Cooling Off a Hot Spot : Workers Scrub Former Nuclear Lab to Remove Radioactivity

With sandblasters and elbow grease, moon-suited technicians are stripping radioactive grime from the nuclear hot lab at the Santa Susana Field Laboratory, the Rockwell International test site in the Simi Hills west of Chatsworth.

The $10.5-million cleanup, being carried out by workers in respirators and plastic suits, is the end of the line for the 31-year-old hot lab, a heavily shielded workshop where intensely radioactive materials were handled by remote control.

At Santa Susana, the most impressive shapes are rock formations. The buildings look anything but sleek or high-tech, and the hot lab itself is a dowdy 16,000-square-foot matchbox of gray sheet metal.

The interior of the hot lab is not ordinary, however. Workers are reminded by a sign on the locker room showers: “Do Not Dump Radioactive Wastes or Wash Contaminated Material Here.” The guts of the building are four heavily shielded “hot cells” where radioactivity clings to fixtures and walls and where most of the cleanup is being done.

Glistening with sweat after a recent day of work, nuclear mechanic Patrick Fallandy peeled off his sweltering protective suit and ran a radiation counter over his hair and chest. Fallandy said his father worked for Rockwell before him and that he felt well-protected.

“I’ve always been pro-nuclear,” said Fallandy, 22. “It’s never scared me because I know all the precautions that are taken.”

Under federal regulations, nuclear workers can be exposed to as much as five rem of radiation per year--the equivalent of 125 to 250 chest X-rays. But Rockwell project engineer Fred C. Schrag said the cleanup crews are exposed to only a small fraction of allowable limits.

The job is “extremely safe” because of precautions and because contamination is low to begin with, Schrag said. The cleanup is designed to make the building safe for unrestricted use.

Decontamination of the hot lab, scheduled for completion by 1993, is part of a broader, federally funded cleanup at Santa Susana, where Rockwell’s Rocketdyne division has worked since the 1950s for the U.S. Atomic Energy Commission and then the Department of Energy. Under the $37.3-million cleanup plan, Rockwell over the next six years is to decontaminate former nuclear reactor buildings, clean up chemically tainted ground water, and bring active non-nuclear energy operations up to environmental standards.

The hot lab cleanup is not the workers’ favorite job, but they say the problem is discomfort, not safety. “Wearing a plastic bag for a few hours kind of takes it out of you,” said Mark Spenard, 33, a senior nuclear mechanic.

The cleanup crews wear respirators and plastic suits and boot to protect them from radioactive particles. Each worker wears a film badge and carries a pocket dosimeter to keep a running total of his radiation dose.

Schrag said the first step in cleaning the hot cells is to wash the walls with water to remove loose radioactive particles. After that, the men use sandblasters to strip contaminated paint from the steel jacket covering the concrete walls.

Cranes and manipulators are dismantled and packaged for disposal as radioactive waste, although some less-contaminated manipulators are being saved for possible resale to other nuclear labs, according to Schrag.

The hot cells, surrounded by 3 1/2-foot-thick walls of steel and concrete, were used to examine and work on spent nuclear fuel and other intensely radioactive materials using remote-controlled manipulators.

According to Schrag, about 20 Rockwell employees are involved in the project--about half engaged in cleaning equipment, walls and floors, the others in oversight functions such as engineering and monitoring safety procedures.

The hot lab was the last active nuclear work site at Santa Susana, once a flourishing center for nuclear research. Rockwell continues to operate the Department of Energy’s Energy Technology Engineering Center at Santa Susana, testing non-nuclear components of nuclear plants.

The 2,668-acre Santa Susana site was established in the late 1940s as a rocket-testing location, for which it is still used. Its nuclear mission began in the mid-’50s, on 290 acres at the northwest edge of the property.

A 1989 Department of Energy report disclosed the presence of low-level chemical and radioactive contamination in buildings and soil at Santa Susana. Although the report said the site appeared to pose no immediate health threat to workers or neighbors, it criticized environmental monitoring of the site as inadequate. The report alarmed area residents.