Cost-Effectiveness of Conventionally and Nuclear-Powered Aircraft Carriers
GAO/NSIAD-98-1 -- August 1998

INTRODUCTION ============================================================ Chapter 1 Since World War II, the carrier battle group has been a key political and military component in achieving the goals of presence, combining robust crisis response capability with the firepower needed to protect U.S. interests should a conflict erupt. These capabilities are known and respected throughout the world, thereby reinforcing deterrence. The aircraft carrier forms the building block of the Navy's forces. The nuclear-powered aircraft carrier (CVN) is the most expensive weapon system in the Nation's arsenal. The Defense Appropriations Act of 1994 Conference Report directed us to study the cost-effectiveness of nuclear-powered aircraft carriers. Accordingly, we (1) compared the relative effectiveness of conventionally powered and nuclear-powered aircraft carriers in meeting national security requirements and (2) estimated the total life-cycle costs of conventionally powered and nuclear-powered carriers. We also examined the implications of an all nuclear carrier force on overseas homeporting in Japan. A conventionally powered carrier is permanently homeported there now and operates in the Western Pacific, but it will eventually be replaced with a nuclear-powered carrier if the trend toward an all nuclear carrier force continues. BUILDING BLOCKS OF U.S. SECURITY STRATEGY AND THE AIRCRAFT CARRIER ---------------------------------------------------------- Chapter 1:1 The National Military Strategy states that the military forces must perform three sets of tasks to achieve the military objectives of promoting stability and thwarting aggression -- (1) peacetime engagement, (2) deterrence and conflict prevention, and (3) fighting and winning the Nation's wars. Accomplishing the specific tasks of the strategy is facilitated by the two complementary strategic concepts of overseas presence and power projection. U.S. forces deployed abroad protect and advance U.S. interests and perform a wide range of functions that contribute to U.S. security. The aircraft carrier battle group, with the aircraft carrier as the centerpiece, is the focal point for the Navy's operational strategy, Forward. . .From the Sea. The strategy underscores the premise that the most important role of naval forces in situations short of war is to be engaged in forward areas, with the objectives of preventing conflicts and controlling crises. The carrier battle group's forward presence demonstrates the Nation's commitment to allies and friends, underwrites regional stability, gains U.S. familiarity with overseas operating environments, promotes combined training among forces of friendly countries, and provides timely initial response capabilities. U.S. naval forces, designed to fight and win wars, must be able to respond quickly and successfully to support U.S. theater commanders. Forces that are deployed for routine exercises and activities undergirding forward presence are also the forces most likely to be called upon to respond rapidly to an emerging crisis. The battle group, along with its Combat Logistics Force ships, carries a full range of supplies needed for combat, including fuel and ammunition, which will sustain the battle group for about 30 days, depending on the tempo of operations, enough food to feed the force for 45 days, and sufficient spare parts and other consumables to last for more than 60 days. Moreover, forward-deployed naval forces can draw on an established worldwide logistics pipeline, including Combat Logistics Force ships plus over 22 strategically-located worldwide fuel storage sites, prepositioned munitions, fuel, and other supplies. This logistics force posture gives the U.S. Navy the ability to remain on-station as long as required. BOTTOM-UP REVIEW ESTABLISHES CARRIER FORCE SIZE ---------------------------------------------------------- Chapter 1:2 The Bottom-Up Review was a 1993 evaluation of the Nation's defense strategy, force structure, and modernization and was done in response to the end of the Cold War and the dissolution of the former Soviet Union. The review concluded that the peacetime presence provided by the Navy's aircraft carriers was so important that even though a force of 8 to 10 aircraft carriers could meet the military's war-fighting requirements, the Navy needed 12 carriers (11 active plus 1 reserve/training carrier) to provide sufficient levels of presence in the three principal overseas theaters (the Western Pacific, the Mediterranean Sea, and the North Arabian Sea/Indian Ocean). QUADRENNIAL DEFENSE REVIEW REAFFIRMS CARRIER FORCE SIZE ---------------------------------------------------------- Chapter 1:3 The Quadrennial Defense