What do the OJ Simpson murder trial and a nuclear waste leak in southern New Mexico have in common?
A single glove.
Legislators at a Radioactive and Hazardous Materials Committee meeting in Los Alamos chuckled when Sen. Peter Wirth, D-Santa Fe, made the comparison. Yet, it was still an accurate summary of a report the lawmakers heard Wednesday about a serious problem for the long-term storage of dangerous contaminants.
Scientists at Los Alamos National Laboratory are still trying to determine exactly what caused a barrel buried at the Waste Isolation Pilot Project to burst open in February, said LANL chemist Nan Sauer, but they now have a pretty good idea of the materials that were involved.
Sauer, leader of the lab's internal technical investigations, has been working on the problem since officials first learned of the contamination alarm at the Carlsbad facility on Valentine's Day.
She told committee members that tests have revealed that the barrel in question contained a rare combination of waste products from the lab: wheat-based kitty litter that was used to absorb plutonium contaminated nitrate salts; material with high acidity; and trace metals such as lead, tungsten and chromium that are components of a glove.
The waste inside the burst barrel and been stored without incident at at lab for about 30 years, Sauer explained. That changed, she said, after the 2012 repackaging of that "parent" barrel into two "daughter" barrels. One became the problem child, No. 68660.
Workers at the lab use containment devices called glove boxes that allow for handling and repacking of waste generated in the research and development of the nations's nuclear stockpile. The gloves that form a barrier for workers are routinely changed and placed into barrels along with waste, as was recorded for No. 68660. But investigators now believe the metals in the glove might have reacted with nitrate salts after temperatures rose in the barrel at WIPP.
"Glove box gloves and nitric acid and lead have been implicated in other energetic events within the DOE complex," Sauer said.
Just how the temps increased to initiate the reaction, however, is still up for debate. Theories about what initiated the reaction include warmth generated by decomposition of the litter (a commercially available substance called Swheat that Sauer says won't be used anymore ). Another hypothesis would put the blame on heat from a truck fire that occurred inside WIPP a half mile from the barrel location about nine days before an air monitor detected the radiation leak. Smoke from the fire might have also affected ventilation systems and led to hotter air, she said.
Sauer noted that the lab is busily performing more tests to try to answer the temperature question to assist with the Department of Energy's accident investigation board.
"We have done a lot of work and narrowed down the parameters to a very specific set of reactions that could have occurred in the drum, and our chemists are continuing to work on answering those questions," she said. "We really feel that we are coming very, very close to the answer in terms of what the chemical reactions were."
Meanwhile, work on characterization and packaging as well as transportation to the WIPP facility has been suspended. About 700 barrels that contain the nitrates and kitty litter are now stored with extra precaution at the lab and at a Texas holding facility where they were already awaiting transportation to Carlsbad at the time of the detected problem, said Peter Maggiore, the National Nuclear Safety Administration's assistant manager for environmental programs at the lab.
Legislators who asked when those operations would resume got a straight answer from Maggiore: No one knows.
"We have not established a date whereby we will resume operations," he said, indicating that until federal investigations wrap up and officials agree on the next steps, the waste will stay put. "Any date that I might give you just wouldn't be a valuable date"
The barrels are part of more than 3,700 cubic meters of waste planned for removal from the lab's Area G and relocated in the the underground salt caves of WIPP by next year. It's clear now that goal won't be met.
Chemists, engineers with expertise in heat transfer and others are part of two technical teams on the the case, Sauer said, noting that investigators are using a broad approach to ensure the best understanding of the nature of the event.
Later in the day, state Environment Department Secretary Ryan Flynn told legislators that he believes the federal and state agencies will work for another six months to a year before there's a resolution. The bottom line, he says, is that LANL or its contractors erred in sending reactive materials to WIPP in violation of permits and rules. Communication breakdowns are also in play, he said.
Maggiore noted that even though some parts of the waste characterization and removal process are halted, the lab continues other cleanup efforts required by an agreement with federal and state regulators including monsoon runoff monitoring upstream from the Santa Fe city and county Buckman water diversion from the Rio Grande.
"We realize that there has been some trust lost in this whole process," Maggiore said. "We do have a lot of work ahead of us to regain that trust."