The Japan Atomic Energy Agency proposed a blueprint Thursday for nuclear technology development that envisions a 1,500-megawatt fast-breeder reactor to succeed the prototype fast-breeder reactor Monju in Tsuruga, Fukui Prefecture.

The agency outlined the plan in a proposal submitted to the Ministry of Education, Culture, Sports, Science and Technology.

Like Monju, the envisaged reactor will use sodium coolant and burn plutonium-uranium mixed oxide fuel (MOX) made from spent fuel, stockpiles of which have been growing rapidly.

The agency plans to build a reactor that is about one-sixth the size of Monju but with an output of about 1,500 mw -- about five times that of Monju.

The government is set to contribute to the U.S.-led Global Nuclear Energy Partnership initiative in the area of fast-breeder reactor technology and fuel reprocessing technology. The agency says the proposal's direction is basically the same as that of GNEP.

According to the proposal, the agency has evaluated its representative octagonal nuclear reactor in five areas, including safety, economic efficiency and resistance to nuclear proliferation.

For the analysis, the agency chose the same type of reactor as Monju, which uses sodium coolant and MOX fuel.

The agency says it will present a detailed plan by 2015. It plans to conduct verification tests at its experimental facility and at Monju to develop a 300- to 500-mw reactor by around 2025.

On fuel reprocessing, the agency plans to develop the method being used by Japan Nuclear Fuel Ltd. at its reprocessing facility in Rokkasho, Aomori Prefecture.

It plans to extract plutonium with other radioactive materials because pure plutonium can easily be used in nuclear weapons.