The Japan Atomic Energy Agency is considering applying for a government safety assessment of its aging Joyo experimental fast reactor in March in hopes of restarting it, according to sources close to the matter.

The government is looking to the Joyo reactor to continue development of fast reactors, given that the JAEA's Monju prototype fast breeder reactor, which was intended to play a key role in the process, is on the verge of being scrapped after a trouble-plagued history stretching back two decades.

In plutonium-fueled fast reactors, fission chain reactions are sustained by fast neutrons. The government has been pursuing fast reactors to "breed" plutonium, meaning more plutonium is produced than consumed.

The Joyo reactor in Ibaraki Prefecture and Monju in Fukui Prefecture were created as the first and second stage of the fast breeder reactor research and development project that commenced in the 1960s.

Joyo, which reached criticality in 1977, is no longer used for fast breeder research. But the reactor has come under the spotlight as the government is leaning toward scrapping Monju.

The government is to decide Monju's fate by the end of the year.

Monju was intended to play a key role in achieving a nuclear fuel cycle aimed at reprocessing uranium fuel used in conventional reactors and reusing the extracted plutonium and uranium.

The reactor uses extracted plutonium and uranium as fuel, but it has remained largely offline since first achieving criticality in 1994, due to a leakage of sodium coolant and other problems.

The 2011 Fukushima crisis was also a blow to the Monju project, which has already cost more than ¥1 trillion of taxpayer money, with many among the public critical of nuclear power projects.