United States General Accounting Office

GAO Report to Congressional Requesters

August 1998 NAVY AIRCRAFT

CARRIERS

Cost-Effectiveness of

Conventionally and

Nuclear-Powered

Carriers

GAO/NSIAD-98-1

GAO United States

General Accounting Office

Washington, D.C. 20548

National Security and

International Affairs Division

B-259298 

August 27, 1998

The Honorable Ted Stevens

Chairman

The Honorable Daniel K. Inouye

Ranking Minority Member

Subcommittee on Defense

Committee on Appropriations

United States Senate

The Honorable C.W. Bill Young

Chairman

The Honorable John P. Murtha

Ranking Minority Member

Subcommittee on National Security

Committee on Appropriations

House of Representatives

The aircraft carrier forms the building block of the Navy’s forward deployed peacetime

presence, crisis response, and war-fighting forces. The nuclear-powered carrier is the most

expensive weapon system in the Nation’s arsenal and represents a significant portion of the

Navy’s shipbuilding and conversion future years defense program. As requested, this report

discusses the cost-effectiveness to the Navy of using conventionally and nuclear-powered

aircraft carriers. As the Defense Department and the Navy assess design concepts for a new

class of carriers, they will evaluate a number of factors, including different propulsion types.

This report contains information and analysis that you may find useful in the process of

allocating future defense resources.

We are sending copies of this report to the Secretaries of Defense, Navy, Energy, and State and

the Director, Office of Management and Budget. Copies will also be made available to others on

request.

Please contact me on (202) 512-3504 if you or your staff have any questions concerning this

report. Major contributors to this report are listed in appendix VIII.

Richard Davis

Director, National Security

Analysis
Executive Summary

Purpose The Defense Appropriations Act of 1994 Conference Report directed GAO

to study the cost-effectiveness of nuclear-powered aircraft carriers. The

aircraft carrier forms the building block of the Navy’s forward deployed

peacetime presence, crisis response, and war-fighting forces. The

nuclear-powered aircraft carrier (CVN) is the most expensive weapon

system in the Nation’s arsenal. Pursuant to the Conference Report, GAO

(1) compared the relative effectiveness of conventionally powered and

nuclear-powered aircraft carriers in meeting national security

requirements, (2) estimated the total life-cycle costs of conventionally

powered and nuclear-powered carriers, and (3) identified implications of

an all nuclear carrier force on overseas homeporting in Japan and

overseas presence in the Pacific region.

Background Navy policy, doctrine, and practice have been to operate aircraft carriers

as the centerpiece of the carrier battle group. The standard carrier battle

group includes the carrier and its air wing, six surface combatants, two

attack submarines, and one multipurpose fast combat supply ship. As a

major element of a carrier battle group, surface combatants provide the

primary defensive capabilities for the group. Navy guidance states that one

or more surface combatants are necessary at all times to escort and

protect the aircraft carrier. Collectively, the battle group’s forces provide

the combatant commanders with an adequately balanced force to

offensively and defensively deal with a range of threats.

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.

Recently, most of the remaining nuclear-powered surface combatants have

been decommissioned early because they were not cost-effective to

operate and maintain.

The 1993 Bottom-Up Review prescribed a force of 12 aircraft carriers. The

Quadrennial Defense Review of 1997 reaffirmed the need to retain 12

carriers. At the end of fiscal year 1997, the Navy’s force consisted of four

conventionally powered carriers and eight nuclear-powered carriers. One

Page 2 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

of the conventionally powered carriers is homeported in Yokosuka, Japan,

and another is in operational reserve status.

The Navy is building two nuclear-powered Nimitz-class 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 to build the last Nimitz-design carrier,

CVN-77. These nuclear-powered carriers will replace three of the four

conventionally powered carriers now in the force.

The U.S.S. Nimitz (CVN-68) begins a 3-year refueling complex overhaul in

fiscal year 1998 at an estimated cost of $2.1 billion (then-year dollars),

followed by the U.S.S. Eisenhower (CVN-69) in fiscal year 2001 at an

estimated cost of $2.3 billion (then-year dollars). Table 1 shows the

changes in the Navy’s carrier force through fiscal year 2018 based on

planned service lives.

Table 1: Navy’s Carrier Force Structure Plan (end of fiscal year)

1996 1998 2003 2008 2013 2018

CV-Active Conus 2 1 0 0 0 0

CV-Japan 1 1 1 0 0 0

CV-Reserve training 1 1 1 1 1 0

Total conventional 4 3 2 1 1 0

Total nuclear 8 9 10 11 10 10

Planned carrier CVX class 0 0 0 0 1 2

Total 12 12 12 12 12 12

Key: CV=conventionally powered carriers.

The Navy is assessing design concepts for a new class of aircraft carriers,

designated the CVX. As a part of this assessment, the Navy will study a

number of factors, including various types of propulsion. The formal

design process for CVX began in 1996. The project received $45.7 million

in fiscal year 1998 and $190.2 million is being requested for fiscal year

1999. One of the principal objectives of the CVX project is to reduce

life-cycle costs by 20 percent. The Navy wants to begin building the first

CVX-78 class carrier in fiscal year 2006 and commission it in 2013. Not

withstanding 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).

Page 3 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

Figure 1: Illustrative Carrier Force Mix with CVX Carriers, 1990-2035

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

90

91

92

93

94

95

96

97

98

99

00

01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

Fiscal year

CV CVX CVN

Number of carriers

Source: GAO analysis of Navy data.

GAO studied the cost-effectiveness of nuclear-powered aircraft carriers,

including analyses of total life-cycle costs and the implications of an all

nuclear-powered fleet on overseas homeporting. After consulting with the

Joint Staff, Office of the Secretary of Defense, and Navy officials, GAO

identified three principal measures of effectiveness to evaluate the relative

Page 4 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

effectiveness of conventionally and nuclear-powered carriers in meeting

national security requirements and objectives: (1) overseas presence,

(2) crisis response, and (3) war-fighting. GAO examined the major

assumptions and requirements used in developing overseas presence,

crisis response, and war-fighting plans and evaluated the recent

operational experience of the conventionally and nuclear-powered carrier

force. GAO also evaluated several characteristics and capabilities of large,

modern conventionally and nuclear-powered carriers. Relying principally

on Navy data, GAO examined the historical and projected costs to acquire,

operate, support, inactivate, and dispose of conventionally and

nuclear-powered carriers such as those now in the force. Unless otherwise

noted, GAO used the Kitty Hawk/John F. Kennedy-class and the

Nimitz-class aircraft carriers in its conventionally and nuclear-powered

carrier cost-effectiveness analysis.

Results in Brief GAO’s analysis shows that conventional and nuclear carriers both have

been effective in fulfilling U.S. forward presence, crisis response, and

war-fighting requirements and share many characteristics and capabilities.

Conventionally and nuclear-powered carriers both have the same standard

air wing and train to the same mission requirements. Each type of carrier

offers certain advantages. For example, conventionally powered carriers

spend less time in extended maintenance, and as a result, they can provide

more forward presence coverage. By the same token, nuclear carriers can

store larger quantities of aviation fuel and munitions and, as a result, are

less dependent upon at-sea replenishment. There was little difference in

the operational effectiveness of nuclear and conventional carriers in the

Persian Gulf War.

Investment, operating and support, and inactivation and disposal costs are

greater for nuclear-powered carriers than conventionally powered

carriers. GAO’s analysis, based on an analysis of historical and projected

costs, shows that life-cycle costs for conventionally powered and

nuclear-powered carriers (for a notional 50-year service life) are estimated

at $14.1 billion and $22.2 billion (in fiscal year 1997 dollars), respectively.

The United States maintains a continuous presence in the Pacific region by

homeporting a conventionally powered carrier in Japan. If the U.S. Navy

transitions to an all nuclear carrier force, it would need to homeport a

nuclear-powered carrier there to maintain the current level of worldwide

overseas presence with a 12-carrier force. The homeporting of a

nuclear-powered carrier in Japan could face several difficult challenges,

Page 5 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

and be a costly undertaking, because of the need for nuclear-capable

maintenance and other support facilities, infrastructure improvements,

and additional personnel. The United States would need a larger carrier

force if it wanted to maintain a similar level of presence in the Pacific

region with nuclear-carriers homeported in the United States.

GAO’s Analysis

Operational Effectiveness

of Conventionally Powered

and Nuclear-Powered

Carriers

To evaluate the relative effectiveness of conventionally and

nuclear-powered aircraft carriers in meeting national security

requirements and objectives, GAO identified three principal measures of

effectiveness: (1) overseas presence, (2) crisis response, and

(3) war-fighting.

Using the Navy’s Force Presence Model and data, GAO’s analysis shows

that, on a relative basis, a force of 12 conventional carriers, when

compared to a force of 12 nuclear carriers, can provide a greater level of

overseas presence in the European Command, the Central Command, and

the Western Pacific1

 or that a force of 11 conventionally powered carriers

can provide an equivalent level of forward presence as a force of 12

nuclear-powered carriers. Because a conventionally powered carrier’s

maintenance requirements are not as stringent and complex as those of a

nuclear-powered aircraft carrier, the conventionally powered carrier

spends a smaller proportion of its time in maintenance than does the

nuclear aircraft carrier and, thus, is more available for deployment and

other fleet operations. Unified Commanders consider the quality of

presence of the two types of carriers to be the same.

Navy carriers have been tasked to respond to various crises across the full

range of military operations, from humanitarian assistance to major

theater wars. Nuclear-powered carriers are known for their abilities to

sustain long duration high-speed transits. Although both types of carriers

can transit to crisis areas at the same top speed, the conventional carriers

take somewhat longer to cover long distances than nuclear carriers due to

their need to refuel. For example, GAO’s analysis of Navy data indicates

that in an 18-day voyage from the U.S. West Coast to the Persian Gulf, a

distance of about 12,000 nautical miles, steaming at a sustained speed of

1

An all conventionally powered carrier force and an all nuclear-powered carrier force were used to

illustrate the relative ability of the two carrier types to fulfill peacetime overseas deployment

requirements. This analysis assumes that a carrier is permanently forward deployed in Japan.

Page 6 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

28 knots, a conventional carrier would arrive about 6 hours later than a

nuclear carrier. On a shorter voyage from the U.S. East Coast to the

eastern Mediterranean Sea, a distance of about 4,800 nautical miles, a

conventional carrier would arrive about 2 hours later than a nuclear

carrier. Neither of these two examples include the time delay caused by

refueling the other ships in the battle group, which would have the same

refueling requirements, regardless of the carrier’s propulsion.

Conventionally powered carriers can be available sooner for large scale

crises because it is easier to accelerate or compress their maintenance.

Carrier maintenance periods can be shortened by varying degrees,

depending on the stage of the maintenance being performed.2

 The degree a

depot maintenance period can be shortened—or surged—depends on

when the decision is made to deploy the carrier. For both types of carriers,

the decision must be made early if the period is to be substantially

shortened. Due to the complexity of its maintenance, a nuclear carrier’s

maintenance period cannot be surged to the same degree as that of a

conventional carrier. In addition, the crews for both carrier types train to

the same standards, except for the power-plant crew, and spend

comparable time in predeployment training.

GAO found little difference in the operational effectiveness of nuclear and

conventional carriers in the Persian Gulf War. Although the Navy had

opportunities to place more nuclear carriers in the combat zone, it

followed previously planned deployment schedules. As a result, five of the

six carriers that participated in the air campaign were conventionally

powered. GAO found that the Navy operated and supported all six carriers

and their battle groups in essentially the same manner during the conflict.

Each battle group was assigned its own dedicated support ships, which

enabled frequent replenishment of fuel and ordnance. Conventional

carriers replenished aviation fuel about every 2.7 to 3.1 days and the

nuclear carrier every 3.3 days—after only a fraction of their fuel and

supplies were exhausted. The distance to targets and the number and mix

of aircraft aboard each carrier, rather than propulsion type, determined

the number of air sorties flown. The average number of sorties flown were

nearly identical for both types of carriers when based on the number of

aircraft assigned to the respective carriers.

2

An employment cycle typically includes three maintenance periods, three predeployment training

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.

Page 7 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

In comparing their characteristics and capabilities, GAO found that the two

types of carriers are similar in many respects. For example, both carriers

follow the same operational guidance; have the same standard airwing;

and, can surge to conduct additional air operations, if necessary. The most

noticeable differences are the nuclear carrier’s ability to steam almost

indefinitely without needing to replenish its propulsion fuel and its larger

aircraft fuel and ordnance storage capacity, thereby further reducing

dependence on logistics support ships. The larger storage capacity is

primarily due to design decisions that have little to do with propulsion

type.3

 Nuclear carriers still need periodic resupply of aviation fuel,

ordnance, and other supplies, and as such, remain dependent on logistics

support ships to sustain extended operations at sea. Logistics support

ships are an integral part of carrier battle groups and accompany the

groups during peacetime deployments, in crisis response, and during

wartime. Nuclear carriers also can accelerate faster than conventional

carriers, enabling them to respond faster if conditions affecting the

recovery of landing aircraft suddenly change, but the Navy could not

provide any examples where an aircraft was lost because a conventionally

powered carrier could not accelerate in sufficient time.

Life-Cycle Costs for

Nuclear-Powered Carriers

Are Higher Than

Conventionally Powered

Carriers

Nuclear-powered carriers cost more than conventionally powered carriers

to acquire, operate and support, and inactivate. GAO estimates that over a

50-year life, the costs of a nuclear-powered carrier is about $8.1 billion, or

about 58 percent, more than a conventionally powered carrier (see

table 2). Historically, the acquisition cost for a nuclear-powered carrier

has been about double that of a conventionally powered carrier. Midlife

modernization4

 for nuclear-powered carriers is estimated to be almost

three times as expensive as a conventionally powered carrier—about

$2.4 billion versus $866 million (in fiscal year 1997 dollars).5

3

Analyses by the Naval Sea Systems Command and the Center for Naval Analyses show that a

Nimitz-class nuclear design with a conventional propulsion system could provide equivalent aviation

ordnance and fuel capacities while retaining the same range and speed characteristics of the current

Kennedy-class conventional carrier.

4

The midlife modernization represents the service life extension program for conventional carriers and

the nuclear refueling complex overhaul for nuclear carriers. Both investments accomplish the common

objectives of extending the operating life of the ship.

5

The initial nuclear fuel load and its installation are included in the acquisition cost category. The

midlife modernization cost category includes removal of the initial fuel load. It also includes the cost

of the replacement fuel load and its installation.

Page 8 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

Table 2: Life-Cycle Costs for a

Conventionally Powered Carrier and a

Nuclear-Powered Carrier (based on a

50-year service life)

Fiscal year 1997 dollars in billions

Cost category

Conventionally

powered carrier

Nuclear-powered

carrier

Investment costa $2.916 $6.441

Ship acquisition cost 2.050 4.059

Midlife modernization cost 0.866 2.382

Operating and support cost 11.125 14.882

Direct operating and support cost 10.436 11.677

Indirect operating and support cost 0.688 3.205

Inactivation/disposal cost 0.053 0.899

Inactivation/disposal cost 0.053 0.887

Spent nuclear fuel storage cost n/a 0.013

Total life-cycle cost $14.094 $22.222

Note: Numbers may not add due to rounding.

aCVN investment cost includes all nuclear fuel cost; CV fuel is included in operations and support

activities.

Source: GAO’s analysis.

GAO estimates that nuclear-powered carriers have cost about 34 percent

more than conventionally powered carriers to operate and support

because personnel and maintenance costs are higher and nuclear-powered

carriers require unique support organizations and activities. Personnel

costs for nuclear carriers are greater because more personnel are required

for a nuclear-powered carrier, nuclear-qualified personnel receive greater

total compensation, and they are required to complete additional training.

For example, a nuclear-powered carrier needs about 130 more personnel

in its engineering and reactor departments than are needed in the

conventionally powered carrier’s engineering department. Also, each year,

nuclear-qualified officers receive up to $12,000 and nuclear qualified

enlisted personnel receive about $1,800 more than personnel do in

nonnuclear jobs.

Nuclear-powered carriers are also more costly to maintain because the

scope of work is larger and considerably more labor hours are required.