Review (QDR), required by the National Defense Authorization Act for Fiscal Year 1997, was designed by the Department of Defense (DOD) to be a fundamental and comprehensive examination of U.S. defense needs from 1997 to 2015: potential threats, strategy, force structure, readiness posture, military modernization programs, defense infrastructure, and other elements of the defense program. The QDR has determined that a total force structure of 12 carriers will allow the United States to sustain carrier battle group deployments at a level that helps shape the international security environment in support of the Nation's security strategy and commitments. To ensure that DOD continued to provide the right levels and types of overseas presence to meet the objectives stated in its strategy, DOD undertook a detailed examination of its overseas presence objectives and posture in all regions. This study, conducted by the Office of the Secretary of Defense and the Joint Staff, built on the pre-QDR work done by the Joint Staff and involved all relevant participants, including the services and the regional Commanders in Chief. The analysis formed the basis DOD considered in making its decisions on the appropriate levels of presence in key regions throughout the world. The demands associated with maintaining an overseas presence play a significant role in determining the size of the carrier force. To illuminate the implications of overseas presence demands an additional analysis was done by the QDR to examine the impact of possible naval force structure options. Using the Navy's Force Presence Model, a range of aircraft carrier force structures were analyzed and compared by the QDR to the forward presence levels then provided in the U.S. European Command, U.S. Central Command, and U.S. Pacific Command areas of responsibility. The analysis concluded that a force of 11 active aircraft carriers plus one operational Reserve/training carrier was necessary to satisfy current policy for forward deployed carriers and accommodate real world scheduling constraints. GENERAL CHARACTERISTICS OF THE MODERN CONVENTIONALLY AND NUCLEAR-POWERED AIRCRAFT CARRIERS ---------------------------------------------------------- Chapter 1:4 Except for their power plants, the conventionally and nuclear-powered aircraft carriers operating in the fleet are very similar in size, form, and function and embark the same standard air wing. As table 1.1 shows, the Kennedy-class conventional carriers and the Nimitz-class nuclear carriers share many common attributes. Table 1.1 General Characteristics of Modern, Large Deck Conventionally and Nuclear-Powered Carriers U.S.S. John F. U.S.S. Nimitz Kennedy (CV-67) (CVN-68) -------------------------- ------------------ ---------------------- Displacement (full load) 82,000 tons 95,000 tons\a Ship dimensions ---------------------------------------------------------------------- Length (overall) 1,051 ft. 1,092 ft. Length (waterline) 990 ft. 1,040 ft. Beam (waterline) 126 ft. 134 ft. Beam (flight deck) 268 ft. 251 ft. Propulsion 8 boilers/4 shafts 2 reactors/4 shafts Shaft horse power (total) 280,000 280,000 Speed 30+ knots 30+ knots Aircraft handling ---------------------------------------------------------------------- Maximum density of 130 130 aircraft\b Catapults 4 4 Elevators 4 4 Crew ---------------------------------------------------------------------- Ship's company\c 3,213 3,389 Air wing 2,480 2,480 Range (unrefueled) \d 1.5 million miles Fuel capacity (in gallons) Aviation fuel (JP-5)\e 1.8 million 3.5 million Ship fuel (DFM) 2.4 million N/A Ordnance (cubic feet)\f 76-80% 94-100% ---------------------------------------------------------------------- \a The full load displacements of the later ships of the Nimitz-class have increased to about 99,000 tons. \b A carrier's total aircraft capacity is called its maximum density. The F/A-18 equivalent is the unit of measure for calculating maximum density. The U.S.S. Carl Vinson (CVN-70) has a maximum density of 127. (See ch. 2 for more information.) \c Number of officers and sailors needed to operate the ship. \d A conventional carrier's cruising range varies with its speed. For example, maintaining a 30-percent fuel reserve, it can sail from San Francisco to Hong Kong at 14 knots. At 28 knots, it can sail from Singapore, across the Indian Ocean, to Bahrain in the Arabian Gulf without refueling while maintaining the same reserve. \e Aviation fuel (JP-5) can be substituted for ship fuel (diesel fuel marine (DFM), also known as F-76) in surface ships. \f Measured as a percentage of the baseline, which includes the first three Nimitz-class carriers (CVN-68-70); later Nimitz-class carriers have enhanced magazine protection that reduces magazine volume. AIRCRAFT CARRIERS OPERATE AS PART OF BATTLE GROUPS ---------------------------------------------------------- Chapter 1:5 To provide a balanced force to deal with a range of threats, the Navy employs aircraft carriers as part of a combat formation of ships--a carrier battle group--of which, it considers the aircraft carrier to be the focal point. The collective capabilities of the battle group's ships allow the group to carry out a variety of tasks ranging from operating in support of peacetime presence requirements to seizing and maintaining control of designated airspace and maritime areas and projecting power ashore against a variety of strategic, operational, and tactical targets as discussed in the Policy for Carrier Battle Groups.