Inaction following the first radioactive leak at the world’s only deep geologic nuclear waste repository was threatening to stamp the most successful government program in history with an undeserved scarlet letter. Fortunately, the State of New Mexico, Los Alamos National Laboratory and the U.S. Department of Energy have moved fast, realizing that time is not our friend in this situation.
Recall that the Waste Isolation Pilot Project, the only operating geologic nuclear waste repository, had its first minor accident on Valentine’s Day after 15 years of perfect operations (NMED). It was a small release of radiation that did not, and will not, harm anyone or have any environmental consequence.
Those of us studying this issue figured since it happened at WIPP, it must be a WIPP problem, so we thought about what could go wrong with the rock or with the way WIPP operates. But WIPP was not the problem at all. The problem was what came to WIPP (Kitty Litter). Some drums slowly got hot, and one blew its top, because of what was in them.
It’s natural that everyone was being very cautious, but we took three months to get back to the suspect drums and so focused on the wrong things like the rock is falling. The initial investigation reports were highly critical of the WIPP facility’s operations and management, yet did not catch the actual cause of this event and instead focused on issues that had little significance to the accident. In fact, the radiation release during this event was almost completely contained by the WIPP safety systems. Only 1.3 millicuries were released into the environment, mostly americium (Am), but an amount of Am many times less than the Am in the smoke detectors of the nearby town of Carlsbad.
At the same time, digging into documents, assay sheets and records (every container and drum is barcoded and tracked) told us what was in those drums and why they generated heat and pressure in a slow burn. These reactions aren’t affected by shocking, shaking, friction or any other things you think of with a bomb, because these are not like bombs. They’re like slow-burning charcoal briquettes. The reactions just require time.
It is understandable that DOE was being careful (WIPP Recovery), not wanting to speculate and muddy the waters, and maybe having to retract something later. It is their job to be very certain and this event was nothing if not bizarre. The possible legal issues alone would scare me catatonic. Also, the types of chemical analyses needed, the difficulty in reconstructing the event, the difficulty of getting into the underground – these are not actions one rushes into.
But DOE’s reticence was being seen as obfuscation and wass getting the State and the public frustrated. Community support is wavering. State support is wavering. If not checked, this process will not end well for DOE, and WIPP might never reopen. So we can’t let this go along on its own formal timescale. We need to take hold of it and take action.
If we do not move quickly, the Carlsbad community, and the entire State of New Mexico, will be unfairly punished for 30 years of support of a mission critical to the United States – that of cleaning up the legacy of the Cold War. No one else stepped up, and no one else will. We need to reward that support by not wasting time and letting the site sink into oblivion because America has become afraid of taking action.
Fortunately, the New Mexico Environment Department realizes this and issued two Administrative Orders to DOE to address, as fast as possible, the two most pressing issues – the drums still hanging around someplace not WIPP, and sealing off the rooms and panels down in WIPP that have some of these drums (NMED LANL Order; NMED WIPP Order).
Using what’s known as Acceptable Knowledge documents that detail the contents of each drum and their treatment histories (such as CCP-AK-LANL-006 and other DOE and contractor documents), we can reconstruct the general story as follows.
Beginning over 30 years ago, activities involving separating americium (Am) from old weapons materials generated a moderate amount of transuranic waste contaminated with americium (Am), plutonium, uranium and minor amounts of other radionuclides, and containing various metal-nitrate salts (strong oxidizers), such as (Mg,Ca)(NO3)2 with minor amounts of Fe, Na and K. When dewatered, these hot evaporator bottoms were poured onto a tray, vacuum dried, flashed crystallized, rinsed with cold water and put in bags, where they sat for 30 years.
Come time for disposal a few years ago, these wastes still had some nitric acid liquid. Department of Transportation regulations require no free liquid (<1%) during transport, so these wastes were stabilized with neutralizers and sorbents like sodium carbonate, triethanolamine and polyacrylate as they were put into drums for packaging and shipment.
