	Background

Congress is involved in the long-running and costly decision regarding the future production of "pits"; a pit is the plutonium core of the primary stage of a nuclear weapon. During the Cold War, the Rocky Flats Plant (CO) made pits on an industrial scale, sometimes over 1,000 pits per year (ppy). Rocky Flats ceased pit production in 1989. Yet the Department of Defense (DOD) requires the National Nuclear Security Administration (NNSA), the separately organized component of the Department of Energy (DOE) in charge of the U.S. nuclear weapons program, to have the capacity to make 50-80 ppy by 2030. This report summarizes the much more detailed CRS Report R43406, U.S. Nuclear Weapon "Pit" Production Options for Congress , by [author name scrubbed]. Currently, Los Alamos National Laboratory (LANL) (NM) produces pits at its PF-4 building, and conducts AC and other supporting tasks at its Chemistry and Metallurgy Research (CMR) building. Pit Fabrication Options

The basis for the following options is that PF-4 is the only U.S. building able to produce pits, as it has high security, a high MAR allowance, and pit production equipment. Increasing its capacity to 80 ppy would entail more production equipment and more MAR. Thus higher capacity requires making MAR and space available. Options Using Modules

One option is to build "modules" at LANL so high-MAR work like processing Pu-238 or casting pits could be moved from PF-4. Each would be built for a specific task. Idaho National Laboratory (INL) and Savannah River Site (SRS) (SC) have both done work with Pu-238. Higher capacity also requires more AC, as the two increase in tandem. PF-4 is not suitable for most AC work. Thus increased pit production would also require finding one or more sites for AC. Options at Los Alamos

Analysts have argued that it would not be desirable to perform all AC at a site other than LANL. All plutonium work requires AC. It would be very costly, if not impossible, to retrofit that capacity into PF-4. Another possibility is to use an existing building at LANL, the Radiological Laboratory-Utility-Office Building (RLUOB, pronounced rulob). Similarly, LANL has not studied in detail how much floor space the AC for 80 ppy would require, but estimates that if all laboratory space in RLUOB could be used with 500-1,000 grams of plutonium and if some additional space could be made available for AC in PF-4, that might suffice. This approach would probably permit NNSA to halt work in CMR by 2019, removing workers and plutonium from a building that is much more at risk of collapse from an earthquake than is RLUOB. Questions for Congress

This report shows that many options could address DOD's requirement for 80 ppy, but it cannot determine which, if any, could meet this requirement because data do not exist on how much MAR and space are needed for AC and pit fabrication for 80 ppy. Likewise, there are little to no data on cost. However, this report raises questions that Congress may wish to have answered in order to decide how to proceed. Questions include:
Is an 80-ppy capacity needed? If so, how much space and MAR in PF-4 would fabrication of 80 ppy require? Could that amount of space be made available by repurposing PF-4 space? How could enough MAR allowance be made available? What would be the cost? What are the pros, cons, and costs of Pu-238 options? Are modules needed, or are other options preferable? Would the additional freed-up MAR and space permit PF-4 to fabricate 80 ppy? How much space and MAR would AC for 80 ppy require? What are the pros, cons, and costs of having SRS or LLNL perform some AC? What would it cost to convert RLUOB to HC-3?
Congress is involved in the long-running and costly decision regarding the future production of "pits"; a pit is a nuclear weapon's plutonium core. Rocky Flats Plant (CO) mass-produced pits during the Cold War; production ceased in 1989. The Department of Energy (DOE), which maintains U.S. nuclear weapons, then established a small pit manufacturing capability at PF-4, a building at Los Alamos National Laboratory (LANL) (NM). PF-4 has made at most 11 pits per year (ppy). DOE also proposed higher-capacity facilities; none came to fruition.
U.S. policy is to maintain existing nuclear weapons. To do this, the Department of Defense has stated that it needs DOE to have the capacity to produce 50-80 ppy by 2030. This report focuses on options to reach 80 ppy. A separate debate, not discussed here, is the validity of the requirement; a lower capacity would be simpler and less costly to attain.
Pit production requires many tasks, but this report focuses on two: pit fabrication, which forms plutonium into precise shapes, and analytical chemistry (AC), which monitors the composition of each pit. Any feasible option requires sufficient "space" (laboratory floor space) and "Material At Risk" (MAR) allowance. Each building for plutonium work is permitted a specified amount of MAR, that is, radioactive material (adjusted for radioactivity) that could be released by an event like an earthquake.
Pits can only be fabricated in PF-4. Increasing its capacity to 80 ppy would require making more MAR and more space available in that building, which in turn would require moving out radioactive material and freeing up space. Both could be done, for example, by moving pit casting or work on plutonium-238 (Pu-238), which is much more radioactive than the plutonium used in weapons, out of PF-4.
One pit fabrication option is to build one or more "modules" to move high-MAR work from PF-4. Modules would be reinforced-concrete structures buried near PF-4. Another option is to use buildings at Idaho National Laboratory or Savannah River Site (SRS) (SC); both sites have done work with Pu-238.
Higher capacity also requires more AC, which increases in tandem with capacity. Most AC is not time-sensitive, so some of it could be done at sites other than LANL. PF-4 is not suitable for most AC work. Thus increasing pit production would also require finding one or more sites for AC. AC requires much less MAR and much more space than pit fabrication, so AC options differ from pit fabrication options. Buildings at Lawrence Livermore National Laboratory (CA) and SRS have ample space suitable for AC. LANL would also need a significant AC capacity to support pit production and other work. An option would be to modify the new Radiological Laboratory-Utility-Office Building (RLUOB) so it could handle more plutonium, permitting it to do more AC.
This report shows that many options are available for making 80 ppy, but it cannot determine which, if any, could support that capacity because data do not exist on how much MAR and space are needed for AC and pit fabrication for 80 ppy. Likewise, there are little to no data on cost. However, the report raises questions that Congress may wish to have answered in order to decide how to proceed:
Is an 80-ppy capacity needed? If so, how much space and MAR in PF-4 would fabrication of 80 ppy require? Could sufficient space be made available by repurposing PF-4 space? How might enough MAR allowance be made available? What are the pros, cons, and costs of Pu-238 options? If modules are built, how many would be needed and what would they cost? How much space and MAR would AC for 80 ppy require? What are the pros, cons, and costs of having SRS or LLNL perform some AC? What would it cost to modify RLUOB?
This report summarizes a more detailed report, CRS Report R43406, U.S. Nuclear Weapon "Pit" Production Options for Congress, by [author name scrubbed].