\1 \2 According to the policy, a battle group can operate in environments that range from peacetime to a ¹non-permissive environment characterized by multiple threats.º The policy also established a ¹standard carrier battle groupº that consists of -- one nuclear- or conventionally powered aircraft carrier;\3 -- one carrier air wing;\4 -- six surface combatants, of which at least three are cruisers or destroyers with Aegis weapons systems, four ships are equipped with Vertical Launching Systems that can fire Tomahawk cruise missiles, and ten antisubmarine warfare helicopters are collectively embarked; -- two attack submarines, one of which is equipped with a Vertical Launch System; and, -- one multipurpose fast combat support ship. The policy further states that a battle group's composition can vary, depending on the mission needs. Figure 1.1, for example, shows ships of the U.S.S. George Washington battle group as they transit the Suez Canal. (President Clinton ordered elements of the battle group to the Arabian Gulf to support U.N. efforts to compel Iraq's compliance with U.N. resolutions.) Figure 1.1: Elements of the U.S.S. George Washington (CVN-73) Carrier Battle Group Transit the Suez Canal Toward the Persian Gulf Note: Pictured are the cruiser U.S.S. Normandy (CG-60) (front), the submarine U.S.S. Annapolis (SSN 760), and the fast combat support ship U.S.S. Seattle (AOE-3) (rear); not pictured, but making the transit, are the U.S.S. George Washington (CVN-73) and the U.S.S. Carney (DDG-64). Members of the George Washington battle group remaining in the Mediterranean Sea include the nuclear-powered cruiser U.S.S. South Carolina (CGN-37), U.S.S. John Rodgers (DD-983), U.S.S. Boone (FFG-28), U.S.S. Underwood (FFG-36), and U.S.S. Toledo (SSN-769). Source: Navy photo. The ships perform various roles within the battle group. The aircraft carrier, with its embarked air wing, is the group's principal means of conducting offensive operations against enemy targets. The air wing's aircraft also help defend the battle group against air, surface, and submarine threats. The surface combatants, with their installed missile systems, guns, and torpedoes, defend the aircraft carrier and the rest of the battle group against air, surface, and submarine attack. With their Tomahawk missile systems, surface combatants can also strike enemy targets ashore. Their embarked antisubmarine helicopters also help defend the battle group against submarine and surface threats. The submarines provide protection, surveillance, and intelligence support to the battle group, and their torpedoes and Harpoon missiles contribute to the battle group's defense against enemy submarines and surface threats. As with the surface combatants, the submarines' Tomahawk missile systems allows them to strike targets ashore. The multipurpose fast combat support ship (AOE) is the only noncombatant ship in the battle group. Its role is the underway replenishment of the ships in the group.\5 As the battle group's station ship, it resupplies ships with fuel (both JP-5 for the aircraft and DFM for the ships), other petroleum products, ammunition, provisions, and other supplies. This replenishment allows the ships to remain at sea for prolonged periods since they do not have to return to port to be resupplied. The AOE classes of ships can easily cruise for sustained periods at battle group speeds, replenishing and rearming the entire battle force. The ship has the armament to operate as an integral part of the battle group. -------------------- \1 Office of the Chief of Naval Operations, OPNAV Instruction 3501.316, Subject: Policy for Carrier Battle Groups, dated February 17, 1995. \2 The specific tasks discussed in the policy are surveillance/intelligence, command and control, air superiority, maritime superiority, power projection, theater ballistic missile defense, operations in support of the peacetime presence mission, amphibious force operations, insertion and withdrawal of land-based forces into uncertain and hostile environments, special operations, combat search and rescue, mine warfare, and