Because of the complex procedures required to maintain nuclear power

plants, shipyard workers must be specifically trained to maintain nuclear

carriers. Additionally, the materials used in nuclear carriers must meet

exacting standards and the shipyards must have the facilities needed for

the specialized work. Also, these projects cost more because of the unique

Page 9 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

industrial base, specialized nuclear suppliers, and the Naval Nuclear

Propulsion Program’s exacting and stringent environmental, health, and

safety standards. Shipbuilders must follow “non-deviation” plans (i.e., no

deviation from the approved plans without government approval). An

unavoidably high cost overhead structure (engineering, quality assurance,

and production control) and costly production work are required in the

naval nuclear propulsion industry. Based on the Navy’s maintenance plans,

GAO estimates that over a 50-year life, nearly 40 percent more labor hours

are needed to maintain a nuclear-powered carrier than are required to

maintain a conventionally powered carrier.

The Navy estimates that it will cost between $819 million and $955 million

to inactivate and dispose of the first Nimitz-class nuclear-powered carrier.

This is almost 20 times more costly than the $52.6 million that is estimated

it will cost to inactivate and dispose of a conventionally powered carrier.

Most of the costs can be attributed to removing contaminated nuclear

equipment and material, including the highly radioactive spent fuel.

Implications of an All

Nuclear Carrier Force on

Homeporting a Carrier in

Japan and Overseas

Presence in the Pacific

Region

Homeporting Navy ships overseas enables the United States to maintain a

high level of presence with fewer ships because the need for a rotation

base to keep forces deployed is smaller. A conventionally powered carrier

has been permanently forward deployed in Japan since 1973. Japan

currently pays a substantial share of the costs for the permanently forward

deployed carrier, including all yen-based labor, berthing and maintenance

facilities improvements, and other support costs such as housing.

The last two conventionally powered carriers, including the carrier now

homeported in Japan, will reach the end of their service lives in the 2008 to

2018 period. The Navy will have to decide if it wishes to change how it

maintains forward presence in the Pacific region. That is, the Navy will

have to decide whether to continue the current approach to presence in

the region and design and acquire a conventionally powered replacement

carrier to homeport in Japan. Alternately, if the Navy wished to provide

the same level of presence in the region with nuclear-powered carriers, it

would need to (1) establish a nuclear-capable maintenance facility and

related infrastructure in Japan to accommodate the nuclear-powered

carrier to be homeported there or (2) expand the force to include the

additional nuclear-powered carriers that would be necessary, but with

ships deployed from the United States.

Page 10 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

While it would be several years before the carrier force would undergo a

complete transition to nuclear propulsion, it would also take several years

to implement any of the strategies that will allow the United States to

maintain a long-term continuous naval carrier presence in the Pacific

region.

Conclusions The Navy is assessing design concepts for a new class of aircraft carriers.

As part of this assessment, it will evaluate a number of factors, including

different propulsion types. GAO’s analysis of measures of effectiveness

(forward presence, crisis response, and war-fighting) shows that

conventionally and nuclear-powered carriers both have effectively met the

Nation’s national security requirements. The analysis also shows that

conventionally powered carriers have lower total life-cycle costs. This

report also discusses the implications of a changing carrier force structure

on providing overseas presence for the Pacific region.

Agency Comments The Departments of Defense (DOD), Energy, and State provided comments

on a draft of this report. DOD’s comments (see app. VII) and GAO’s detailed

evaluation are included in the report where appropriate.

Overall, DOD partially concurred with the report. Specifically, DOD

concurred there is a life-cycle cost premium associated with nuclear

power. However, DOD believed GAO’s estimate of that premium was

overstated by several billion dollars because of what DOD believed are

analytic inconsistencies in GAO’s analysis. DOD also believed the draft

report did not adequately address operational effectiveness features

provided by nuclear power.

DOD did not agree with GAO’s approach of making cost-per-ton comparisons

between the two types of carriers currently in the force, believing the

conventionally powered carriers reflect 40-year old technologies. DOD

believed a more appropriate cost comparison would include pricing

conventionally and nuclear-powered platforms of equivalent capabilities.

According to DOD, any analysis of platform effectiveness should include

mission, threat, and capabilities desired over the life of the ship. Further, it

stated the draft report did not adequately address future requirements but

relied on historical data and did not account for platform characteristics

unrelated to propulsion type. That is, many of the differences may be

explained by platform size, age, and onboard systems than by the type of

propulsion.

Page 11 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

Congress asked GAO to examine the cost-effectiveness of conventionally

and nuclear-powered aircraft carrier propulsion. Such an analysis seeks to

find the least costly alternative for achieving a given requirement. In this

context, GAO used as the requirement DOD’s national military strategy,

which is intended to respond to threats against U.S. interests. That

strategy encompasses overseas peacetime presence, crises response, and

war-fighting capabilities. GAO used those objectives as the baseline of its

analysis and selected several measures to compare the effectiveness of

conventionally and nuclear-powered carriers. Those measures were

discussed with numerous DOD, Joint Staff, and Navy officials at the outset.

Those measures reflect the relative capabilities of each propulsion type,

including the nuclear-powered carrier’s greater aviation fuel and

munitions capacity and unlimited range. Notwithstanding the enhanced

capabilities of nuclear propulsion, GAO found that both types of carriers

share many of the same characteristics and capabilities, that they are

employed interchangeably, and that each carrier type possesses certain

advantages. GAO also found that both types of carriers have demonstrated

that each can meet the requirements of the national military strategy. GAO’s

analysis shows that conventionally powered carriers can meet that

strategy at a significantly lower life-cycle cost.

The primary reason that GAO’s analysis shows a higher premium for

life-cycle costs of a nuclear-powered carrier is because different

methodologies were used. The GAO methodology compared the

investment, operating and support, and inactivation/disposal costs of

operational carriers. This approach allowed GAO to use historical costs to

the extent possible. GAO also used a cost-per-ton approach to develop its

acquisition cost estimate. This approach is an accepted method for

estimating procurement costs and has been used by the Navy.

The GAO methodology showed that the life-cycle cost premium associated

with nuclear propulsion was about $8 billion per carrier over a 50-year life

versus about $4 billion using the Navy’s approach. GAO’s and the Navy’s

estimated life-cycle costs for a nuclear-powered carrier were very similar

even though different methodologies were used. However, the life-cycle

cost of a conventionally powered carrier using the two methodologies

varies significantly—$14 billion versus $19 billion. Several factors account

for the variance. For example, a different universe of ships was used to

determine the estimated cost for a Service Life Extension Program. In

estimating procurement costs, the Navy used actual labor hours for the

U.S.S. John F. Kennedy (CV-67), adjusted to reflect current labor,

overhead, and material rates for a nuclear shipbuilding facility, Newport

Page 12 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Executive Summary

News Shipbuilding. Operating and support costs varied, in part, because

DOD used fully burdened fuel delivery costs and a different methodology

for estimating personnel costs.

GAO believes its methodology of reviewing a historical perspective

covering a wide range of peacetime presence, crises response, and

war-fighting scenarios that both types of carriers faced during the past 

20 years is sound. A full discussion of GAO’s methodology can be found in

appendix I. GAO continues to believe that this assessment will be helpful to

the Navy as it assesses design concepts for a new class of aircraft carriers.

The Energy Department concurred with DOD’s comments addressing

estimates of costs associated with nuclear reactor plant support activities

and storage of naval spent fuel. These comments and GAO’s evaluation of

them are discussed in appendix VII. The State Department noted that the

entry of nuclear-powered vessels into Japanese ports remains sensitive in

Japan and there would have to be careful consultations with the

government of Japan should the U.S. government wish to homeport a

nuclear-powered carrier in Japan.

Page 13 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Executive Summary 2

Chapter 1 

Introduction

20

Building Blocks of U.S. Security Strategy and the Aircraft Carrier 20

Bottom-Up Review Establishes Carrier Force Size 21

Quadrennial Defense Review Reaffirms Carrier Force Size 21

General Characteristics of the Modern Conventionally and

Nuclear-Powered Aircraft Carriers

22

Aircraft Carriers Operate as Part of Battle Groups 24

The Aircraft Carrier’s Employment Cycle 26

Aircraft Carrier Force Structure and Acquisition Plan 28

The Nuclear Propulsion and Aircraft Carrier Programs 31

The Nuclear Power Debate 34

High Costs Led Navy to Stop Building Nuclear-Powered Surface

Combatants

36

Objectives, Scope, and Methodology 38

Chapter 2 

Operational

Effectiveness of

Conventionally and

Nuclear-Powered

Carriers

39

Both Types of Carriers Have Been Effective Fulfilling Forward

Presence Requirements

39

Several Factors Affect the Time Needed for the Carrier Force to

Respond to a Crisis or Major Theater War

49

Conventionally and Nuclear-Powered Carriers Were Both

Effective in the Persian Gulf War

55

Conventionally and Nuclear-Powered Carriers Share Many

Similar Characteristics and Capabilities but Differ in Others

62

Agency Comments and Our Evaluation 72

Chapter 3 

Life-Cycle Costs for

Nuclear-Powered

Aircraft Carriers Are

Greater Than for

Conventionally

Powered Carriers

74

What Is a Life-Cycle Cost Analysis? 75

Investment Costs Are Higher for Nuclear-Powered Carriers Than

for Conventionally Powered Carriers

76

Nuclear Carriers Are More Expensive to Operate and Support

Than Conventional Carriers

80

Nuclear Carriers Are More Costly to Inactivate and Dispose of

Than Conventional Carriers

94

Agency Comments and Our Evaluation 96

Page 14 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Chapter 4 

Implications of an All

Nuclear-Powered

Carrier Force on

Naval Presence in the

Pacific

99

Conventionally Powered Carrier Force Structure Has Been

Declining

99

Benefits of Homeporting a Carrier in Japan 100

Homeporting a Nuclear-Powered Carrier in Japan Could Be

Difficult and Costly

101

Providing Regional Presence With Carriers Homeported on the

West Coast

104

Agency Comments and Our Evaluation 104

Appendixes Appendix I: Ojectives, Scope, and Methodology 106

Appendix II: Conventionally Versus Nuclear-Powered

Cost-Effectiveness Debate—the Rationale for Nuclear Power

123

Appendix III: Underway Replenishment Extends the Endurance

of Carriers

127

Appendix IV: Comparison of the Transit Time of Conventionally

and Nuclear-Powered Carriers Responding to Selected Crises

134

Appendix V: Operations of Carriers in the Persian Gulf War 139

Appendix VI: List of Aircraft Carrier Hull Numbers, Names, and

Authorization and Commissioning and Decommissioning Dates

146

Appendix VII: Comments From the Department of Defense 147

Appendix VIII: Major Contributors to This Report 190

Related GAO Products 191

Tables Table 1: Navy’s Carrier Force Structure Plan 3

Table 2: Life-Cycle Costs for a Conventionally Powered Carrier

and a Nuclear-Powered Carrier

9

Table 1.1: General Characteristics of Modern, Large Deck

Conventionally and Nuclear-Powered Carriers

23

Table 2.1: Notional Carrier Maintenance Cycles 44

Table 2.2: Presence Coverage Provided by Deployable Forces of

12-, 11-, and 10-Conventional and Nuclear Carriers

47

Table 2.3: Number of Deployable Carriers Required to Provide

100, 80, and 60 Percent Presence Coverage

48

Table 2.4: Comparison of Nuclear and Conventional Carrier

Transit Times

50

Table 2.5: Composition of a Standard Carrier Air Wing 64

Table 3.1: Life-Cycle Costs for Conventional and Nuclear Aircraft

Carriers

74

Page 15 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Table 3.2: Investment Costs for Conventional and Nuclear

Aircraft Carriers

76

Table 3.3: Acquisition Cost Estimates for the Conventionally and

Nuclear-Powered Carrier

78

Table 3.4: Life-Cycle Direct and Indirect Operating and Support

Costs for a Conventionally and Nuclear-Powered Carrier

80

Table 3.5: Personnel Costs for Conventionally and

Nuclear-Powered Carriers

81

Table 3.6: Propulsion Plant Personnel for Conventional and

Nuclear Carriers

82

Table 3.7: Special Pay and Bonus Incentives Available for Nuclear

Personnel in Fiscal Year 1997

84

Table 3.8: Nuclear Fuel Cost for a Nimitz-class Carrier 85

Table 3.9: Comparison of Life-Cycle Fuel Cost for Conventionally

and Nuclear-Powered Carriers

85

Table 3.10: Life-Cycle Cost for Depot Maintenance of a

Conventionally and a Nuclear-Powered Carrier

88

Table 3.11: Propulsion Plant Pipeline Training Costs for a

Conventionally and Nuclear-Powered Carrier

91

Table 3.12: Cost to Deliver Fossil Fuel to a Conventionally

Powered Carrier

92

Table 3.13: Cost to Provide Nuclear Support Activities to a

Nuclear Carrier

93

Table 3.14: Navy Cost Estimate for the Dry Storage of a

Nuclear-Powered Carrier’s Spent Nuclear Fuel

95

Table 4.1: Conventionally Powered Carrier Force—Last Full Year

in Active Service

100

Table I.1: Comparison of Life-Cycle Costs for the Conventionally

Powered Carrier and the Nuclear-Powered Carrier Using

Different Fuel Price Scenarios

117

Table I.2: Discounted and Undiscounted Life-Cycle Costs for a

Conventionally and Nuclear-Powered Carrier

122

Table III.1: Capacities of Selected Combat Logistics Force Ships 127

Table III.2: Average Daily Fuel and Ordnance Consumption Rates

for Selected Ship Classes

128

Table III.3: Battle Group Ship Range and Endurance at Various

Speeds

129

Table III.4: Battle Group Propulsion Fuel Underway

Replenishment Requirements During Transits

130

Table III.5: Battle Group Comparative Transit Capabilities With

AOE Support

131

Page 16 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Table IV.1: Steaming Time/Speed of Carriers Deploying to Desert

Shield/Storm

135

Table V.1: Average Sorties Per Day Per Carrier During Desert

Storm

141

Table V.2: Comparison of the Average Number of Sorties

Generated By Each Carrier

142

Table V.3: Average Sorties Per Operating Day Generated By Each

Carrier

143

Table V.4: Frequency of Aviation Fuel Replenishment by Persian

Gulf Carriers During January and February 1991

144

Table VII.1: Maintenance Period Characteristics of

Conventionally and Nuclear-Powered Surface Combatants and

Aircraft Carriers

173

Figures Figure 1: Illustrative Carrier Force Mix with CVX Carriers,

1990-2035

4

Figure 1.1: Elements of the U.S.S. George Washington Carrier

Battle Group Transit the Suez Canal Toward the Persian Gulf

25

Figure 1.2: Aircraft Carrier Employment Cycle 27

Figure 1.3: Aircraft Carrier Force Structure for Fiscal Years

1994-2020

29

Figure 1.4: Illustrative Carrier Force Mix with CVX Carriers,

1990-2035

31

Figure 1.5: Naval Nuclear Propulsion Program Infrastructure 33

Figure 2.1: Comparison of Nuclear and Conventional Aircraft

Carrier Maintenance Cycles

43

Figure 2.2: An Oiler Providing Simultaneous Replenishment to a

Surface Combatant and the Nuclear-Powered Carrier U.S.S.

George Washington

51

Figure 2.3: Comparative Ability to Surge From an SRA and a PIA 53

Figure 2.4: Comparative Ability to Surge From a COH and a DPIA 54

Figure 2.5: Comparison of Previously Planned Carrier

Deployments With Actual Desert Shield/Storm Deployments

58

Figure 3.1: Life-Cycle Cost Components 75

Figure 3.2: Acquisition Cost per Ton for Conventional and

Nuclear Carriers

77

Figure 3.3: Midlife Modernization Cost for CVN-68, CVN-69 and

Kennedy-class Conventional Carriers

79

Figure 3.4: Grade Structure for the Enlisted Propulsion Plant

Personnel for Conventionally and Nuclear-Powered Carriers

83

Page 17 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Figure 3.5: Notional Depot Maintenance Cycle for Conventionally

and Nuclear-Powered Carriers

87

Figure I.1: Crude Oil, Fossil Fuel, and Major Events Affecting U.S.

