New Mexico nuclear waste accident a ‘horrific comedy of errors’ that exposes deeper problems via The Ecologist

Last February’s explosion at the WIPP dump for long-lived intermediate-level nuclear waste from the US’s nuclear weapons program remains unexplained, writes Jim Green. But with the site’s history of ignored warnings, ‘missing’ safety culture, lack of supervision and dubious contractor appointments, it surely came as no surprise – and further accidents appear inevitable.

The precise cause of the February 14 accident involving a radioactive waste barrel at the world’s only deep geological radioactive waste repository has yet to be determined, but information about the accident continues to come to light.

The Waste Isolation Pilot Plant (WIPP) in New Mexico, USA, is a dump site for long-lived intermediate-level waste from the US nuclear weapons program. More than 171,000 waste containers are stored in salt caverns 2,100 feet (640 meters) underground.

On February 14, a heat-generating chemical reaction – the Department of Energy (DOE) calls it a ‘deflagration’ rather than an explosion – compromised the integrity of a barrel and spread contaminants through more than 3,000 feet of tunnels, up the exhaust shaft, into the environment, and to an air monitoring approximately 3,000 feet north-west of the exhaust shaft. [1]

The accident resulted in 22 workers receiving low-level internal radiation exposure.

‘The contractors were not exactly meticulous’

Investigators believe a chemical reaction between nitrate salts and organic ‘kitty litter’ used as an absorbent generated sufficient heat to melt seals on at least one barrel.

But experiments have failed to reproduce the chemical reaction, and hundreds of drums of similarly packaged nuclear waste are still intact, said DOE spokesperson Lindsey Geisler. “There’s still a lot we don’t know”, she said. [2]

Terry Wallace from Los Alamos National Laboratory (LANL) said: “LANL did not consider the chemical reactions that unique combinations of radionuclides, acids, salts, liquids and organics might create.” [3]

[…]

Major deficiencies at Los Alamos National Laboratory

Of immediate relevance to the February 14 WIPP accident are problems at Los Alamos National Laboratory (LANL). The waste barrel involved in the accident was sent from LANL to WIPP. LANL staff approved the switch from an inorganic clay absorbent to an organic material in September 2013.

That switch is believed to be one of the causes of the February 14 accident. LANL also approved the use of a neutraliser that manufacturers warned shouldn’t be mixed with certain chemicals. [10]

[…]

“In particular, we noted that:

• Despite specific direction to the contrary, LANL made a procedural change to its existing waste procedures that did not conform to technical guidance provided by the Department for the processing of nitrate salt waste; and
• Contractor officials failed to ensure that changes to waste treatment procedures were properly documented, reviewed and approved, and that they incorporated all environmental requirements for TRU waste processing. These weaknesses led to an environment that permitted the introduction of potentially incompatible materials to TRU storage drums. Although yet to be finally confirmed, this action may have led to an adverse chemical reaction within the drums resulting in serious safety implications.”

Compromised response to the accident

A degraded safety culture was responsible for the accident, and the same failings inevitably compromised the response to the accident. Among other problems: [4,6]

• The DOE contractor could not easily locate plutonium waste canisters because the DOE did not install an upgraded computer system to track the waste inside WIPP.
• The lack of an underground video surveillance system made it impossible to determine if a waste container had been breached until long after the accident. A worker inspection team did not enter the underground caverns until April 4 – seven weeks after the accident.
• The WIPP computerized Central Monitoring System has not been updated to reflect the current underground configuration of underground vaults with waste containers.
• 12 out of 40 phones did not work so emergency communications could not reach all parts of WIPP in the immediate aftermath of the accident.
• WIPP’s ventilation and filtration system did not prevent radiation reaching the surface, due to neglect.
• The emergency response moved in slow motion. The first radiation alarm sounded at 11.14pm. Not until 9.34am did managers order workers on the surface of the site to move to a safe location.

Everything that was supposed to happen, didn’t. Everything that wasn’t supposed to happen, did.