A company that is developing a nuclear-powered battery that could last more than 100 years and revolutionize the power industry says it has moved a step closer to a patent for the device.

Peripheral Systems Inc. said that its subsidiary, Nucell Inc., has received a "notice of allowance" for a patent on its resonant nuclear battery, a device that transforms radioactive decay into electrical energy.The battery was created by Paul M. Brown, 30, a physicist who sold Nucell to Peripheral last year but remains involved in the battery's development.

Peripheral was founded in 1983 to manufacture hard disks for the computer industry but switched to high-intensity lighting equipment and a microwave antenna to filter signals from satellites. In 1986, Peripheral acquired X-Ray Inc. of Seattle, a company that uses X-rays to test metals for various industries, including the aerospace industry.

Philip H. Talbert, chairman of Peripheral, said in a press release issued Monday that the notice of allowance for the nuclear-powered battery was a "milestone which should enable the company to consummate certain licensing and joint venture development efforts that are pending with major utilities, defense contractors and governmental agencies."

The company signed an agreement in May with Atomic Energy of Canada Ltd. in Ottawa, a government-owned corporation, to help fund research on the battery.

The battery uses a technology that polarizes the radioactive particles emitted by the decay of cobalt, turning them into electricity.

If the battery proves commercially successful, it could help eliminate reliance on fossil fuels and make Peripheral a major industrial supplier.

However, Peripheral was sued in January by the Idaho state Department of Finance, which alleged that its Nucell subsidiary fraudulently solicited investors in Idaho and omitted facts in its stock offering, including failure to disclose that experts at the Idaho National Engineering Laboratory thought Brown's invention had no merit.

Talbert was unavailable for comment on any developments in that legal action, and Idaho officials said only that the lawsuit was proceeding in southwestern Idaho's 4th District Court.