Crude Oil Prices

116

Figure I.2: Diagram of a Pressurized Water Reactor 118

Figure I.3: Demand for Power by Nuclear-Powered Ships Based

on Force Structures in Fiscal Years 1995, 2000, and 2015

120

Page 18 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Contents

Abbreviations

AOE fast combat support ship

CLF Combat Logistics Force

CNA Center for Naval Analyses

COH complex overhaul

CV conventionally powered aircraft carrier

CVBG notional conventional battle group

CVN nuclear-powered aircraft carrier

CVNBG notional conventional and nuclear battle group

DFM diesel fuel marine

DOD Department of Defense

DOE Department of Energy

DPIA Docking Phased Incremental Availability

DSRA Drydocking Selected Restricted Availability

EOC Engineered Operating Cycle

FASAB Federal Accounting Standards Advisory Board

GAO General Accounting Office

IMP Incremental Maintenance Program

JFACC joint force air component commander

JP-5 jet fuel (Navy aircraft fuel)

NAVSEA Naval Sea Systems Command

nm nautical mile

NTU New Threat Upgrade

MSC Military Sealift Command

OPNAV Office of the Chief of Naval Operations

OPTEMPO operating tempo

PERA Planning, Engraving, Repairs, and Alterations

PERSTEMPO Personnel Tempo of Operations

PIA Phased Incremental Availability

QDR Quadrennial Defense Review

RCOH Refueling Complex Overhaul

SNF spent nuclear fuel

SRA Selected Restricted Availability

SLEP Service Life Extension Program

VAMOSC Visibility and Management of Operating and Support

Cost

Page 19 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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

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

Page 20 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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

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

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

Page 21 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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

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.

Page 22 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

Table 1.1: General Characteristics of

Modern, Large Deck Conventionally

and Nuclear-Powered Carriers

U.S.S. John F. Kennedy

(CV-67)

U.S.S. Nimitz

(CVN-68)

Displacement (full

load) 82,000 tons 95,000 tonsa

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 aircraftb 130 130

Catapults 4 4

Elevators 4 4

Crew

Ship’s companyc 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%

aThe full load displacements of the later ships of the Nimitz-class have increased to about 99,000

tons.

bA 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.)

cNumber of officers and sailors needed to operate the ship.

dA 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.

eAviation 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.

Page 23 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

Aircraft Carriers

Operate as Part of

Battle Groups

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

“non-permissive environment characterized by multiple threats.”

The policy also established a “standard carrier battle group” 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

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.)

Page 24 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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.

Page 25 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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.

The Aircraft Carrier’s

Employment Cycle

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

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.

6

According to a Naval Air Force, Atlantic Fleet official, the carrier becomes a “surge” carrier when it

successfully completes “ship and air wing” training.

Page 26 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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

Return from 

Deployment

Maintenance 

Availability Sea Trials Unit Training

Ship & Airwing 

Training

Battle Group 

Training

Preparation for 

Overseas 

Movement

Deploy

Operating interval Operating interval

Source: Our analysis of Navy data.

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

Page 27 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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.

Aircraft Carrier Force

Structure and

Acquisition Plan

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.)

Page 28 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

Figure 1.3: Aircraft Carrier Force Structure for Fiscal Years 1994-2020

Fiscal year

94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

U.S.S. Independence (CV 62) *

U.S.S. Kitty Hawk (CV 63) *

U.S.S. Constellation (CV 64) *

U.S.S. America (CV 66)

U.S.S. John F. Kennedy (CV 67) ** n n

U.S.S. Enterprise (CVN 65) n

U.S.S. Nimitz (CVN 68) nnn

U.S.S. Dwight D. Eisenhower (CVN 69) nnn

U.S.S. Carl Vinson (CVN 70) nnn

U.S.S. Theodore Roosevelt (CVN 71) nnn

U.S.S. Abraham Lincoln (CVN 72) nnn

U.S.S. George Washington (CVN 73) nnn

U.S.S. John C. Stennis (CVN 74) B B n n

P.C.U. Harry S. Truman (CVN 75) BBBB

Ronald Reagan (CVN 76) BBBBBBBB

CVN-77 BBBBBBB

CVX-78 BBBBBBB

CVX-79 BBBBBBB

Key: 

* CV with a midlife modernization ** Operational reserve carrier n Midlife modernization period

B New carrier building period Conventionally powered carriers Nuclear-powered carriers

CVX class

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

Page 29 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

(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).

Page 30 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

Figure 1.4: Illustrative Carrier Force Mix with CVX Carriers, 1990-2035

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

90

91

92

93

94

95

96

97

98

99

00

01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

Fiscal year

CV CVX CVN

Number of carriers

Source: Our analysis of Navy data.

The Nuclear

Propulsion and

Aircraft Carrier

Programs

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

Page 31 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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.

Page 32 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

Figure 1.5: Naval Nuclear Propulsion Program Infrastructure

• Joint DOE / Navy effort

• Responsible for design, development, operation, and disposal

 of Naval nuclear propulsion plants

NAVAL

REACTORS

385 people

Specialized Industrial Base

Approximately 625 Vendors

Dedicated Laboratories

Bettis/Knolls

5,800 Employees/$650 million

Prototypes/Moored Training Ships

Schools Train 2,100 Students/Year

 Nuclear Power School

 Nuclear Field "A" School

Field Offices

180 Naval Reacotrs 

Representatives

Shipyards

4 Public/2 Private

Temporary Nuclear Fuel Storage

INEEL

Waste Transport Waste

Reactor Compartment Disposal

Disposal

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

Page 33 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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

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: “Increased 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.”

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

Page 34 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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 million8

 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.”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

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.

Page 35 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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.”

High Costs Led Navy

to Stop Building

Nuclear-Powered

Surface Combatants

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

10Combat Logistics Force Ships for CV and CVN Battle Forces, CRM 91-257, dated February 1992.

Page 36 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

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 “the military

value of an all nuclear-powered Aegis ship program does not warrant the

increased costs or, alternatively, the reduced force levels.” 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,

Page 37 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 1 

Introduction

maintenance, and other supporting infrastructure costs were more

expensive than their modernized, conventionally powered counterparts.

Objectives, Scope,

and Methodology

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.

Page 38 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Our analysis indicates that conventionally powered and nuclear-powered

carriers both have been effective in meeting national security objectives

and requirements, share many characteristics and capabilities, and that the

Navy employs them interchangeably. Our analysis shows that

conventionally and nuclear-powered carriers both have been effective in

fulfilling U.S. forward presence, crisis response, and war-fighting

requirements. Both carrier types embark the same standard air wing and

train to the same mission requirements. We also found that each carrier

type possesses certain advantages. For example, conventionally powered

carriers spend less time in extended maintenance and, as a result, can

provide more forward presence coverage. By the same token, nuclear

carriers can carry larger quantities of aviation fuel and munitions and, as a

result, are less dependent upon at-sea replenishment. Both types of

carriers in the Persian Gulf War effectively performed their war-fighting

missions.

We compared the two carrier types from the standpoints of their ability to

fulfill U.S. forward presence, crisis response, and war-fighting

requirements. Our comparison represents a historical perspective—the

experiences of the Navy over the past several years operating a mixed

force of conventionally powered and nuclear-powered ships.1

 That

perspective addresses a broad spectrum of operations that includes

providing routine peacetime presence, the Navy’s response to emerging

crises such as the movement of Iraqi forces to the Kuwait border in 1994,

and the open conflict of Operation Desert Storm.

Both Types of Carriers

Have Been Effective

Fulfilling Forward

Presence

Requirements

Both conventionally and nuclear-powered carriers are employed overseas

without consideration of propulsion type. Joint Staff and combatant

command officials told us that the quality of presence provided by both

types of carriers is indistinguishable. Conventionally powered carriers

spend a smaller proportion of their time in depot-level maintenance than

nuclear-powered carriers and, thus, are more available for deployment to

meet presence and other fleet requirements. An all conventionally

powered carrier force could either provide a greater level of overseas

presence or require fewer carriers to meet U.S. peacetime presence

requirements than would an all nuclear-powered force.

1

With the exception of the first nuclear carrier, the U.S.S. Enterprise (CVN-65), the nuclear carriers

operating with the fleet have all been 90,000 ton-plus Nimitz-class ships—the Navy’s most recent

carrier class. Conversely, the conventional carriers operating in the fleets have included ships of the

World War II-era Midway-class, the first large-deck carriers of the Forrestal-class, the subsequent Kitty

Hawk-class, and the U.S.S. Kennedy (CV-67)—a ship that was originally designed for nuclear

propulsion.

Page 39 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Both Carrier Types Satisfy

Theater Commanders’

Needs

The Navy has employed a mixed force of conventional and nuclear

carriers since the U.S.S. Enterprise’s commissioning in 1962. During our

discussions, officials of the Joint Chiefs of Staff, two unified commands,

and the Navy could recall no instances since the Enterprise’s

commissioning where the United States failed to achieve its objectives

because a conventionally powered carrier, rather than a nuclear-powered

carrier, was employed. Officials from the Joint Staff and at two unified

commands said that a carrier’s type of propulsion is not a critical factor in

making employment decisions. The unified command officials said that

their concern is the mix and number of aircraft on board the carrier and

that both types generate the same number of aircraft sorties—the critical

purpose of the aircraft carrier. They also said that they had never

specifically requested the scheduling and deployment of a

nuclear-powered, rather than a conventionally powered, aircraft carrier.

Overseas presence promotes regional stability by giving form and

substance to the Nation’s bilateral and multilateral security commitments

and helps prevent the development of power vacuums and instability. It

contributes to deterrence by demonstrating the Nation’s determination to

defend U.S., allied, and friendly interests in critical regions and better

positions the United States to respond rapidly to crises. The presence

posture enhances the effectiveness of coalition operations across the

spectrum of conflict by promoting joint and combined training,

encouraging responsibility sharing on the part of friends and allies, and

facilitating regional integration.

The Pacific Command uses a “Forward Presence Matrix” as part of its

cooperative engagement strategy for the Pacific Region. The matrix

outlines the Command’s goals and states how it intends to achieve them,

including port visits, exercises with foreign navies, Navy-to-Navy talks,

personnel exchanges, and community relations projects. According to

Command officials, the matrix makes no distinction between

conventionally and nuclear-powered carriers—it is not an important

issue—the only issue is having a carrier as a tangible indicator of U.S.

presence.

Unified command and Navy officials could not identify any instances

where a presence mission or operation was adversely affected because a

conventional rather than a nuclear carrier responded. However, many

officials believed that a nuclear-powered carrier could respond more

quickly over long distances and that because a commander is not

Page 40 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

concerned about the ship’s fuel consumption, a nuclear-powered carrier

can “just do it.”

Conventionally Powered

Carriers Are More

Available Due to Their Less

Demanding Maintenance

Requirements

Because their maintenance requirements are not as stringent and complex

as those of nuclear-powered aircraft carriers, conventional aircraft

carriers spend a smaller proportion of their time in maintenance than do

nuclear aircraft carriers and, thus, are more available for deployment and

other fleet operations.

During their service lives, aircraft carriers progress through a maintenance

cycle of alternating operating intervals and depot-level maintenance

periods.2

 In addition to the normal depot maintenance periods,

nuclear-powered carriers must complete a refueling complex overhaul

(RCOH) midway through their service lives.3

 While the conventional carriers

do not have a similar requirement, during the 1980s and early 1990s, six

underwent modernization, five of which had their service lives extended

through the Service Life Extension Program (SLEP).4

 Given the large scope

of its 1993 comprehensive overhaul and its expected service life, we

included the U.S.S. John F. Kennedy (CV-67) among the six carriers.5

We compared the proportion of time the two carrier types spent in

depot-level maintenance from October 1984 through December 1996 and

found that, collectively, the ships of each type spent about 30 percent of

their time undergoing depot-level maintenance. However, during that time,

three conventional carriers underwent a SLEP while, because of their

relatively short times in service, none of the Nimitz-class nuclear carriers

2

Depot-level maintenance is normally performed in naval shipyards, private shipyards, or ship repair

facilities. In addition to completing necessary repairs, modifications and alterations are made that

improve the ships’ capabilities. Because the procedures to maintain nuclear power plants are complex

shipyard workers must be specifically trained to maintain nuclear carriers. Additionally, the materials

used in nuclear carriers must meet exacting standards and the shipyards must have the facilities for

the specialized work.

3

During a nuclear reactor’s operation, the nuclear material in the core splits or is “burned” as part of

the fission process that produces the heat that generates the steam that powers the ship.

Consequently, the core becomes progressively less efficient in generating the required heat and,

therefore, at some point, must be replaced. Generally, a Nimitz-class carrier should be refueled after it

has been in service for about 23 years, during the third complex overhaul (COH) or the fourth Docking

Phased Incremental Availability (DPIA). Practically, the ship’s operating tempo will also affect when it

is refueled. In developing its maintenance schedules the Navy plans for a 32-month refueling period.

4

The objective of a SLEP was to restore and preserve the carrier’s mission capabilities so that it could

remain a first-line, battle group ship for up to 45 years of service. The modernizations averaged 32

months—ranging from 24 to 42 months.

5

The Kennedy now has a longer projected service life than the average of the carriers with a SLEP.

Page 41 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

were refueled.6 When we adjusted the data to reflect the time they would

typically have spent in an overhaul, the conventional carriers would have

collectively spent 24 percent of their time in depot-level

maintenance—about 6 percent less time than did the nuclear carriers with

complex overhauls.

The difference between the two carrier types is generally consistent with

their notional (planned) maintenance cycles. Figure 2.1 shows the notional

(planned) maintenance cycle for conventional carriers extends over 

72 months. The Nimitz-class nuclear carriers have been maintained within

the parameters of an Engineered Operating Cycle (EOC), which, in its

current form, extends over either 102 or 108 months, depending on the

length of the overhaul at the end of the cycle. However, the Navy is

changing the Nimitz-class maintenance cycle to an Incremental

Maintenance Program (IMP), which will reduce the cycle time to 

76.5 months.

6

We did not include the Forrestal’s SLEP in this adjustment since it did not occur entirely within our

time period.

Page 42 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Figure 2.1: Comparison of Nuclear and Conventional Aircraft Carrier Maintenance Cycles

AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

A

A

A

A

A

A

A

A

A

A

COH 2

Operating interval

S 

R 

A

COH

0 18 21 39 42 60

Conventional Carrier

Nuclear Carrier (Incremental Maintenance Program) - Planned

DRSA

18 21 84

Nuclear Carrier (Engineered Operating Cycle) - Current

PIA

S 

R 

A

Operating interval

Operating interval

S 

R 

A

Operating interval Operating interval PIA

Operating interval

72

S 

R 

A

Operating interval DPIA

0

0 18 24 42 48 66 76.5

Notes: Duration 

 (in months) 

 CV CVN (EOC) CVN (IMP) 

COH = Complex Overhaul 12 18/24 na 

DPIA = Docking Planned Incremental Availability na na 10.5 

DSRA = Drydocking Selected Restricted Availability 4 5.5 na 

Operating interval generally includes a deployment 18 18 18 

PIA = Planned Incremental Availability na na 6 

SRA = Selected Restricted Availability 3 3 na

 

Operating interval

39 44.5

Operating interval

62.5

Operating interval

102 108

COH 1

65.5

Source: Navy data.

Because less depot-level maintenance is needed, conventionally powered

carriers would be available for fleet operations about 5 percent more than

nuclear carriers during a single maintenance cycle. As table 2.1 shows, this

is consistent with the adjusted data for the October 1984 through

December 1996 period.

Page 43 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Table 2.1: Notional Carrier

Maintenance Cycles

Single maintenance cyclea Over service lifeb

Percent of time

Type

Available for

operations

In depot

maintenance

Available for

operations

In depot

maintenance

CV 75 25 74 26

CVNc

EOC 69 31 d d

IMP 71 29 69 31

aBased on one cycle, as shown in figure 2.1.

bOur analysis assumed a carrier’s service life is to be 50 years for either conventional or nuclear

power. The depot-level maintenance includes a SLEP for the conventional carriers and a RCOH

for the nuclear carriers.

cAll data is for Nimitz-class only and does not include U.S.S. Enterprise (CVN-65).

dNot calculated.

Source: Our analysis of Navy data.

