"Bunker Busters": Robust Nuclear Earth Penetrator Issues, FY2005-FY2007
Released: 2006-02-21T00:00:00

Summary:
Earth penetrator weapons, often called "bunker busters," burrow into the ground some tensof feet before detonating, greatly increasing their ability to destroy buried targets. The United Stateshas several types of conventional earth penetrators. The current U.S. nuclear earth penetrator, theB61-11 bomb, cannot penetrate certain types of terrain in which hardened underground facilities maybe located, so the Air Force and the National Nuclear Security Administration (NNSA) are studyinga more effective penetrator, the Robust Nuclear Earth Penetrator (RNEP).
While Secretary of Defense Rumsfeld said in 2003 that RNEP was a study, NNSA's FY2005budget document showed a five-year total of $484.7 million if RNEP were to proceed beyond thestudy phase. NNSA said no decision had been made to proceed, and out-year figures were shownto meet congressionally-mandated budgeting requirements and were not a request. RNEP requestsare, of course, subject to congressional approval, rejection, or modification. The five-year figuresparked congressional debate. The FY2005 National Defense Authorization Act contained the fullRNEP request, $27.6 million. The House and Senate both rejected amendments to that bill thatwould have eliminated RNEP funds. However, P.L. 108-447 , the FY2005 ConsolidatedAppropriations Act, appropriated no funds for RNEP. As a result, NNSA could not work on RNEPin FY2005.
The FY2006 RNEP request was $4.0 million for NNSA for studies, and $4.5 million for theDepartment of Defense (DOD) to study integrating RNEP onto the B-2 bomber. The House passedthe FY2006 Energy and Water Development Appropriations Bill, H.R. 2419 , with noNNSA RNEP funds. The House passed the FY2006 National Defense Authorization Bill, H.R. 1815 , providing the requested DOD funds and transferring the NNSA funds toDOD. The House Appropriations Committee's mark of H.R. 2863 , the FY2006 DODAppropriations Bill, provided $4.0 million for a conventional (nonnuclear) penetrator study. Committee staff indicated that the bill included the $4.5 million for DOD, and that the committee'sintent was that DOD use the money to study integration of a conventional penetrator onto the B-2. The bill as passed by the House retained these provisions. The Senate Armed Services Committee'smark of S. 1042 , the FY2006 National Defense Authorization Bill, recommendedproviding the NNSA funds as requested but denying the DOD funds on grounds that the DODprogram should await completion of NNSA's feasibility study. The Senate provided $4.0 millionfor NNSA for RNEP in H.R. 2419, rejecting an amendment by Senator Feinstein to deletethe funds. The Senate Appropriations Committee's mark of H.R. 2863 recommendedeliminating DOD funds requested for RNEP. On October 25, Senator Domenici said that NNSA haddropped its RNEP request and planned to focus earth penetration on conventional weaponstechnology, so, he said, energy and water conferees agreed to drop funding for RNEP. H.R.1815 as signed into law ( P.L. 109-360 ) provided no funds for RNEP, but $4.0 million forDOD for a conventional penetrator study.
For FY2007, NNSA requested no funds for RNEP, and has closed out the project. Accordingly, this report will not be updated further.

subsections: section_title: Background
paragraphs: Potential adversaries and others have built hardened underground facilities to protect keyassets. Conventional weapons are unable to destroy many such facilities, though opinions differ onwhether nonnuclear means can disable or isolate them. Surface-burst nuclear weapons would havelimited effectiveness against deeply buried facilities. In contrast, a nuclear weapon that burrows intothe ground a few meters before detonating would be more effective because it would transfer muchmore of its energy into the ground.
The United States has one type of nuclear earth penetrator, the B61-11 bomb, which wasaccepted into the stockpile in September 2001. (1) That weapon, though, according to an article by several scientistsfrom Los Alamos National Laboratory, "cannot survive delivery into certain types of terrain in whichsuch [hardened underground] facilities may be located." (2) The Administration proposes RNEP as a study of modificationsto convert existing B83 nuclear bombs to an earth penetrator configuration. Another bomb, the B61,had also been under consideration earlier. The Air Force has been leading the study, which startedin May 2003, with NNSA in charge of studying modifications of specific warheads. Accordingly,the Department of Defense (DOD) and the National Nuclear Security Administration (NNSA), whichis the Department of Energy (DOE) agency in charge of the U.S. nuclear weapons program,requested funds to study the Robust Nuclear Earth Penetrator (RNEP).
RNEP has been the most controversial nuclear weapon program in Congress for the past fewyears. Supporters argue that it is needed to attack hard and deeply buried targets (such as leadershipbunkers or WMD production facilities) in countries of concern, thereby deterring or defeatingchallenges from such nations; critics assert that RNEP would lower the threshold for use of nuclearweapons and prompt other nations to develop nuclear weapons to deter U.S. attack. Secretary ofDefense Donald Rumsfeld said in May 2003 that RNEP "is a study. It is nothing more and nothingless." (3) The plan was thatthe RNEP study would cost $15 million a year for FY2003-FY2005. While Congress appropriatedthe FY2003 request of $15.0 million, the FY2004 request met much criticism. The House rejectedan amendment by Representative Tauscher to transfer funds from RNEP to conventional means ofattacking buried targets. The Senate tabled an amendment by Senator Dorgan and another by SenatorFeinstein to bar funds for RNEP, and adopted an amendment by Senator Nelson (FL), and a similaramendment by Senator Reed, to require congressional authorization to start development engineering(discussed below) or later phases of RNEP. (The Nelson amendment became Section 3117 of P.L.108-136 , the FY2004 National Defense Authorization Act.) Congress reduced the FY2004appropriation to $7.5 million.
