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"Forget the Rest" blog


Reference:  Los Alamos Talking points regarding “Plutonium in Warhead Cores (“Pits”) Stable to 150 Years Aging Tests at Nuclear Weapons Lab Extend Earlier Results, Increasing Confidence Results Highlight Lack of Need for New Pit Production Facility” , Mello, 12/6/2012

The reference article provides an interpretation of the LLNL Science and Technology Article that goes well beyond the actual data and evidence provided by this article.  The bullets below are intended to provide a Los Alamos perspective for the key points made by the Los Alamos Study Group.

LASG:  “Thus it is the aging of the plutonium components themselves, not anything else, which is germane to plutonium infrastructure decisions.”

LANL:  First, the lifetime of a pit and the lifetime of the Pu are two different things entirely. The LLNL S&T article addresses Pu aging of small samples, not pit aging and certainly not primary or weapon system aging.  The extension of plutonium lifetime to pit lifetime is an extrapolation and is not supported by the referenced data. Second, infrastructure decisions are primarily germane due to a degrading infrastructure that must be kept operational in an escalating regulatory environment (CMR to CMR-Replacement being an example).  

LASG: “The probability of prior results being mistaken (despite the extensive peer review they had) and therefore of acute pit failure, is now lower than ever”

LANL: This is an extrapolation.  The LLNL articleexamines phase stability and void swelling in plutonium under ambient conditions.  It gives us confidence that these particular aging effects are not a significant concern.  It does not address the remaining aging effects or other alloys under consideration.

LASG: “Pit production for the stockpile is not needed…”

LANL: Agreed with specific limitations.  Pit production to replace pits in the deployed stockpile due to plutonium aging is not required, nor is it planned to occur.  If thissituation were otherwise, the NNSA decision in the SSMPEIS would have established a Modern Pit Facility pathway and be constructing a “large” production facility capable of producing several hundred pits per year and spending billions of dollars a year to do it.  

LASG:  “…..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”

LANL:   This statement makes a key assumption thatexcess pits in existence can universally be re-used.  The facts are that all pits are not equal and some are more difficult than others to “promote” in order to achievemodern safety requirements.  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.

LASG:  “Barring such artificial, created “needs,” no large new plutonium pit manufacturing capability is needed to maintain an extremely large, diverse nuclear stockpile for the foreseeable future -- for generations.”

LANL:  Overall, an accurate statement depending upon a common definition of  “large” and interpretation of “maintain”.

The NNSA faced the decision to construct a “large”(meaning a capacity of hundreds of pits per year) production facility in 2007 and the project known as either the Modern Pit Facility (MPF) or the Consolidated Plutonium Complex (CPC) was terminated.  The article in Science and Technology Review summarizing Livermore's plutonium aging study, along with an earlier study at Los Alamos, re-affirms the DOE decision not to build a large-capacity "Modern Pit Facility" and instead pursue a limited manufacturing capability in existing and planned facilities at Los Alamos.  A continued limited manufacturing capability is essential as noted in the S&T article.

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.  This could lead to pit manufacturing at the limited rates determined by the NNSA through the NEPA process and described in the SSMPEIS.  

LASG: “It would be counterproductive to plan or design for such a large facility now because the planning and design bases would change so much prior to any necessity for construction that the effort would need to be updated again and again

LANL:  LASG seems to be applauding the SSMPEIS decision here to do limited, capability based pit manufacturing in existing facilities and planned replacement facilities rather than construct a high capacity pit manufacturing facility, and Los Alamos is in agreement.  

LASG:  “ These results are being reported by LLNL, not LANL, and they are only being reported now. ….”

LANL:  The international scientific community has continued its dialogue on plutonium aging in the open forum of the Plutonium Futures – the Science and the Actinides international conferences.  In the July 2012 Plutonium Futures conference, there were at least 14 presentations related to Pu aging from LANL, LLNL, AWE, CEA and Russian scientists, while at least 10 presentations were given at the September 2010 conference.  Since 2006, there have been a number of open literature peer-reviewed journal articles on various aspects of plutonium aging from around the world.

LASG: “The plutonium laboratory which is producing these results is slated to be downgraded from a secure nuclear facility under current National Nuclear Security Administration (NNSA) plans.  This would leave LANL as the sole arbiter of pit aging.”

LANL:  Both LLNL and Los Alamos will continue to pursue the valuable collaboration into the science of plutonium aging and pit lifetimes.  The security status change at the superblock facility will not preclude LLNL from continuing to pursue plutonium gaining experiments.

LASG:  ”Why were these evolving results withheld until now, instead of being released, say, annually?

LANL:  The Study Group asserts that these results have somehow been withheld.  As mentioned, the plutonium scientific communities have been discussing these studies continually.  The actual scientific report has not been issued or peer reviewed.  Scientific results are properly released when a study is completed.  Interim reports are always shared and discussed within the scientific community, and the final results are submitted and peer reviewed for completeness.  This is the normal mechanism of science, and we expect the LLNL scientists will be submitted these data for publication, at which time the data will be properly disclosed to the scientific community.

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