Funding Cut for the Bunker Buster

Tasneem Jamal

Sarah Estabooks

The Ploughshares Monitor Winter 2005 Volume 26 Issue 4

For the second year in a row, US congressional funding for the Robust Nuclear Earth Penetrator (RNEP) program has been cut. The RNEP, commonly known as the ‘bunker buster’, has received widespread criticism from both Republicans and Democrats and, in 2004, appropriators zeroed the budget request. This year Congress once again agreed to cut the funding. Indications are that this cut signifies the end of the controversial program, although not the end of ambitions to create new nuclear weapons.

Funding for nuclear weapons programs comes under the Energy and Water Development Appropriations Bill, as the primary responsibility for these weapons is held by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE). The RNEP program was originally proposed within the Advanced Concepts Initiative for development of new nuclear weapons.

The nuclear doctrine laid out in the 2001 Nuclear Posture Review conceived of new tactical nuclear weapons designed to meet the perceived targets of the war on terror. The Advanced Concepts Initiative, including the RNEP, was part of a bundle of controversial programs that emerged in response to the Review. In 2003, Congress agreed to lift the Spratt-Furse ban on developing low-yield nuclear weapons, or ‘mini nukes’. A proposal was made to study the requirements to reduce the timeline for nuclear test readiness to 18 months. Finally, funding was requested for a Modern Pit Facility to produce the Plutonium pits for nuclear warheads.

The robust nuclear earth penetrator, designed to burrow and destroy deeply buried and hardened targets using high-yield nuclear warheads, was a response to the caves and bunkers encountered in Afghanistan. A study to explore the modification of the B61-11 bomb (a conventional penetrator) to a nuclear penetrator was proposed by the NNSA in the budget request for 2003.

The RNEP study was initially designed to cost US$15-million per year for the fiscal years from 2003 to 2005. After receiving the full amount for fiscal year 2003, the RNEP study encountered resistance in the 2004 appropriations negotiations. General opposition to the program inspired two amendments: one that designated the funds to non-nuclear penetrating technologies only and the other that cut funding completely. In the final bill, $7.5-million was appropriated for the RNEP, but the work was restricted to the research and development phase, with no engineering work.

Critics of the RNEP concept hold that burrowing capacity is so limited that the RNEP would require a large-yield nuclear warhead to destroy a hardened target, with no way to contain the fallout. They also believe that the RNEP could lower the threshold for nuclear use, including against non-nuclear armed states. Along with others, the Chairman of the House Sub-committee for Energy and Water Development Appropriations, David Hobson (R-OH), is concerned that the development of new nuclear weapons sends a ‘do as we say, not as we do’ message to potential proliferators.

The 2004 budgetary process saw renewed debate over the RNEP when the budgetary request laid out a new five-year plan for the study with a $484.7-million price tag. There was widespread concern among both House and Senate members that this dramatic funding increase reflected a shift beyond a study to development and testing. A Congressional Research Service report (Medalia 2004, p. CRS-3) notes, “The FY2005 request document therefore seems to cast serious doubt on assertions that RNEP is only a study.”

In a surprising move, Hobson moved to eliminate funding for the RNEP from the House bill. There was bi-partisan support for the cut, and the RNEP was zeroed in the House version of the appropriations bill. Although the Senate had approved the funding, the cut was retained in the final Energy and Water Development Appropriations Bill.

Despite last year’s bipartisan support for cutting the RNEP, the administration reintroduced the item in its February 2005 budget request for fiscal year 2006. Although the previous five-year plan allotted $27.6-million for the RNEP in 2006, the actual Department of Energy request was a relatively modest $4-million for an impact test of a model warhead into concrete. A second request of $4.5-million was made within the Department of Defense request for the Air Force to examine the requirements to modify the B-2 bomber to carry the RNEP.

In a press release issued during October negotiations to rectify House and Senate versions of the Energy and Water Development Appropriations Bill, Senator Pete Domenici (R-NM), chairman of the Senate subcommittee, announced that DOE funding for the Robust Nuclear Earth Penetrator was zeroed.

For the second year in a row, David Hobson had led the House to cut funding for the RNEP and transfer it to DOD to test non-nuclear penetrating technology. Hobson’s skepticism about any justifiable need for a RNEP is well documented. In an address to the Arms Control Association in February 2005 he stated: “Neither the Department of Defense nor the Department of Energy has ever articulated to me a specific military requirement for a nuclear earth penetrator.”

The fiscal year 2006 Senate bill approved the requested funding for the RNEP and assigned the work to Sandia National Laboratories. It did, however, retain the stipulation that the work could not advance to the engineering stage (US Senate 2005, pp. 155-156).

Pete Domenici’s recent announcement (2005) that RNEP funding was to be cut in the final Appropriations Bill noted that the Senate agreed to cut the funding “at the request of the National Nuclear Security Administration.” Domenici said, “The NNSA indicated that this research should evolve around more conventional weapons rather than tactical nuclear devices. With this department change in policy, we have agreed not to provide DOE with funding for RNEP.” New evidence has emerged suggesting that the NNSA maintained its support for the project and for the impact test to be held at Sandia, where work commenced in 2004, and did not instigate the move to cut funding.1

In light of the 2005 and 2006 funding cuts, it seems highly unlikely that the bunker buster will reappear in its current form in the 2007 budgetary request. This is not to say that the push for new nuclear warheads will die. Daryl Kimball of the Arms Control Association (2005) has identified the ‘reliable replacement warheads’ program as another troubling development on the horizon. This program is proposed as an option to sustain existing capabilities, while lowering costs and not requiring testing. Kimball argues that if the program is given carte blanche, “the weapons labs may, in the end, be able to achieve their controversial new nuclear weapons research ambitions denied with the defeat of RNEP.” Furthermore, a replacement program could increase pressure to renew warhead testing and break the current moratorium.

While the RNEP program might be dead, the drive for new and useable nuclear weapons has not died. Modernization of the US nuclear arsenal for tactical missions was called for in the Nuclear Posture Review and so continued monitoring is needed.

Further detail and analysis of bunker busters can be found in The Ploughshares Monitor, Summer 2003 and Winter 2004, available on the Project Ploughshares website.


  1. See the blog of Jeffrey Lewis, which includes text from the NNSA’s ‘Appeal’ to Congress, and an email from NNSA Policy Planning Director John Harvey clarifying the official position.


Domenici, P. 2005 “Domenici: NREP Funds Dropped from Appropriations Bill,” Press releases of Senator Pete Domenici.

Hobson, D. 2005, “U.S. Nuclear Security in the 21st Century,” address to the Arms Control Association, February 3.

Kimball, D. 2005, “Nuclear Bunker-Buster (As We Know It) Is Dead,” Arms Control Association. 26 October.

Medalia, J. 2004, “Robust Nuclear Earth Penetrator Budget Request and Plan, FY2005-FY2009,” CRS Report for Congress RS21762, 24 March.

United States Senate 2005, Senate Report 109-084—Energy and Water Appropriations Bill, 2006.

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