For details on congressional action on FY2008 authorization and appropriations bills, see CRS Report RL32929, The Reliable Replacement Warhead Program: Background and Current Developments , by Jonathan Medalia , which provides background and tracks legislation and developments. It selected the California design in March 2007 as the first RRW, or RRW-1. The choice between LEP, RRW, or some combination is important because it will set the course for U.S. nuclear weapons for decades to come, and each year it is up to Congress to decide whether to fund these programs as requested, or modify or cancel them. 1585 and S. 1547 , respectively) and the energy and water appropriations bill reported by the Senate Appropriations Committee ( S. 1751 ) recommended holding RRW in Phase 2A in FY2008. The House Armed Services Committee called for a congressional commission on U.S. strategic posture in its FY2008 national defense authorization bill, H.R. For example, the program is "to improve the reliability, longevity, and certifiability of existing weapons and their components"; a goal is "to develop replacement components for nuclear warheads"; another goal is "[t]o ensure that the nuclear weapons infrastructure can respond to unforeseen problems, to include the ability to produce replacement warheads"; "any new weapon design must stay within the design parameters validated by past nuclear tests"; and a committee's "qualified endorsement of the RRW initiative is based on the assumption that a replacement weapon will be designed only as a re-engineered and remanufactured warhead for an existing weapon system in the stockpile." Others maintain that certification using SSP has been a political assessment rather than a technical one. Accordingly, in this view, NNSA will not know for sure if SSP, and thus RRW or LEP, work until it conducts nuclear tests. They question if RRW will improve reliability. The design teams claim a key advantage for the competing designs: because the designs start fresh, designers can increase margin. 109-364 ( H.R. RRW's supporters point to the use of IHE as an advantage of RRW. It contributes to other goals, such as making manufacturing easier and reducing cost. Critics hold that LEP might also increase safety. Cost

			20. How much is enough? Others feel that RRWs will reduce this burden once they are deployed. RRW advocates argue that minor changes from LEPs may reduce confidence in current warheads over the long term, while RRW designs should provide high confidence because they stay well within parameters defined by nuclear test data and have wider margins than current warheads. NNSA has not made certified pits since then. It includes the Life Extension Program and the RRW program. [4] The Senate Armed Services Committee set goals in its FY2006 report:
The committee understands from the testimony of the Administrator of the National Nuclear Security Administration (NNSA) that the goals of this program are: (1) to increase the security and reliability of the nuclear weapons stockpile; (2) to develop replacement components for nuclear warheads that can be more easily manufactured with more readily available and more environmentally benign materials; (3) to develop replacements that can be introduced into the stockpile with assured high confidence regarding their effect on warhead safety and reliability; (4) to develop these replacements on a schedule that would reduce the possibility that the United States would ever be faced with the need to conduct a nuclear test in order to diagnose or remedy a reliability problem in the current stockpile; (5) to reduce infrastructure costs needed to support the stockpile, while increasing the responsiveness of that infrastructure; and (6) to increase confidence in the stockpile to a level such that significant, additional reductions in numbers of non-deployed `hedge' warheads can be made.
Current U.S. nuclear warheads were deployed during the Cold War. The National Nuclear Security Administration (NNSA) maintains them with a Life Extension Program (LEP). NNSA questions if LEP can maintain them indefinitely on grounds that an accretion of minor changes introduced in replacement components will inevitably reduce confidence in warhead safety and reliability over the long term.
Congress mandated the Reliable Replacement Warhead (RRW) program in 2004 "to improve the reliability, longevity, and certifiability of existing weapons and their components." Since then, Congress has specified more goals for the program, such as increasing safety, reducing the need for nuclear testing, designing for ease of manufacture, and reducing cost. RRW has become the principal program for designing new warheads to replace current ones.
The program's first step was a design competition. The winning design was selected in March 2007. If the program continues, NNSA would advance the design of the first RRW, assess its technical feasibility, and estimate cost and schedule in FY2008; start engineering development by FY2010; and produce the first deployable RRW between FY2012 and FY2016. Congressional actions on the FY2008 national defense authorization bills (H.R. 1585, S. 1547) and energy and water appropriations bills (H.R. 2641, S. 1751) have called this schedule into question. For details, see CRS Report RL32929, The Reliable Replacement Warhead Program: Background and Current Developments, which provides background and tracks legislation and developments. Each year, Congress would decide whether to fund the program as requested, modify it, or cancel it, and whether to continue or halt LEP.
RRW's supporters argue that the competing designs meet all goals set by Congress. For example, they claim that certain design features will provide high confidence, without nuclear testing, that RRWs will work. Some critics respond that LEP should work indefinitely and question if RRW will succeed. They hold that LEP meets almost all goals set by Congress, and point to other LEP advantages. Others maintain that the scientific tools used to create RRW designs have not been directly validated by nuclear tests, and that the accretion of changes resulting from LEP makes the link of current warheads to the original tested designs increasingly tenuous. In this view, nuclear testing offers the only way to maintain confidence in the stockpile. RRW raises other issues for Congress: Is RRW likely to cost more or less than LEP? How much safety, and how much protection against unauthorized use, are enough? Should the nuclear weapons complex be reconfigured to support RRW? And what information does Congress need to choose among the alternatives?
This report is intended for Members and staff interested in U.S. nuclear weapon programs. It will be updated occasionally.