The National Nuclear Security Administration completed the smaller of two subprojects that aim to expand an underground, zero-yield nuclear-weapon testing laboratory in Nevada, the agency said Tuesday.
The Access and Life Safety Infrastructure portion of the greater U1a Complex Enhancements Project hit the CD-4 milestone on June 30, the semiautonomous Department of Energy nuclear weapons agency wrote in a press release. CD-4 is the project management milestone that marks the end of construction and the beginning of operations.
In its 2023 budget request, released in March, the National Nuclear Security Administration (NNSA) estimated the Access and Life Safety Infrastructure subproject would cost about $50 million to build. Construction began in 2017, according to an NNSA website. An agency spokesperson did not immediately respond to a request for comment about the final bill.
The U1a Complex Enhancements Project has fallen behind schedule several times. Construction could take until December 2027 to complete, according to the NNSA’s 2023 budget request. That’s a year later than the estimate in the agency’s previous budget request.
The U1a Complex Enhancements Project broadly aims to expand an underground laboratory for subcritical experiments: explosive plutonium tests that the NNSA says reveal the effects of age on nuclear weapons without creating a sustained nuclear fission reaction.
In the Access and Life Safety subproject, Nevada National Security Site prime contractor Mission Support and Test Services (MSTS) installed the equipment necessary for people to go in and out of the underground facility and remain comfortable and safe underground.
The second U1a Complex Enhancement subproject, Laboratory and Support Infrastructure, has proved more challenging. Increasing costs and delays there, alluded to in NNSA’s latest contractor report card for the Honeywell-led site prime, have driven the entire underground expansion behind schedule.
In its 2023 budget request, NNSA said the Laboratory and Support Infrastructure subproject could take until the end of December 2027 to complete and cost more than $565 million. The subproject will expand existing underground test space and renovate some of the crewed facilities there.
The expanded U1a complex will eventually house a billion-dollar x-ray camera called Scorpius, a replacement for the current Dual-Axis Radiographic Hydrodynamic Test facility built around 2000 to create images of subcritical experiments for test-site personnel and weapon designs at the Los Alamos and Lawrence Livermore National Laboratories.
Subcritical experiments, involving the compression of small plutonium samples with conventional explosives inside a steel sphere, help the NNSA gauge the degree to which aging U.S. nuclear weapons retain their designed destructive capacity. The W80-4 air-launched cruise missile warhead, initial delivery of which recently slipped two years to September 2027, was to be among the first weapons evaluated by Scorpius in the new underground subcritical lab.
