June 26, 2007 (LPAC)--Mitsubishi Heavy Industries announced that it has established a new company to develop and manufacture the fast breeder reactor, which "breeds" more nuclear fuel than it uses up in producing electricity. Japan has designated the fast reactor as its main nuclear reactor of the 21st Century, replacing the conventional light water reactors.

From the beginning of the postwar civilian nuclear programs, breeder reactors were considered an essential part of completing the nuclear fuel cycle, making countries with limited uranium resources more self-sufficient in nuclear fuel.

Mitsubishi FBR Systems, Inc., or MFBR, has been selected as the core company in Japan's fast breeder development, and will start operation on July 1st. A demonstration reactor is planned for completion in 2015.

Fast breeder reactors use liquid-metal sodium for the reactor coolant. In the breeder reactor, fast neutrons burn uranium and plutonium mixed-oxide fuel, which is surrounded by a blanket of uranium. The fission reactions in this blanket create more new plutonium than is used up.

The Japanese already have an experimental fast reactor, Joyo (1977), and a prototype fast reactor, Monju (1994).

In contrast. the United States, under the Bush Administration's Global Nuclear Energy Partnership, with its aim of policing proliferation, plans to develop a fast reactor not to breed more fuel but only to burn up the high-level isotopes from spent nuclear fuel. The U.S. fast breeder program was killed in the early 1970s, as part of the "nonproliferation" campaign that was actually aimed at shutting down civilian nuclear power.