Conventionally Powered

Carrier Force Could

Provide More Overseas

Presence Than a Like-Sized

Nuclear Force

An all conventionally powered carrier force could either provide a greater

level of overseas presence or require fewer carriers to meet U.S.

peacetime presence requirements than would an all nuclear-powered

force. Providing the carriers needed to meet U.S. forward presence

objectives in peacetime is an important determinant of the Navy’s carrier

force structure. In its 1993 Bottom-Up Review, DOD concluded a force of 10

aircraft carriers could meet the military’s war-fighting requirements, but it

retained 12 carriers (11 active carriers plus 1 deployable training carrier)

to meet the larger peacetime forward presence requirements in the three

principal overseas theaters.7

 (Those theaters include the Western Pacific,

Indian Ocean, Persian Gulf, and Mediterranean Sea.) Currently, these

carriers provide substantial, although not continuous presence.8

 The

Global Naval Force Presence Policy sets priorities and provides

scheduling guidance.

7

DOD’s report on the recently completed Quadrennial Defense Review stated that the Navy would

maintain a force of 12 aircraft carrier battle groups.

8

DOD’s Bottom-Up Review concluded that, with a 12-carrier force, the Navy could provide full-time

coverage in one of the three regions while there would be a minimum of a 2-month gap in coverage

during a year in each of the other two regions. According to the Global Naval Force Presence Policy,

during gaps, a carrier battle group in another theater must be able to reach the “gapped” theater within

a specified time frame.

Page 44 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Global Naval Force Presence

Policy

During peacetime, the Chairman of the Joint Chiefs of Staff, service chiefs,

and chiefs of the five unified geographic commands establish long-range

planning guidance for the location and number of U.S. naval forces

assigned to all regions on a fair-share basis.9

 This scheduling

guidance—Global Naval Force Presence Policy—can be adjusted, as

necessary, to meet unexpected contingencies. This policy results in

planned gaps in various theaters, particularly in the Mediterranean Sea and

the Indian Ocean. The policy represents a balanced distribution of naval

assets while preserving personnel policy objectives. The policy does not

differentiate between conventional and nuclear carriers.

The naval forward presence requirements articulated by the Commanders

in Chief of the European, Central, and Pacific Commands largely

determine how the Navy deploys to meet its global commitments. The

commanders base their requirements on the strategic objectives set for

their theaters by the National Command Authorities10 and the strategic

situation in their theaters. According to a Navy doctrinal publication,

“Overseas presence promotes national influence and access to critical

global areas, builds regional coalitions and collective security, furthers

stability, deters aggression, and provides initial crisis-response capability.”

The commanders believe that sustained, forward deployed, combat ready

forces are vital to achieving these goals and are critical to ensuring timely

crisis response.

In its August 1994 assessment, Naval Forward Presence Report, DOD

analyzed peacetime presence options for naval forces to meet the five

geographic unified commands’ unconstrained requirements for naval

presence. It concluded that the unified commands’ naval force

requirements generally exceeded the levels of available assets. The report

stated that

“the totality of this set of all-encompassing requirements is beyond what could be

reasonably covered by naval forces alone, it is a representation of the broad scope of

presence missions confronting the theater commander” and that “any exercise in

determining alternative force structures must necessarily account for other service

contributions . . . .”

9

There are a total of nine unified combatant commands, five of which are called geographic unified

commands, or theater commands. The five theater commands are the Atlantic, Central, European,

Pacific, and Southern Commands. The commanders in chief of these commands are responsible for all

operations within their designated geographic areas.

10The President and the Secretary of Defense or their duly deputized alternates or successors

constitute the National Command Authority.

Page 45 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

The assessment also stated that the most important overseas presence

requirements can be met through a range of measures, including

“tethers,”11 other service forces, and greater acceptance of periodic

presence in some cases. Changing assumptions, such as operating tempo,

availabilities, and originating ports and destinations, can also alter

conclusions about force requirements. The Navy has periodically assessed

naval force requirements using a model to calculate the total force

necessary to meet the unified commands’ presence requirements for given

assumptions and inputs.

The Navy deploys one carrier battle group and one amphibious ready

group with an embarked, special operations-capable Marine expeditionary

unit for a substantial portion of each year in the three theaters. According

to the presence policy, if neither a carrier battle group nor an amphibious

group is near an unfolding crisis, an equivalent force can be deployed to

the vicinity on short notice from another theater.

An important constraint that bounds the ability to employ carriers in

support of forward presence is Personnel Tempo of Operations

(PERSTEMPO). The Navy initiated the PERSTEMPO Program in 1985 to balance

support of national objectives with reasonable operating conditions for

naval personnel, coupling the professionalism associated with going to sea

with a reasonable home life. The Program is built around the following

goals:

• a maximum deployment length of 6 months,

• a minimum turn around ratio of 2.0:1 between deployments, and

• a minimum of 50 percent time in homeport for a unit over a 5-year cycle.

The importance the Navy places on meeting PERSTEMPO goals is found in

the presence policy that states that in scheduling carriers to meet these

presence requirements, “CNO Perstempo goals remains inviolate.”

Calculating Aircraft Carrier

Overseas Presence

Requirements

Our analysis of force requirements estimates for overseas presence,

derived from the Navy’s Force Presence Model, shows an all conventional

carrier force could either provide a greater level of overseas presence or

require fewer carriers to meet U.S. peacetime presence requirements than

11Tether refers to the practice of maintaining ships at acceptable distances away from a specific area of

presence operations while allowing them to return within a specified number of days. The tethered

presence policy is a Chairman, Joint Chiefs of Staff, and DOD policy that is supported by funding in the

fiscal year 1998 budget and the Future Years Defense Program for fiscal years 1998 through 2003. This

policy results in lower force level requirements than those needed to support continuous presence in

all three major regions.

Page 46 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

would an all nuclear carrier force.12 Several variables enter into the

equation that calculates the carrier force level required to attain a level of

peacetime presence. These variables include the time spent in depot-level

maintenance, the restrictions imposed by the PERSTEMPO policy, the

distance carriers must transit from their U.S. homeports to the overseas

theater, the speed of the transit, and the length of deployment. Depot-level

maintenance time is the single distinguishing variable when calculating

conventionally and nuclear-powered carrier requirements.

As table 2.2 shows, an all conventional carrier fleet generally could

provide about 9 percent more presence coverage—an average of 

32 days—in the European and Central Commands, while providing

full-time coverage in the Western Pacific, than could an all nuclear fleet.

Table 2.2: Presence Coverage

Provided by Deployable Forces of 12-,

11-, and 10-Conventional and Nuclear

Carriers

All conventional force All nuclear force

Annual presence coveragea

Deployable carriersb Days Percent Days Percent

12 369 101 336 92

11 336 92 303 83

10 303 83 274 75

aCoverage provided to both the European and Central Commands over the course of a year.

Includes a carrier homeported in Japan providing full-time presence in the Western Pacific. This

example assumes that a nuclear-powered carrier can be permanently forward deployed in Japan.

(Ch. 4 discusses the implications of this assumption in greater detail.)

bAn additional carrier would be added to the above levels for each one that is in SLEP or RCOH

or that serves as a dedicated training carrier.

Source: Our analysis using the Force Presence Model.

Table 2.3 shows the results of our analysis of the comparative number of

carriers needed to provide various levels of overseas presence. Our

estimates indicate that an all conventional carrier fleet generally needs

about one less carrier to provide presence in the European and Central

Commands and the Western Pacific than would an all nuclear fleet.

12The Navy uses this model to estimate the number of ships needed to provide overseas presence

under specific conditions.

Page 47 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Table 2.3: Number of Deployable Carriers Required to Provide 100, 80, and 60 Percent Presence Coverage

CVN CVN CVN

100 Percenta 80 Percenta 60 Percenta

CV EOCb IMPc CV EOCb IMPc CV EOCb IMPc

Number of carriersd 12 13 13 10 11 11 8 9 9

a Percentage of time a carrier is present in European and Central Commands’ areas of

responsibility. Totals include the one carrier homeported in Japan, providing 100-percent

presence coverage to the Western Pacific, regardless of propulsion type. (See ch. 4 for more

information.)

bNuclear carrier maintained under the EOC strategy.

cNuclear carrier maintained under the IMP strategy.

dRounded up to the next whole carrier. An additional carrier would be added to the above levels

for each one that is in a SLEP or a RCOH or that serves as a dedicated training carrier.

Source: Our analysis using the Force Presence Model.

Neither the number of deployable carriers shown in table 2.2 nor the totals

shown in table 2.3 provide for such needs as a training carrier or take into

account extended maintenance periods such as nuclear carrier refuelings

or conventional carrier service life extensions.13, 14 Meeting those needs

could require an additional one or two carriers.

To minimize any factors other than propulsion type that could influence

the number of carriers needed to provide forward presence, we based our

calculations on the Navy’s standard transit distances and the standard

fixed transit speed of 14 knots.15 The only delay we included in the transits

was a 1-day delay for transiting the Suez Canal where appropriate.16 The

total requirement for the European and Central Commands is based on the

assumption that Atlantic and Pacific Fleet ships would meet the presence

requirements of those two Commands in the same proportion as they are

currently scheduled for in the 1996 to 2000 time frame. We used the Navy’s

13The Navy considers that it needs one carrier to meet the needs of the pilot training pipeline and to fill

occasional gaps in its ability to meet peacetime presence requirements with the other carriers, as

demonstrated by the Kennedy’s recent deployment.

14One conventional carrier was nearly continuously in SLEP while that program was underway. As the

nuclear carrier fleet ages into the 21st Century, a similar situation will exist from a refueling overhaul

standpoint.

15Our calculations assume that the carriers are homeported in Norfolk, Virginia, and San Diego,

California.

16This delay occurred when an Atlantic Fleet carrier entered the Central Command’s area of

responsibility or when a Pacific Fleet carrier provided presence in the Mediterranean Sea.

Page 48 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

notional values, as inputs for operation cycle length (IMP cycle for nuclear

carriers), deployment length, number of deployments per cycle, and

overhaul length.

Several Factors Affect

the Time Needed for

the Carrier Force to

Respond to a Crisis or

Major Theater War

Several factors affect how quickly both types of carriers can respond to a

crisis or mobilize for a major theater war. One factor is the speed the

carrier and its accompanying battle group can maintain during their

voyage to the crisis. Another factor is the degree to which any on-going

depot-level maintenance periods and training periods can be shortened to

accelerate deployment of the carrier.

Nuclear-Powered Carrier’s

Unlimited High Speed

Range Reduces Transit

Times

Because nuclear-powered carriers do not need to slow for underway

replenishment of propulsion fuel, they can transit long distances faster

than can conventional carriers. Even though both types have similar top

speeds, a conventional carrier normally slows to a speed of about 14 knots

during underway replenishment. Our analysis showed that a conventional

carrier, steaming at 28 knots, would arrive about 6 hours later than a

nuclear carrier on a 12,000-nautical mile (nm) voyage (the distance from

San Diego, California, to the Persian Gulf) and would have been refueled

three times. On a 4,800-nautical mile voyage (the distance from Norfolk,

Virginia, to the eastern Mediterranean Sea), the conventional carrier,

steaming at 28 knots, would arrive about 2 hours later than a nuclear

carrier. As table 2.4 shows, in most cases, a nuclear carrier completes a

transit more quickly than does a conventional carrier.

Table 2.4 compares carrier transit times only. Carriers being escorted by

conventionally powered surface combatants would transit more slowly

because of the escorts’ need to replenish more frequently. As a result, the

overall transit speeds of both types of carrier battle groups would be

slower than those shown, if all of the ships in the battle group were to

arrive in the same vicinity at about the same time. A comparison of transit

times of nuclear and conventional carriers that have responded to several

crises in this decade is presented in appendix IV.

Page 49 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Table 2.4: Comparison of Nuclear and

Conventional Carrier Transit Times Transit time (days)

Transit distance (nm)

Transit

speed

(knots) CVN CVa

CV

refuelingsb

4,800 (Norfolk, Va., to the Eastern Mediterranean Sea)

20 10.0 10.0 0

24 8.3 8.4 1

28 7.1 7.2 1

8,600 (Norfolk, Va., to the Persian Gulf via the Suez Canal)c

20 17.9 18.0 1

24 14.9 15.0 1

28 12.8 13.0 2

12,000 (San Diego, Calif., to the Persian Gulf)c

20 25.0 25.1 2

24 20.8 21.0 2

28 17.9 18.1 3

aTransit time is based on the conventional carrier slowing to 14 knots for the duration of each

refueling.

bThe number of refuelings required is based on refueling the conventional carrier when its

propulsion fuel level reaches 30 percent of capacity.

cThis distance is to the central part of the Gulf.

Source: Our analysis of Navy data.

Figure 2.2 shows an oiler providing simultaneous replenishment with a

Spruance-class destroyer and the nuclear-powered carrier

U.S.S. George Washington (CVN-73) while transiting the Atlantic Ocean.

Page 50 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Figure 2.2: An Oiler Providing Simultaneous Replenishment to a Surface Combatant and the Nuclear-Powered Carrier

U.S.S. George Washington (CVN-73)

Source: Navy photo.

A Conventionally Powered

Carrier Can More Easily

Surge From Maintenance

If a carrier is required in an emergency, maintenance periods can be

shortened by varying degrees, depending on the stage of the maintenance

being performed. Navy officials said that it is easier to shorten the

conventional carriers’ maintenance periods than it is for those of the

nuclear carriers and that this is an important factor governing the carriers’

ability to respond to a major crisis. The degree to which a carrier

undergoing depot-level maintenance can be “surged” for deployment by

shortening that maintenance period depends on how much of the period

has been completed when the surge decision is made. For both types of

carriers, the decision must be made early if the period is to be

Page 51 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

substantially shortened. However, Navy officials said, and documents

show, that due to the complexity of its maintenance, a nuclear carrier’s

maintenance period cannot be shortened to the same degree as that of a

conventional carrier. Also, a nuclear carrier’s refueling overhaul cannot

normally be shortened or accelerated since rushing the process would be

neither economical nor prudent from a safety standpoint.

Figure 2.3 illustrates the degree to which a conventional aircraft carrier

can be surged out of an ongoing Selected Restricted Availability (SRA) and

a nuclear aircraft carrier can be surged out of an ongoing Phased

Incremental Availability (PIA) when the decision to do so is made at

various times during the normal duration of those maintenance periods.

The periods can be substantially shortened only if the decision is made

early in the maintenance periods. Maintenance on both carrier types could

be considerably curtailed if less than 15 percent of the scheduled

maintenance time had been completed. However, a nuclear carrier’s

maintenance would normally proceed to its normal completion after about

33 percent of its scheduled maintenance had been completed, while a

conventional carrier could complete up to 40 percent of its maintenance

before proceeding to its normal completion. The figure also shows that a

conventional carrier undergoing an SRA could be available to the fleet

much quicker in an emergency than a nuclear carrier undergoing a PIA.

Page 52 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Figure 2.3: Comparative Ability to Surge From an SRA and a PIA

 Days in maintenance

 

 Conventional SRA Nuclear PIA

 Day of notification to surge

Notional duration

SRA - 3 months

PIA - 6 months

Source: Our analysis of Navy data.

Figure 2.4 illustrates the difference in the ability between a conventional

carrier undergoing a COH and a nuclear carrier undergoing a DPIA to surge

from maintenance. Again, the decision to accelerate the maintenance

period must be made early—before 15 percent is completed—if it is to be

substantially shortened. Additionally, the periods will proceed to normal

completion after about 33 and 40 percent of the nuclear and conventional

carriers’ maintenance periods, respectively, have been completed.

Page 53 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Figure 2.4: Comparative Ability to Surge From a COH and a DPIA

 Days in maintenance

 

 Conventional COH Nuclear DPIA

 Day of notification to surge

Notional duration

COH - 12 months

DPIA - 10.5 months

Source: Our analysis of Navy data.

As the two figures show, while a conventional carrier can be more easily

surged out of an SRA than a nuclear carrier can be surged out of a PIA, the

reverse is true when a carrier is in either a COH or a DPIA. However, as

figure 2.1 shows, SRAs and PIAs are the most common types of depot

maintenance periods. Thus, from an overall depot-level maintenance

standpoint, conventional carriers could more readily mobilize in response

to a major crisis.

Page 54 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Both Types of Carriers

Train to Common

Requirements

The degree to which interdeployment training can be compressed is

unrelated to a carrier’s type of propulsion. Crews of nuclear and

conventional carriers undergo the same interdeployment training except

for training specifically related to the power plants. Two important factors

in compressing interdeployment training are an air wing’s proficiency and

the turnover in the ship’s crew since the last deployment.

