TOKYO: A company backed by Microsoft founder Bill Gates and Toshiba are in early talks to jointly develop a small nuclear reactor, the Japanese electronics giant said Tuesday.

The Nikkei business daily earlier reported that the two sides would team up to develop a compact next-generation reactor that can operate for up to 100 years without refueling to provide emission-free energy.

The daily said the joint development would focus on the Traveling-Wave Reactor (TWR), which consumes depleted uranium as fuel. Current light-water reactors require refueling every few years.

"Toshiba has entered into preliminary talks with TerraPower," said Toshiba spokesman Keisuke Ohmori. "We are looking into the possibility of working together."

Gates is the principal owner of TerraPower, an expert team based in the US state of Washington that is investigating ways to improve emission-free energy supplies using small nuclear reactors.

Unlike the current reactors at mega power plants, the smaller types could be introduced by cities or states or in developing countries more easily.

Ohmori said Gates, together with other TerraPower executives, had visited a Toshiba laboratory for nuclear power research near Tokyo last year.

"TerraPower is developing a small nuclear reactor and Toshiba is developing a different kind of small reactor. They were interested in Toshiba's technology and aiming at practical realisation" of small reactors, he said.

Ohmori said the two sides had just begun to "exchange information" but stressed that "nothing concrete has been decided on development or investment."

Gates is expected to use his personal wealth to back the development of TWRs and his investment could reach several billion dollars, the Nikkei said.

The news boosted Toshiba's share price by around four percent Tuesday.

The Nikkei said TerraPower had decided to join hands with Toshiba as it lacks the know-how to manufacture nuclear power equipment.

Toshiba, which owns US nuclear plant maker Westinghouse, has developed a design for an ultracompact reactor that can operate continuously for 30 years.

The company is preparing to apply for US approval to start constructing the first such reactor as early as 2014 and put it into practical use by the end of the decade, Ohmori said.