During the Cold War, the Rocky Flats Plant (CO) manufactured as many as 2,000 pits per year (ppy). In one track, Plutonium Facility 4 (PF-4), the main plutonium building at Los Alamos National Laboratory (LANL) (NM), would house a pilot plant to develop pit production processes and manufacture a small number of pits. A Department of Defense (DOD) official stated in 2013 that "there is no daylight between the Department of Energy and the Department of Defense on the need for both a near-term pit manufacturing capacity of 10 to 20 and then 30 by 2021, and then in the longer term for a capacity of 50 to 80 per year." Specifically, regardless of what capacity is needed, and when, Congress and the Administration will need to decide among options. This report presents three key decisions and an approach to help structure them. It shows that it is not known whether available amounts suffice. Space and MAR requirements for manufacturing 80 ppy have never been calculated rigorously, though they could be. Over time, however, various factors will affect availability and requirements. "Material At Risk" (MAR) is "the amount of radioactive materials … available to be acted on by a given physical stress." It is configured for AC. Margin , in this case, is the amount by which (1) space available for pit manufacturing exceeds (2) space required to manufacture 80 ppy, and the amount by which (3) MAR available for pit manufacturing exceeds (4) MAR required to manufacture 80 ppy. AC also has space and MAR requirements but, as discussed in " Options for Analytical Chemistry ," margins are not at issue because the nuclear weapons complex has ample space and MAR for AC for 80 ppy. While MAR and space margins could be calculated precisely for the present moment, they cannot be calculated in advance because many actions, events, decisions, and discoveries have the potential to create uncertainties that could increase or decrease availability of, or requirements for, space and MAR, thus increasing or decreasing margin. If not, what can be done to provide it? Decision 2: Once enough margin for space and margin for MAR are provided for pit manufacturing, what steps can be taken to maintain these margins over decades in the face of uncertainties? Decision 3: For AC, space and MAR available across the nuclear weapons complex exceed space and MAR required by a considerable amount, so margin is not an issue. Producing 80 ppy would require increasing AC capacity. LANL has provided data from which this report calculated how much MAR and space various options would make available. It would be simple to compare data on the required MAR and space, once they become available, against the amount of MAR and space released by each option to see which options provide a positive margin. Questions Requiring Data on MAR and Space

Questions such as the following can only be answered with data on how much MAR and space suffice for pit manufacturing and supporting AC for 80 ppy:
Once certain seismic upgrades are completed, is there expected to be enough MAR margin for PF-4 to accommodate the added MAR needed to manufacture 80 ppy? At issue: How much AC should be done at LANL, what is needed to make the space and MAR at LANL sufficient to support that amount of AC, and how much, if any, AC should be done at other sites? This involves validating weapons codes, among other things.
A "pit" is the plutonium "trigger" of a thermonuclear weapon. During the Cold War, the Rocky Flats Plant (CO) made up to 2,000 pits per year (ppy), but ceased operations in 1989. Since then, the Department of Energy (DOE) has made at most 11 ppy for the stockpile, yet the Department of Defense stated that it needs DOE to have a capacity of 50 to 80 ppy to extend the life of certain weapons and for other purposes. This report focuses on 80 ppy, the upper end of this range.
Various options might reach 80 ppy. Successfully establishing pit manufacturing will require, among other things, enough laboratory space and "Material At Risk" (MAR). MAR is essentially the amount of radioactive material permitted in a building that could be released in an accident; there must be enough MAR available for manufacturing within the MAR "ceiling." PF-4, the main plutonium building at Los Alamos National Laboratory (LANL), or other structures would house manufacturing. Analytical chemistry (AC), which analyzes the composition of samples from each pit to support manufacturing, will also require availability of MAR and space.
For an option to support 80 ppy, MAR and space available for manufacturing and AC must exceed MAR and space required for 80 ppy. "Margin" is the amount by which an available amount exceeds a required amount. This report presents amounts of MAR and space potentially available for manufacturing under several options, though they may require updating. Calculation of margin—needed to determine if an option passes a minimum test for feasibility—also requires data on MAR and space required for 80 ppy, yet these data have never been calculated rigorously. As a result, it is not known if an option would increase capacity too little (making an option infeasible), too much (making an option too costly), or by an appropriate amount. Congress could direct the National Nuclear Security Administration, which operates the nuclear weapons program, to provide data on space and MAR required to manufacture 80 ppy. These data would permit calculation of space margin and MAR margin as static numbers. However, the situation is dynamic: uncertainties may materialize over time, increasing or decreasing margin.
AC poses different issues. It is needed to support production. It requires much space but uses little MAR. The nuclear weapons complex has ample excess space and MAR available for AC, so margin is not at issue, though such factors as logistics might become an issue.
Thus, three key decisions face Congress in deciding how to produce 80 ppy:
Decision 1: For pit manufacturing, is there currently enough margin for space and MAR in PF-4? If not, what can be done to provide it? Decision 2: Once enough margin for space and margin for MAR are provided for pit manufacturing, what steps can be taken to maintain these margins over decades in the face of uncertainties? Decision 3: How much AC should be done at LANL, what is needed to make the space and MAR at LANL sufficient to support that amount of AC, and how much, if any, AC should be done at other sites?
Choosing among options also requires data on how options compare on cost and other metrics, setting up a process for downselection.
This report is best viewed in color, as it contains many multicolored graphics.