The Reliable Replacement Warhead (RRW) was a proposed new American nuclear warhead design and bomb family that was intended to be simple, reliable and to provide a long-lasting, low-maintenance future nuclear force for the United States. Initiated by the United States Congress in 2004, it became a centerpiece of the plans of the National Nuclear Security Administration (NNSA) to remake the nuclear weapons complex.
In 2008, Congress denied funding for the program, and in 2009 the Obama administration called for work on the program to cease.
Background During the Cold War, the United States, in an effort to achieve and maintain an advantage in the nuclear arms race with the Soviet Union, invested large amounts of money and technical resources into nuclear weapons design, testing, and maintenance. Many of the weapons designed required high upkeep costs, justified primarily by their Cold War context and the specific and technically sophisticated applications they were created for. With the end of the Cold War, however, nuclear testing has ceased in the United States, and new warhead development has been significantly reduced. As a result, the need for high technical performance of warheads has decreased considerably, and the need for a longer-lasting and reliable stockpile has taken a high priority.
Prior nuclear weapons produced by the U.S. had historically become extremely compact, low weight, highly integrated, and low-margin designs which used exotic materials. In many cases the components were toxic and/or unstable. A number of older US designs used high explosive types which degraded over time, some of which became dangerously unstable in short lifetimes (PBX 9404 and LX-09).W68 warhead at globalsecurity.org Accessed 2006-05-03Warhead Accidents at Banthebomb.org Accessed 2006-05-03Explosives section in nuclear weapons FAQ Accessed 2006-05-03LLNL explosives accident training web page Accessed 2006-05-03 Relatives of 3 Killed in Blast At Nuclear Plant Lose Suit from Oct 3, 1981 New York Times, Accessed 2006-05-03 Some of these explosives have cracked in warheads in storage, resulting in dangerous storage and disassembly conditions.DEFENSE NUCLEAR FACILITIES SAFETY BOARD - Pantex Plant Activity Report for Week Ending January 16, 2004 Accessed 2006-05-03
Most experts believe that the insensitive explosives (PBX 9502, LX-17) currently in use are highly stable and may even become more stable over time.Highs Explosives in Stockpile Surveillance Indicate Constancy. Science and Technology Review. Dec. 1996. http://www.llnl.gov/str/pdfs/12_96.2.pdf
The use of beryllium and highly toxic beryllium oxide material as neutron reflector layers was a major health hazard to bomb manufacturer and maintenance staff. The long term stability of plutonium metal, which may lose strength, crack, or otherwise degrade over time is also a concern. (See Nuclear weapons design and Teller-Ulam design for technical context.)
The question of whether the plutonium-gallium alloy used in the cores of the weapons suffered from aging has been a major topic of research at the weapons laboratories in recent decades. Though many at the labs still insist on scientific uncertainty on the question, a study commissioned by the National Nuclear Security Administration to the independent JASON group concluded in November 2006 that "most plutonium pits have a credible lifetime of at least 100 years".JASON group, [Pit lifetime] (20 November 2006), online at http://www.nukewatch.org/facts/nwd/JASON_ReportPuAging.pdf . The oldest pits currently in the US arsenal are still less than 50 years old.
Concept The concept underlying the RRW program is that the US weapons laboratories can design new nuclear weapons that are highly reliable and easy and safe to manufacture, monitor, and test. If that proves to be possible, designers could adapt a common set of core design components to various use requirements, such as different sized missile warheads, different nuclear bomb types, etc.
NNSA officials believe the program is needed to maintain nuclear weapons expertise in order to rapidly adapt, repair, or modify existing weapons or develop new weapons as requirements evolve. They see the ability to adapt to changing military needs rather than maintain additional forces for unexpected contingencies as a key program driver.Statement of Thomas P. D’Agostino However, Congress has rejected the notion that the RRW is needed to meet new military requirements. In providing funds for 2006, the Appropriations Committee specified, "any weapons design under the RRW program must stay within the military requirements of the existing deployed stockpile and any new weapon design must stay within the design parameters validated by past nuclear tests".U.S. Congress. House. Making Appropriations for the Energy and Water Development for the Fiscal Year Ending September 30, 2006, and for Other Purposes. H.Rept. 109-275. p. 159.
According to a Task Force of the Secretary of Energy's Advisory Board (SEAB), the RRW program and weapon designs should have the following characteristics: Support an adaptable 1,700-2,200 weapon sustained force level (3.1) Resolve an issue with the weapons stockpile within 12 months Adapt a weapon to a new requirement in 18 months Design a new weapon within 36 months Be ready for full production within 48 months Be capable of conducting an underground nuclear test within 18 months Produce all new weapons using Insensitive High Explosive (see TATB and Plastic bonded explosive) and replace all existing weapons which use other explosives (3.1.2) Produce new weapons with the full spectrum of security and use control safety features available today, some of which are intrinsic to the basic design of a weapon and cannot possibly be retrofitted into the design of an existing weapon (3.1.3) Designs which trade off higher weight and larger volume to maximise: (3.1.4) Certification without nuclear testing Inexpensive manufacture and disassembly Ease of maintenance, surveillance, and disposition Modularity (primaries, secondaries, non-nuclear) across systems Maximizing component reuse and minimizing life-cycle costs Comparable or improved levels of reliability to existing designs, using larger margins and simpler components (3.1.5) Lower cost (3.1.6) Designs which can be designed and certified without necessarily undergoing nuclear testing (3.1.7) Consolidation of many nuclear weapon production and maintenance functions to one site (4.1) (in passing) Designs avoiding the use of beryllium or beryllium Oxide in the weapon fission reflector (4.6)
However, the full SEAB disavowed the Task Force's recommendations regarding the RRW, because the Task Force did not consider the program's potentially adverse impacts on U.S. nonproliferation objectives, which were beyond its expertise.