The Navy’s Aircraft Carrier Training and Readiness Manual, which does

not differentiate between nuclear and conventional carriers, describes the

interdeployment training cycle. The cycle progresses through three phases

of training—unit, ship and air wing, and battle group. The cycle also

includes other activities such as in-port periods and preparation for

deployment. Despite the common training program, our analysis of

interdeployment cycle data since fiscal year 1984 shows that

interdeployment training periods of conventional carriers have averaged

9.8 months while those of nuclear carriers have averaged 10.6 months.

Conventionally and

Nuclear-Powered

Carriers Were Both

Effective in the

Persian Gulf War

The Navy generally adhered to peacetime carrier deployment and

maintenance schedules that had been established before Iraq invaded

Kuwait and did not take any special actions to ensure a greater nuclear

carrier presence during Operations Desert Shield and Desert Storm. Our

review of data summarizing carrier operations and support during Desert

Storm showed that both types of carrier were effective in their

war-fighting missions. Details about the carriers’ participation in Desert

Storm are contained in appendix V.

Given the presence of U.S. Air Force and allied aircraft, geographic

constraints, and the relatively benign threat environment in the Persian

Gulf and Red Sea carrier operating areas, Desert Storm may not be

representative of the type of conflict in which nuclear carriers could

demonstrate any of its operational advantages over conventional carriers.

However, Desert Storm represents the most extensive and extended

combat use of carrier aviation since the Vietnam conflict—before nuclear

carriers comprised a significant portion of the U.S. carrier fleet.

Additionally, it is the prototype of one of the two major theater wars or

dangers that have been, and continue to be, a key element of U.S. military

policy since the demise of the Soviet Union. Furthermore, Navy doctrine

states the future role of naval forces has shifted from the Cold War-era

independent blue-water, open-ocean naval operations on the flanks of the

Soviet Union to a new emphasis on joint littoral operations in an

expeditionary role against regional challenges. Thus, the nature of Desert

Page 55 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Storm portends the types of conflict in which U.S. forces expect to be

engaged in the foreseeable future.

Pre-Established Carrier

Schedules Were Followed

to Respond to Desert

Shield/Desert Storm

According to DOD’s April 1992 report to the Congress entitled Conduct of

the Persian Gulf War, during the first 2 months after the Iraqi invasion, the

Commander in Chief, Central Command, believed there was a “window of

vulnerability” when it was uncertain whether Coalition forces could defeat

an Iraqi invasion of Saudi Arabia. As shown in figure 2.5, carriers generally

deployed, returned from deployment, and began maintenance as

scheduled during this period.

Page 56 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Page 57 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Figure 2.5: Comparison of Previously Planned Carrier Deployments With Actual Desert Shield/Storm Deployments

Midway

(CV-41)

Forrestal

(CV-59)

Saratoga

(CV-60)

Ranger

(CV-61)

Independence

(CV-62)

Enterprise

(CVN-65)

America

(CV-66)

Kennedy

(CV-67)

Nimitz

(CVN-68)

Eisenhower

(CVN-69)

Vinson

(CVN-70)

Roosevelt

(CVN-71)

October November December January February March April May June July August

FY-1990

DEPLOY

DEPLOY

DEPLOY

DSRA

DSRA

DSRA

DSRA

DEPLOY

DEPLOY

DEPLOY

DEPLOY

DEPLOY

DEPLOY

DSRA

DSRA

SRA

DEPLOY

DEPLOY

DEPLOY

DEPLOY

DEPLOY

SRA

SRA

DEPLOY

Page 58 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

September October November December January February March April May June July August September

FY-1991

Desert Shield/Desert Storm

Actual

Planned

COH

DSRA

Deploy

PSA

RCOH

SRA

Complex Overhaul

Drydocking Selected Restricted Availability

Deployment

Post Shakedown Availability

Refueling Complex Overhaul

Selected Restricted Availability

DEPLOY

DEPLOY

RCOH

DEPLOY

DEPLOY SRA

DEPLOY

SRA

COH

DEPLOY

DEPLOY

DEPLOY

DSRA

DSRA

DEPLOY

DEPLOY

SRA

DEPLOY

DEPLOY

SRA

SRA

DEPLOY SRA

RCOH

DSRA

DEPLOY

SRA

COH

DEPLOY

DEPLOY

DEPLOY

(Figure notes on next page)

Page 59 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Note 1: Carriers’ names highlighted in bold participated in Desert Shield/Desert Storm.

Note 2: This schedule does not include either the Kitty Hawk (CV-63) which was undergoing

Service Life Extension Program (SLEP) during the entire period, or Constellation (CV-64) which

entered SLEP on July 1, 1990.

Note 3: Planned deployment dates reflect the first day of the month when the deployment is to

start, and the last day of the month when the deployment is to end.

Source: Our analysis of Navy data.

The Navy had several opportunities for a greater nuclear carrier presence

in Desert Shield/Desert Storm but followed established deployment and

maintenance schedules, as discussed below.

• The U.S.S. Eisenhower (CVN-69) was well into a scheduled 6-month

deployment when Iraq invaded Kuwait. The Eisenhower entered the Red

Sea on August 8th, remaining for 16 days, until relieved by the

U.S.S. Saratoga (CV-60). Instead of being retained in theater during the

initial period of uncertainty and concern following the invasion, the

Eisenhower immediately departed for Norfolk and began shipyard

maintenance in late October. Two conventionally powered carriers, the

U.S.S. Kennedy (CV-67) and the Saratoga, were deployed for 7-1/2 months

throughout all of Desert Shield/Desert Storm.

• The U.S.S. Carl Vinson (CVN-70) returned from a 6-month deployment on

July 31, 1990, just 2 days before the Iraqi invasion. According to the Navy’s

tactical training manual, “Selected units [ships] returning from deployment

can be retained for a period in a surge readiness status to meet

contingency requirements.” Instead, nonessential materials and supplies

were offloaded during August and September, and the ship began a

complex overhaul on September 29, 1990, lasting until April 1993.

• The U.S.S. America (CV-66) completed shipyard maintenance on 

August 2nd, the day of the Iraqi invasion, and underwent a significantly

compressed 5-month training period, deploying for the war in

December 1990. In contrast, the U.S.S. Nimitz (CVN-68), which had

completed scheduled shipyard maintenance in April 1990, was used to

qualify Reserve and student pilots in carrier landings for most of August

and spent all of September and most of October in port in Bremerton,

Washington. The ship did not deploy until February 25, 1991, 3 days before

the end of the war.

• The U.S.S. Enterprise (CVN-65) arrived in Norfolk in March 1990, after

completing a 6-month around-the-world deployment from Alameda,

California. From the time of its arrival in Norfolk until the start of a RCOH

Page 60 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

in January 1991, the ship spent over 7 months in port, and about 1 month

at sea conducting carrier landing qualifications and independent steaming

activities. The Enterprise became nonoperational on August 15, 1990, less

than 2 weeks after the Iraqi invasion, when the crew began removing

everything not needed for the overhaul, which lasted over 3-1/2 years.

Ultimately, the Navy deployed six carriers to fight in Desert Storm—the

nuclear-powered U.S.S. Theodore Roosevelt (CVN-71) and five

conventionally powered carriers: the World War II vintage U.S.S. Midway

(CV-41), the U.S.S. Saratoga (CV-60), the U.S.S. Ranger (CV-61), the 

U.S.S. America (CV-66), and the U.S.S. John F. Kennedy (CV-67).

Logistics Support of All

Carriers Was Comparable

The Navy operated and supported all six carriers in essentially the same

manner. Each carrier battle group was assigned its own dedicated support

ships, which enabled frequent replenishment of fuel and ordnance.

All carriers were replenished about every 3 to 3-1/2 days, well before fuel

and ordnance reached critical levels. Using Center for Naval

Analyses-generated fuel and ordnance consumption rates, we estimate

that the nuclear-powered U.S.S. Theodore Roosevelt (CVN-71) expended

about 8 percent of its jet fuel and 2 percent of its ordnance per day, while

the conventional carriers expended about 15 percent of their jet fuel and

5 percent of their ordnance per day. It is our observation that the carriers

were resupplied whenever the opportunity arose, in accordance with naval

doctrine, to maintain a high state of readiness.

Air Operations Were

Comparable Among the

Carriers

The distance to targets and the number of aircraft assigned to each carrier

were primarily responsible for the differences in sorties launched by each

carrier. Carriers operating in the Persian Gulf generated more missions

than the Red Sea carriers because they were considerably closer to their

targets. While the Roosevelt launched more sorties than any other carrier,

it, along with the Kennedy, had the most aircraft assigned aboard (78). The

Roosevelt operated in the Persian Gulf, while the Kennedy operated in the

Red Sea. In contrast, two other Persian Gulf carriers, the Midway and the

Ranger, had only 56 and 62 aircraft, respectively. When sorties were

averaged based on the number of aircraft assigned, each of the Persian

Gulf carriers averaged about 53 sorties per aircraft.

None of the carriers operated around-the-clock. Instead, they rotated on

an operating schedule that would enable them to have intervals of off-duty

Page 61 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

time for rest and replenishment. When sorties were analyzed based on

operating days, the Roosevelt averaged 106 sorties per day compared to 89

for the Midway. However, the latter had 22 fewer aircraft aboard. When

the number of assigned aircraft was considered, the Midway led all

carriers with an average of 1.59 sorties per aircraft per operating day,

followed by the Ranger with 1.41 sorties, and the Roosevelt with 1.36

sorties.

Conventionally and

Nuclear-Powered

Carriers Share Many

Similar

Characteristics and

Capabilities but Differ

in Others

Even though the nuclear carriers are newer and larger than the

conventional carriers, the two ship types have several common

characteristics and capabilities. They are similar in that they

• are subject to the same operational guidance;

• carry the same number and types of aircraft in their air wing and can

generate the same number of sorties;

• have top speeds in excess of 30 knots;

• do not differ with respect to their survivability; and

• can produce adequate supplies of fresh water.

However, there are some differences. For example, nuclear carriers

• have larger storage areas for aviation fuel and ordnance and

• are better able to recover landing aircraft due to their superior

acceleration.

The similarities in these key features have allowed the Navy to employ

both types of carriers interchangeably for routine deployments overseas

and employment in contingency operations.

Operational Guidance

Does Not Distinguish

Between Carrier Types

When establishing the required capabilities of aircraft carriers, providing

operational guidance, and preparing plans for employing them, the Joint

Chiefs of Staff, unified commanders, and the Navy do not distinguish

between conventional and nuclear carriers. Both carrier types are

expected to carry out the same tasks, operate under similar conditions,

and are allocated to peacetime presence missions and wartime tasks

irrespective of propulsion type. For example, the document that discusses

carrier missions and required operational capabilities states that the

mission of multipurpose aircraft carriers is to operate offensively in a high

density, multithreat environment. It lists specific tasks and readiness

requirements but does not distinguish between the two carrier types. It

Page 62 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

also lists various readiness conditions under which the carriers must

sustain operations. In meeting these conditions, there is no differentiation

between conventional and nuclear carriers.

Neither is there any differentiation in carrier types in setting requirements

for overseas presence or in allocating assets to achieve presence

objectives. The Joint Chiefs of Staff-approved Global Naval Force

Presence Policy, for example, states the requirements for carrier presence

in terms of the number of carriers allocated to each theater without

specifying the type of carrier.

Similarly, the guidance various headquarters and commands provide on

transit speed, escorts, and fuel and ordnance loads does not differentiate

between carrier types. The guidance we reviewed specifies the same

maximum transit speeds for all carriers and requires that one or more

surface combatants, such as a cruiser or a destroyer, are necessary at all

times to escort and protect the aircraft carrier irrespective of propulsion

type. The guidance also states that all ships will replenish their supplies

after reaching a specified minimum level, which is the same for both

conventional and nuclear carriers.

The operational planning process for wartime does not distinguish

between the two propulsion types. Joint Staff officials said that a carrier’s

type of propulsion is virtually transparent at their level. The Joint Staff

apportions carriers to the unified commanders irrespective of propulsion

type, and regional commanders prepare their operational plans based on

the expectation that they will receive this specified number of carriers if

the plans are executed. With the current mixed fleet of nuclear and

conventional carriers, the specific carriers that will respond if the plans

are executed will depend on the availability and readiness status of the

individual carriers at that time.

Page 63 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Conventionally and

Nuclear-Powered Carriers

Employ a Standard Air

Wing

The Navy’s Policy for Carrier Battle Groups prescribes a standard

composition for the air wings assigned to aircraft carriers. The standard

composition is the same for both conventionally powered and

nuclear-powered aircraft carriers.17 The composition of an air wing is

shown in table 2.5.

Table 2.5: Composition of a Standard

Carrier Air Wing

Aircraft Mission

Number of

aircraft

F-14 Strike/fighter 14

F/A-18 Strike/fighter 36

E-2C Airborne early warning 4

EA-6B Suppression of enemy air defense/electronic

warfare 4

S-3B Antisubmarine warfare/anti-surface ship

warfare/air refueling 8a

ES-3A Electronics intelligence 2

H-60 Antisubmarine warfare/search and rescue/utility 6

Total 74

aThe S-3 is normally used to refuel the wing’s other aircraft during the launch/recovery process.

However, it is not well-suited for refueling the other aircraft on long-range missions. On those

missions, the air wing’s aircraft frequently refuel from Air Force tanker aircraft such as the KC-135

and the KC-10.

We examined the air wing composition of five carrier deployments (three

conventional and two nuclear) and found that both carrier types deployed

with only minor variations in the number of aircraft prescribed in the

policy. Some deployments that included both carrier types carried one to

three more support aircraft than the standard wing.

With the embarked standard air wing, the two types of carriers are

expected to generate the same number of sorties per day. During a crisis, a

carrier may be tasked to fly more than the normal number of sorties or

“surge” operations. The Battle Group Policy states that for augmented

17As noted in chapter 1, the aircraft carrier “maximum density” is the same for both the

U.S.S. John F. Kennedy (CV-67) and Nimitz-class (CVN-68) carriers. An aircraft carrier’s capacity for

carrying aircraft is expressed as aircraft carrier maximum density, a comparative number of F/A-18

equivalents that can be carried aboard a ship. Maximum density takes into account the space on the

hanger and flight decks that the aircraft and helicopters in the air wing need as well as space for other

items such as boats, boat skids, aircraft ground support equipment, forklifts, cranes, and aircraft jacks.

It also allows for the clearances needed between the aircraft and between the aircraft and ship

structures. The Navy’s guidance on aircraft carrier density states that 75-78 percent of maximum

density is the optimum number of aircraft to have aboard and that deck loading in excess of 80 percent

must be coordinated with headquarters. Ship officials said that about 47-50 aircraft on the flight deck

at any one time provides the flexibility to conduct flight operations and move aircraft on the flight

deck and between the flight deck and hangar bay.

Page 64 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

operations (during which an additional 12 strike-fighter aircraft would be

assigned to the carrier), carriers must be able to generate 170 sorties per

day during the initial crises response, 140 sorties per day for 3 to 5 days,

and 90 sorties per day thereafter for sustained operations.

Both types of carriers are subject to the same limitations of crew fatigue

(both aircrew and ship’s company) and equipment maintenance, which

could affect sortie generation. For example, Navy regulations limit how

much flight personnel can fly and mandate rest periods. Officials told us

that deck crews and ordnance personnel would also be stressed during

periods of increased sortie generation. Additionally, both types of carriers

have the same catapult and arresting gear equipment that is subject to a

strict inspection and maintenance schedule. These factors can limit a

carrier’s ability to generate sorties before aviation fuel and ordnance levels

are depleted. As a result, the type of propulsion does not affect the length

of time either carrier type could sustain periods of increased sortie

generation.

Top Speeds Are Similar The two types of carriers have similar top speeds—in excess of 30 knots.

Additionally, neither type has any unique, propulsion-related constraints to

maintaining speeds at that level for extended periods. One difference

when sailing at high speeds is the conventional carrier’s need to slow for

underway refueling. However, as discussed earlier, the impact is minimal.

According to Navy and shipyard officials, the method used to generate

steam does not determine a carrier’s top speed. Factors such as shaft

horsepower, shaft torque limits, propeller design, displacement, and the

naval architectural characteristics of the hull are the determinates of

speed.

