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"Forget the Rest" blog


For immediate release May 18, 2015

Los Alamos-Supported Congressional Study Suggests Efficiency Improvements for Plutonium Warhead “Pit” Manufacturing

Billion-Dollar Underground “Modules” Apparently Not Needed Even for Aggressive Manufacturing Requirements Set by Congressional Hawks

Contact: Greg Mello, 505-265-1200 or 505-577-8563

Albuquerque – This past Friday the Congressional Research Service (CRS) published an in-depth study of possible plutonium warhead core (“pit”) manufacturing efficiencies, the latest in a series of reports and briefings on this topic (a total of seven prior CRS products are provided here.)

The full report will be posted on our plutonium infrastructure web page as soon as it becomes publicly available, likely later today.  Meanwhile the author’s summary is provided below.  Congressional access can see the full report here (“Nuclear Weapon ‘Pit’ Production: Options to Help Meet a Congressional Requirement,” by Jonathan Medalia, CRS, 5/14, Report R44033).  CRS is barred from directly publishing its reports.

Like previous reports on this topic, today’s report was developed in cooperation with on-the-ground subject matter experts at Los Alamos National Laboratory (LANL) and elsewhere, and has been peer reviewed by a wide range of independent authorities. 

Symmetric, hollow plutonium shells are the innermost component in the fissile cores of the first-stage nuclear explosives (“primaries,” atomic bombs) in all US nuclear weapons.  According to LANL, pit production is not needed to address plutonium aging (see admission and links to studies in this dialog).[1]  Pit production is however needed if new warheads are to be built using new (as opposed to reused) pits.  

Whether production is needed or not, section 3112 of the FY2015 National Defense Authorization Act, directs the National Nuclear Security Administration (NNSA) to ramp up production of pits to demonstrate a production capacity of 80 pits per year for at least a 90-day period in 2027.  This congressionally-mandated production demonstration, if it is not changed, challenges existing LANL capabilities, a situation which this CRS report addresses. 

Previous CRS reports have shown that despite decades of study and hundreds of millions of dollars in failed investments, defensible answers are still unavailable to the basic questions of how much space is required, and how much plutonium capacity (“Material at Risk,” MAR) is required, for pit production.   

Today’s report takes a different tack.  Without knowing how much space and MAR are required, CRS provides ways to increase one or both of these.  In other words it explores measures to increase the production efficiency and capacity of LANL’s main plutonium facility (building PF-4).  It does not, as previous reports have done, examine the roles other existing NNSA buildings might play in expanding pit production, although these are still relevant. 

Leaving aside the important questions of why it is necessary to produce 80 pits per year, or why existing NNSA facilities elsewhere cannot be better utilized for parts of the pit production mission (such as it is), the main alternative to better management at PF-4 is the construction of new underground plutonium manufacturing modules at LANL. 

If built, two 5,000 square foot “modules” are expected to cost $2.2 billion, giving a per square foot cost of $220,000, even more than the $152,000/sq. ft. estimate for NNSA’s previous failed project at this location, the Chemistry and Metallurgy Research Replacement Nuclear Facility (CMRR-NF).  

Study Group Director Greg Mello: “Today’s report is a major addition to the discussion about the so-called “need” to expand nuclear weapons production infrastructure at LANL.  For the past 25 years, every effort to do so has been a fiasco.  This report, the latest from Dr. Medalia, tells how to avoid another fiasco.

“While some of the recommendations do not comply with DOE internal safety regulations, others are common-sense steps that could save literally billions of dollars.  Hopefully this report will begin a long-overdue, wider discussion of how to properly manage LANL’s plutonium facility.  

“NNSA is currently under congressional fire for not managing its facilities better, not just at LANL but everywhere.  This report, especially when read in combination with the previous ones from Dr. Medalia, should help the agency avoid unnecessary expense and management risk, while also in some cases increasing safety and waste generation by eliminating unnecessary work. 

“The pit production requirements imposed by the Republican-controlled Congress are unnecessary for the stockpile and an intrusion into management.  Hopefully they will be changed.  In the meanwhile Dr. Medalia has provided an essential and highly-informed road map for Congress, the Executive, and civil society.  

