Materials shortages, technology changes and other factors have pushed major enhancements to a nuclear-weapon testing facility in Nevada back three years and inflated the overall project cost to $1.8 billion, according to the National Nuclear Security Administration’s 2024 budget request.
Supply chain disruptions and other problems caused by the COVID-19 pandemic also contributed to the project delays, which could run up against the military’s schedule for fielding new and refurbished nuclear warheads in the 2030s.
Once scheduled to be complete by fiscal 2027, the Enhanced Capability for Subcritical Experiments (ECSE) project at the Nevada National Security Site’s U1a underground complex, which includes installing a sophisticated new x-ray camera to measure explosive plutonium tests, is now slated for completion in late fiscal 2030.
“During project design, challenges resulted in multiple design modifications under appropriate change control,” according to the request. “The growth in the project’s estimated costs have been driven by … technology changes – incorporation of more advanced technology, to include full solid state pulsed power, to provide expanded capabilities and flexibility to meet the data needs for the Subcritical Experiment program in support of multiple weapon systems.”
Upgrading the agency’s subcritical experiments capability involves expansion of the Nevada site’s existing underground laboratory to accommodate the large modern diagnostic systems necessary to evaluate plutonium implosion system experiments that help maintain the nation’s nuclear weapon stockpile.
As recently as last year, the NNSA listed fiscal year 2026 as the target date for commencing subcritical experiments with the new Scorpius x-ray imager at the expanded U1a complex.
Scorpius, within the Advanced Sources and Detectors program, passed its critical decision-three milestone on Nov. 30 of last year. Its CD-4 is now scheduled for the third quarter 2030, or before April 2031. CD-3 signals the beginning of construction, CD-4 the end.
A key milestone schedule for the program included in the NNSA budget documents lists fiscal year 2031 as the target date for beginning subcritical experiments in the U1a complex, using Scorpius and other Advanced Sources and Detectors.
The NNSA requested a total $279.6 million for ASD in its fiscal 2024 budget request.