Defense and Navy officials also said that other restraints preclude

routinely sailing at high speeds for extended periods. Air crews have to fly

periodically during a transit to remain qualified. Because a carrier would

be unable to conduct flight operations during a 30-knot plus sustained

voyage, the air crews would have to spend several days after arrival at the

destination requalifying before they could be operationally employed.18

Officials at one of the unified commands said that they would prefer to

have a carrier battle group with trained crews arrive in their theater later

than have one with an air wing that needed to requalify arrive earlier.

18At high transit speeds, a carrier may not be able to maneuver as necessary to conduct flight

operations.

Page 65 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

High sea states and inclement weather could also preclude sustained, high

speed voyages. A ship cannot sail fast in heavy weather without punishing

the ship and its crew, regardless of its type of propulsion. Additionally,

while the escorts in the battle group are generally capable of speeds in

excess of 30 knots, they experience greater difficulty than carriers

sustaining high speeds in very rough sea conditions. Also, as a Navy

official pointed out, even at 30 knots, a long transit from the West Coast to

the Central Command’s area of responsibility would still take about 

2 weeks.

Propulsion Type Does Not

Materially Affect Carrier

Survivability

To successfully attack and degrade a U.S. aircraft carrier’s ability to

perform its mission, an enemy must detect the carrier and fix its location

with sufficient accuracy so that one or more weapons can strike it.

Additionally, the lethality of the attacking weapon(s) must be of sufficient

magnitude to severely damage or sink the carrier. Officials of the Naval

Sea Systems Command told us, according to their survivability analyses,

neither type of carrier possesses any inherent, overriding advantage over

the other in its susceptibility to detection or its vulnerability to the damage

inflicted by the weapons.19 They also said that the two types of carriers are

very similar in construction, were built to the same shock standards, and

use similar machinery and equipment. Thus, while there are some

differences, neither has a distinct advantage withstanding or recovering

from the effects of enemy weapons that can be attributed specifically to

the ship’s propulsion type.20

Naval Sea Systems Command officials believe that the nuclear carrier’s

speed and unlimited range give it a distinct operational advantage, but

they also told us that there were no analytical studies addressing these

operational factors to support this belief. They said that these attributes

allow a nuclear-powered carrier to employ tactics that minimize the risk of

detection, thus reducing its overall susceptibility to attack. Additionally, a

conventional carrier must be periodically refueled with propulsion fuel.

Thus, it is susceptible to attack while alongside an oiler because it is

19DOD defines survivability as the capability of a system and crew to avoid or withstand a man-made

hostile environment without suffering an abortive impairment of its ability to accomplish its

designated mission. Susceptibility is the degree to which a weapon system is open to effective attack

due to one or more inherent weakness (a function of operational tactics, countermeasures, probability

of enemy fielding a threat, etc.). Vulnerability is the characteristic of a system that causes it to suffer a

definite degradation as a result of having been subjected to a certain level of effects in an unnatural

hostile environment. Both susceptibility and vulnerability are considered to be subsets of survivability.

20The officials said that, while the more recent nuclear carriers have been built with enhanced

magazine protection, this same level of protection could be incorporated in newly constructed

conventional carriers.

Page 66 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

steaming a steady course at a steady speed. A nuclear carrier is not as

exposed to this susceptibility because it does not have to replenish its

propulsion fuel.

Both types of carriers, however, must periodically replenish their supply

of aviation fuel. Since carriers normally replenish all supplies and fuel

during an underway replenishment, a conventional carrier normally takes

on ship propulsion fuel (DFM) and JP-5 simultaneously. However, the

nuclear carrier still retains an advantage because, with its greater JP-5

capacity, it does not have to refuel as often.21 Additionally, while refueling

does restrict a carrier’s ability to maneuver, the carrier typically moves to

the rear to be less exposed when replenishing fuel, ammunition, and other

supplies. That operation takes place under the defensive umbrella of the

surface combatants of the battle group.

Fresh Water Production

Capabilities Are Similar

An adequate fresh water supply is critical to both types of ships. The steam

that drives the turbines that propel the carriers through the water and

powers the catapults that launch the aircraft is produced from fresh water.

Fresh water is also used to cool equipment, for damage control, and to

wash aircraft and the flight deck.22 Both types of carriers need to retain

fresh water reserves. About half of a nuclear carrier’s fresh water storage

capacity is for use as emergency reactor coolant. Finally, there is the

requirement for “hotel services,” the water the crew uses daily for

preparing meals, drinking, laundry, and personal hygiene. According to

Newport News Shipbuilding officials, both types of carriers have

essentially the same water requirements.

Some of the older conventional carriers produce about 20,000 gallons a

day less than the Nimitz-class, which can produce about 400,000 gallons

per day. However, the U.S.S. Kennedy (CV-67) can produce 50,000 gallons

a day more than the Nimitz-class. Navy officials said that any differences

in fresh water production between conventional and nuclear carriers may

be due to the conventional carriers’ age. Newport News Shipbuilding

officials also said that the differences are due to increases in the number

of aircraft and personnel, not to differences in the propulsion type.

21During Operation Desert Storm, the conventionally powered carriers in the Persian Gulf replenished

aviation fuel about every 2.7 to 3 days. The U.S.S. Roosevelt, the only nuclear-powered carrier in the

Desert Storm air campaign also operating in the Persian Gulf, replenished its aviation fuel about every

3.3 days.

22Some Navy officials told us that conventional carriers use more fresh water to wash their aircraft to

remove the boiler stack gas residue.

Page 67 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Some Navy officials said that in harsh environments such as the Persian

Gulf, conventional carriers frequently resort to water rationing to provide

for essential services. Our review showed that the conventional carriers’

ability to produce fresh water is similar to that of nuclear carriers and that

rationing does not occur that frequently.

Other Navy officials we met with discounted the problem of rationing

aboard conventional carriers. They believe that fresh water shortages are,

in many instances, indicative of management problems or inefficiencies

aboard the ship—leaking boilers or pipes, for example. Some officials

stated that, during their service, they had experienced water rationing as

frequently, if not more frequently, aboard nuclear carriers as they had

aboard conventional carriers. Officials, who had recently served aboard

three conventional carriers in the Persian Gulf said that the ships had

experienced no water rationing.

Nuclear Carriers’ Design

Affords Greater Ordnance

and Aviation Fuel Storage

Capacity

The design of nuclear carriers has provided greater aviation fuel and

ordnance storage capacity than conventional carriers, while their

propulsion system has provided almost unlimited steaming endurance.

Together, these factors could give nuclear carriers a decided operational

advantage and superior war-fighting capability over their conventional

counterparts if no at-sea logistics support were present. In reality,

however, at-sea logistics support is present, and both carrier types and

their surface escorts depend on this support to sustain operations.

The Larger Storage Capacity of

Nuclear Carriers Is Due

Primarily to Ship Design

The larger fuel and ordnance storage capacities of the nuclear carrier are

primarily due to ship design differences that have little to do with the type

of propulsion and the fact that nuclear carriers do not have to store large

amounts of propulsion fuel. A ship’s length, height, and width determine

its internal volume, and as a result, the amount of fuel and ordnance that

can be carried. Due to its larger hull size, the Nimitz-class nuclear aircraft

carrier is about 10 percent larger than the last conventional carrier.23

According to officials at Newport News Shipbuilding, the hull size of the

nuclear carrier was more to provide increased space for ordnance,

aviation fuel, and other supplies.

23The conventional carrier U.S.S. Kennedy (CV-67) has about 75 percent of the storage capacity of the

first three nuclear ships of the Nimitz-class and about 80 percent of that of the

U.S.S. Roosevelt (CVN-71) and the latter ships of the Nimitz-class. These latter ships have less storage

space due to the addition of enhanced overhead and side protection that earlier Nimitz-class carriers

lacked.

Page 68 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

The debate that took place when the Navy was originally considering

building more nuclear aircraft carriers, in addition to the

U.S.S. Enterprise (CVN-65), illustrates this point. For example, Admiral

Rickover, in a 1964 letter to the Secretary of the Navy arguing that CV-67

be nuclear-powered, cited advantages of the Enterprise.

24 The letter states

that the Enterprise hull is 50 feet longer than the CV-67’s hull, which

provides the 60-percent increase in ammunition storage. It also states the

“. . . conventional carrier could also be built in an Enterprise size hull. This

would provide an equivalent increase in the ammunition in the

conventional carrier and would also provide a[n] . . . small increase (about

15%) in aviation fuel.”

Additionally, a 1992 Center for Naval Analyses research memorandum

documenting the feasibility of five alternative aircraft carrier concepts

developed by the Naval Sea Systems Command stated that, other than

endurance range, a carrier built with a Nimitz-type hull but powered by a

Kennedy-type oil-fired steam plant would be essentially equivalent to the

Nimitz-class design. With enough propulsion fuel for a range of 8,000

nautical miles—a distance equal to about one-third the way around the

world—at 20 knots (the equivalent of the current conventional carriers),

the conventional variant would have the same magazine and aviation fuel

(JP-5) capacities as today’s CVN-68 class.

At-Sea Replenishment Offsets

the Conventional Carrier’s

More Limited Storage Capacity

and Endurance

While nuclear carriers can operate for years before requiring propulsion

fuel, they have a finite storage capacity for aviation fuel, ordnance, and

other supplies. In addition, they are escorted by conventionally powered

escorts, such as cruisers and destroyers, that require underway support

due to their smaller fuel capacities and relatively high rate of fuel

consumption. All surface combatant ships are highly dependent on regular

resupply at sea.

The Navy operates a Combat Logistics Force fleet of about 40 ships that

resupply combatant ships at sea with ship and aircraft fuel, ordnance,

food, and other supplies. The Combat Logistics Force enables combatant

ships to operate at sea almost indefinitely, if required, without returning to

port to replenish their stocks. The Combat Logistics Force consists of two

basic types of ships—station ships and shuttle ships. Station ships, such as

the AOE multipurpose fast combat support ship, are an integral element of

carrier battle groups, routinely resupplying the other ships in the group.

24Admiral Rickover prepared the letter in his capacity as the Manager of Navy Reactors at the Atomic

Energy Commission.

Page 69 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

AOEs can simultaneously deliver fuel, ordnance, and other supplies.25 The

station ships provide the initial logistic support in theater until shuttle

ships, such as fleet oilers and ammunition and other supply ships, can

catch up. According to Navy logistics doctrine, station ships support a

typical battle group with fuel for 20-30 days, consumables (other than fuel

and ordnance) for 75 days, and spare parts for 90 days.

The station ships, in turn, are generally replenished by ships that shuttle

from forward naval bases to the battle group. At times, these

single-product shuttle ships also replenish the combatant ships directly.

The Combat Logistics Force represents additional days of sustainability

for the naval force by serving as an extension of the combatant ships’

bunkers, magazines and store rooms. See appendixes III and V for a

more-detailed discussion of the impact of the Combat Logistics Force on

carrier battle group operations.

We compared the endurance of a notional conventional carrier battle

group to a nuclear carrier battle group using Navy fuel and ordnance

consumption rates contained in a 1993 Center for Naval Analyses report.26

The notional battle groups we used consisted of either a conventional or

nuclear carrier, plus two Ticonderoga-class Aegis guided missile cruisers

(CG-47/52s), two Spruance-class destroyers (DD-963s), and two Arleigh

Burke-class Aegis guided missile destroyers (DDG-51s). Each battle group

was supported by one Sacramento-class supply ship (AOE-1). We

estimated that the conventional battle group would have enough (1) fuel to

steam for 29 days, (2) aviation fuel to operate at a tempo comparable to

the final days of Desert Storm for 17 days, and (3) aircraft ordnance for 

30 days. The conventional escorts of the nuclear carrier battle group

would have enough fuel to steam for 34 days, while the nuclear carrier

would have enough (1) aviation fuel to operate at a tempo comparable to

the final days of Desert Storm for 23 days and (2) ordnance to operate for

41 days.

25The multipurpose fast combat supply ship (AOE) is the only noncombatant ship in the battle group

and has the speed to keep up with the other ships. The Navy currently has four Sacramento-class

(AOE-1) ships, and three slightly smaller Supply-class (AOE-6) ships, with one more being built. When

an AOE is not available, a combination of ships can be used to carry out its role, such as oilers (AO)

and ammunition ships (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.

26Center for Naval Analyses Report 205, “Sizing the Combat Logistic Force,” June 1993. The Center

used 1990 and 1991 fleet data contained in the Navy Energy Usage Reporting System (NEURS) for fuel

consumption and aircraft fuel and ordnance consumption based on the final days of Desert Storm.

Page 70 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Nuclear Carriers Have a

Greater Acceleration

Capability

Navy officials said that a nuclear carrier would be better able to recover

landing aircraft if wind and weather conditions suddenly changed or if the

aircraft experienced mechanical difficulties, since it could accelerate more

quickly than a conventional carrier to generate the additional “wind over

deck” needed to safely land an aircraft.27 The officials said that, under

such conditions, a nuclear carrier can accelerate much quicker than a

conventional carrier can because its reactors are always “on line.”

According to Navy data, a nuclear carrier needs about 1-1/2 minutes to

accelerate from 10 to 20 knots and about 3 minutes to accelerate from 10

to 30 knots. On the other hand, a conventional carrier steaming with four

boilers on line producing steam can accelerate from 10 to 20 knots in

about 2-1/2 minutes to 5 minutes. However, it cannot achieve 30 knots with

four boilers—all eight boilers are needed.28 If its eight boilers are on line, it

needs as little as 12-1/2 minutes to accelerate from 10 to 30 knots.

However, according to Navy officials, it can take as long as 1-1/2 to 2 hours

to place boilers that are in a standby condition into full operation.

According to fleet and ship officials, additional factors, such as preparing

the flight deck, may affect the recovery of aircraft. They said that a ship’s

crew is aware of wind conditions during flight operations and, on a

conventional carrier, they will normally have enough boilers on line so

that the carrier can respond in a timely manner to recover landing aircraft.

In addition, aerial tankers are always airborne during aircraft recovery to

ensure that planes do not run low on fuel while waiting to land. Officials

also noted that on a light wind day, both conventional and nuclear carriers

may restrict flight operations rather than risk a situation where not enough

wind over deck could be generated.

Our review of Naval Safety Center data concerning carrier landings and

Class A mishaps indicated that landing accidents of that magnitude are

rare.29 The Center identified 10 carrier-related landing mishaps from 1986

through 1996 (6 aboard conventional carriers and 4 aboard nuclear

carriers). During that time period, there were about 545,000 and 470,000

landings aboard conventional and nuclear carriers, respectively. One

27The “wind over deck” is the sum of a carrier’s speed and natural wind speed. Carrier aircraft have a

minimum required “wind over deck” to safely land aboard a carrier. The “wind over deck” required

varies by aircraft type and condition. A Navy official said that an F-14, for example, needs about 25

knots wind across the deck. There are some instances that would require natural wind in excess of 10

knots, even if the carrier was steaming at its top speed.

28For example, the Kennedy’s top speed, with four boilers on line, is about 26 knots.

29DOD defines a Class A flight mishap as one involving a DOD aircraft with an intent to fly, which

resulted in damages totaling $1 million or more, a destroyed aircraft, a fatality, or a permanent total

disability.

Page 71 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

Center official and fleet officials told us that the flight deck’s layout plays a

greater role in safety than does the ship’s ability to accelerate. Such design

features are not related to the ship’s type of propulsion.

Navy officials could not provide us examples of aircraft being lost because

a conventional carrier could not accelerate fast enough. Additionally, a

Naval Safety Center official told us that the Center had no record of an

aircraft crashing because a carrier could not increase its speed quickly

enough.

Agency Comments

and Our Evaluation

DOD believed the draft report did not adequately address operational

effectiveness features provided by nuclear power. According to DOD, any

analysis of platform effectiveness should include mission, threat, and

capabilities desired over the life of the ship. Further, it stated the draft

report did not adequately address future requirements but relied on

historical data and did not account for platform characteristics unrelated

to propulsion type. That is, many of the differences may be explained by

platform size, age, and onboard systems than by the type of propulsion.

The Congress asked us to examine the cost-effectiveness of conventionally

and nuclear-powered aircraft carrier propulsion. Such an analysis seeks to

find the least costly alternative for achieving a given requirement. In this

context, we used as the requirement DOD’s national military strategy,

which is intended to respond to threats against U.S. interests. That

strategy encompasses overseas peacetime presence, crises response, and

war-fighting capabilities. We used those objectives as the baseline of our

analysis and selected several measures to compare the effectiveness of

conventionally and nuclear-powered carriers. Those measures were

discussed with numerous DOD, Joint Staff, and Navy officials at the outset.

