Sandia Shuts Off Fusion Reactor

December 23, 2003
By John Fleck
Journal Staff Writer

Sandia National Laboratories has shut down its showpiece "Z" nuclear fusion research reactor after discovery of elevated levels of the hazardous metal beryllium in parts of the reactor building.

The shutdown happened Friday, when letters were sent to hundreds of Sandia workers alerting them to the problem and offering medical screening to see if they have been exposed.

One case of beryllium lung disease had previously been reported at Sandia, but it hasn't yet been linked to the problem in the Z building.
There is as yet no evidence any other workers were exposed to the dangerous metal, Sandia officials said Monday.

"Sandia views this as a very serious issue," said Al West, Sandia's environment, safety and health director. "We don't want to get anybody contaminated."

Dust from beryllium, a hard, lightweight metal used in nuclear weapons, can cause both chronic and long-term lung disease. Beryllium disease has been a major worker health problem within the United States' nuclear weapons complex, especially at nuclear weapons factories near Denver and in Tennessee.

The Z reactor uses banks of huge capacitors to store electricity and then quickly zap small targets at the machine's heart, generating brief pulses of energy rivaling those found in stars or nuclear blasts.

Earlier this year, Sandia announced that it had achieved tiny bursts of nuclear fusion in Z tests, an achievement Discover magazine ranked as one of the 100 most important science stories of 2003.

Half of the blasts, some 50 per year, use beryllium in the targets, said Jeff Quintenz, head of Sandia's pulsed power program.

The contamination was found after some lab employees questioned why they were doing maintenance work in a room adjacent to the Z machine without wearing respirators or having the room decontaminated.

A survey of the room found their concerns were well-founded, with levels of beryllium dust in some parts of the room that were above Energy Department mandatory cleanup levels, said Lisa Hooper, Sandia's industrial hygienist.

The gymnasium-sized room that houses the Z machine itself is regularly decontaminated with special vacuum cleaners to remove beryllium dust. But similar decontamination hadn't been done in the adjacent workroom where the contamination was found.

At Sandia, workers who regularly handle beryllium undergo routine screening for beryllium exposure, according to Hooper. Two workers at Sandia have been diagnosed with chronic beryllium disease, according to Sandia spokesman John German, including one who got the disease while working at the Energy Department's Rocky Flats nuclear weapons factory.

The second case involves a maintenance worker who did spend time in the Z building, German said, though it is not clear if there is a connection.

No results are in from the new round of testing launched after the Z building contamination was discovered. Letters have been sent out to about 400 workers in the lab's facilities division. The workers do maintenance, some construction and custodial work.

Letters also have been sent to lab subcontractors whose employees may have been in the Z building.

Scientists believe 40 percent of the population has a genetic vulnerability to beryllium disease.

A 2001 study found 81 cases of chronic beryllium disease among workers at Rocky Flats, near Denver. More than one in 10 beryllium machinists showed signs of exposure. The Rocky Flats study also showed that one in 20 custodians had been exposed.

Chronic beryllium disease, which can be caused by low-level exposure, results from scarring of the lungs, reducing the victim's ability to get oxygen into the bloodstream.

Quintenz said he hopes Z can be restarted after the New Year, once decontamination is complete and new procedures are in place to ensure the problem doesn't reoccur.

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