In response to this reduction, NNSA planned to spend almost all of the $7.5 million to studythe B83 as an RNEP candidate, and little on the B61 study. (4) The B83 study was being conducted by Lawrence LivermoreNational Laboratory, in Livermore, CA, and Sandia National Laboratories' Livermore branch; theB61 study was the responsibility of Los Alamos National Laboratory, Los Alamos, NM, and SandiaNational Laboratories' headquarters site in Albuquerque, NM. For FY2005, Congress eliminatedRNEP funding. For FY2006, the Administration requested $4.0 million for NNSA to conduct a sledtest, in which a penetrator body would be shot down a test track and slammed into a material, suchas a concrete block, to help design and evaluate penetrators. For FY2006, the Administration alsorequested $4.5 million for DOD to study linking RNEP to the B-2 bomber. The appropriation was$4.0 million for DOD to conduct the sled test.
To address some technical issues that have arisen in the RNEP debates, the Bob StumpNational Defense Authorization Act for FY2003, P.L. 107-314 , Section 1033, called for a NationalAcademy of Sciences report on effects of nuclear and conventional earth penetrator weapons(EPWs). The report, released in April 2005, had nine key conclusions: (1) many high-value buriedfacilities can be held at risk by nuclear but not conventional EPWs; (2) penetration to a depth of 3meters captures most effects of EPWs on buried targets; deeper penetration puts the weapon atgreater risk; (3) EPWs cannot penetrate deeply enough to contain nuclear weapon effects fully; (4)casualties from a nuclear weapon burst at shallow depth or on the surface are essentially the same;(5) detonating a nuclear weapon at shallow depth increases the energy transmitted to a buried target,permitting a reduction in yield by a factor of 15 to 25; (6) attacks using nuclear EPWs near urbanareas could produce thousands to over a million casualties, or hundreds to several hundred thousandfor attacks in rural areas; (7) a nuclear EPW could reduce civilian casualties in an urban area by afactor of 2 to 10 compared to a surface-burst weapon with 25 times the yield; (8) a nuclear weaponwould have to detonate within a chamber where chemical or biological agents were stored to destroythe agents; the same is true of nonnuclear "thermobaric" bombs, which generate high heat andpressure; and (9) in a nuclear attack on a chemical weapon facility, nuclear effects would probablykill many more civilians than would the released chemical agent, while a nuclear attack on abiological facility could kill similar numbers of civilians from nuclear effects and released biologicalagents, depending on weapon yield and amount of agent. (5) 
This report discusses the history of RNEP in Congress and the Administration for theFY2005 and FY2006 budget cycles. For a more extensive history and technical background, see CRS Report RL32130 , Nuclear Weapon Initiatives: Low-Yield R&D, Advanced Concepts, EarthPenetrators, Test Readiness , and CRS Report RL32599(pdf) , 'Bunker Busters': Sources of Confusion inthe Robust Nuclear Earth Penetrator Debate , both by Jonathan Medalia. Any consideration ofRNEP in the second session of the 109th Congress may hinge on whether the Administration requestsfunds for the program in the FY2007 budget.
section_title: Developments in the FY2005 Budget Cycle
subsections: section_title: The FY2005 Budget and Plan
paragraphs: Congress required NNSA -- and DOE before NNSA was created -- to provide a five-yearbudget projection (current year plus four out-years) in the National Defense Authorization Acts forFY1997 ( P.L. 104-201 , Section 3155), FY2000 ( P.L. 106-65 , Section 3253), and FY2001 ( P.L.106-398 , Sections 3154 and 3155). The FY2005 budget cycle was the first in which NNSApresented detailed out-year projection with the current request. In the FY2005 request, the projectedfigures for RNEP were: FY2005 (request), $27.6 million; FY2006, $95.0 million; FY2007, $145.4million; FY2008, $128.4 million; and FY2009, $88.4 million, for a five-year total of $484.7million. (6) The FY2005request also presented a plan for RNEP. All figures for FY2005-FY2009 are subject tocongressional approval, rejection, or modification.
The research program for FY2003-FY2009 was thus estimated to cost $498.3 million -- $6.1million spent for FY2003, $7.5 million appropriated for FY2004, and $484.7 million, as noted, forFY2005-FY2009. If RNEP were to proceed through development and production, additional costswould include completing production engineering, and manufacturing components to convert theselected weapon into an earth penetrator. These figures include NNSA costs, such as for thepenetrator case, but exclude Air Force costs for the guidance unit (tail assembly, guidance computer,etc.) NNSA cannot provide an estimate of total program cost because it has not completed the coststudy.
By way of background, the Departments of Defense and Energy agreed years ago to a formalset of phases by which modified nuclear weapons move through research, development, production,deployment, and retirement, often called the Phase 6.X process. The key phases for RNEP are:Phase 6.2, feasibility study and option down select; Phase 6.2A, design definition and cost study;Phase 6.3, development engineering, in which the nuclear weapons laboratories produce a completedwarhead design; and Phase 6.4, production engineering, in which the design is adapted forproduction and a system to manufacture the weapon is created. In its FY2005 request, NNSA statedthe performance targets for RNEP as follows:
FY2005: "Complete 56% of scheduled RNEP Phase 6.2/6.2A activity." Further, "In FY2005, subsystem tests and a full system test of the proposed design will becompleted."
FY2006: "Complete 100% of scheduled RNEP Phase 6.2/6.2Aactivity."
FY2007: "Report results of RNEP Phase 6.2/6.2A to Nuclear WeaponsCouncil [a joint Department of Defense (DOD)-DOE agency that coordinates nuclear weaponprograms] Obtain, if applicable, RNEP Phase 6.3 appropriate authorization. Complete initial 25%of scheduled RNEP Phase 6.3 activity (if authorized)."
