VIENNA, Sept. 19 — Warren E. Buffett, the billionaire investor and philanthropist, pledged $50 million on Tuesday to help set up an international nuclear fuel bank that aspiring powers could turn to for reactor fuel instead of making it on their own.
Mr. Buffett’s aim is to curb the risks of nuclear proliferation by providing an alternative to the kind of indigenous production of nuclear fuel that Iran is embarking upon, and that countries like Argentina, Australia and South Africa have recently announced plans to pursue.
Nuclear experts say indigenous production carries with it the risk of military diversion for nuclear arms, and that the risk is rising as a growing number of countries around the world embrace atomic power or plan to expand their nuclear programs.
“This pledge is an investment in a safer world,” Mr. Buffett said in a statement.
“The concept of a backup fuel reserve has been discussed for many years,” he said. “Its creation is inherently a governmental responsibility, but I hope that this pledge of funds will support governments in taking action to get this concept off the ground.”
His pledge came at an international conference here in Vienna where nations are exploring how to create multinational fuel banks as a way to aid nuclear development while avoiding new risks.
Multinational banks and plants are seen as having a security advantage because member states can watch one another to prevent weapon diversions.
Mr. Buffett’s pledge is meant to jump-start the creation of a reserve fuel bank run by the International Atomic Energy Agency, the global nuclear watchdog based in Vienna. He made it through the Nuclear Threat Initiative, a private group in Washington that he advises.
Sam Nunn, a former Democratic senator from Georgia and the group’s chief executive, announced the $50 million pledge here, calling it a crucial step toward a new order that enhances peaceful aspects of atomic energy. “We are in a race between cooperation and catastrophe,” he said, “and, at this moment, the outcome is unclear.”
Mr. Nunn said a country’s decision to import fuel, rather than make it indigenously, could pivot on whether the country can be guaranteed an assured supply.
“We believe that such a mechanism can be achieved,” he said, “and that we must take urgent, practical steps to do so.”
Mr. Buffett’s pledge is contingent on two years of developments in which the nuclear agency moves to establish the fuel bank and one or more countries contribute an added $100 million or an equivalent amount in reactor fuel.
Mohamed ElBaradei, the director general of the international atomic agency, said Mr. Buffett’s pledge “will provide urgent impetus to our efforts to establish mechanisms for nondiscriminatory, nonpolitical assurances of supply of fuel for nuclear power plants.”
Laura Holgate, a vice president of the Nuclear Threat Initiative, said $150 million in fuel would represent less than 1 percent of that used globally each year, and would be enough to fuel a typical power reactor.