Bill Gates is investing in new ways to address energy needs

A company backed by Microsoft chairman Bill Gates is in talks with Japan's Toshiba to develop a new generation of nuclear reactors.

Mr Gates' TerraPower and Toshiba are investigating technology for mini-reactors, which are more cost-efficient than conventional units.

The hope is that the new reactors might be suitable for use in cities or emerging-market countries.

Toshiba emphasised that the two sides were only in early-stage talks.

Mr Gates is the principal owner of TerraPower, which investigates ways to improve emission-free energy supplies using small nuclear reactors.

Japan's Nikkei newspaper, which first reported the talks, said that Mr Gates could put tens of millions of dollars of his own money into a joint venture with Toshiba.

Developing markets

Mini-reactors could last up to 100 years without refuelling, unlike today's units which need replenishing every few years.

Toshiba is the world's third-largest maker of microchips and also owns the Westinghouse reactor design company.

TerraPower is looking into so-called travelling-wave reactors (TWRs), which use depleted uranium as fuel and can last far longer.

"There would be demand for this type of reactor in newly developing countries," said Deutsche Securities analyst Takeo Miyamoto.

Toshiba is already looking into technology that would enable mini-reactors to last about 30 years without refuelling.

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

He said that Mr Gates had visited a Toshiba laboratory for nuclear power research near Tokyo last year to discuss the project.

The two sides have begun to "exchange information" but "nothing concrete has been decided on development or investment," Mr Ohmori said.