"Bunker Busters": Robust Nuclear Earth Penetrator Issues, FY2005 and FY2006

Publication Date: August 2005

Publisher: Library of Congress. Congressional Research Service

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Research Area: Military and defense

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Abstract:

Earth penetrator weapons, often called "bunker busters," burrow into the ground some tens of feet before detonating, greatly increasing their ability to destroy buried targets. The United States has several types of conventional earth penetrators. The current U.S. nuclear earth penetrator, the B61-11 bomb, cannot penetrate certain types of terrain in which hardened underground facilities may be located, so the Air Force and the National Nuclear Security Administration (NNSA) are studying a more effective penetrator, the Robust Nuclear Earth Penetrator (RNEP).

While Secretary of Defense Rumsfeld said in 2003 that RNEP was a study, NNSA's FY2005 budget document showed a five-year total of $484.7 million if RNEP were to proceed beyond the study phase. NNSA stated that no decision had been made to proceed with RNEP and that out-year figures were shown to meet congressionally-mandated budgeting requirements and were not a request. RNEP requests are, of course, subject to congressional approval, rejection, or modification. The five-year figure sparked congressional debate. The FY2005 National Defense Authorization Act contained the full RNEP request, $27.6 million. The House rejected an amendment by Representative Tauscher to transfer funds from RNEP and the Advanced Concepts Initiative (ACI), another nuclear program, to Air Force conventional munitions, and the Senate rejected an amendment by Senators Kennedy and Feinstein to delete funds for RNEP and ACI. P.L. 108-447, the FY2005 Consolidated Appropriations Act, transferred the $9.0 million requested for ACI to a different program and contained no funds for RNEP. As a result, NNSA cannot work on RNEP in FY2005.

The FY2006 RNEP request is $4.0 million for NNSA for studies, and $4.5 million for the Department of Defense (DOD) to study integrating RNEP onto the B-2 bomber. The House passed H.R. 2419, the FY2006 Energy and Water Development Appropriations Bill, with no NNSA RNEP funds. The House passed H.R. 1815, the FY2006 National Defense Authorization Bill, providing the DOD funds as requested and transferring the NNSA funds to DOD. The House Appropriations Committee's mark of H.R. 2863, the FY2006 DOD Appropriations Bill, provided $4.0 million for a study of a conventional (nonnuclear) penetrator. Committee staff indicated that the bill includes the $4.5 million for DOD, and that the committee's intent is that DOD use the money to study integration of a conventional penetrator onto the B-2. H.R. 2863 as passed by the House retained these provisions. The Senate Armed Services Committee's mark of S. 1042, the FY2006 National Defense Authorization Bill, recommends providing the NNSA funds as requested, but denying the DOD funds on grounds that the DOD program should wait until completion of NNSA's feasibility study. The Senate provided $4.0 million for NNSA for RNEP in H.R. 2419, rejecting an amendment by Senator Feinstein to delete the funds.

This report will be updated to reflect further action on the FY2006 request.