With the National Nuclear Security Administration’s capacity to manufacture new nuclear weapon cores still a question mark, the Navy is studying whether the recently funded W93 submarine-launched ballistic missile warhead needs a brand new plutonium pit, the admiral in charge of the service’s nuclear weapon systems said Thursday.
“We are, in the [Department of Defense], trying to determine what is the right path forward given what [the National Nuclear Security Administration’s] NNSA’s capability is … not just today, but where we think it will be in the future,” Vice Adm. Johnny Wolfe, the Navy’s director for strategic systems programs, said in a public videoconference.
The Navy is “ trying to get to the right balance of new pits, refurbished pits or old pits” for W93, said Wolfe, who spoke to the press and public in a forum hosted by the Washington-based non government group, the Mitchell Institute for Aerospace Studies.
W93 will eventually replace the W76 and W88 warheads that tip the Navy’s Trident II D5 ballistic missiles. W93 will also fly aboard the Trident’s eventual replacement and last for much of the planned life of the Columbia-class ballistic missile submarines slated to begin replacing the current Ohio-class boats in the early 2030s as the sea-based leg of the U.S. nuclear triad.
The National Nuclear Security Administration, part of the Department of Energy, is building new factories to cast plutonium pits at the Los Alamos National Laboratory in New Mexico and the Savannah River Site in Aiken, S.C., but the Air Force has dibs on the entire throughput for the immediate future.
The NNSA plans to begin casting multiple war-ready pits at Los Alamos in 2024, ramping up to a total of at least 80 a year by 2030 using both the New Mexico and Savannah River plants. NNSA has said it will be “challenging” to bring the Savannah River factory online by that date.
The Air Force’s Ground Based Strategic Deterrent (GBSD) missile fleet, set to replace Minuteman III missiles starting in 2030 or so, will need new pits for each of its W87-1 warheads. The Air Force is ordering more than 650 GBSD missiles, though some will receive W87-0 warheads with old pits.
Still, the NNSA notionally plans to make fewer than 100 pits annually into the 2030s. The agency has not said when it might produce the first war-ready W93, but in prior budget requests, when the weapon now known as W93 was called the Next Navy Warhead, NNSA thought the first production unit might arrive in 2034.
The NNSA expects the W93 to cost about $14 billion, in 2020 dollars, excluding the cost of the Navy-made Mk VII aeroshell that will ensconce it. That is according to the agency’s latest Stockpile Stewardship and Management Plan. The weapon will be based on a nuclear-explosive design that was tested underground at full yield before the U.S. ceased such tests in the early 1990s, NNSA has said. The United Kingdom will use the Mk VII aeroshell for its next submarine-based, ballistic-missile warhead, but not the exact W93 nuclear-explosive package.
