, because no facilities to make MOX fuel exist in the United States, the plan is to manufacture four fuel rods in France as an experiment ahead of full-fledged implementation.

The arrangement of having armed transport ships protect each other instead of an escort by military vessels was first tried in 1999 when MOX fuel was transported from Britain and France to Japan.

The anti-nuclear groups have said that while it is difficult to use the hardened MOX fuel to make atomic bombs, such high-purity weapons-grade plutonium can easily be processed to make nuclear weapons.

An atomic bomb can be manufactured with just 4 to 5 kilograms of plutonium, the groups said.

==Kyodo