News Extra: Fire and radiation leak could cause closure of US underground nuclear waste repository
02 June 2014
A manager at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, has said that the rectification of problems at the site could result in its closure to new shipments for at least 18 months, and possibly for as long as three years.
WIPP, Carlsbad, New Mexico: Photo - DOE
Jim Blankenhorn, the recovery manager for site contractor Nuclear Waste Partnership (NWP), told a meeting on May 8 that since a February truck fire followed by a radiation leak several days later, the repository has been closed to shipments and that decontamination and other work to bring the site back online could potentially take up to 36 months.
According to the Carlsbad Current Argus, Blankenhorn also said the US Department of Energy had recently focused its investigation into the incidents on up to four waste streams.
The accident likely happened more than 2,000 feet underground in a waste-storage vault, when an out-of-the-ordinary radiation spike was recorded at the facility which caused plant managers to suspend all operations. Personnel at the facility discovered the source of the radiation was a leak inside one of the salt tunnels where radioactive material is buried.
Nitrate salts in waste from Los Alamos National Laboratory (LANL) were thought to be the most likely cause, having been found to have the potential to create a chemical reaction when in contact with organic material. LANL and another site had recently switched to an organic absorbent which had the potential to cause a fire.
New Mexico Environment Department Secretary Ryan Flynn called for the immediate closure of all but one of the storage panels at the plant, the country’s only functioning subterranean nuclear waste repository.
Seven panels have been mined underground at WIPP for nuclear waste storage and three of them remain open, including Panel 7, where the DOE believes the radiation leak originated. According to contractual obligations, DOE must now close all open panels where the radiation leak is not suspected to have occurred.
Flynn criticised DOE and NWP for not disclosing the source of the other suspect waste stream and for not being forthright with the public.
The DOE halted shipments of nuclear waste containers from LANL after investigators pointed to their possible involvement in the incidents. But according to the Albuquerque Journal, Los Alamos is under a tight deadline to get the plutonium-contaminated waste off its northern New Mexico campus before the wildfire season peaks.
The closure of WIPP to new shipments was ordered after an independent monitoring centre found radioactive isotopes in an air sensor about a half mile from the southeastern New Mexico plant.
A filter at the Carlsbad Environmental Monitoring and Research Center found the highest ever levels detected at or around the site, although these were far below those deemed unsafe by the Environmental Protection Agency.
These readings come after a radiation alert that closed the plant to all non-essential personnel last weekend after an underground sensor detected airborne radiation. Department of Energy officials say most operations remain closed, but they have not released any further information.
21 workers tested positive for radiation exposure after the leak, but WIPP and DOE officials said this was too low to constitute a health threat.
Two weeks earlier, a truck hauling salt in an underground mine at the site caught fire, stopping operations for a few days. Officials said that fire was in an area separate from where nuclear waste is stored. In both instances the DOE has said public safety has not been threatened.
The accident at the Waste Isolation Pilot Plant is the first-known release of radiation since the facility began taking the waste from Los Alamos National Laboratory and other nuclear weapon development sites 15 years ago.
An accident investigation report, released late-April by the DOE’s Office of Environmental Management, cited poor management, ineffective maintenance and a lack of proper training and oversight at WIPP. The report also found that much of the operation failed to meet standards for a nuclear facility.
DOE Accident Investigation Board Chairman Ted Wyka identified the root cause as a "degradation of key safety management and safety culture."
Specific problems included the fact that workers had not been trained well for a leak event, so when the alarms went off, it was more than 10 hours before workers took shelter.
Investigators found the only way for some ventilation controls to be operated was for workers to enter the contaminated area and become contaminated themselves, which did happen.
Other equipment problems included an air filter system protecting the surface from an underground leak was poorly designed and should have been replaced years earlier. Also, a radiation monitor near the leak was broken most of the time.
The individual storage rooms are designed to be blocked off and isolated when filled with waste. Because of the impermeable nature of the salt seams that surround them, even if the waste containers leak, the radiation should be contained. Panel 7, where this leak is believed to have occurred, had not been blocked off.