FUKUI — Fukui Prefecture gave the final go-ahead Thursday for Kansai Electric Power Co.'s plan to use mixed plutonium-uranium oxide fuel at its Takahama nuclear plant.

The controversial project, which could start as early as November, will mark the first time MOX fuel will be used at a nuclear plant in Japan.

MOX is a combination of uranium and plutonium extracted from spent nuclear fuel. It will be used in conventional uranium-burning light-water reactors.

Besides Kepco, Tokyo Electric Power Co. also plans to use the fuel, to be shipped from Europe this autumn, at plants in Fukushima and Niigata prefectures.

While the government considers the project a vital part of its nuclear fuel recycling policy, critics cite safety concerns.

Fukui Gov. Yukio Kurita gave his written approval of the MOX project to Kepco President Yoshihisa Akiyama at the prefectural headquarters Thursday morning.

The central government has already completed safety inspections of the No. 4 reactor at Kepco's Takahama plant on Wakasa Bay facing the Sea of Japan, about 90 km southwest of the city of Fukui.

Tepco's Fukushima and Niigata plants have yet to go through the procedure, although governors of the two prefectures have already approved the utility's MOX plans.

Gov. Kurita had earlier explained that the prefecture would cautiously examine the plan. But soon after he won re-election in April, he made it clear he would decide by June.

Kurita told reporters that the prefecture made the decision to approve the MOX plan because its safety has been confirmed.

Kepco's Akiyama also said his firm will do its best to ensure safety of the project. He said he hopes to start loading MOX fuel at the Takahama plant by the end of November.

To win the prefecture's consent, the central government has offered various measures to promote the local economy.

If the MOX shipment from reprocessing plants in Europe arrives in Japan by the end of September as planned by Kepco, the utility will suspend operation of the Takahama plant to load the fuel and restart the plant with the new fuel.

MOX fuel for Tepco will also arrive in the same shipment from Europe. The utility plans to load the fuel into the No. 3 reactor of its Fukushima-Daiichi plant during regular checkups from October to February.

Kepco has so far refused to disclose any information concerning the schedule or route of the shipment, citing fears of possible hijacking, although Akiyama said Thursday that the firm will try to unveil some information after consulting government authorities. But ships carrying the fuel are expected to leave a European port sometime in July.

The environmentalist group Greenpeace, which is protesting the shipment, has identified the vessels to be used as the 4,709-ton Pacific Teal and 5,087-ton Pacific Pinstripe, both owned by Britain's Atomic Energy Authority.

Japan decided in February 1997 to introduce MOX at the nation's atomic plants to promote the recycling of spent nuclear fuel. The nation plans to start burning MOX in 16 to 18 reactors by 2010.

Japan has entrusted British and French firms to reprocess spent fuel from its nuclear plants. Because the government has promised not to own surplus stocks of weapons-grade plutonium, the nation has to steadily consume plutonium extracted from spent fuel.

A plan for fast-breeder reactors, which were to play the central role in Japan's plutonium consumption, was sidelined after the December 1995 sodium leak at the Monju prototype fast-breeder reactor in Fukui. That left the MOX project — once considered a stopgap measure before commercialization of fast-breeder reactors — as the only alternative for dealing with excess plutonium.

Last December, the government's Nuclear Safety Commission issued a statement saying it would guarantee the safety of operations using MOX at the Takahama plant.

But critics protest that the safety of MOX has yet to be validated.

The Tokyo-based Citizens' Nuclear Information Center says the use of MOX will reduce safety margins at nuclear plants, and a group of U.S. experts has warned that use of fuel containing plutonium will only expose residents around the plants to greater health risks in cases of severe accidents.