FUKUOKA (Kyodo) Kyushu Electric Power Co. on Thursday began loading a controversial nuclear fuel into the Genkai nuclear power plant in Saga Prefecture as it prepares to make Japan's first attempt to reliably produce "pluthermal" electricity.

The fuel, called plutonium-uranium mixed oxide (MOX), is being loaded into Genkai's No. 3 reactor.

The power plant is scheduled to try generating plutonium-thermal power as early as December but may face delays due to public safety concerns.

The loading process will be shown to the media Friday but is expected to take until Monday to complete.

The utility plans to restart the reactor in early November and gradually increase output from early December, Kyushu Electric officials said.

MOX is spent nuclear fuel that has been recycled abroad to extract the plutonium. The new fuel was being kept in a pool at the plant for underwater loading that requires the use of a special crane, they said.

Kyushu Electric is in the process of replacing about a third of the 193 uranium fuel assemblies in the reactor, a process that began with regular checks in late August. About 16 of the fuel assemblies will be switched from uranium to MOX.

But public worries linger: Japan's reactors are not designed for pluthermal use.

The electric power industry has repeatedly delayed a state-backed plan to start pluthermal power generation at 16 to 18 reactors between next year and fiscal 2015 because of accidents and safety scandals.

Despite delays, Shikoku Electric Power Co. and Chubu Electric Power Co. plan to follow Kyushu Electric's lead on pluthermal power generation in 2010.

The government is promoting pluthermal power as the pillar of its recycling-based nuclear fuel-cycle policy.