The Z Pulsed Power Facility at the Sandia National Laboratories in Albuquerque, N.M., was slated to come back online Wednesday after a serious accident in June knocked the facility out of commission for three weeks, a senior laboratory employee said this week.
The June 17 accident, which shook Sandia’s high-energy density physics lab longer and harder than a typical Z-machine shot, badly damaged 18 of the pulsed-power facility’s 36 generators.
There is evidence one generator fired prematurely “because a piece of debris was present on the spark gap,” Chris Bourdon, senior manager for Z Experimental Capability Management, wrote in an email.
That set off a cascade of failures that knocked other generators offline, putting the Z machine out of commission for almost a month.
Nobody was injured during the June 17 misfire, the Sandia spokesperson said, although one lab employee received an electrical shock a week after the accident while examining one of the failed generators. The employee “had numbness to their hand and forearm for about 2-4 hours after the shock,” but was cleared to return to work the same day of the incident, Bourdon said by email.
As for what the debris was, “it’s hard to tell,” Bourdon said. “The debris was completely destroyed.”
The Z machine is one of the National Nuclear Security Administration’s (NNSA) high-energy density physics facilities. These facilities subject small targets made of various materials to extremes of temperature and pressure similar to the early stages of a nuclear detonation. The operations help the NNSA verify the potency and functionality of aging nuclear-weapon components and materials without resorting to nuclear-explosive tests.
The failed Z machine shot interrupted an experiment called Plasma Transport 19A. The multi-shot experiment will go on, Bourdon said, with the remaining shots keeping their previously assigned places in the queue of 62 Z machine firings scheduled through December.
The Z machine has suffered this sort of malfunction before, Bourdon said. The last time was in 2016, although June’s misfire “caused more damage than the previous event.”
