The Japan Atomic Energy Agency and Mitsubishi Heavy Industries Ltd. will soon sign a memorandum of understanding with a U.S. venture firm to provide technical support for its fast reactor development project, sources close to the matter said Saturday.

The agency, which has a history of operating sodium-cooled fast reactors such as the Monju prototype fast-breeder reactor in Fukui Prefecture and the Joyo experimental fast reactor in Ibaraki Prefecture, is considering providing operational data and designs to TerraPower, a company co-founded by Microsoft Corp.'s Bill Gates.

TerraPower plans to build a fast reactor with an output of 345,000 kilowatts using sodium as a coolant in the state of Wyoming from 2024. The U.S. Department of Energy is providing funding for the project, which is expected to be completed in 2028.

While the specifics of the collaboration are still being discussed, the agency is also considering using its sodium experimental facility Athena in Ibaraki Prefecture to develop safety technology, according to the sources.

Japan is pursuing a nuclear fuel recycling policy in which plutonium extracted from spent nuclear fuel at power plants is reused, with fast reactors playing a key role in the plan.

But domestic development has come to a halt following the decommissioning of the Monju reactor, which was intended to be a fast reactor that produces more plutonium than it consumes, prompting resource-poor Japan to explore opportunities for overseas collaboration.

The Joyo experimental fast reactor, which was created as the first stage of the fast breeder reactor development project, currently remains suspended.