sustainment. \3 The policy does not differentiate between nuclear and conventional aircraft carriers in its discussion of a carrier battle group's tasks. \4 The same standard air wing is assigned to both conventionally and nuclear-powered carriers. That wing consists of a mix of 74 fighter, attack, electronic countermeasure, antisubmarine, search-rescue, and surveillance aircraft. (See table 2.5 for a complete list.) \5 When an AOE is not available, a combination of ships can be used to carry out its role. These include oilers (AO or T-AO) and ammunition ships (AE and T-AE). However, these other types of ships do not carry the range of products that an AOE carries and, since their top speeds are about 20 knots, they do not have the speed to keep up with the other ships in the battle group at all times. THE AIRCRAFT CARRIER'S EMPLOYMENT CYCLE ---------------------------------------------------------- Chapter 1:6 The employment operations of both types of carriers follow a typical cycle comprised of depot-level maintenance periods and intervals during which a carrier prepares for and deploys to overseas theaters. As shown in figure 1.2, the cycle normally begins with a depot-level maintenance period. When the maintenance is completed, the carrier begins interdeployment training, which includes training with the air wing.\6 With the training's successful completion, the aircraft carrier and its air wing, as part of a battle group, are ready to deploy. Upon returning from an overseas deployment, the carrier enters a short stand-down period during which it may be retained in a surge readiness status--a nondeployed carrier that would be tasked to respond to an emerging overseas crisis. After the stand-down, it begins a maintenance period--starting a new cycle. Figure 1.2: Aircraft Carrier Employment Cycle The length of a carrier's employment cycle, sometimes called its maintenance cycle, depends on the carrier's propulsion type and the maintenance strategy it uses. Each cycle typically includes three depot-level (i.e., shipyard) maintenance periods and three deployments. For the conventionally powered carrier, two of the maintenance periods last 3 months and the other maintenance period lasts 12 months; and, for the nuclear-powered carrier, the first two periods last 6 months and the final period lasts 10-1/2 months. For both carrier types, an 18-month operating interval, including the 6-month deployment, separates the maintenance periods. -------------------- \6 According to a Naval Air Force, Atlantic Fleet official, the carrier becomes a ¹surgeº carrier when it successfully completes ¹ship and air wingº training. AIRCRAFT CARRIER FORCE STRUCTURE AND ACQUISITION PLAN ---------------------------------------------------------- Chapter 1:7 The number of conventionally powered aircraft carriers in the force is diminishing. At the end of fiscal year 1997, the Navy's force included four conventionally powered carriers and eight nuclear-powered carriers. One of the conventionally powered carriers is homeported in Yokosuka, Japan, and another, the U.S.S. John F. Kennedy (CV-67), is in the Reserve Fleet. Figure 1.3 shows the Navy's projected carrier force through fiscal year 2020, including its refueling complex overhaul (RCOH) schedule. (See app. VI for a complete list of hull numbers, names, commissioning, and decommissioning dates.) Figure 1.3: Aircraft Carrier Force Structure for Fiscal Years 1994-2020 Source: Our analysis of U.S. Navy data. The Navy is building two Nimitz-class nuclear-powered carriers, the Harry S. Truman (CVN-75) and the Ronald Reagan (CVN-76), which are scheduled to be delivered in fiscal years 1998 and 2003, respectively. In fiscal year 2001, the Navy will begin building the last Nimitz-design nuclear-powered carrier, CVN-77, estimated to cost over $4.4 billion (then-year dollars). The U.S.S. Nimitz (CVN-68) begins its 3-year refueling complex overhaul in fiscal year 1998 at the cost of $2.1 billion (then-year dollars), followed by the U.S.S. Eisenhower (CVN-69) in fiscal year 2001 at the cost of $2.3 billion (then-year dollars). The formal design process for a new carrier class, designated the CVX, began in 1996. The CVX project received $45.7 for fiscal year 1998 and $190.2 has been requested for 1999. Construction of the first carrier of the new class, CVX-78, is expected to begin in 2006, with commissioning planned for 2013. The objective of this carrier project is to develop a class of aircraft carrier for operations in the 21st century that (1) maintains core capabilities of naval aviation, (2) improves affordability of the carrier force, and (3) incorporates an architecture for change. Another is to reduce life-cycle costs by 20 percent. The propulsion type for CVX-78 has not yet been decided. Notwithstanding the