FY2008: "Complete 65% of RNEP Phase 6.3 activity (if appropriatelyauthorized)."
FY2009: "Complete 100% of scheduled RNEP Phase 6.3 activity (ifauthorized). Complete 15% of scheduled RNEP Phase 6.4 activity (if appropriatelyauthorized)." (7)
The FY2005 request therefore seemed to cast serious doubt on assertions that RNEP is onlya study. However, NNSA Administrator Linton Brooks stated:
We included funds in our out-year budget projectionsto comply with legislative requirements for five-year budget projections. The out-year projectionsare placeholders in the event the President decides to proceed with development and Congressapproves. No decision will be made until the study is completed. The law is clear that beginning6.3 engineering development requires Congressional approval. (8)
The legislation that he referred to is P.L. 108-136 , FY2004 National Defense AuthorizationAct, Section 3117, which states:
The Secretary of Energy may not commence theengineering development phase (phase 6.3) of the nuclear weapons development process, or anysubsequent phase, of a Robust Nuclear Earth Penetrator weapon unless specifically authorized byCongress.
An NNSA manager responsible for the program stated that, if out-year funds were notincluded in the FY2005 budget, NNSA would have faced two choices that it deemed unsatisfactory: (1) By the time the budget for one fiscal year is submitted, the budget for the next fiscal year islargely fixed; without the placeholder, a decision to proceed with RNEP could not have beenimplemented until the second fiscal year. (2) Alternatively, without the placeholder, a decision toproceed with RNEP could have been implemented promptly only by taking the needed funds out ofother programs. The budget projection reflects costs that might be expected if RNEP were to proceed to Phases 6.3 and 6.4. The manager emphasized that no decision had been made on whetheror not to proceed with those phases pending completion of the Phase 6.2/6.2A study. (9) 
The RNEP study was initially projected to cost $45 million -- $15 million a year forFY2003-FY2005. The numbers, however, have changed for each year. For FY2003, delay insubmission of a DOD study required by the FY2003 National Defense Authorization Act ( P.L.107-314 , Section 3146) delayed the start of NNSA's RNEP study, so $6.1 million was spent of the$15.0 million appropriated. For FY2004, Congress cut the appropriation to $7.5 million. ForFY2005, the request was $27.6 million, and the appropriation zero, vs. $15.0 million originallyplanned, and for FY2006 the appropriation was zero for RNEP but $4.0 million for a relatedconventional penetrator study.
section_title: Criticisms, Questions, and Responses
paragraphs: Critics reacted to the RNEP budget projection and plan presented with the FY2005 request. Representative Tauscher, in a letter to NNSA Administrator Linton Brooks, stated that "This is thefirst notice that we have received of a significantly ramped up activity," and that "the planning andbudgeting for further steps in the 6.X process in the next five years speaks to a clear intent to developthese modified nuclear weapons at a time when the feasibility study has not been completed and theDepartment of Defense has not submitted a request for this weapon." (10) Steven Aftergood of theFederation of American Scientists argued that there are not five-year budgets for every researchprogram that might lead to development. He reportedly said, "If they had placeholders for everyfunding scenario, they'd have to request an infinite amount of money. ... This is an expression ofintent to move ahead with an expanded program." (11) Another critic, Jay Coghlan, director of Nuclear Watch of NewMexico, was quoted as saying, "The present administration is definitely seeking to expand U.S.nuclear capabilities -- while at the same time it denounces any kind of effort by others to do thesame." (12) 
Programmatic Questions. The followingparagraphs present questions from Representative Tauscher's letter, responses from AdministratorBrooks, (13) andadditional information based on discussions with staff from NNSA, Los Alamos NationalLaboratory, and Lawrence Livermore National Laboratory. Representative Tauscher wrote:
For FY2005 the budget request describes the RNEPactivities as including "subsystems tests and full system test of the proposed design." Such activitiesappear to go beyond research activities and may be interpreted to fall into 6.3 activities. In yourview, why are such activities consistent with legislation passed by Congress last year? What specificactivities would be associated with the initial year of 6.3 work on the RNEP inFY2007?
Administrator Brooks responded:
The "subsystem and full system tests of the proposeddesign" refer to impact tests to be performed on surrogate penetrator bodies at Sandia NationalLaboratories' sled track facility. These tests are consistent with the definition and requirements fora Phase 6.2 feasibility study. We need to understand whether the penetrator bodies are survivableto ground penetration in the required geologies before feasibility can beassessed.
The context of this question is that the FY2004 National Defense Authorization Act, P.L.108-136 , Section 3117, requires specific congressional authorization before starting Phase 6.3 orsubsequent phases of RNEP. NNSA indicated that one type of physical test (as distinct from acomputer simulation) is planned as part of the 6.2/6.2A study: a series of "sled track tests" at SandiaNational Laboratories. Some would be done as full system tests, in which the various componentsof an RNEP would be assembled in a penetrator body (a strong, heavy, pointed metal case) withouta guidance system or fissile materials. (14) This assembly would be mounted on a sled that is sent down atrack at high speed and slammed into a large concrete block to test how well the componentswithstand the deceleration required of an earth penetrator weapon. This type of test is included inthe 6.2/6.2A study because NNSA deems it essential to assess feasibility. In turn, a successfuldemonstration of feasibility is a necessary condition for the weapon to proceed to Phase 6.3. Inpreparation for the full system tests, a number of subsystem sled tests will be conducted, in whichcandidate RNEP components are slammed into a water target. These were to have started in the thirdquarter of FY2005, and to be held at Sandia's sled track, located at Kirtland Air Force Base inAlbuquerque, NM.
