Fifteen years after the end of the Cold War, the risk of nuclear disaster is as great as ever with terrorists zealously pursuing atomic weapons, Mohamed ElBaradei, the director general of the U.N. nuclear agency, said Saturday in accepting the 2005 Nobel Peace Prize.

ElBaradei and the International Atomic Energy Agency he leads received the coveted award in the Norwegian capital for their efforts to control the spread of nuclear weapons -- a job ElBaradei nearly lost because of a dispute with the United States over Iran and Iraq.

"We are in a race against time," ElBaradei, a 63-year-old Egyptian, said about efforts to keep nuclear weapons away from terrorists. "In four years, we have completed perhaps 50 percent of the work. But this is not fast enough."

To escape self-destruction, the world must make atomic weapons as much of a taboo as slavery or genocide, ElBaradei said in his acceptance speech. It has been 60 years since the atomic bombings of Hiroshima and Nagasaki in Japan, yet the world is still deeply concerned by nuclear programs in Iran and North Korea.

The Bush administration has bristled at ElBaradei's positions on the nuclear threat posed by Iran and Iraq and unsuccessfully lobbied to block his appointment to a third and final four-year term at the U.N. agency this year.

ElBaradei and the IAEA locked horns with the United States in the run-up to the Iraq war by challenging U.S. claims that former president Saddam Hussein possessed weapons of mass destruction. No such weapons were ever found.

More recently, ElBaradei's refusal to back U.S. assertions that Iran has a covert nuclear weapons program hardened opposition to him within the Bush administration.

As ElBaradei received his award, Iran's top nuclear official said his country would enrich uranium and produce nuclear fuel, despite an international drive to curb such efforts. Gholamreza Aghazadeh, the head of Iran's Atomic Energy Organization, did not say when the processes would begin. Iran insists its nuclear program exists for peaceful purposes, not for developing weapons.

The Nobel prizes are always presented on Dec. 10, the anniversary of the 1896 death of Alfred Nobel, the Swedish industrialist who invented dynamite and established the prizes in his will. The prizes in literature, physics, chemistry, medicine and economics were handed out in Stockholm.

The winner of the prize for literature, Harold Pinter, was prevented by poor health from traveling to Sweden to accept his award. Pinter, 75, has been treated for cancer in recent years. The British playwright's publisher accepted the award on his behalf.

In Oslo, ElBaradei and the Yukiya Amano of Japan, chairman of the IAEA's Board of Governors, accepted the Peace Prize to applause from a crowd that included Norway's King Harald V and Queen Sonja.

ElBaradei said his half of the $1.3 million prize would go to orphanages in his native Egypt, while the IAEA planned to establish a fund for cancer and nutritional research.

The chairman of the awards committee, Ole Danbolt Mjoes, praised the winners' efforts to curb the spread of nuclear weapons. He also issued a reminder.

"The atom bombs fell on Hiroshima and Nagasaki 60 years ago," he said. "Since then, the world has been united in the wish that nothing like that must ever happen again."

Mohamed ElBaradei, left, head of the International Atomic Energy Agency, and Yukiya Amano, the board of governors chairman, accepted the prize.