SANTA FE, N.M. — The National Nuclear Security Administration is backing up Los Alamos National Laboratory in its statement this week that a recent safety violation did not pose a risk of an accidental nuclear fission chain reaction.
“At no time was there any risk of an inadvertent criticality,” said a statement from an NNSA spokesman. “There was also no risk of injury or exposure to the workforce or public. The laboratory has since taken steps to help prevent a similar event in the future, and the qualifications of the workers involved were suspended pending rigorous retraining.”
A recent report by the oversight Defense Nuclear Safety Facilities Board says that in August, a LANL crew that had cast a shell for a plutonium “pit” — the trigger for a nuclear weapon — moved it “into a location that already contained plutonium metal,” exceeding plutonium limits. The board described the incident as a “criticality safety event.”
When too much plutonium is put in close quarters, a criticality reaction, producing a potentially fatal blast of radiation, can take place. In this case, the plutonium limit violation was discovered five days later when the pit shell was moved again.
The NNSA said Tuesday “there are multiple layers of defense to prevent accidents involving these materials,” accounting for “the fact that people will occasionally make mistakes and that equipment will occasionally malfunction.
“All violations of operating procedures and equipment failures, however, are examined closely to minimize recurrence, even when those incidents have no impact on the safety of the workers, facility, or the public,” the statement said. It said “there has not been a nuclear criticality accident at a Department of Energy nuclear facility in nearly 40 years.”
Greg Mello, of the Albuquerque-based Los Alamos Study Group advocacy and research organization, said in response to the NNSA statement that if there was no problem with LANL’s plutonium limit violation, “why did NNSA and LANL have the rules in question, the rules that were violated?
“Does NNSA encourage its contractors to violate its rules? To violate posted material limits?”