decision on the propulsion type for the CVX, a majority of the Navy's carriers will be nuclear-powered for at least the next 30 years (see fig. 1.4). Figure 1.4: Illustrative Carrier Force Mix with CVX Carriers, 1990-2035 Source: Our analysis of Navy data. THE NUCLEAR PROPULSION AND AIRCRAFT CARRIER PROGRAMS ---------------------------------------------------------- Chapter 1:8 The aircraft carrier program is managed by the Navy, but all programs having a nuclear component come under the jurisdiction of the Director, Naval Nuclear Propulsion Program, a joint Department of Energy (DOE) and Navy organization. The Director is assigned to design, build, operate, maintain, and manage all technical aspects of the Naval Nuclear Propulsion Program. Established in 1947, the Program delivered the first nuclear-powered submarine in 1954 and the first nuclear-powered carrier, the U.S.S. Enterprise (CVN-65), in 1961. The U.S.S. Nimitz (CVN-68) was commissioned in 1975. The Program, responsible for the cradle to grave management of all nuclear propulsion plants in the Navy, currently manages several laboratories, schools, shipyards, operating reactors, and vendors (see fig. 1.5). The Program is directly supported by two government-owned, contractor-operated laboratories dedicated solely to naval nuclear propulsion work, Bettis Atomic Power Laboratory and Knolls Atomic Power Laboratory. The laboratories have a combined workforce and annual budget of about 5,800 people and $625 million. Their missions are to develop safe, militarily effective nuclear propulsion plants and ensure the continued safe and reliable operation of naval reactors. The missions are achieved through continuous testing, verification, and refinement of reactor technology. Figure 1.5: Naval Nuclear Propulsion Program Infrastructure Note: INEEL is the Idaho National Engineering and Environmental Laboratory. Source: Navy and DOE. Two other DOE laboratories support the Program, the Idaho National Engineering and Environmental Laboratory and the Pacific Northwest National Laboratory Hanford Site. The Idaho National Engineering and Environmental Laboratory houses the Navy's expended core facilities. The Navy sends expended nuclear cores from retired or refueled reactors to that laboratory to measure fuel consumption and explore design improvements for future reactors. Until a few years ago, the cores were also reprocessed at the laboratory's facilities so that uranium from the cores could be recovered and recycled. Now, the expended fuel is held in temporary storage water tanks. The laboratory also provides other reactor and radioactive waste management support to the Program. The Hanford site is the ultimate repository of reactor compartments from decommissioned nuclear ships (less their highly radioactive expended fuel). THE NUCLEAR POWER DEBATE ---------------------------------------------------------- Chapter 1:9 Propelling the Navy's aircraft carriers and surface combatants with nuclear power has been the subject of much debate. Key issues have been whether the cited operational advantages that nuclear power confers offset the increased costs of nuclear-powered surface ships and the value of battle groups composed of a mixture of nuclear-powered and conventionally powered fossil fuel ships. Nuclear power advocates within DOD and the Navy have cited certain advantages to justify the nuclear-powered carrier program. They point out that nuclear-powered carriers have larger storage areas for aviation fuel and ordnance, can steam almost indefinitely without having to be refueled, and have superior acceleration, thereby enabling them to better recover aircraft. In a 1963 memorandum, the Secretary of the Navy advocated that the U.S.S. John F. Kennedy (CV-67) should be constructed with nuclear-power: ¹Increased range and staying power, plus a reduction in vulnerability provided by nuclear propulsion, will make naval forces much stronger and more useful as instruments of national policy and power.º Appendix II contains a detailed discussion of the advantages cited at that time for nuclear power in surface ships. Others, however, balanced their desire for the benefits derived from nuclear propulsion against nuclear propulsion's increased costs. In January 1960, Admiral Arleigh Burke, Chief of Naval Operations, submitted a report on the attack aircraft carrier as part of his testimony during congressional hearings before the House Committee on Appropriations.