The government has disclosed that two scientists undertook a desperate mission in 1975 to retrieve plutonium from a Vietnamese reactor under sniper fire, only to learn years later the canister they carried out during the Vietnam War had been mislabeled.
The mislabeling was discovered in 1979 by Thomas Blankenship, security director for the Department of Energy's Nevada Operations Office. His discovery meant that despite the best efforts of American military and civilian officials, about 3 ounces of plutonium remained in Vietnam.
That amount, however, is far less than what is needed to build a bomb.
The whole incident became public in recent weeks as the result of the DOE's decision to open records that had previously been classified. Energy Secretary Hazel O'Leary said the incident, while an eye-opener, is not one of catastrophic proportions.
The scientists involved in the retrieval mission feared they might fail or even get killed.
"Looking back, I figure we had only a 50-50 chance of pulling it off," said Wally Hendrickson, who now works at the nuclear reservation in Hanford, Wash.
Weeks after rescuing what he thought was 80 grams of weapons-usable plutonium, Hendrickson was rescued by helicopter from the roof of the U.S. Embassy in Saigon as U.S.-backed South Vietnam fell. He was one of the last Americans to leave Vietnam in 1975.
"One lady said, if the (Viet Cong) caught us they would chop off our heads," Hendrickson said. "They were probably right."
The canister retrieved by Hendrickson and John Horan, a scientist at the Department of Energy's Idaho Falls facility, sat at Hanford for three years before the labeling mistake was discovered in 1979 and it was found to hold the decayed remains of another radioactive isotope, polonium.
For years, the fact the United States may have left a canister of plutonium behind in Vietnam remained a secret.
"The documents were classified to protect the fact the plutonium was unaccounted for," the Energy Department said in a press release. But the paper trail also hints at errors in record-keeping, including sending the wrong forms to the International Atomic Energy Agency (IAEA).
Department officials were all but stunned when they recently found the documents as part of their effort to make public millions of pages of what had previously been classified documents. They immediately notified the State Department, the IAEA and the Vietnamese government.
O'Leary said investigators, with the cooperation of the Vietnamese government, believe they might already have found the plutonium, still at a research reactor in Dalat. An international team is scheduled to inspect the Dalat facility in February.
Hendrickson said he was surprised to learn the canister he and Horan had brought out of Vietnam was the wrong one.
"I thought I had the right one," said Hendrickson, who calls himself a "technical guy" with four engineering degrees. He is working on a tank safety program at Hanford.
The plutonium and other radioactive materials had been transferred to the South Vietnamese government by the United States in 1962 as part of the Atoms for Peace program. The reactor at Dalat was used to produce radioisotopes for research and medical purposes.
In the spring of 1975, as the Communists were on the verge of conquering South Vietnam, the director of the Dalat reactor came to the U.S. Embassy in Saigon to remind American officials that plutonium and highly enriched uranium were stored at the reactor.
The reminder set off panic in the embassy, and immediately volunteers were sought. Hendrickson, who was 39 at the time, and Horan stepped forward.
The U.S. ambassador in Saigon had told them if the village was overrun, they were on their own and their best escape route was to walk 50 miles through the jungle to the coast. The mission took place on Easter Sunday in hopes the Viet Cong would be lulled into thinking Americans would be celebrating the religious holiday.
Hendrickson said he became worried only when an embassy official kept reminding them they were volunteers and they were told they would not be rescued if things went awry.
"It dawned on me how serious this was," he said. "The government seemed a little casual about this, but it was dangerous."
A cargo plane carrying special equipment to handle the radioactive materials flew them into Dalat and they stayed two days working around the clock.
"We saw Viet Cong prisoners in the city and Vietnamese forces were sweeping the area," Hendrickson said. "We worked day and night, no sleep, little food. Horan got shot at one night."
After packing up the nuclear materials, Hendrickson and Horan flew out on a plane loaded with refugees just hours before Dalat fell.
"It was really nerve-wracking," he said. "It wasn't so much bravery, we were just dedicated to get this stuff out."