It was recommended sometime later that inorganic kitty litter made from silicate minerals be added as a sorbent (widely used in radiochemistry as well as the home litter box), but also to dissipate heat and generally mitigate auto-oxidation reactions of the kind we think occurred in these drums in WIPP. Anhydrous citric acid (a reducer) was used to bring the pH down if over-adjusted.
For reasons perhaps related to good intentions, or merely related to dust generation, the inorganic kitty litter was replaced by organic wheat-based litter early on in the process. There were a few other components of not much import in the drums, but additional organic components just added more fuel.
Some decisions regarding these additives are vague and not attributable to a real chemist. Citric acid should never be used with metal-nitrate salts, because of the rapid evolution of heat. Similarly for acrylates. The use of organic additives for whatever purpose adds fuel to this mixture. And organic litters have the wrong properties for their intended function but being organic, they too add to the amount of fuel that could burn. I do think the correct litter alone would have prevented these reactions.
When real chemists did look at this mixture, they were appalled.
These drums were assigned as a specific waste stream and were able to be tracked through a barcode system. The suspect drums that breached in WIPP were from waste stream LA-MIN02-V.001 in which all drums were mixed with the incorrect litter. 368 of these drums were identified as being disposed of in WIPP: 313 in Panel 6, and 55 in Panel 7 Room 7.
Investigators have looked at several rows of waste on either side of the breached drum looking for evidence of damage or any breaches in other waste containers, but found nothing.
So we know where they are, we know where the contamination is, and we know how to clean this up. Two actions need to be taken immediately, and are the subject of the two NMED Administrative Orders issued last week.
First, there are more drums like these out there, not having been shipped to WIPP yet. They need to be rounded up, put under safe conditions, treated or repackaged. This has nothing to do with WIPP. As of today, it appears that LANL has secured all these drums in special explosion-proof containers in isolated areas with fire-suppression capabilities, and is monitoring them continuously (see photo of overpack). This was done quite quickly once the waste stream was identified. Their final disposition is being planned.
Second, the drums already in WIPP, in Panel 6 and Panel 7 (Room 7) need to be sealed off with bulkheads like we do all the time, and shut off from the ventilation system. Metal bulkheads can handle these energetic events easily, and as the salt creeps in, they will be contained as only 2,000 feet of massive molecularly-tight salt can do.
Panel 6 is full and complete, so putting up two bulkheads is the first logical step. Room 7 in Panel 7 can be finished with crushed salt and also two bulkheads. Room 6 Panel 7 is contaminated and could be sacrificed by just filling with crushed salt and bulkheaded. (see figures of different types of room seals).
The second NMED Administrative Order calls for DOE to submit a plan by the end of next week to accomplish sealing of these rooms.
The other rooms in Panel 7 and the exhaust paths and shaft are not very contaminated and can be deconned without great cost or time. Plans for these are forthcoming as well.
WIPP operations could then resume in less than a year without wasting billions of dollars and without completely derailing nuclear clean-up activities across the country. This was not a WIPP problem, but WIPP will fix it. Greater oversight of the waste packaging, and implementing the recommendations of the accident reports that pointed out various operational deficiencies, won’t take long and can be executed quickly without great cost.
If we don’t move quickly, it will cost billions and could derail the only successful nuclear waste disposal program in the world. Also, this response is a test to see if America can handle the environmental issues surrounding nuclear better than other countries who shall remain nameless.
If WIPP can’t resume operations, we will be forced to stop putting our nation’s nuclear waste in a safe place and it will either stay right where it is, or go to a second-rate place. This would bode ill for other nuclear-related issues such as our high-level defense waste or our nuclear waste confidence proceedings needed for NRC to issue new reactor licenses.
The need for this repository has not changed. The fact that the salt is the best rock type has not changed. The excellent 15-year operational and safety record of WIPP prior to this event has not changed. This event did not result from a flaw of WIPP itself, but from operations elsewhere from WIPP.
If WIPP resumes in short order, we will be able to deal with the waste backlog across the country in a year or two. WIPP was ahead of schedule and under budget before this event. The recovery costs won’t be very large if we move fast. Most important, however, with WIPP back online we will have a chance of actually disposing of our legacy nuclear weapons waste within a hundred years from when they began being produced in the first place.