\7 According to that report, "[Nuclear power] does not provide a dramatic new mode of operation for the carrier as it does for the submarine. It does provide a greatly increased endurance before refueling, and the capability for long periods of steaming at high speeds. However, because of the aircraft fuel requirement, the tight logistic bonds of hydrocarbon fuels for the carrier are not severed by the use of nuclear propulsion." "For this reason, the military tactics for aircraft carriers are not altered nearly so drastically by nuclear power as are those for submarines . . . There are no misgivings about the existence of military advantages in a nuclear-powered aircraft carrier. These have been stated before, and are still true. In light of increasingly accurate knowledge of the additional cost, however, these military advantages simply do not compare well with the military potential in other needed areas which can be purchased for this money." In regards to the cost of nuclear propulsion, Admiral Burke, who previously had advocated an all-nuclear surface fleet noted in 1960 that ". . . budgetary considerations have forced us to review and weigh most carefully the inherent advantages of the nuclear-powered carrier against the additional cost involved in its construction. The nuclear-powered carrier would cost about $743 million\8 more than an oil-fired carrier. We can build into the conventionally powered carrier all of the improvements that have gone into the nuclear-powered U.S.S. Enterprise (CVN-65). . . except that nuclear plant. . . The funds gained in building this CVA with a conventional rather than a nuclear power plant have been applied in this budget to the procurement of other badly needed ships, aircraft, and missiles for the Navy.º\9 Even though the Navy still wanted nuclear propulsion, increasingly scarce resources necessitated a general belt tightening; the marginal costs of nuclear propulsion were not viewed as justifiable on the basis of the benefits derived, particularly when other needs had to be satisfied. The Secretary of Defense argued that the Navy could buy about five antisubmarine surface combatants--which were needed to defeat the grave threat posed by the expanding Soviet submarine force--with the funds saved by buying a conventionally powered carrier rather than a second nuclear-powered carrier. Three decades later, the dependence of surface combatants on at-sea replenishment remains. According to a 1992 Center for Naval Analyses study (CNA),\10 "There seems to be little substance to the conventional wisdom that CVNs [nuclear carriers] are less demanding logistically than CVs [conventional carriers], and that, consequently, there may be significant savings and profound freedoms for employment relating to the battle force formed on the CVN. What might have been true for an all nuclear battle force, is of little consequence when examining an aircraft carrier accompanied by conventionally powered escorts." The study also concluded that "Engaged battle forces need the support of many CLF [Combat Logistics Force] ships. All other things being equal, the presence of a few nuclear-powered units will not reduce the logistic pipeline, significantly. The increased capacity for ordnance and aviation fuel in the CVN design is not sufficient to untether the force from the pipeline. The hoped for increase in freedom of operational employment for CVNs is further restricted by the fossil-fuel dependence of the accompanying surface combatants." -------------------- \7 U.S. Congress, House Committee on Appropriations, DOD Appropriations Bill, 1961, Hearings before a Subcommittee of the House Committee on Appropriations, 86th Cong., 2nd session, 1960. Part 2, p. 32. \8 The original text cited $130 million. We escalated the dollar amount to fiscal year 1997 dollars. \9 U.S. Congress, House Committee on Appropriations, DOD Appropriations Bill, 1961, Hearings before a Subcommittee of the House Committee on Appropriations, 86th Cong., 2nd Session, 1960. Part 2, p. 19. \10 Combat Logistics Force Ships for CV and CVN Battle Forces, CRM 91-257, dated February 1992. HIGH COSTS LED NAVY TO STOP BUILDING NUCLEAR-POWERED SURFACE COMBATANTS --------------------------------------------------------- Chapter 1:10 Throughout the 1960s and most of the 1970s, the Navy pursued a goal of creating a fleet of nuclear carrier task forces. The centerpiece of these task forces, the nuclear-powered aircraft carrier, would be escorted by nuclear-powered surface combatants and nuclear-powered submarines. In deciding to build nuclear-powered surface combatants, the Navy believed that the greatest benefit would be achieved when all the combatant ships in the task force were nuclear-powered. The Navy ceased building nuclear-powered surface combatants after 1975 because of the high cost. More recently, most of the remaining nuclear-powered surface combatants were decommissioned early because they were not cost-effective to operate and maintain. Nuclear-powered surface combatants share many of the characteristics of the nuclear-powered carrier--unlimited high speed endurance, sustainability, and