More advanced tests would be conducted in Phase 6.3. In one type, "vibration flyaroundtests," a mock-up of the weapon would be mounted on an aircraft and flown to validate that theweapon would not be damaged by the vibration of the aircraft and to determine the weapon'saerodynamic stability. In this test, the device would not be released. Another type of test, whichwould occur later in the development process once the guidance system was developed, wouldinvolve dropping a mock-up of the weapon from an aircraft. Both types of test would use surrogatematerial (a heavy metal) instead of fissile materials. Other tests would probably be conducted aswell.
Representative Tauscher also asked:
With regard to the Annual Performance Results andTargets, what technical, military, and other criteria would the NNSA consider and what decisionswould be made before it requests legislative authorization to begin 6.3 work? Who is involved inthe determination to begin 6.3 work and why does the budget indicate that this might happen in FY2007? Similarly, what criteria would the NNSA use to base its decision to go from phase 6.3 to 6.4in FY 2009?
Administrator Brooks replied:
The National Nuclear Security Administration (NNSA)does not make the decision to proceed to Phase 6.3 or subsequent phases. If NNSA and the AirForce agree that the Phase 6.2/6.2A study results support proceeding to Phase 6.3 engineeringdevelopment, the Nuclear Weapons Council (NWC) could consider whether to proceed further. Ifthe NWC recommends going forward, NNSA would move beyond the study stage only if thePresident approves and funds are authorized and appropriated by theCongress.
He further stated that the criteria NWC would use in this decision include "the feasibility andmilitary utility of the design definition, and the projected cost and schedule established in the Phase6.2/6.2A Study," and that "If RNEP does proceed to 6.3, the President and Congress will make aseparate decision on whether to proceed to Phase 6.4, Production Engineering."
To support a decision to move RNEP to Phase 6.3, NNSA would address cost, schedule, andfeasibility, while the Air Force would address military requirements. As a hypothetical example,NNSA might say that an RNEP would have a specified cost, could be ready by a certain date, andwould have certain characteristics (weight, accuracy, depth of penetration, etc.) The Air Force mightdecide not to proceed if the penetration ability was too low or if a nonnuclear alternative existed, orit might recommend proceeding if the proposed RNEP was the only way to accomplish what itconsidered a critical military mission. The decision to request congressional approval would beworked through the Nuclear Weapons Council and ultimately be made by the President. Thedecision on whether or not to proceed with Phase 6.3 was projected to occur in FY2007 because thePhase 6.2/6.2A study was expected to conclude late in FY2006. With elimination of RNEP fundsfor FY2005 and FY2006, these decisions would be set back. They would be rendered moot if theAdministration chooses not to proceed with the program, which might be revealed in the FY2007request.
RNEP Budget and Need for CongressionalApproval. For many Members, the five-year cost of RNEP as presented in theFY2005 budget document came as a surprise not only in the amount, but also in what appeared tobe an intent contrary to legislation barring Phase 6.3 or greater work on RNEP without congressionalauthorization. Senator Domenici said:
I was surprised to see that the request -- that nearly $500million is provided for the Robust Nuclear Earth Penetrator in the out year funding. ... Thedepartment [DOE] should not assume such large sums in its budget without congressional approvalor direction. ... I want it explained to this committee unequivocally what we are doing and what weare authorizing, and what we are not doing and what we are not authorizing, because nobody on thiscommittee is voting to do this. We're voting to study it if it wins, but not to do it. To study it is asmall amount of money. To do it is a lot of money. (15)
Senator Reid said to NNSA Administrator Linton Brooks:
I am a little concerned, maybe even put off by the notionthat you've included a half a billion dollars in your out year spending plan as what you call a placeholder for bunker busting, pending White House and congressional decisions. I'm not sure that wecan allow this to go forward. This is a large place holder. Many remain unconvinced that this is anappropriate path. (16)
Senator Kennedy said to Secretary of Energy Spencer Abraham:
... you're rushing ahead with the nuclear weapons,including the mini-nukes and the nuclear bunker busters. I'll give you a chance to be able to explainhow this program, which was $45 million two years ago is now up to almost $.5 billion. ... Why arewe going ahead and are going to be requesting $.5 billion from Congress on new nuclear weapons,the bunker buster? (17)
In a colloquy, Senator Warner expressed his concern on the RNEP budget and SecretaryAbraham offered an explanation:
Senator Warner: Let's talk about the Robust NuclearEarth Penetrator. And I was looking at the out years, and particularly 2006, looking at a fairlysubstantial increase. And I bring to your attention the fact ... in 2004, the Department of Energy --we put in the legislation -- may not proceed to the engineering development phase three or tosubsequent phases without a specific authorization from Congress. And can you correlate thatsubstantial '06 bump up with this statutory provision, which I hope willremain?
Secretary Abraham: The statutory provision, Mr.Chairman, would, of course, govern any decision to move from a stage of research or preliminaryinquiry to the engineering phase. We are required to provide five-year budgets, however, so thatpeople can look down the road and make a proper sort of assessment of what potential expenses willbe. (18)
Is There a Military Requirement for RNEP? Another concern is that there is no military requirement for RNEP.
Senator Reed: ... Is there a specific military requirementfor the RNEP today?
Secretary Abraham: It was the conclusion of the NuclearPosture Review that a threat that needed to be addressed in the 21st century in the immediate periodahead of us would be hard, deeply buried targets. A number of approaches to dealing with that werethen asked to be researched. This is just one of them. It's a threat that rose to the level of beingincluded in that review.
Senator Reed: There's no doubt about the threat. Butit's your opinion that the position of the administration is there is a specific military requirement forthe RNEP, not for a device to counter deeply buried targets, but for the RNEP? Is that yourposition?
