A U.S. Department of Energy (DOE) physics laboratory has shut down its particle accelerators indefinitely after an accident left a worker badly burned. Lab administrators are searching for ways to improve their safety record. Repercussions of the accident are also being felt at DOE's other science laboratories, which are reevaluating their protocols for electrical safety.
On 11 October, an electric discharge struck a technician at the Stanford Linear Accelerator Center (SLAC) in Menlo Park, California, while he replaced a circuit breaker near a 480-volt power panel. Electricity from the panel ignited the worker's clothes, and he suffered second- and third-degree burns to his torso, arms, and thighs. The accident occurred in the "klystron gallery," a 3.6-kilometer-long building that generates radio waves that propel particles through the accelerator. The worker is in serious condition at a nearby burn center, says SLAC spokesperson Neil Calder.
DOE's nine other science laboratories are now reviewing their procedures for working with electrical equipment while it is powered, a practice known as "hot work" that is discouraged and requires permits. Argonne National Laboratory in Illinois "has put new restrictions" on hot work, and Brookhaven National Laboratory in Upton, New York, is planning a weeklong safety review for all employees in response in part to the SLAC accident.
SLAC's linear accelerator was running at the time of the accident and was shut down immediately. A week later laboratory director Jonathan Dorfan suspended all other lab work and instructed employees to devote all their attention to reading the laboratory safety manual and writing safety protocols for their individual tasks. Workers are returning to other tasks as they complete their safety reviews, Calder says.
In the meantime, DOE investigators are trying to find out precisely what happened and whether the technician violated SLAC's hot work rules and other safety protocols. In a recent internal review, a laboratory safety team questioned SLAC's hot work practices and suggested that workers were cutting corners for the sake of expedience.
The accelerators at SLAC will lie idle until investigators complete their work in 2 to 3 weeks, DOE makes its recommendations, and the laboratory responds to them--a process that could take months. "This is a tragic accident, and we're trying to get to the bottom of it," says Milton Johnson, chief operating officer for DOE's Office of Science in Washington, D.C. "The consequences for the laboratory are severe."