their larger size than their sister ships. The first nuclear-powered surface combatant was initially developed and fielded at about the same time as the first nuclear-powered carrier, in 1961. A total of nine nuclear-powered surface combatants were purchased with the final ship authorized in fiscal year 1975. Nuclear-powered surface combatants were intended to be part of all nuclear-powered task forces, but this goal never materialized. In 1974, nuclear power seemed so promising that the Congress, in title VIII of the DOD Authorization Act for Fiscal Year 1975, stated that as a matter of policy all future U.S. warships intended to serve with the strike forces should be nuclear-powered. Exceptions would require a presidential finding that providing nuclear power was not in the national interest. On February 13, 1976, the President formally made a finding that constructing all nuclear surface combatants for the strike forces was not in the national interest. It was the Secretary of Defense's assessment that ¹the military value of an all nuclear-powered Aegis ship program does not warrant the increased costs or, alternatively, the reduced force levels.º Further, he proposed a mixed propulsion program to provide nuclear-powered surface combatants, which could undertake crisis response and other operations in areas far from supply bases, and conventionally powered Aegis ships to supplement the nuclear-powered surface combatants in protection of high-value forces (including carriers) under conditions of sustained conflict. However, no more nuclear-powered surface combatants were acquired. In fiscal year 1993, the Navy decided to decommission the newest class of nuclear-powered surface combatants instead of refueling them. These ships are being inactivated after an average of 17 years of service and with nearly half of their planned service life remaining. The decision was based on two factors--the need to reduce force structure in order to recapitalize the force and the ships' need for expensive nuclear refueling overhauls. Faced with declining budgets and large fiscal requirements, the Navy determined that the midlife modernization and upgrading through a refueling complex overhaul were not cost-effective. Even though there would be a near-term inactivation cost, the Navy would not incur the expense of a more costly refueling complex overhaul. Moreover, the decision would provide an opportunity to divest a large surface nuclear infrastructure supporting a small ship population. Another rationale for the decision to decommission the nuclear-powered surface combatant force was that a decision to invest in a refueling complex overhaul would drive retention of this force for the next 20 years. Operationally, the nuclear-powered surface combatants are expensive, and they are maintenance and infrastructure intensive ships. Personnel, training, maintenance, and other supporting infrastructure costs were more expensive than their modernized, conventionally powered counterparts. OBJECTIVES, SCOPE, AND METHODOLOGY --------------------------------------------------------- Chapter 1:11 The Defense Appropriations Act of 1994 Conference Report directed the Comptroller General to study the cost-effectiveness of nuclear-powered aircraft carriers. Overall, our objectives were to (1) evaluate the adequacy of conventionally and nuclear-powered aircraft carriers in meeting the Nation's forward presence, crisis response, and war-fighting requirements and (2) estimate the total life-cycle costs of conventionally and nuclear-powered aircraft carriers. The conferees noted the study should include (1) a life-cycle cost analysis, including the costs of processing and disposing of nuclear waste and spent fuel; (2) an estimate of the costs associated with processing and disposing of nuclear fuel and other nuclear material for the existing nuclear-powered fleet; and (3) the implications of an all nuclear carrier force on overseas homeporting. To accomplish our objectives, we met with officials in DOD, State, and DOE and reviewed studies and reports concerning the U.S. military strategy, policy, employment concepts, missions, requirements, operations, characteristics, and costs relating to conventionally and nuclear-powered carriers. We also reviewed carrier peacetime deployment, surge, and war-fighting operations; performed several analyses controlling for the effects of propulsion type on conducting these operations; reviewed and evaluated conventionally and nuclear-powered carrier cost information; and, developed life-cycle cost estimates. (See app. I for a list of contacts and locations visited and a more detailed discussion of the methodology we used in our analyses.) We performed our review in accordance with generally accepted government auditing standards.