Weapons scientists need hands-on experience, panel says
Designing and building prototypes of new nuclear weapons is the only way to ensure that the workforces of the weapons laboratories are prepared to produce a functioning nuclear warhead if necessary, said the co-chairs of a National Academies of Sciences, Engineering, and Medicine committee. While speaking with lawmakers recently, Paul Peercy, dean of engineering at the University of Wisconsin, and Jill Dahlburg, superintendent of the space science division at the Naval Research Laboratory, asserted that simulations and modeling alone can’t qualify a new generation of weapons scientists who have no experience building an actual weapon.
“It’s like cooking,” Dahlburg told the House Armed Services Committee on 12 January. “If you are trying to train someone else to make what you are already cooking, how to cook, you can write down a recipe, and they can follow it. If they’ve never cooked before, the odds are they won’t really know how to do it. You can make a video they can look at and try from that. But the odds are they won’t have quite the same expertise as if they actually come into the kitchen with you and they learn what you mean by a pinch of salt, or stirring the flour with the butter.”
The design and fabrication of prototypes should exercise the full range of skills needed to produce a new weapon, Dahlburg said. “You have to make sure these people know every aspect of what they are doing.” The nuclear components that are designed by Los Alamos and Lawrence Livermore National Laboratories should be fully integrated with all of the non-nuclear components built by Sandia National Laboratories. But the prototype would be tested without the actual nuclear components.
Echoing Dahlburg’s remarks, Peercy explained, “We do not have a complete understanding of the physics of the materials and the processes that go into the weapons. You do the best you can with experiments, but you can’t reach all the experimental regions that you need. Then you do models and simulations based on [those experiments]. But you find that two different models give different answers. The question is which one is right?”
Dahlburg noted that prototyping will improve understanding of the status and direction of foreign nuclear weapons programs. It also will help determine the best and most cost-effective approaches to resolving problems that arise during routine inspections of the US nuclear arsenal and to extending the lifetimes of current warheads.
No new warhead design competitions have been held between Los Alamos and Livermore since 1992, Dahlburg noted.
In its congressionally mandated report Peer Review and Design Competition in the NNSA National Security Laboratories, the National Academies’ committee warned that the number of science and engineering personnel with hands-on experience in nuclear weapons design and nuclear explosive tests will reach zero in the next decade (see Physics Today, December 2015, page 32).
But Representative Jim Cooper (D-TN), noting that the recommendations stopped short of full nuclear testing, asked the witnesses, “How can you make it real without making it real?” He complained that the National Academies’ committee had sought no input from the US State Department, which would likely have pointed out how the prototyping exercise might conflict with US nonproliferation goals.