The Lawrence Livermore National Laboratory’s Nimble series of subcritical experiments, the next in line at the test site after Los Alamos’ Nightshade Series, was scheduled to run at least through Sept. 30, a lab official said last week.
“We’re targeting Nimble to be done by the end of FY22 or the beginning of FY23,” Bradley Wallin, principal associate director for weapons and complex integration at Lawrence Livermore, said on the sidelines of the Monitor’s annual Nuclear Deterrence Summit last week.
That is more or less the schedule that the National Nuclear Security Administration (NNSA) published in late 2020, when as part of its annual Stockpile Stewardship and Management Plan the agency said the Nimble series would wrap up in fiscal year 2022.
The first in the Nimble series — an experiment dubbed “Twin Peaks,” according to the NNSA’s 2022 budget request — had been scheduled to fire in the spring of 2022, Wallin told the Exchange Monitor in August at the previous Deterrence Summit.
NNSA “executed” three subcritical experiments at the Nevada National Security Site in fiscal year 2021, the agency wrote in the latest performance evaluation summary for test-site prime Mission Support and Test Services.
The subcritical series scheduled to precede Nimble was known as Nightshade: a set of three experiments designed by the Los Alamos National Laboratory. Nightshade A fired in November 2020, a month into the 2021 fiscal year, Nightshade B fired in June 2021, and Nightshade C, the finale, was scheduled to fire in September 2021, the final month of the fiscal year.