The RRW program has not to date publicly announced that it has developed any new nuclear weapon designs which are intended to be placed into production. Presumably, once that occurs, the weapons will receive numbers in the US warhead designation sequence, which currently runs from the Mark 1 nuclear bomb (aka Little Boy) to the W92 nuclear warhead, which was cancelled in the 1990s. RRW designs would presumably receive designations after that number, though new RNEP nuclear bunker buster weapons could conceivably be type-standardized and numbered prior to any RRW reaching that point, if the RNEP program does proceed.
Selected design
On March 2, 2007, the NNSA announced that the Lawrence Livermore National Laboratory RRW design had been selected for the initial RRW production version.Design Selected for Reliable Replacement Warhead , NNSA Press release, March 2, 2007.
One of the selection reasons given was that the LLNL proposed design was more closely tied to historical underground tested warhead designs. It was described by Thomas P. D'Agostino, acting head of the National Nuclear Security Administration, as having been based on a design which was test fired in the 1980s, but never entered service.Govt. Picks Design for Nuclear Warhead, NY Times / AP, March 2, 2007
LLNL staff have previously hinted in the press that LLNL was considering a design entry based on the tested but never deployed W89 design.Scientists Dream Up New Nukes , Ira Hoffman, Alameda Times-Star, Feb 6, 2006. Accessed March 2, 2007 This warhead had been proposed as a W88 warhead replacement as early as 1991.An Assessment of US Nuclear Weapons and related Nuclear Test requirements: a post-Bush analysis , URCL-LR-109503, R.E. Kidder, 1991. Accessed March 2, 2007Report to Congress: Assessment of the Safety of US Nuclear Weapons and Related Nuclear Test Requirements , URCL-LR-107454, R.E. Kidder, 1991, Accessed March 2, 2007 The W89 design was already equipped with all then-current safety features, including insensitive high explosives, fire-resistant pits, and advanced detonator safety systems. The W89 was also reportedly designed using recycled pits from the earlier W68 nuclear weapon program, recoated in vanadium to provide the temperature resistance.Pit Tubes and Pit Re-Use at Pantex, in Plutonium: the last Five Years , Blue Ridge Environmental Defense League, 2001, accessed March 2, 2007 The W89 warhead was test fired in the 1980s. It had entered Phase 2A technical definition and cost study in November, 1986, and Phase 3 development engineering and was assigned the numerical designation W89 in January 1988.University of California 1989 nuclear weapons labs status report The lead designer, Bruce Goodwin, referred to the primary as the "SKUA9" design which he said had been tested a number of times.
The W89 warhead design was a by weapon, with a weight of and yield of . As noted above, major safety features inherent in the tested W89 design include: Insensitive and fire-resistant LX-17 Polymer-bonded explosive, a type of high explosive using TATB as its main explosive ingredient (see Insensitive munitions) Fire-resistant pit Type D Permissive Action LinkPermissive Action Links at the nuclearweaponarchive.org website, accessed March 5, 2007 Strong link weak link detonation chain safety mechanismsPrinciples of Nuclear Weapons Security and Safety, Carey Sublette, 1997, at nuclearweaponarchive.org, accessed March 11, 2007
Modifications for the RRW design would probably have included replacing beryllium neutron reflector layers with another material, and increased performance margins throughout the design, possibly including more fissile material in the pit and a thicker radiation case or hohlraum (see Teller-Ulam design: Basic principle).
History 2006 In an April 15, 2006, article by Walter Pincus in the Washington Post, Linton F. Brooks, administrator of the US National Nuclear Safety Administration, the US nuclear weapon design agency within the United States Department of Energy, announced that two competing designs for the Reliable Replacement Warhead were being finalized by Lawrence Livermore National Laboratory and Los Alamos National Laboratory, and that a selection of one of those designs would be made by November 2006, to allow the RRW development program to be included in the Fiscal 2008 US government budget.
The article confirmed prior descriptions of the RRW, describing the weapons in the following terms:
The next-generation warheads will be larger and more stable than the existing ones but slightly less powerful, according to government officials. They might contain "use controls" that would enable the military to disable the weapons by remote control if they are stolen by terrorists.
Based on prior weapons programs, the RRW should be assigned a numerical weapon designation when the design selection is made.