U.S. Nuclear Weapon “Pit” Production Options for Congress

Summary

A “pit” is the plutonium core of a nuclear weapon. Until 1989, the Rocky Flats Plant (CO) mass-produced pits. Since then, the United States has made at most 11 pits per year (ppy). U.S. policy is to maintain existing nuclear weapons. To do this, the Department of Defense states that it needs the Department of Energy (DOE), which maintains U.S. nuclear weapons, to produce 50-80 ppy by 2030. While some argue that few if any new pits are needed, at least for decades, this report focuses on options to reach 80 ppy.

Pit production involves precisely forming plutonium—a hazardous, radioactive, physically quirky metal. Production requires supporting tasks, such as analytical chemistry (AC), which monitors the chemical composition of plutonium in each pit.

With Rocky Flats closed, DOE established a small-scale pit manufacturing capability at PF-4, a building at Los Alamos National Laboratory (LANL). DOE also proposed higher-capacity facilities; none came to fruition. In 2005, Congress rejected the Modern Pit Facility, viewing as excessive the capacity range DOE studied, 125-450 ppy. In 2012, the Administration “deferred” construction of the Chemistry and Metallurgy Research Replacement Nuclear Facility (CMRR-NF) on grounds of availability of interim alternatives and affordability.

Nonetheless, options remain:

Build CMRR-NF. Congress mandated it in the FY2013 cycle, but provided no funds for it then, and permitted consideration of an alternative in the FY2014 cycle.

Remove from PF-4 tasks not requiring high MAR and security. Casting pits uses much plutonium that an accident might release (“Material At Risk,” MAR) and requires high security. Making 80 ppy would require freeing more MAR and floor space in PF-4 for casting.

Provide regulatory relief so RLUOB could hold 1,000 grams of plutonium with few changes to the building. AC for 80 ppy needs much floor space but not high MAR or high security. Several options involve LANL’s Radiological Laboratory/Utility/Office Building (RLUOB). Regulations permit it to hold 26 grams of weapons-grade plutonium, the volume of two nickels; AC for 80 ppy would require 500 to 1,000 grams and perhaps space elsewhere. Augmenting RLUOB to hold the latter amounts within regulations would be costly even though the radiation dose if the building collapsed would be very low. Regulatory relief would save time and money, but would raise concerns about compliance with regulations. A complementary option is to perform some AC at Lawrence Livermore National Laboratory or Savannah River Site.

Move plutonium-238 work to Idaho National Laboratory or Savannah River Site. Fabricating plutonium-238 into power sources for space probes entails high MAR, but not high security because it is not used in pits. Moving it would free MAR and floor space in PF-4. At issue is whether to conduct all plutonium work at LANL, the plutonium “center of excellence.”

Build concrete “modules” connected to PF-4. This would enable high-MAR work to move out of PF-4, so PF-4 and modules could do the needed pit work. At issue: are modules needed, at what cost, and when.

Several options have the potential to produce 80 ppy and permit other plutonium activities at relatively modest cost, in a relatively short time, with no new buildings, and with minimal environmental impact. Determining their desirability and feasibility would require detailed study.

Observations include:

Differing time horizons between Congress and DOE, and between political and technical imperatives, cause problems.

Doing nothing entails costs and risks. Keeping a 1950s-era building open while options are explored exposes workers to a relatively high risk of death in an earthquake.

Congress may wish to consider limiting a building’s permitted plutonium quantity by estimated dose instead of MAR. A facility can be safe even if it is not compliant with regulations.

The political system is more flexible than the regulatory system. Regulations derive their authority from statutes. Regulators, bound by these statutes, cannot make cost-benefit tradeoffs regarding compliance. In contrast, the political system has the authority, ability, and culture to decide which tradeoffs are worth making.