Nuclear Warhead "Pit" Production: Background and Issues for Congress

Publication Date: March 2004

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Military and defense

Type:

Abstract:

A "pit" is the fissile core of a nuclear warhead. In modern warheads, it creates a nuclear explosion that triggers a substantially larger thermonuclear explosion. All pits currently in the U.S. nuclear stockpile were made at the Rocky Flats Plant near Denver, CO, which opened in 1952. The Department of Energy (DOE) halted pit manufacturing operations there in 1989; the United States has been unable to make stockpile-quality pits -- and therefore complete nuclear warheads -- since then.

Inability to make pits may have adverse consequences. For example: (1) The United States cannot replace pits for the W88 warhead (for the Trident II missile) that are destroyed during evaluation; currently, only one W88 evaluation pit remains, so use of more W88 pits would reduce deployable warheads. (2) Pits deteriorate over time, though the rate at which that happens is under study. If pits of a given type deteriorate so much as to be no longer reliable, or if an unanticipated defect arises, then hundreds to thousands of deployed warheads might have to be withdrawn.

The National Nuclear Security Administration (NNSA), which manages the U.S. nuclear weapons program, has a five-part plan to restore pit production capability: (1) Establish a small facility (PF-4) at Los Alamos National Laboratory (NM) to fabricate pits, initially for the W88. Los Alamos manufactured the first pit to stockpile standards in April 2003. (2) Develop procedures to certify W88 pits -- to provide high confidence without nuclear testing that the pits will work as intended. NNSA expects that, in 2007, Los Alamos will be able to certify W88 pits that it makes. Only certified pits can enter the stockpile. (3) Conduct experiments (not nuclear tests) in support of W88 pit certification at the Nevada Test Site. (4) Conduct pit manufacturing and certification for other pits. (5) Plan a Modern Pit Facility (MPF) with a higher capacity than PF-4, to reach full operational capability in FY2021. NNSA estimates total cost at $1.46 billion for items (1) and (2), smaller amounts for items (3) and (4), and $2 billion to $4 billion for item (5).

Congress has long shown interest in the program. It generally supports low-rate production at Los Alamos. It raised concern over budgeting and the pace of pit certification, but now praises NNSA for "turning around" the W88 pit program. On MPF, the FY2004 defense authorization act supported the Administration's schedule. The appropriations act reduced funding; conferees stated that until Congress reviews nuclear stockpile plans, "it is premature to pursue further decisions" on MPF. MPF's schedule to reach full operational capability slipped a year between 2003 and 2004.

Congress faces several issues as it considers the pit program. Is NNSA's plan for certification reasonable? Does the United States need new pits (beyond limited quantities for the W88)? If so, what capacity is needed? Can PF-4 be expanded to build enough pits to avoid the need for MPF? Could MPF's schedule be accelerated? Should its schedule be delayed?

This report is intended for those interested in the U.S. nuclear weapons program. It will track the pit budget request and program, and will be updated as needed.