LANL: No risk of ‘criticality’ accident
Recent incident called ‘a serious screw up’
SANTA FE — Los Alamos National Laboratory says there was no risk of an accidental nuclear reaction in a recent safety violation where plutonium limits were exceeded during casting work at the lab.
“The incident on August 18, 2017 was not a criticality accident,” a lab spokesman said in a statement.
“Our workers self-reported the fact that certain administrative limits were exceeded. There was never any risk of a criticality accident.
“However, because of the Laboratory’s focus on adhering to our safety rules, we suspended the workers’ qualifications until they completed the appropriate re-training.” A criticality accident is an uncontrolled nuclear fission chain reaction that produces a potentially fatal blast of radiation. The lab spokesman said there has not been an actual criticality accident at Los Alamos in more than 60 years.
But a longtime lab observer and critic says the error reported publicly by the Defense Nuclear Facilities Safety Board (DNFSB) was not trivial, considering the lab’s history of safety issues and a federal mandate that LANL ramp up production of plutonium “pits,” the triggers for nuclear weapons. “It’s hard to assess how serious it was,” said Greg Mello of the Albuquerque-based Los Alamos Study Group. “We don’t have enough information.
“But given the scrutiny and the lab’s repeated problems with criticality and the impact on the (lab’s) mission, it’s a serious screw up.” No pits have been produced since 2011 and the lab is supposed to make 80 a year by about 2030.
Mello said the lab’s casting work on the “shell” of a pit — the focus of the DNFSB’s report — was “a showcase operation” and focus of “a great deal of management attention and expectation.”
“They really have struggled to get this right,” he said.
In 2016, LANL was the only one of the Department of Energy’s nuclear facilities to receive a failing “does not meet safety expectations” safety rating for criticality.
The DNFSB’s recent report says that on Aug. 18, a crew that had cast the plutonium pit shell moved it “into a location that already contained plutonium metal,” exceeding plutonium limits. When too much plutonium is put in close quarters, a criticality reaction can take place. The violation was discovered three days later.
The DNFSB report said “this was the first shell cast in the facility in about four years and the second time that a restarted operation encountered conduct-of-operations issues related to the criticality safety of material movements shortly after resuming nuclear work” since last year.
At a June DNFSB hearing in Santa Fe, a top official at the DOE’s National Nuclear Security Administration said a study was considering whether plutonium work should be continued at Los Alamos or moved elsewhere. The same official said criticality safety at LANL is making progress, but “not where we need to be.”
Still, New Mexico Democratic U.S. Senators Martin Heinrich and Tom Udall recently amended the latest defense budget bill to require the Trump administration to meet a number of requirements, including certification from the Secretary of Defense, before it could move pit production away from Los Alamos.