Secretary Abraham: No. The position of theadministration is that we should inquire about or that we should make inquiries and investigate avariety of approaches to dealing with the hard, deeply buried target. Whether or not this approachis feasible is the first question. And the second is whether or not it's preferable to other approachesthat would involve conventional weapons. And we have not completed the first phase of thatinquiry, let alone the second. (19)
NNSA has stated that "requirement" has been used in two senses. (20) Before DOD or NNSAstart a concept study, there is a perceived need for a capability. This type of need used to be calleda "requirement," but DOD now uses the term "desired capabilities and characteristics." In the caseof RNEP, this perceived need has reportedly been documented in classified form. An unclassifieddocument dealt more generally with defeat of hard and deeply buried targets. (21) "Requirement" is also usedfor a specific weapon as applied to the acquisition process. According to NNSA, DOD "will nothave an acquisition requirement before there is a well defined system or component for them toacquire. In the nuclear weapon life cycle, that will not occur until the completion of the Phase2A/6.2A study."
section_title: Legislative Activity on RNEP, FY2005
paragraphs: The two defense authorization bills -- H.R. 4200 , as reported from the HouseArmed Services Committee, and S. 2400 , as reported from the Senate Armed ServicesCommittee -- both contained the full amount requested for RNEP, $27.6 million. The House ArmedServices Committee "strongly reaffirms the importance" of the RNEP Phase 6.2/6.2A study. Itfurther stated,
The committee also takes note that a recent DefenseScience Board Task Force study on Future Strategic Strike Forces specifically recommended thatresearch be initiated on nuclear weapons that produce much lower collateral damage than thoseweapons in the existing nuclear stockpile. The committee also reminds the NNSA that any effortsbeyond a study could only be pursued if the President approves and funds are authorized andappropriated by Congress. (22)
Representatives Tauscher, Markey, Skelton, Dicks, Allen, and Spratt offered an amendmenton RNEP and other topics to H.R. 4200 . It was defeated, 204-214, on May 20 (roll no.203). The text of the amendment is as follows:
Additional amounts for ordnance technology and forstrategic capability modernization.
1. (a) Air Force Conventional Munitions- The amountin section 201(3) for research, development, test, and evaluation for the Air Force is hereby increasedby $25,000,000, of which -- 
(1) $10,000,000 is to be available in program element0602602F, Conventional Munitions, for ordnance technology applicable to defeat of weapons ofmass destruction and hardened, deeply buried targets; and
(2) $15,000,000 is to be available in program element0603601F, Conventional Weapons Technology, for ordnance technology applicable to defeat ofweapons of mass destruction and hardened, deeply buried targets.
(b) Defense-wide Strategic Capability Modernization-The amount in section 201(4) for research, development, test, and evaluation, Defense-wide, ishereby increased by $11,557,000, to be available for program element 0603910D8Z, StrategicCapability Modernization.
(c) Offset- The amount in section 3101(a)(1) forweapons activities is hereby reduced by $36,557,000, of which -- 
(1) $27,557,000 is to be derived from the StockpileServices Robust Nuclear Earth Penetrator study; and
(2) $9,000,000 is to be derived from the StockpileServices Advanced Concepts program.
(The Advanced Concepts Initiative funds R&D, prior to development engineering, of"laboratory workload activities to potentially enhance the military capabilities of the stockpile, incoordination with the DOD." (23) See CRS Report RL32130 , Nuclear Weapon Initiatives: Low-Yield R&D, Advanced Concepts, Earth Penetrators, Test Readiness , by Jonathan Medalia.)
Senators Kennedy and Feinstein introduced amendment no. 3263 to S. 2400 ,the FY2005 defense authorization bill, to bar the use of FY2005 funds for RNEP or the AdvancedConcepts Initiative. The Senate debated the amendment on June 3 and 15, and rejected it on thelatter date, 55-42.
Senator Bennett submitted the following amendment 3403 to S. 2400 on June7. He withdrew it on June 23.
At the end of subtitle B of title XXXI, add thefollowing: 
Sec. 3122. Requirement of specific authorization ofCongress for full-scale underground nuclear test of robust nuclear earth penetrator.
Section 3117 of the National Defense Authorization Actfor Fiscal Year 2004 (Public Law 108-136; 117 Stat. 1746) is amended by inserting, "or conduct afull-scale underground nuclear test of such weapon," after "Robust Nuclear Earth Penetratorweapon."
For reference, Section 3117 of P.L. 108-136 is as follows:
Sec. 3117. Requirement for specific authorization ofCongress for commencement of engineering development phase or subsequent phase of robustnuclear earth penetrator.
The Secretary of Energy may not commence theengineering development phase (phase 6.3) of the nuclear weapons development process, or anysubsequent phase, of a Robust Nuclear Earth Penetrator weapon unless specifically authorized byCongress.
On June 9, 2004, the Energy and Water Development Subcommittee of the HouseAppropriations Committee approved the FY2005 energy and water development appropriations billby voice vote. The measure provided no funds for RNEP. (24) The full committeeapproved the bill by voice vote on June 16. The committee bill provided no funds for RNEP. Thecommittee explained its position on RNEP and ACI as follows:
The Committee continues to oppose the diversion ofresources and intellectual capital away from the most serious issues that confront the managementof the nation's nuclear deterrent. ... the Committee remains unconvinced by the Department [ofEnergy]'s superficial assurance that the RNEP activity is only a study and that advanced conceptsis only a skills exercise for weapons designers. The Committee notes that the management directionfor fiscal year 2004 sent to the directors of the weapons design laboratories left little doubt that theobjective of the program was to advance the most extreme new nuclear weapon goals irrespectiveof any reservations expressed by Congress. ... the Committee's priorities are maintaining our Nation'snuclear deterrent in a safe and secure condition and maintaining our Nation's integrity in theinternational effort to halt the proliferation of weapons of mass destruction. The Department'sobsession with launching a new round of nuclear weapons development runs counter to thosepriorities. The Committee directs the NNSA to focus wholly on its primary mission of maintainingthe safety, security, and viability of the existing stockpile ..." (25)
On June 25, the House considered the bill, H.R. 4614 , and passed it, asamended, 370-16. No amendments were offered to the Weapons Activities section.
