Subcritical nuclear tests remain useful for maintaining the U.S. nuclear weapons stockpile in the absence of nuclear explosive testing, the JASON defense advisory panel affirmed in a letter report last year. But “a gap exists in the current US capability to carry out and diagnose such experiments,” the panel said.
Subcritical experiments simulate aspects of nuclear explosions using chemical explosives. But since a subcritical mass of plutonium (or a surrogate material) is used, no actual nuclear explosion occurs.
The main purpose of subcritical experiments is to identify and decrease uncertainties in weapon performance. “For all weapons in the current stockpile, at the present time margins are adequate and uncertainties are within margins, both for normal operation and for nuclear safety should accidents occur,” the JASON panel said. “However, future aging of these weapons and their remanufacture may increase uncertainties, and JASON finds that scaled [subcritical] experiments in Pu [plutonium] may significantly reduce uncertainties that may arise in the future.”
But “JASON finds that x-ray radiography is needed to diagnose subcritical experiments in Pu… and that the US currently lacks adequate radiography at U1a [the nuclear complex in Nevada] for this purpose.”
The JASON letter report was prepared for the National Nuclear Safety Administration at the direction of Congress. A copy was released by NNSA last week under the Freedom of Information Act.
See Enhanced Capabilities for Subcritical Experiments, JSR-16-Task-011, October 7, 2016.
The United States Air Force has forward deployed about one-third of its B-2 stealth bombers to Diego Garcia, or about half the B-2s considered fully operational at any given time.
Over the past year, the campaign to abolish nuclear weapons has experienced numerous wins that were celebrated at the Meeting of State Parties.
China is NOT a nuclear “peer” of the United States, as some contend.
China’s total number of approximately 600 warheads constitutes only a small portion of the United States’ estimated stockpile of 3,700 warheads.
Dr. Lim will help develop, organize, and implement FAS’s growing contribution in the area of catastrophic risk including on core areas of nuclear weapons, AI and national security, space, and other emerging technologies.