Thomas Neff, Who Turned Soviet Warheads Into Electricity, Dies at 80

As the Soviet Union disintegrated, Thomas L. Neff came up with an improbable idea. What if Soviet nuclear warheads could light up American cities rather than obliterate them? What if the United States could buy the uranium cores of the deadly arms and turn them into reactor fuel?

Despite vast hurdles and skepticism, Dr. Neff pulled it off, pioneering an East-West deal that gave bankrupt Moscow hard currency, reduced nuclear threats and produced one of the greatest peace dividends of all time. Over two decades, his bright idea turned some 20,000 Russian nuclear arms into electricity, lighting billions of American lightbulbs.

Dr. Neff, a physicist, died on July 11 when, after having breakfast with his wife at their home in Concord, Mass., he collapsed and never regained consciousness. He was 80.

His daughter, Catherine C. Harris, said the cause was a subdural hematoma, or bleeding from the brain.

His feat of nuclear weapon conversion, if now a poorly known chapter of atomic history, was hailed in the early 1990s by federal officials astonished at what Dr. Neff had accomplished. “Instead of lighting up mushroom clouds, this stuff is going to light up homes,” Philip G. Sewell, a Department of Energy official who took part in negotiations for the uranium transfer, said in 1992 of the recycled Soviet arms. “It’s kind of incredible.”

At the time, many experts worried that Moscow’s arsenal might fall into unfriendly hands. The jitters intensified as Russia announced plans to store thousands of unused weapons from missiles and bombers in what American experts saw as decrepit bunkers policed by impoverished guards of dubious reliability. Many people worried. Few knew what to do.