In the Senate, the energy and water bill was held up by disputes over the Yucca Mountain(NV) civilian nuclear waste repository. (26) The Energy and Water Development AppropriationsSubcommittee did not report a bill to the full committee. For a time, it appeared that it would notbe possible to include energy and water appropriations in the omnibus appropriations bill, and thatFY2005 spending for energy and water would be done under a year-long continuing resolution. (27) However, a compromiseworked out at the last minute permitted inclusion of energy and water appropriations in H.R. 4818 , Consolidated Appropriations Act, 2005. (28) 
Piecing together numerous press reports, the arrangement that broke the logjam includedseveral elements. (1) RNEP and ACI were eliminated, and several other nuclear weapons programswere eliminated, reduced, or modified. (2) Conferees freed up $800 million from various parts ofthe omnibus bill, some of which was used to provide $577 million for Yucca Mountain instead ofthe $131 million in the House bill. (3) Conferees provided substantial increases for three projects atLos Alamos and Sandia National Laboratories. (29) According to one report, "In return for letting Hobson cut thebunker-buster and other new nuclear weapons initiatives, Domenici got money he wanted for workat Sandia and Los Alamos, Domenici acknowledged in an interview." (30) Another report stated: "Sen. Pete Domenici (R-NM), one of the chief backers of RNEP and ACI funding in Congress, toldreporters this week that he agreed to the spending cuts for both programs in order to get the omnibusbill finished." (31) 
section_title: Developments in the FY2006 Budget Cycle
subsections: section_title: The FY2006 RNEP request
paragraphs: For FY2006, NNSA cast a program more modest in its cost, scope, and schedule than it wasfor FY2005. Rather than show a five-year projection, NNSA, recognizing that a separate decisionwould be needed to go beyond the study phase, projected a cost for the study only, ending inFY2007, and reduced the scope of the study from the B83 and B61 to the B83 only. As a result, thecost was much lower, $4.0 million for FY2006 and $14.0 million for FY2007. (32) As Ambassador Brooksexplained,
The reason the level is so much less is we have cut backon what it is that we propose to do. Originally, we proposed to examine two different warheads. Fundamentally, what we're doing is taking a warhead, putting a very hard case on it, controlling itsattitude very precisely, so that it can penetrate a few meters into rock and still stay intact and go off,that way the energy goes into the ground. We've concluded that we can demonstrate whether or notthe concept is feasible by looking at only one warhead. We selected the B83, which is one of the twobombs we were looking at, because that was where we were when the program was stopped. (33)
Further, NNSA stated:
The Robust Nuclear Earth Penetrator (RNEP) categoryincludes funding for the Phase 6.2/2A Air Force-led study. The decision to complete this study wasreaffirmed with DOD in January 2005. Activities include participating in integrated NNSA-DODintegrated product teams for development of RNEP requirements and programmatic documents;system design and integration; planning, cost and risks analyses; and phenomenology studies. Thestudy is scheduled for completion in FY 2007. In FY 2006, activities include conduct of a B83impact test, analyzing test data, and supporting integration meetings with the DOD. (34)
The Senate Armed Services Committee stated that the funding is "to prepare and execute thesled track impact test at Sandia National Laboratories on the feasibility of case hardening and targetpenetration." (35) 
DOD also requested FY2006 funds for RNEP, included in the Air Force budget. Accordingto an Air Force legislative liaison officer:
The Air Force will spend $4.5M in FY 2006 and $3.5Min FY 2007 to complete the joint study that began in FY 2003. As part of the joint study in theseyears, the Air Force will perform analysis and specify requirements for integrating the conceptualweapon on the B-2 platform (e.g., software and hardware modifications), identify environments theweapon would have to withstand (e.g., temperature, acceleration, and shock and vibration), anddefine capabilities needed for the navigation, guidance and control (NG&C) -- (e.g., accuracy andimpact parameters). We will also develop estimates of the associated costs. (36)
An Air Force document provides further details on the FY2006 DOD RNEP request. Thedocument states that Nuclear Weapons Support
Supports pre-acquisition studies/analyses to determinefeasibility and develop definition, and cost of navigation, guidance, and control (NG&C) conceptsas well as evaluate B-2 aircraft integration issues associated with the joint Department of Defense(DOD) and Department of Energy (DOE) Robust Nuclear Earth Penetrator (RNEP) concept asapproved/directed by the Nuclear Weapons Council (NWC).
