Investigators have discovered that several heavy bags used to prevent radiation leaks at the Waste Isolation Pilot Plant were damaged, the Department of Energy said Thursday.
The magnesium oxide bags, weighing up to 4,200 pounds each, sit atop sealed containers of nuclear waste stored underground at the WIPP repository and are put in place to “prevent the radioactive material from releasing into the environment over a 10,000-year period,” according to a statement.
On Feb. 14, radiation leaked from the underground repository into the environment but did not reach levels considered unsafe for the public. The cause of the radiation leak, and what damaged the bags, is not yet known.
Air samples taken since Feb. 18 have shown no contamination, WIPP said Thursday.
Deputy Recovery Manager Tammy Reynolds said the damaged bags were found in the storage room where the leak is believed to have occurred. She described at a town hall meeting in Carlsbad how at least one bag had been “grossly disturbed,” with its outer material apparently “disintegrating,” she said. Others were misshapen.
As for what may have happened, Reynolds said, “We’re not ruling out any possibilities at this point.”
Magnesium oxide is a granular white substance that absorbs carbon dioxide and moisture.
WIPP has been closed to shipments of transuranic waste from the nation’s nuclear facilities since February, when a fire underground struck Feb. 5, followed by the radiation leak. Officials have said the two incidents are unrelated.
Last week, an accident investigation board issued a report on the radiation leak faulting WIPP management for its “failure to fully understand, characterize and control the radiological hazard.”
The board’s report cited problems in the underground ventilation system and the inadequate attention paid to the kind of safety precautions necessary at a nuclear facility.
WIPP is the nation’s only deep geologic repository for the waste of the country’s nuclear defense program, including waste from Los Alamos National Laboratory.