Radioactive waste from the US nuclear weapons complex is disposed of at the Waste Isolation Pilot Plant (WIPP) in New Mexico. It is the only operating disposal facility on earth for very radioactive or very long-lived nuclear waste. WIPP’s mission is to “start clean, stay clean.” But there were two back-to-back accidents deep underground this February. Radioactivity from one of them traveled to the surface, contaminated people, and has been detected more than half a mile away. “Start clean, stay clean” is now out of reach.
WIPP was built in an ancient salt bed 2,150 feet beneath the Chihuahuan Desert in southeast New Mexico. It holds waste from the US nuclear weapons complex that is hazardous for 240,000 years and must be isolated from the human biosphere. The maximum capacity of WIPP is 175,564 cubic meters (6.2 million cubic feet). Much of the waste is stacked in 55-gallon barrels in very large rooms that have been excavated from the salt, though some is handled differently because it is so radioactive. Above ground, the WIPP facility covers 16 square miles.
WIPP opened in 1999 and the Idaho National Laboratory has been the single largest shipper of waste there. WIPP is now slightly more than half full, and its closure is planned for about 2030. If it had operated for those 30 years without itself becoming contaminated, WIPP would have achieved its mission to “start clean, stay clean.” That would have been important for southeast New Mexico and for any future attempts – anywhere – to isolate the most dangerous nuclear waste.
WIPP is an active mine. Even as waste is being put into rooms that have already been excavated, workers are digging out salt and moving it to the surface to create additional disposal space. In the morning of February 5, a truck used to remove salt caught fire. The fire was fairly small and in a part of WIPP that hasn’t yet been filled with nuclear waste. But it was surprisingly difficult to extinguish. The fire suppression system didn’t immediately put the fire out, and six workers were treated for smoke inhalation the day of the fire, and four were still being monitored by site medical staff more than a week later. Both shifts were on when the fire started, so there were 86 people underground, more than usual. It took 37 minutes for everyone to evacuate, and the ventilation system had to be left on to give those people air. After everyone was out, the entire ventilation system was shut down to cut off air to the fire.
The Defense Nuclear Facilities Safety Board, an independent investigator, had already flagged some of the problems encountered this month. In June 2011, the DNFSB outlined its concerns that WIPP’s fire suppression system was inadequate, including for “small fires” such as the diesel-fueled vehicle. The problems have clearly not been fixed, and a DNFSB follow-up team came to WIPP to investigate the current fire.
The February 5 fire was more than 2,000 feet away from any nuclear waste, and no contamination was released.
But on February 14, something happened at WIPP that sent plutonium and americium more than a mile – from some location underground, 2,150 feet up at least one shaft, and at least 3,150 feet northwest to an air monitoring station. It was the middle of the night; no one was underground at the time, and no one has been down since. So far, thirteen people who were working on the surface when the alarm went off have tested positive for inhalation of plutonium and americium. (Site officials have not said how many people were on the surface that night.) More people, including those who came to work the next morning (but the site has not said how many there were), are being tested.
According to the DOE, the first step to try to figure out what has happened in WIPP will be to drop in probes to evaluate the risk of sending people down. We don’t know when that first step will be taken.
We also don’t know what caused the release, though the president of the contractor that runs WIPP has speculated that it could have been caused by an underground ceiling collapse. We don’t know how much contamination was released above ground, though WIPP officials say the filtration system worked. But only the air exhaust shaft is filtered and it only kicks in after radiation is detected. The shaft that lets air in and the shafts used to lower waste and remove salt are not, and during the February 5 fire, smoke billowed out of the salt shaft. We don’t know how far the contamination spread, but there’s no particular reason to think that it only traveled to the places it’s been found so far. Lots of soil samples will need to be taken to determine where it has traveled, or is continuing to be blown by the winds. We don’t know where in WIPP’s system of rooms and tunnels the release occurred or how contaminated it is down there. We don’t know how – or even if – the underground contamination will be cleaned up.
Here at home, the head of environmental management for DOE-Idaho has said that the Site can continue to dig up plutonium-contaminated waste. There’s a lot of permitted space to stage waste at INL that’s ready to ship but cannot be as long as WIPP is closed. People from INL will be helping with the accident investigation and next steps.
In New Mexico the Department of Energy faces all the immediate hurdles thrown up by the contamination of WIPP and a good deal more, as well. WIPP supporters have long wanted to expand its mission, and the current push to allow consolidated storage of spent nuclear fuel or high-level waste looked like an opening. But the risk of that has undoubtedly receded. Public concern across the state is high and is reflected in state government. After the second accident, New Mexico Environment Secretary Ryan Flynn said, “Events like this simply should never occur. From the state’s perspective, one event is far too many.” He noted that the Environment Department will take into account the recent incidents if it is asked to evaluate future permits to expand WIPP or allow additional kinds of waste to be sent there.