FY 2006 funding is a combination of $1.0M inRDT&E-AF [research, development, test, and evaluation, Air Force] and $3.5M in O&M-AF[operation and maintenance, Air Force] funding. The RDT&E-AF funding will complete logisticsand aircraft integration planning as well as develop nuclear certification criteria. The O&M fundingwill support the development of a conceptual NG&C design and risk assessment, identification ofB-2 software/hardware issues, and other related B-2 logistics and integration efforts. (FY 2005 Base$0) (37)
The $1.0 million is included in $15.4 million for program element 0604222F, "NuclearWeapons Support," within RDT&E, Air Force. (38) The $3.5 million is included in $287.2 million for programelement 3400F, line 020, "Primary Combat Weapons," within O&M, Air Force. (39) 
A question that arose in 2004 was if DOD supported RNEP. In 2005, DOD answeredaffirmatively. NNSA Administrator Linton Brooks testified in April 2005,
After last year's action by the Congress [on RNEP], weasked the Department of Defense to review the continuing need. The Secretary of Defensepersonally reviewed that, and at his direct personal request we have included the money in the budgetfor this year. He did this not because he's particularly interested in developing a new weapon, butbecause there are adversaries who are building deeply buried facilities, and it is unwise for there tobe anything that's beyond the reach of U.S. power. (40)
According to a press report, Secretary of Defense Donald Rumsfeld wrote a memo in January 2005to then-Secretary of Energy Spencer Abraham that stated "'I think we should request funds in FY06and FY07 to complete the [RNEP] study. ... You can count on my support for your efforts torevitalize the nuclear weapons infrastructure and to complete the RNEP study.'" (41) 
There was also a suggestion that DOD's request was crucial to DOE's decision to includeRNEP in the FY2006 budget. According to a press report, "'The reason the money was put in thebudget was the result of a direct request from [the Defense Department] to finish the study,' saidAnson Franklin, a spokesman for the Energy Department's National Nuclear SecurityAdministration. 'The Secretary of Defense was consulted, and based on that information we put itback in the budget.'" (42) 
section_title: Legislative Activity
paragraphs: The House Appropriations Committee recommended eliminating NNSA funds for RNEPfrom the Energy and Water Development Bill, H.R. 2419 , as it did in the FY2005 bill. The report stated,
The Committee continues to oppose the diversion ofresources and intellectual capital away from the more serious issues that confront the managementof the nation's nuclear deterrent, primarily the transformation of the Cold War nuclear weaponscomplex and existing stockpile into a sustainable enterprise. The Committee has been disappointedat the bureaucracy's adherence to an initiative that threatens Congressional and public support forsustainable stockpile initiatives that will actually provide long-term security and deterrent value forthe Nation. (43)
The House passed the bill, 416-13, on May 24, with no amendments on RNEP, and only a few briefmentions of it in prepared remarks. (Note that the bill did not address the Air Force RNEP request,which fell under the jurisdiction of the DOD Appropriations Subcommittee.)
The House Armed Services Committee recommended providing the DOD RNEP funds asrequested, but transferring the $4.0 million in NNSA funds to a separate program in DOD. Inexplaining the transfer, the committee's report stated, "Based on the applicability of the sled testresults to various options for HDBT [hard and deeply buried target] defeat, the committee believesthat this [NNSA RNEP] study is more appropriately conducted under a program element within theDepartment of Defense." (44) Accordingly, "The committee authorizes $4.0 million in PE[program element] 64327F for a penetrator test that would evaluate the feasibility of various optionsfor different types of penetrators that could hold HDBTs at risk. The committee intends that thisstudy be completed by the end of fiscal year 2006." (45) However, 23 of the 28 committee Democrats stated that thereport language "could be construed to allow the sled test to inform whether a nuclear payload couldbe used in high-speed penetration of hard geologies," and urged that the test "should be conductedin a manner that only informs conventional payloads." (46) The House passed the bill, H.R. 1815 , 390-39, onMay 25 with no amendment or debate on RNEP. Representative Heather Wilson, in discussing theenergy and water bill, stated, "It is my understanding that this study will now move to theDepartment of Defense and outside of the jurisdiction of the Energy and Water Appropriationssubcommittee." (47) Itis unclear whether the move of RNEP funds from NNSA to DOD was done with that purpose inmind.
The House Appropriations Committee's FY2006 DOD Appropriations Bill, H.R. 2863 , contained $4.0 million for a "conventional penetrator study" as a new program under "Hardand Deeply Buried Target Defeat System." (48) Further, it retained $4.5 million within the categories "NuclearWeapons Support" and "Primary Combat Weapons" that was requested for integrating RNEP withthe B-2. (49) Committeestaff explained that the committee intended that the study be of nonnuclear means of hard and deeplyburied target defeat, and not of RNEP. As a corollary, the staff continued, since the RNEP study wasnot funded but the $4.5 million was linked to the B-2, the committee intended that the latter sum beused to study integrating conventional earth penetrators with the B-2. (50) The House passed H.R.2863, 398-19, on June 20, with no change to the foregoing provisions. (51) 
The Senate Armed Services Committee reported the defense authorization bill, S. 1042 , on May 17. It recommended eliminating the $4.5 million in DOD funding ongrounds that "evaluation of RNEP feasibility by the Department of Energy is not scheduled to becompleted prior to 2007." (52) Further, "The committee does not believe that these activitiesare necessary to evaluate the feasibility of RNEP." (53) The committee recommended providing the $4.0 million thatNNSA requested for RNEP. (54) The Senate began considering the bill on July 20. On July 22,the Senate debated an amendment (SA 1415) by Senator Kennedy to transfer NNSA RNEP fundsto the Washington, DC, Army National Guard. The amendment was withdrawn on November 4, andthe bill passed, 98-0, on November 15.
The Senate Appropriations Committee reported the energy and water bill, H.R. 2419 , on June 16. The committee recommended $4.0 million for NNSA for the RNEP study, andurged that sled tests be conducted at Sandia National Laboratories in Albuquerque, NM, asplanned. (55) On June30, the Senate rejected, 43-53, an amendment by Senator Feinstein to eliminate the $4.0 million fromthe bill. (56) The Senatepassed the bill, as amended, 92-3, on July 1.
