LOS ALAMOS SAYS PU STUDY DOESN’T NEGATE NEED FOR PIT MANUFACTURING

Los Alamos National Laboratory this week sought to strongly counteract claims that a recent plutonium aging study diminishes the need for a limited pit manufacturing capability, arguing that the study just looked at small samples of plutonium and not how pits age. A recent Lawrence Livermore National Laboratory study revealed that plutonium is now expected to last at least 150 years, and while Los Alamos did not question Livermore’s findings in the document circulated this week and obtained by NW&M Monitor, it strongly opposed suggestions made by outside groups that the new aging studies provide evidence for curtailing pit production and more reasons for deferring construction on the Chemistry and Metallurgy Research Replacement-Nuclear Facility, which officials had suggested was necessary to support expanded pit production at Los Alamos. “A continued limited manufacturing capability is essential …” Los Alamos said. “The efforts to ‘maintain’ the existing stockpile include life extension programs which will require pits to achieve higher safety standards than may be possible through exclusive reuse of existing pits.” Los Alamos also suggested that the need for new facilities was not solely driven by production needs. “Infrastructure decisions are primarily germane due to a degrading infrastructure that must be kept operational in an escalating regulatory environment,” the lab wrote.

The Los Alamos Study Group, which circulated the Livermore study, was among the loudest groups suggesting that the results add to the evidence that new plutonium pit manufacturing is not needed “unless somehow a grossly uneconomical scheme is devised in which the present inventory of roughly 5,000 backup pits, beyond the roughly 5,000 pits now in the nuclear stockpile, is deemed insufficient,” Study Group Director Greg Mello said. Mello was joined this week by arms control experts at the Center for Arms Control and Non-Proliferation, who suggested that the Livermore study provides further justification for the Obama Administration’s decision to defer work on CMRR-NF for at least five years. “The study that Lawrence Livermore has put out that says that it’s at least 150 years and counting is getting to be a really long time, not forever and ever and ever, but a really long time,” said Phillip Coyle, the Senior Science Fellow at the Center for Arms Control and Non-Proliferation and the former Associate Director for National Security and International Affairs for the Office of Science and Technology Policy under President Obama. “If everybody had known about this latest data they might have argued for a longer delay; they might have said we could wait 10 years or 20 years or 150 years.”

CMRR-NF Subject of Significant Debate

The fate of CMRR-NF has been hotly debated ever since the Administration formally deferred the project in February, choosing instead to pursue an alternate plan that would use existing facilities to meet the nation’s plutonium needs. On the heels of informal talks, House and Senate lawmakers began to formally hash out differences between their versions of the Fiscal Year 2013 Defense Authorization Act this week as conference negotiations officially began, and both chambers supported—in different ways—the CMRR-NF project, bucking the Administration and House and Senate appropriators, which have supported the alternate plutonium strategy. Kingston Reif, the Director of Nuclear Non-Proliferation at the Center for Arms Control and Non-Proliferation, suggested that current budget realities make deferring the project the right approach. “If a cheaper alternate is available, despite whatever pledges may have been made two years ago under an entirely different fiscal environment, it makes sense to look at potential cheaper alternatives,” he said. “If a cheaper alternative can be found that allows us to sustain the stockpile and maintain a safe, secure and reliable stockpile, we don’t see why it’s not something that we shouldn’t pursue.”

The new 150-year estimate of the lifetime of plutonium is based on a continuation of studies that began in the 1990s. The accelerated aging is done by spiking weapons-grade plutonium-239 with the plutonium-238 isotope, which undergoes more rapid radioactive decay. That allows scientists to measure the buildup of defects in the material caused by the decay, which creates helium as a byproduct that builds up into microscopic bubbles. The accelerated aging plutonium samples tested at Livermore have now reached the equivalent of 150 years in age, along with naturally aged plutonium that is now in excess of 50 years old, and the problems scientists had feared have not materialized in a way that could degrade the plutonium’s performance, according to the report.

LANL: Study Doesn’t Tell Whole Story

Los Alamos noted, however, that the Livermore study examined the lifetime of small samples of plutonium and not the aging of actual pits or primaries or the weapons systems as a whole. It also noted that the Livermore study was limited to “phase stability and void swelling” in plutonium. “It gives us confidence that these particular aging effects are not a significant concern,” Los Alamos said. “It does not address the remaining aging effects or other alloys under consideration.” Los Alamos also suggested that pit production was needed in some cases because current pits are not able to be used in new life extension programs. “The facts are that all pits are not equal and some are more difficult than others to ‘promote’ in order to achieve modern safety requirements,” the lab said. “These requirements include the use of insensitive high explosives, the resistance to plutonium dispersion in the event of a fire and others intended to minimize the consequences in the event of an accident.” —Todd Jacobson