Those measures reflect the relative capabilities of each propulsion type,

including the nuclear-powered carrier’s greater aviation fuel and

munitions capacity and unlimited range. Notwithstanding the enhanced

capabilities of nuclear propulsion, we found that both types of carriers

share many of the same characteristics and capabilities, that they are

employed interchangeably, and that each carrier type possesses certain

advantages. We also found that both types of carriers have demonstrated

that each can meet the requirements of the national military strategy.

We believe our methodology of reviewing a historical perspective covering

a wide range of peacetime presence, crises response, and war-fighting

scenarios that both types of carriers faced during the past 20 years is

Page 72 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 2 

Operational Effectiveness of Conventionally

and Nuclear-Powered Carriers

sound. A full discussion of our methodology can be found in appendix I.

We continue to believe that this assessment will be helpful to the Navy as

it assesses design concepts for a new class of aircraft carriers.

Page 73 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

A nuclear-powered carrier costs about $8.1 billion, or about 58 percent,

more than a conventionally powered carrier to acquire, operate and

support for 50 years, and then to inactivate. The investment cost for a

nuclear-powered carrier is more than $6.4 billion, which we estimate is

more than double that for a conventionally powered carrier. Annually, the

costs to operate and support a nuclear carrier are almost 34 percent higher

than those to operate and support a conventional carrier. In addition, it

will cost the Navy considerably more to inactivate and dispose of a

nuclear carrier (CVN) than a conventional carrier (CV) primarily because

the extensive work necessary to remove spent nuclear fuel from the

reactor plant and remove and dispose of the radiologically contaminated

reactor plant and other system components. (See table 3.1.)

Table 3.1: Life-Cycle Costs for

Conventional and Nuclear Aircraft

Carriers (based on a 50-year service

life)

Fiscal year 1997 dollars in millions

Cost category CV CVN

Investment costa

Ship acquisition cost $2,050 $4,059

Midlife modernization cost 866 2,382

Total investment cost $2,916 $6,441

Average annual investment cost $58 $129

Operating and support cost

Direct operating and support cost $10,436 $11,677

Indirect operating and support cost 688 3,205

Total operating and support cost $11,125 $14,882

Average annual operating and support cost $222 $298

Inactivation/disposal cost

Inactivation/disposal cost $53 $887

Spent nuclear fuel storage cost n/a 13

Total inactivation/disposal cost $53 $899

Average annual inactivation/disposal cost $1 $18

Total life-cycle cost $14,094 $22,222

Average annual life-cycle cost $282 $444

Note: Numbers may not add due to rounding.

aCVN investment cost includes all nuclear fuel cost; CV fuel is included in operations and support

activities.

Source: Our analysis of Navy data.

Page 74 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

What Is a Life-Cycle

Cost Analysis?

One of the most persistent challenges facing DOD is the ability to provide

adequate resources for the acquisition, operations, and support of its

systems and equipment. A life-cycle cost analysis provides managers with

important information for a number of purposes, including improved

long-range planning and budgeting, decisions about replacing aging

equipment, and comparisons of competing programs and systems. A

keystone to sound acquisition decisions is having an estimate of the total

cost of a program or equipment over its full life (i.e., life-cycle cost). For

this reason, a life-cycle cost analysis has been part of the DOD acquisition

system for many years.

The life-cycle cost is the sum total of direct, indirect, recurring, and

nonrecurring costs of a system over its entire life through its disposal. The

important point is that the total cost is not just the initial near term cost.

Typically, a life-cycle cost analyst will focus attention on the annual

operating and support cost because it usually accounts for the largest

share of the total cost. The most common cost components that are

included in a life-cycle cost analysis are shown in figure 3.1.

Figure 3.1: Life-Cycle Cost Components

Operations and Support

 Direct costs 

 --Personnel 

 --Depot maintenance 

 --Fuel 

 Indirect costs 

 --Training 

 --Technical services 

 --Logistics support 

Disposal

 Inactivation 

 Disposal

Operations and Support

 Research and development 

 

 Ship acquisition 

 Military construction

Source: GAO.

We developed a life-cycle cost model to estimate the life-cycle cost for a

nuclear- and a conventionally powered aircraft carrier. We used the

Nimitz-class carrier as our baseline for the nuclear carrier. We selected the

Page 75 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Kennedy-class1 as the baseline for a conventional carrier because it is

comparable in size to the Nimitz-class carrier, it can employ an air wing

that is similar to that on a Nimitz-class carrier, and there was adequate

historical cost data available to build our cost estimates. Detailed

information about the methodologies we used to develop our cost

estimates is discussed in this chapter and appendix I.

Investment Costs Are

Higher for

Nuclear-Powered

Carriers Than for

Conventionally

Powered Carriers

Ship acquisition and midlife modernization costs for a nuclear-powered

carrier are double that estimated for a conventionally powered carrier.

(See table 3.2.)

Table 3.2: Investment Costs for

Conventional and Nuclear Aircraft

Carriers

Fiscal year 1997 dollars in millions

Investment category CV CVN

Ship acquisition $2,050 $4,059

Midlife modernization 866 2,382

Total $2,916 $6,441

Note: Numbers may not add due to rounding.

Source: Our analysis of Navy data.

Acquisition Cost Historically, nuclear carriers have cost more to acquire than conventional

carriers, for several reasons. First, they are larger and heavier than

conventional carriers. Second, the acquisition cost for a nuclear carrier

includes nuclear fuel cost. Finally, the unique industrial base, specialized

nuclear suppliers, and the Naval Nuclear Propulsion Program’s exacting

and stringent environmental, health, and safety standards add to this cost.

For example, an unavoidably high cost overhead structure (engineering,

quality assurance, and production control) and costly production work are

required in the naval nuclear propulsion industry. Shipbuilders must

1

For our analysis, the Kennedy-class includes the CV-63, CV-64, CV-66, and CV-67 as these carriers are

similar in size, displacement, crew size, and maintenance plans, and are often grouped together.

Page 76 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

follow “non-deviation” plans (i.e., no deviation from the approved plans

without government approval).

We obtained acquisition cost data for 27 carriers that were authorized or

built since 1942. Figure 3.2 shows, in constant dollars, the acquisition cost

per ton2

 of conventionally and nuclear-powered carriers. Acquisition costs

for the Nimitz-class nuclear-powered carriers have averaged about

$3.9 billion3

 while the last conventionally powered carrier, the

U.S.S. John F. Kennedy (CV-67), cost $2.1 billion. Regardless of the year

the ship was commissioned, nuclear carriers cost more than conventional

carriers.

Figure 3.2: Acquisition Cost per Ton

for Conventional and Nuclear Carriers

(fiscal year 1997 dollars)

25,000 

30,000 

35,000 

40,000 

45,000 

50,000 

55,000 

60,000 

1940 1950 1960 1970 1980 1990 2000 2010 

Year of commission

CV9

CV10

CV11

CV12

CV14

CV15

CV32

CV41CV43

CV59

CV60

CV61

CV62

CV63

CV64

CV66CV67

CVN65

CVN68

CVN69

CVN70

CVN71

CVN72

CVN73

CVN74

CVN75

CVN76

Dollars per ton

Source: Navy.

2

To allow for increases in both ship weight and cost, the acquisition cost per ton is produced by

dividing the ship’s acquisition cost by its tonnage. We used the ship’s light displacement tonnage that

did not include weight due to the ship’s fuel, water, or ammunition.

3

Includes nuclear fuel cost.

Page 77 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

The acquisition costs of about $2.1 billion for the conventional carrier and

$4.1 billion for the nuclear carrier were based on an estimating

methodology similar to one used by us in an earlier study4

 and by the

Center for Naval Analyses. Historical acquisition cost per ton and the

ship’s displacement tonnage were used to provide rough order of

magnitude estimates for the acquisition costs of a Kennedy-class and a

Nimitz-class ship. (See table 3.3 and app. I for a detailed discussion of the

methodology.)

Table 3.3: Acquisition Cost Estimates

for the Conventionally and

Nuclear-Powered Carrier

Fiscal year 1997 dollars

Cost per tona

Ship

displacementb Estimated cost

CV $35,191 58,268 $2,050,500,000

CVN $51,549 78,741 $4,059,000,000

Note: Numbers may not add due to rounding.

aWe determined the ratio between the cost per ton of CV-67 and CVN-68 (less any nuclear fuel

related cost) and applied this ratio to the average cost per ton for the CVN-68 class to estimate

the cost per ton for a newly acquired conventional carrier. We used the average cost per ton for

the CVN-68 class as the estimated cost per ton for the nuclear carrier.

bDisplacement as measured in light tons.

Source: Our analysis of Navy data.

Midlife Modernization Our analysis shows that it will cost the Navy nearly three times as much to

refuel, overhaul, and modernize a nuclear carrier than it will a

conventional carrier. Both carrier types require some level of midlife

modernization to allow the Navy to use the ships for nearly 50 years. When

a nuclear carrier has been in service for nearly 24 years,5

 it will undergo a

2-1/2 year refueling complex overhaul (RCOH), which includes refueling the

reactor plant, repairing the propulsion plant, restoring the ship’s material

condition, and performing modernization efforts. The nuclear carrier is

expected to operate another 24 years after the RCOH. Similarly, at about 

age 30, a conventional carrier can undergo a 2-1/2 year Service Life

Extension Program (SLEP) which includes restoring the ship’s condition,

installing system upgrades and performing modernization efforts. After a

SLEP, the conventional carrier should operate an additional 15 years or

4

Navy’s Aircraft Carrier Program: Investment Strategy Options (GAO/NSIAD-95-17, Jan. 1995).

5

Given current operating tempo, its nuclear fuel is expected to last about 24 years before it needs to be

replaced. Midlife modernization will take place at the time of refueling.

Page 78 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

more. In both cases, the actual work required for midlife modernization

will vary for each individual ship, depending on the ship’s condition.

Figure 3.3 shows the estimated RCOH cost for the first two Nimitz-class

carriers and the actual cost for SLEPs performed on the Kennedy-class6

conventional carriers. We used the Navy’s best estimate for the RCOH

planned for the CVN-68 as the estimated midlife modernization cost for the

nuclear carrier. For our cost model, we used the average historical cost for

SLEPs performed on the Kennedy-class conventional carriers as the

estimated midlife modernization cost for the conventional carrier.

Figure 3.3: Midlife Modernization Cost

for CVN-68, CVN-69 and

Kennedy-class Conventional Carriers Fiscal year 1997 dollars in billions

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

CVN-68 CVN-69 CV-63 CV-64 CV-67 CV Average

$2.38 $2.38

$1.16

$0.90

$0.54

$0.87

Nimitz-class Kitty Hawk/Kennedy-class

Note: We used estimated cost for nuclear carriers and actual cost for the conventional carriers.

Source: Navy.

6

The CV-66 did not undergo a SLEP.

Page 79 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Nuclear Carriers Are

More Expensive to

Operate and Support

Than Conventional

Carriers

We estimate that it will cost about $14.9 billion to operate and support a

nuclear carrier over its lifetime, which is nearly 34 percent more than the

$11.1 billion we estimate it will cost to operate and support a conventional

carrier. As shown in table 3.4, the cost for a conventionally powered

carrier’s fossil fuel is more than offset by the added cost for a

nuclear-powered carrier’s personnel and depot maintenance. A major cost

difference between the two carrier types is in the indirect cost category for

support activities provided by DOE to the nuclear carriers.

Table 3.4: Life-Cycle Direct and

Indirect Operating and Support Costs

for a Conventionally and

Nuclear-Powered Carrier

Fiscal year 1997 dollars in millions

Cost category CV CVN

Direct operating and support costs

Personnel $4,636 $5,206

Fossil fuel 738 n/a

Depot maintenancea 4,130 5,746

Otherb 933 724

Total direct operating and support costs $10,436 $11,677

Indirect operating and support costs

Training $161 $1,107

Fossil fuel delivery 469 n/a

Nuclear support activities n/a 2,045

Otherc 58 53

Total indirect operating and support costs $688 $3,205

Total operating and support costs $11,125 $14,882

Note: Numbers may not add due to rounding.

aIncludes routine maintenance, repairs, and ship modernization work but not the cost of midlife

modernization.

bIncludes a number of direct unit cost categories such as spare parts, supplies, and intermediate

maintenance.

cIncludes a number of indirect support cost categories such as publications, ammunition

handling, and technical services.

Source: Our analysis of Navy data.

Direct Operation and

Support Costs

Nuclear carriers have higher personnel costs than conventional carriers

primarily because they require additional personnel and their nuclear

personnel receive special pay and bonuses. Depot maintenance costs are

greater for a nuclear carrier because more labor is needed to maintain it

Page 80 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

than is needed for a conventional carrier. In a separate analysis, we found

that the total cost related to nuclear fuel over a nuclear carrier’s lifetime

exceeded the lifetime cost for a conventional carrier’s fossil fuel. We did

not review the reasons for the cost differences for other elements in the

direct cost category because it included costs from a number of

subcategories such as travel, spare parts, and intermediate maintenance.

In most cases, the cost difference for each individual subcategory was not

significant enough to warrant detailed review.

Personnel Costs The personnel cost for a nuclear carrier is estimated at about $5.2 billion

over its lifetime compared to about $4.6 billion for a conventional carrier

(see table 3.5). Our estimated personnel cost is based on historical

personnel cost reported by the Navy’s Visibility and Management of

Operating and Support Cost (VAMOSC) Management Information System

database for the CV-67 class and CVN-68 class carriers as well as an

additional 30.6 percent to account for accrued retirement cost, which is

not captured by that database.

Table 3.5: Personnel Costs for

Conventionally and Nuclear-Powered

Carriers

Fiscal year 1997 dollars in millions

CV CVN

Annual personnel cost $71 $80

Annual accrued retirement 22 24

Total annual $93 $104

Life-cycle cost $4,636 $5,206

Note: Numbers may not add due to rounding.

Source: Our analysis of Navy data.

To determine why the nuclear-powered carrier’s personnel cost is higher,

we analyzed ship manpower documents. On the basis of our work, we are

reasonably certain that most of the cost difference can be attributed to the

different propulsion plants and not some other ship characteristic. Our

work further indicates that the higher cost are the result of three factors:

increased personnel needed to operate the nuclear propulsion plant,

higher grade structure for propulsion plant personnel and bonuses, and

special duty pay for nuclear personnel.

A nuclear carrier has a requirement for nearly 3,400 personnel compared

to about 3,200 for a conventional carrier. A majority of the added

personnel can be traced to the departments that operate the propulsion

Page 81 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

plant.7 Table 3.6 provides a comparative summary of the required

propulsion plant personnel for nuclear and conventional carriers.

Table 3.6: Propulsion Plant Personnel

for Conventional and Nuclear Carriers Personnel CV CVN Difference

Officersa 22 33 11

Enlisted 597 716 119

Total 619 749 130

aIncludes warrant officers.

Source: Navy.

Some of the higher personnel cost for the nuclear carrier can be attributed

to the grade structure of propulsion plant personnel. Nuclear propulsion

plant personnel are a higher grade level than propulsion plant personnel

for a conventional carrier. As shown in figure 3.4, nearly 50 percent of a

nuclear carrier’s enlisted propulsion plant personnel are E-5 and above

whereas 75 percent of a conventional carrier’s propulsion personnel are

E-4 and below.

7

This includes the Engineering Department for the conventionally powered carrier and the

combination of the Engineering and Reactor Departments for the nuclear-powered carrier.

Page 82 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Figure 3.4: Grade Structure for the

Enlisted Propulsion Plant Personnel

for Conventionally and

Nuclear-Powered Carriers

0 

20 

40 

60 

80 

100 

CV CVN

AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA AAAA

AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA

AAAA

AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA AAAA AAAA AAAA

AAAA AAAA AAAA AAAA

AAAA

AAAA AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

AAAA

E-7 and above

E-6

E-5

AAAA AAAA AAAA

AAAA AAAA

A

A

A

A

A

E-4

E-3 and below

Percent

Source: Our analysis of Navy data.

The higher personnel cost for a nuclear carrier can also be attributed to

special pay and bonuses. The Navy uses a variety of incentive pay and

bonuses to attract and retain nuclear personnel (see table 3.7).

