LANL drum was root of WIPP accident

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DOE > TAT report says mix of components led to ‘thermal runaway’ at repository

By The Staff

Drum 68660, shipped to the Waste Isolation Pilot Plant in Carlsbad from Los Alamos National Laboratory was where all the trouble started.
The Technical Assessment Team (TAT) 277-page report was released Thursday afternoon by the Department of Energy. The TAT’s mission was to find out the root cause of the problems that led to the breach of a waste drum at WIPP, which released radioactive fumes that sickened 21 workers in February 2014.
The TAT’s overarching conclusion was that “chemically incompatible contents of Drum 68660 from Los Alamos National Laboratory in combination with physical conditions (e.g., the configuration of the materials in the drum) supported exothermic chemical reactions leading to a thermal runaway)….”
Thermal and pressure effects resulted in the movement of material during the release event.
Drum 68660, as far as TAT could determine, was the sole cause of the release. According to the report, the thermal runaway was internal in that drum and not cause by outside phenomena.
According to the report’s fact sheet, Drum 68660 breached as a result of internal chemical reactions.
“Experiments showed that various combinations of nitrate salt, Swheat Scoop, nitric acid, and oxalate self-heat at temperatures below 100 degrees Celsius. Computer modeling of thermal runaway was consistent with the observed 70-day birth-to-breach of Drum 68660.”
The TAT report also stated that uranium, plutonium and americium isotopic measurements on post-event samples were “consistent with the recorded contents of Drum 68660 and suggest that this drum was the source of the radioactive contamination.”
The findings were in line with what most experts theorized was the cause of the release. There had been some speculation in the days following the release that combustion or a thermal pulse from a truck fire 9 days earlier may have led to the breach, but the TAT found no evidence the two accidents were related.
It also found no evidence to suggest Drum 68660 was processed, handled, transported, or stored any differently from other processed LANL waste drums.
The report was put together by the TAT, which included technicians from Savannah River National Laboratory, Oak Ridge, Lawrence Livermore, Pacific Northwest and Sandia National Laboratories. Savannah River was the lead lab involved in putting out the report.
No one from LANL was on the TAT.
The WIPP site, a deep geologic repository near Carlsbad, provides permanent underground disposal of defense-related transuranic and TRU-mixed wastes.
On Feb. 14 of last year, the incident in the P7R7 area of WIPP resulted in the release of radioactive material into the environment. There was no personnel in the repository during the time of the release, but the sickened individuals were identified to have been exposed to low levels of internal contamination.
In the aftermath of the event, WIPP was ordered to be shut down indefinitely. It has not yet been reopened.
For Los Alamos National Security, it was docked approximately 90 percent of its potential management fee by the National Nuclear Security Administration for 2014, citing the WIPP accident as the reason for the slashed fee.
In late 2014, the New Mexico Environment slapped LANS with $36.6 million cleanup fee for violations stemming from the breach.