RECORDS SHOW DARING MISSION WAS IN VAIN.

Byline: Les Blumenthal Scripps-McClatchy Western Service

The government disclosed Wednesday that two daring 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.

``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 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 of 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.

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.

Energy Secretary Hazel 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.

The 80 grams, or about three ounces, of plutonium is far less than what is needed to build a bomb.

``I don't want this hyped,'' O'Leary said. ``We are talking about a very small amount.''

But prolonged personal exposure to the plutonium could be hazardous.

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 declassified documents paint a picture of a high-risk mission to retrieve the plutonium and other nuclear materials as the Viet Cong moved in on Dalat from three sides.

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.''