Todd Jacobson
NS&D Monitor
3/13/2015
A decision to replace the conventional high explosive (CHE) in the W88 warhead as part of a planned alteration was largely driven by a “problem” with the warhead rather than timing and workforce issues, Nuclear Weapons Council Chairman Frank Kendall told the Senate Armed Services Strategic Forces Subcommittee last week. The National Nuclear Security Administration had planned to replace the arming, fuzing and firing mechanism as well as the neutron generator and gas transfer system on the W88 as part of the Alt 370 program—a “light” version of a life extension program—but decided earlier this year to also “refresh” the conventional high explosive in the warhead that is used on the Navy’s submarine-launched ballistic missiles.
Previously, the NNNSA said the decision was made to extend the life of the warhead to compensate for a delay to the Navy portion of an interoperable warhead—a First Production Unit on the warhead has been pushed back to 2035—but Kendall for the first time last week disclosed that there were more significant issues with the warhead driving the decision. “We found some money to address a conventional high explosive problem in one of our warheads, which we had hoped would last longer than it’s going to be,” Kendall said at a March 5 subcommittee hearing in response to questions about the cost of modernizing the nation’s nuclear deterrent. “But we’re seeing signs that it will not and we have to replace that, so that’s added a few hundred million dollars of cost which we were able to cover.”
CHE ‘Refresh’ to Cost About $530 Million
The CHE “refresh” is likely to cost about $530 million, NNSA weapons chief Don Cook said, bumping up the cost of the W88 Alt 370 from about $1.5 billion to about $2 billion. Cook said because the warhead was going to be worked on at Pantex as part of the Alt 370, the NNSA examined the high explosive and determined it would need to be replaced before the Navy portion of the interoperable warhead was completed in 2035. “Our view through the surveillance was we just don’t have the confidence it’s going to last that long,” Cook said. “I won’t point to a problem per se. I’ll point to a lack of confidence if we were to extend the life out that long.”
He said it’s important to ensure the high explosive in the warhead don’t degrade or increase in sensitivity. “The elements that are in the composites that make high explosive have limited life and compared to the life of plutonium pits or the life of the secondary elements or many other things they’re actually shorter than those things,” Cook said.
The Waiting is the Hardest Part
Cook said the surveillance details on the warhead are classified, but he said it wasn’t worth the risk of waiting until there was a major issue. He also noted that waiting was less of a risk when the First Production Unit on the warhead was slated for 2025. But that was before the interoperable warhead—which would be used on Air Force and Navy ballistic missiles—was delayed five years and the Navy portion delayed another five years to 2035. “We could’ve said well let’s hope things last that long but then if we had to return the Navy weapons to Pantex again that’s a lot of logistics we have to do and we have an additional cost,” Cook said. “We still would have to replace the CHE but we would have a whole round of weapons movement. We can avoid that whole round of additional weapons movement costs this time around.”
Because the Air Force portion of the interoperable warhead will be addressed before the Navy version, with a FPU slated for 2030, Cook said the same high explosive issues do not exist in the W78, which tops the Air Force’s intercontinental ballistic missiles. “Because we’re going to pay attention to that sooner we don’t need to do that one,” Cook said. “If we push that off further we would have a similar type of need to refresh the W78 conventional high explosive.”