“Slight changes in policy – a decrease in the number of non-deployed, “reserve” ICBM warheads, or a decrease in the number of ICBMs, or a decision to retain existing ICBM warhead pits longer, among others – would eliminate the supposed “need” for pit production.  Such small steps are very far from being nuclear “disarmament” – which is in fact what we need.  One cannot help concluding that spending money on nuclear weapons is, for NNSA and its powerful contractors, an end in itself.  That story will end badly.” 

The author’s summary:

A pit is the plutonium core of a thermonuclear weapon. Imploding it with conventional explosives provides the energy to detonate the rest of the weapon. The Rocky Flats Plant made up to 2,000 pits per year (ppy) through 1989; since then, the United States has made 29 pits for the stockpile. Yet the FY2015 National Defense Authorization Act requires the National Nuclear Security Administration (NNSA), which manages the nuclear weapons program, to produce at a rate of 80 ppy for 90 days in 2027. How can that requirement be met?
Pits are to be made at Los Alamos National Laboratory’s main plutonium facility, PF-4. To manufacture pits, a facility must have enough laboratory floor space and a high enough limit for Material At Risk (MAR), the amount of radioactive material a worst-case accident could release.
Producing 80 ppy requires enough “margin,” the space or MAR available to produce pits minus space or MAR required for that production rate. While space and MAR available have been calculated, amounts required to produce 80 ppy have never been calculated rigorously, leaving space and MAR needs undefined. Further, the report cannot address whether certain options could meet the 2027 date because time to implement them cannot be determined. Accordingly, this report presents 16 options that seek to increase the feasibility of producing 80 ppy by 2027, including:
• The radiation dose an individual would receive from a worst-case accident determines MAR permitted in PF-4. A ten-factor equation calculates dose as a function of MAR. NNSA uses worst-case values in this equation, yet median values may provide sufficient conservatism. Median values reduce calculated dose by orders of magnitude, permitting a large increase in PF-4 MAR. Yet merely doubling permitted MAR might suffice for producing 80 ppy. Providing this increase through construction at PF-4 could be costly and take years.
• In determining MAR for PF-4, the closest offsite individual is at a nearby trailer park. Relocating it would place the next closest individual farther away. The added distance would reduce dose, permitting increased MAR in PF-4.
• Using a different meteorological model and different assumptions would greatly reduce the currently calculated dose, perhaps permitting doubling PF-4 MAR.
• Plutonium decays radioactively, creating elements that various processes remove to purify plutonium. One process generates byproducts; plutonium is recovered from them with processes that take space and MAR. Since the United States has tons of plutonium surplus to defense needs, byproducts could be dispositioned as waste.
• Pits use weapons-grade plutonium (WGPu). U.S. WGPu is about 50 years old. About nine-tenths of plutonium-241, a WGPu isotope, decays to americium-241 in that time. Since plutonium-241 is the source of americium-241 in WGPu, removing the current americium-241 would prevent WGPu from ever reaching its americium-241 limit, permitting reduction in equipment for that process and reducing worker radiation exposure.
• A plutonium isotope used in space probes, plutonium-238, is extremely radioactive. It accounts for a small quantity of PF-4 plutonium but a quarter of PF-4’s MAR. Building a “module” near PF-4 for plutonium-238 work would free MAR and space in PF-4, so one module might suffice instead of two or three. 
• To reduce risk of collapse, loss of life, and radiation release from an earthquake, NNSA increased the seismic resilience of PF-4. More steps are planned; more could be taken.
Achieving the congressionally mandated capacity will probably require choosing among options to create a package. MAR margin could be increased by relocating a trailer park, using a new meteorological model, installing rugged containers in the PF-4 production line, increasing PF-4’s seismic resilience, and using less conservative assumptions in the MAR-to-dose equation. Similar choices exist for other options.  At issue for Congress: What are the risks, costs, and benefits of the options? What is the optimum combination of options?


[1] We said, “Pit production for the stockpile is not needed…” LANL agreed with us “with specific limitations:” 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 this situation 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.  (emphasis added).”

NNSA has posted 2010 Study Group recommendations on pit production here.  These are also available on our web site (U.S. Plutonium "Pit" Production: Additional Facilities, Production, Restart are Unnecessary, Costly, and Provocative, Nov 20, 2010).  Further analyses of this topic can be found on our CMRR pagebut may be obscure.  Feel free to call. 

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