The Senate Appropriations Committee reported the FY2006 DOD appropriations bill, H.R. 2863 , on September 29. It eliminated the $3.5 million for RNEP in the Air Forceoperation and maintenance account under line 20, "Robust Nuclear Earth Penetrator Support," andeliminated the $1.0 million for RNEP in the Air Force research, development, test, and evaluationaccount under line 66, "Nuclear Weapons Support." Also under line 66, it eliminated another $1.4million requested for counterproliferation support to counter future threats such as deeply buriedtargets.
While the conference on the energy and water bill was underway, Senator Domenici issueda press release stating that NNSA had dropped its request for continued research on RNEP, and thatconferees had therefore dropped RNEP funding. According to the Senator,
The focus will now be with the Defense Department andits research to earth penetrating technology using conventional weaponry. The NNSA indicated thatthis 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 forRNEP. (57)
The conference report ( H.Rept. 109-275 ) provided no funds for RNEP. The Energy and WaterDevelopment Appropriations Act was signed into law ( P.L. 109-103 ) November 19, 2005.
The authorization conference report provided no funds for RNEP, but instead added $4.0million to DOD in program element 64327F, Hard and Deeply Buried Target Defeat System, "toconduct a sled test and a study on the physics of penetrating geologic media, to be completed by theend of fiscal year 2006." (58) The measure was signed into law ( P.L. 109-163 ) January 6,2006.
The DOD appropriations conference report deleted $3.5 million for RNEP Support underPrimary Combat Weapons within the Operation and Maintenance, Air Force, account. Under theResearch, Development, Test, and Evaluation, Air Force, account, it provided $4.0 million for aconventional penetrator study under Hard and Deeply Buried Target Defeat System and deleted $1.0million for RNEP under Nuclear Weapons Support. (59) The measure was signed into law ( P.L. 109-148 ) December 30,2005.
section_title: Clarification of Key Points in FY2006 Hearings
paragraphs: Hearings in 2005 added information on topics that may arise in any future debate, such asthe yield of RNEP, the collateral damage the weapon would likely cause, and the militaryrequirement for RNEP. The following colloquy occurred at a hearing in February:
Representative Terry Everett: ... Could youplease tell me directly if there's a military need for this, for robust earth -- nuclear earthpenetrator?
Secretary of Defense Donald Rumsfeld: ... Itis a question that's difficult to answer, because sometimes they say "military requirement". Andthat's a formal process. There was no military requirement for military aircraft, for example. Therewas no military requirement for unmanned aerial vehicles until they came along. And so, what Ibelieve, there is a need for the study -- which is what we're talking about here, and not a weapon. We're talking about taking existing weapons and doing a study to see if they can be reduced in theirpower, their lethality to a level that's lower than the current weapons are so that they might have theability to penetrate the earth in a way that could help protect the United States of America. I thinkthat it is clearly in our country's interest to do the study. Has it -- [speaking to General RichardMyers, Chairman, Joint Chiefs of Staff] You want to comment on whether there's a, quote, "militaryrequirement" specifically?
General Myers: You bet. Our combatantcommander that is charged by this nation to worry about countering the kind of targets, deeply buriedtargets certainly thinks there's a need for this study. And General Cartwright has said such. I thinkthat. I think the Joint Chiefs think that. And so, the study is that. It's not a commitment to goforward with a system, it's just to see if it's feasible. (60)
This colloquy occurred at a hearing in March:
Representative Ellen Tauscher: I just want toknow is there any way an RNEP of any size that we would drop will not produce a huge amount ofradioactive debris?
NNSA Administrator Linton Brooks: No, thereis not.
Representative Tauscher: Secretary Rumsfeldlast week confused the debate over the RNEP when he told our committee that the RNEP study, "istaking existing weapons and doing a study to see if they can be reduced in their power, lethality, toa level that is lower than current weapons." My understanding was that the RNEP study was notgoing to change the physics package of the warhead but simply look at ways to repackage the deviceso it can penetrate hard geologies. Am I right or are you also looking at lowering the yield of, say,the B83 to perhaps under five kilotons?
Administrator Brooks: We are not looking atchanging the yield of the physics package. ...
Ambassador Brooks: I really must apologizefor my lack of precision if we in the administration have suggested that it was possible to have abomb that penetrated far enough to trap all fallout. I don't believe that -- I don't believe the laws ofphysics will ever let that be true. ...
This is a nuclear weapon. This is a nuclearweapon that is going to be hugely destructive and destructive over a large area. No sane personwould use a weapon like that lightly, and I regret any impression that anybody, including me, hasgiven that would suggest that this is going to be any easier a decision -- I mean if this weapon werein the arsenal today, it would still be a hugely difficult decision for any president to even contemplateit. So I -- the administration believes and I personally believe that this study should continue, butit -- I want to -- I do want to make it clear that any thought of sort of nuclear weapons that aren'treally destructive is just nuts. (61)
To summarize, the foregoing passages, by clarifying several points that were at issue inearlier debates on RNEP, may help focus any future debate.
There is no formal military requirement for RNEP.
There is considerable interest by DOD and the armed services in learning,through the proposed RNEP study, whether RNEP is feasible.
The possible conversion of a B83 bomb to an RNEP would not involvechanging the yield of the weapon.
RNEP -- and probably any other nuclear earth penetrator -- would not penetratethe ground deeply enough to contain fallout. Use of RNEP would therefore cause a "huge" amountof fallout and destruction.
Because RNEP, if it is deployed, would be a nuclear weapon, a presidentialdecision to use it would be very difficult.
section_title: Developments in the FY2007 Budget Cycle
paragraphs: NNSA requested no funds for RNEP for FY2007. The program appears nowhere in itsFY2007 request document. (62) NNSA stated in January 2006 that it disbanded the RNEP teamsin March 2005, and stated in February 2006 that it has closed out the project. (63)