WASHINGTON -- After a secret odyssey over two continents and the highways of the eastern United States, the last of a shipment of weapons-grade Soviet uranium strong enough to make 20 nuclear bombs arrived yesterday at a government facility in Tennessee.
Government officials described the capture of the material -- totaling about 1,320 pounds of highly enriched uranium 235 packed in foam-filled steel containers -- as a major coup in the battle against nuclear proliferation.
Its arrival ended a nine-month operation called Project Sapphire in which the United States transferred the radioactive material from the former Soviet republic of Kazakhstan for safekeeping.
And it completed a project that ended at the Oak Ridge, Tenn., facility where the uranium for the Hiroshima bomb was produced.
"This is a good day," President Clinton said of the task yesterday. "One more threat of nuclear terrorism and proliferation has been removed from the world."
Defense Secretary William J. Perry said: "We have put this
bomb-grade nuclear material forever out of the reach of potential black-marketeers, terrorists or new nuclear regimes."
And David Wall, of the Department of Energy's historic Y-12 plant in Oak Ridge, where the material is being stored, said:
"If there's one thing we all feel, it's that the world's a safer place than it was last week."
Set against rising fears that nuclear material from the former Soviet Union might fall into terrorist hands, the seizure of such material last summer in Germany and the recent nuclear crises in North Korea, the seeds of the operation were sown last February.
Government officials said that President Nursultan Nazarbayev, of the central Asian republic of Kazakhstan, approached the United States with concerns about the security of nuclear material left at a former Soviet research facility that made uranium for naval propulsion reactors.
The United States, wary that such material might fall into the wrong hands, shared the concern. "It's a real problem," a senior administration official said yesterday. "There are people really shopping for this kind of material."
Although the official said the uranium had been made for use in a naval propulsion system and not in a bomb, it was still weapons-grade.
The two countries agreed that the uranium, stored about 20 miles outside the town of Ust Kamenogorsk in eastern Kazakhstan, should be removed to the United States. There followed months of delicate diplomatic negotiations with Russia
and other countries and on Oct. 7 the president ordered the operation to begin.
Two days later a team of 31 people from the departments of Defense and Energy as well as from private companies flew to Kazakhstan to begin the operation.
They had to bring in most of their own equipment and had to construct their own lab, handling and testing facilities inside an old building at the nuclear complex.
Officials said they received the utmost cooperation from Kazakhstan -- whose ambassador and turquoise and yellow flag appeared at a Pentagon briefing on the subject yesterday. The country was being compensated for its help, but Secretary of State Warren M. Christopher declined to say exactly how.
Meanwhile, the transfer team, often wearing paper anti-contamination suits and special breathing gear, had to hurry because of the approach of winter. Workers labored 12 hours a day, six days a week for six weeks, Energy Secretary Hazel R. O'Leary said.
The uranium was transferred from its old containers, baked dry for shipment and placed in a series of 1,400 stainless steel containers about the size of quart oil cans. Those containers were then placed in larger, foam-filled stainless steel barrels and loaded with forklifts aboard giant C-5 Air Force transports.
Delayed slightly by bad weather, the flights out began Sunday about 4 p.m. It took three C-5s to carry the material. They made non-stop 20-hour flights, refueling twice in the air, before reaching the Dover, Del., Air Force Base.
The uranium was then loaded onto special Department of Energy trucks, called Safe and Secure Transports, and driven to Oak Ridge in four three-truck convoys. Government officials declined say what route the convoys took.
The first convoy arrived at Oak Ridge at about 6:30 a.m. Tuesday and the last at about 8 a.m. yesterday.
Energy Department officials said the Y-12 facility, operated for the department by Martin Marietta, dates back to the mid-1940s, when it was built as part of the Manhattan Project that developed the atomic bomb.
After the war it was used to manufacture components for nuclear weapons, and since 1992 has been chiefly used to store unneeded or dismantled nuclear materials.
Ms. O'Leary said the hope was that the Soviet uranium would eventually be "blended down" for use in commercial reactors.
Asked about local reaction to the uranium's arrival, Mr. Wall, in Oak Ridge, said:
"This material is very similar to material we've safely stored at Y-12 for decades. And the local community is very supportive."
Overall, Ms. O'Leary, the energy secretary, said yesterday, "this is a very happy day."