Page 83 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Table 3.7: Special Pay and Bonus

Incentives Available for Nuclear

Personnel in Fiscal Year 1997

Enlisted

Enlistment bonus Up to $4,000

Selective reenlistment bonus Up to $30,000a

Special duty assignment pay Up to $275 per monthb

Officers

Accession bonus Up to $8,000

Annual incentive Up to $12,000c

aVariable bonus based on award level. Nominal bonus of $22,000 for a 6-year reenlistment of an

E-5 with 24 months in service.

b An E-5 would receive $150 per month.

cVariable bonus based on active duty commitment length.

Source: Navy.

Fuel Costs We estimate it costs $738 million to provide fossil fuel over a conventional

carrier’s 50-year life. Historical data indicate that a conventional carrier

uses about 500,000 barrels of fossil fuel each year or about 25 million

barrels over its lifetime. Our estimate was developed by multiplying the

estimated barrels of fuel consumed by $29.52, which was the average per

barrel price the Navy paid for fossil fuel from fiscal year 1991-95. Because

of historical interest and speculation as to escalation in fossil fuel prices,

we examined trends in fossil fuel prices and performed a sensitivity

analysis of a conventional carrier’s life-cycle cost if fuel prices were to

double (see app. I).

The fuel cost for a conventional carrier is clearly visible as an operating

and support cost. Conversely, the fuel cost for a nuclear carrier is included

within the investment cost (e.g., acquisition, midlife modernization) and,

therefore, is not clearly identified. We compared the costs of fossil and

nuclear fuel and found that the life-cycle cost for nuclear fuel is greater

than for fossil fuel.

Given current operating tempo, the nuclear fuel cores for the Nimitz-class

carrier are expected to provide enough power for about 24 years. When

the initial fuel cores are depleted, the cores are removed and replacement

fuel cores are installed. Replacement cores will be removed when the ship

is inactivated at the end of its service life. To provide a comparison of fuel

cost, the Navy identified portions of the investment costs that directly

relate to the initial and replacement cores (see table 3.8).

Page 84 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Table 3.8: Nuclear Fuel Cost for a

Nimitz-Class Carrier Fiscal year 1997 dollars in millions

Total cost

Initial core

Uranium $24

Fuel core procurement 308

Fuel installation 12

Fuel removal at midlife 150

Replacement core

Uranium 24

Fuel core procurement 308

Fuel installation 64

Fuel removal at inactivation 85

Life-cycle nuclear fuel cost $975

Note: Numbers may not add due to rounding.

Source: Navy.

The uranium costs shown were based on what it cost to manufacture

during the late 1980s, when it was last manufactured for the Navy. The

uranium used to fuel nuclear reactors is supplied by DOE.

8 DOE ceased

production of defense grade uranium in 1991. There is sufficient uranium

to operate the Navy’s nuclear force for decades. Excess uranium can be

reconfigured and sold to private utility companies for use in commercial

reactor plants. An alternative cost methodology based on the opportunity

cost for the uranium appears in appendix I.

Table 3.9 provides a comparative summary of fuel costs for conventionally

and nuclear-powered carriers.

Table 3.9: Comparison of Life-Cycle

Fuel Cost for Conventionally and

Nuclear-Powered Carriers

Fiscal year 1997 dollars in millions

Fuel type

Total life

cost

Annualized

cost

CVN nuclear fuel $975 $19.5

CV fossil fuel $738 $14.8

Source: Our analysis of Navy data.

8

All domestic enrichment services were handled by DOE until 1993, when these operations were

transferred to the United States Enrichment Corporation.

Page 85 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Depot Maintenance Cost We estimate that the life-cycle cost for depot maintenance for a

conventional carrier is about $4.1 billion compared to about $5.7 billion for

a nuclear carrier. Depot maintenance activities include routine

maintenance, repairs, alterations, and fleet modernization expected to be

performed over the life of the carrier. Midlife modernization activities,

although performed at the depot-level, are not included in our estimated

depot maintenance cost. Rather, they are included as part of investment

costs.

Our cost estimates were not based on the historical depot maintenance

costs captured by the Navy’s VAMOSC database for several reasons. First,

the cost data collected for the nuclear carriers reflected depot

maintenance performed under the Engineered Operating Cycle (EOC)

maintenance plan. Since the Navy is changing its depot maintenance

strategy for nuclear carriers, we did not believe that historical costs would

provide the best estimate for depot maintenance costs. Second, the VAMOSC

data, which captured costs for each fiscal year between 1985 and 1994 and

the 10-year average cost, could lead to over- or underestimating this cost

because of the carriers’ age. For instance, the average depot maintenance

cost for nuclear carriers reflected maintenance and fleet modernization

work performed on nuclear ships that had been in commission, on

average, 10 years or less. Conversely, the average depot maintenance cost

for conventional carriers reflected maintenance and fleet modernization

work performed on carriers that had been in commission for an average 

25 years.

Because of these reasons, we developed depot maintenance cost estimates

based on the Navy’s notional plans for routine maintenance and fleet

modernization for conventionally and nuclear-powered carriers. Estimates

of how often depot maintenance will be needed (interval), how many

months the ship will be in maintenance (duration), and how much

shipyard labor (labor workdays) will be needed for the carrier are guided

by the Chief of Naval Operations. Figure 3.5 shows the notional depot

maintenance cycle for the two carrier types.

Page 86 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Figure 3.5: Notional Depot Maintenance Cycle for Conventionally and Nuclear-Powered Carriers (in months)

Operating interval

S 

R 

A

COH

0 18 21 39 42 60

Conventional Carrier

Nuclear Carrier

PIA

S 

R 

A

Operating interval

Operating interval Operating interval PIA

Operating interval

72

Operating interval DPIA

0 18 24 42 48 66 76.5

Notes: Duration Labor workdays 

 (in months) (in thousands) 

 CV CVN CV CVN

COH = Complex Overhaul 12 na 495 na 

DPIA = Docking Planned Incremental Availability na 10.5 na 340 - 437 

Operating interval generally includes a deployment 18 18 

PIA = Planned Incremental Availability na 6 na 194 - 248 

SRA = Selected Restricted Availability 3 na 77 na

 

Source: Navy.

To estimate depot maintenance cost, we determined the number and types

of depot maintenance periods that would occur over each of the carrier’s

50-year service life. Based on the Navy’s notional plans, we determined

that the nuclear carrier would need about 38 percent more workdays of

labor for anticipated depot-level maintenance and fleet modernization

over its 50-year life than the conventional carrier. Next, we developed an

estimated cost for each type of depot maintenance by multiplying the

number of labor workdays9

 by the composite labor workday rates10 for

9

The Navy provided labor workdays estimated for both maintenance and fleet modernization for each

type of depot maintenance.

10The Navy provided composite public and private shipyard rates that are the average cost for labor

and overhead.

Page 87 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

public and private shipyards. We estimated additional depot costs for

materials, centrally procured equipment, spare parts, and other

miscellaneous items based on our analysis of historical costs for these

items. Table 3.10 summarizes the estimated depot maintenance and fleet

modernization costs for nuclear and conventional carriers.

Table 3.10: Life-Cycle Cost for Depot

Maintenance of a Conventionally and a

Nuclear-Powered Carrier

Fiscal year 1997 dollars in millions

Depot maintenance type

Number in

lifetime

Cost per

type

Life-cycle

cost

CV

SRA 17 $51.3 $872

COH 6 543.0 3,258

Total $4,130

CVN

PIA1 2 $188.3 $377

PIA2 4 214.6 858

PIA3 9 240.8 2,167

DPIA1 1 327.7 328

DPIA2 2 376.8 754

DPIA3 3 421.2 1,263

Total $5,746

Note: Numbers may not add due to rounding.

Source: Our analysis of Navy data.

The actual depot maintenance cost for the nuclear carrier could be more

than our estimate and lower than our estimate for the conventional carrier

because we used composite or average shipyard labor rates. However, our

earlier work11 showed that the actual labor cost for nuclear work was

higher than the labor cost for nonnuclear work. Specifically, we found that

the average cost of $213 per workday for nuclear labor (then-year dollars)

was 25 percent more than the average cost for nonnuclear labor, which

was about $170 per workday. We also found that the applied overhead for

nuclear work was an average of $303 per workday, nearly 60 percent more

than the average overhead of $189 per workday for nonnuclear work.

Maintenance of nuclear ships costs more due to the complex nature of

nuclear work. Shipyards must provide a greater level of service, pay higher

11Nuclear-powered Ships: Accounting for Shipyard Costs and Nuclear Waste Disposal Plans

(GAO/NSIAD-92-256, July 1, 1992).

Page 88 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

costs for specially trained and skilled workers, and maintain specialized

shipyard departments that support nuclear work, such as radiological

controls, nuclear engineering, nuclear planning, and nuclear quality

assurance. In addition, shipyards must make provisions to package and

dispose of nuclear waste that is generated during maintenance. The cost to

process low-level waste generated during maintenance was included in the

depot maintenance cost estimate. Parts and other materials used in

nuclear systems are often of a unique design and require specialized

material.

Indirect Operation and

Support Costs

A significant sustaining base is needed to support both the nuclear and the

conventional carriers. Some examples include logistics services, training,

engineering, and software support. The VAMOSC database captures many of

the costs for these activities and reports a portion of the costs as an

indirect operating and support cost for each ship. However, we identified

several supporting activities and functions that were not captured or were

partially captured by that database, such as training, fossil fuel delivery

and nuclear support activities.

Indirect support costs for a nuclear carrier are significantly more than

those for a conventional carrier. We estimate a nuclear carrier’s indirect

support cost—$3.2 billion—is nearly five times more than the estimated

$0.69 billion for a conventional carrier. This difference is primarily due to

several expensive activities that support the nuclear carrier but are not

needed for the conventional carrier.

Training Cost We estimate that the Navy spends nearly $1 billion more to provide a

steady flow of trained personnel to operate and maintain a nuclear

carrier’s propulsion plant than it does to train personnel to operate and

maintain a conventional carrier’s propulsion plant. The primary reason is

the nuclear carrier has a greater requirement for personnel with

specialized skills than a conventional carrier does.

Our estimate was not based on the historical VAMOSC database because it

does not capture certain training costs that are central to the differences in

the propulsion system, nor does its allocation method provide visibility to

reasons for the cost difference. Therefore, we developed estimates for

initial and specialized training pipeline costs for both carrier types.

To estimate indirect training cost, we used a methodology similar to one

developed by the Navy’s Center for Cost Analysis. The methodology is

Page 89 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

based on determining the annual training requirement needed to provide a

steady flow of skilled personnel that are required in the propulsion plant

departments for each carrier type. The annual training requirement is

determined by the number of billets, crew turnover, and attrition.12 For our

analysis, we determined the annual training requirement initial skills

training for four enlisted ratings (machinist’s mates, electrician’s mates,

electronics technicians and boiler technicians)13 and the annual training

requirement for additional specialized14 training beyond the initial level.

We selected these skill types because they accounted for most of the

difference between the required skills for propulsion plant departments of

the two types of carriers. We also determined the annual training

requirement for specialized officers skills.15 Using information provided by

the Navy, we identified the training courses required for these skills, and

the Chief of Naval Education and Training provided the cost per graduate

for each course. The Chief of Naval Education and Training did not have

cost information for the required 26 weeks for practical training required

for specialized officer and enlisted nuclear skills. Therefore, we estimated

the cost per officer and enlisted student based on Navy budget data.

Table 3.11 compares the indirect training costs.

12Annual training requirement = ((billet /turnover) *attrition).

13As of October 1, 1996, the boiler technicians rating was merged with the machinist’s mates rating.

14We focused on Navy Enlisted Classifications (NECs) that are earned after required training has been

satisfied.

15We focused on additional qualification designation (AQD) for officer billets, which indicated a

requirement for skills and knowledge beyond those implicit by the officer’s billet classification or

submarine specialty.

Page 90 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Table 3.11: Propulsion Plant Pipeline

Training Costs for a Conventionally

and Nuclear-Powered Carrier

Fiscal year 1997 dollars in millions

Initial

training

Special

training

Annual

cost

Life-cycle

cost

Conventional carrier

Enlisted $2.50 $0.71 $3.21 $160.62

Officers a

Total $2.50 $0.71 $3.21 $160.62

Nuclear carrier

Enlisted $4.28 $16.47 $20.75 $1,037.57

Officers a 1.38 1.38 69.10

Total $4.28 $17.85 $22.13 $1,106.67

Note: Numbers may not add due to rounding.

aOur model assumed the training cost for officer’s initial training would be the same for both

carriers.

Source: Our analysis of Navy data.

Fossil Fuel Delivery We estimate that it costs about $469 million to deliver fossil fuel to a

conventional carrier over its lifetime. Our estimate is based on a Navy

methodology16 that allocates a portion of the annual operating and support

cost for these facilities and ships to each barrel of fossil fuel issued. For

example, since Navy depots store fuels other than fossil fuel, the total cost

to operate and maintain these facilities is allocated based on the

proportion of fossil fuel to total fuel issued from each depot. This cost is

then divided by the number of barrels of fossil fuel delivered to produce

the delivery cost per barrel. The same method was used to determine the

cost per barrel for the Navy ships and oilers operated by the Military

Sealift Command (MSC) that deliver fossil fuel. Table 3.12 shows how the

fossil fuel delivery cost of $18.77 per barrel cost was computed. Assuming

a conventional carrier uses about 500,000 barrels of fossil fuel per year, or

25 million barrels over its lifetime, we estimate that it will cost about

$469 million to deliver fuel to the conventionally powered carrier.

16The Navy’s cost methodology, which has been used for many years, includes an annualized

acquisition cost as well as the annual operating and support cost. However, our analysis does not

include an allocation of acquisition cost because we did not have comparable acquisition cost data for

facilities (i.e., DOE laboratories) that support the delivery of nuclear power to the Navy’s fleet.

Page 91 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Table 3.12: Cost to Deliver Fossil Fuel to a Conventionally Powered Carrier

Fiscal year 1997 dollars

Activity/ship type

Annual operating

and support

Portion

allocated to

fuel delivery

Cost allocated for

fuel delivery

Barrels of fuel

issued Cost per barrel

Fleet supply centersa $54,295,049 41.77% $22,679,042 10,526,000 $2.19

Ships

Navy shipsb $294,480,540 45-65% $144,815,575

MSC oilers $273,057,960 100% $273,057,960

Total $567,538,500 $417,873,535 25,198,595 $16.58

Total per barrel delivery cost $18.77

Number of barrels delivered over

a conventional carrier’s lifetime 25,000,000

Total cost to deliver $469,250,000

Note: Numbers may not add due to rounding.

aThe cost per barrel for the fleet supply centers also includes an allocation of $0.04 for the annual

operation of service craft.

bNavy ships included are the AO, AOE, and AOR class ships. The percentage of the ship cost

allocated to the delivery of fossil fuel varied from 45 to 65 percent.

Source: Our analysis of Navy data.

Nuclear Support Activities We estimate that it will cost about $2.04 billion to provide supporting

services to the nuclear carriers. Most of this cost is due to the work

performed by the activities of the Bettis and Knolls Atomic Power

Laboratories, large research and engineering facilities that are solely

dedicated to support the Navy’s nuclear propulsion program.

More than half of the laboratories’ activities are funded through the DOE

appropriation for the Naval Nuclear Propulsion Program. DOE’s budget for

the Program averaged $731 million annually during the 1990s. Program

activities are primarily focused on operational research, development, and

testing17 for the purpose of gaining a better understanding of reactor

behavior fundamentals, evaluating reactor performance, and verifying and

improving the accuracy of models. The laboratories evaluate cladding,

structural, and component materials suitable for use in the operating

nuclear plant and develop and test nuclear fuel. The laboratories also

evaluate equipment and systems that transfer, convert, store, control, and

17The Navy’s research development test and evaluation budget is the source for obtaining funds needed

for specific development, test, and evaluation of new reactors. For example, about $413 million

(then-year dollars) of the budget for fiscal years 1994 to 1998 will fund the laboratories’ development

of the reactor for the New Attack Submarine. These funds are not included in this discussion.

Page 92 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

measure power that the naval reactor has created. The DOE-funded

activities are an integral and necessary component to providing effective

military nuclear propulsion plants to the Navy and to ensure their safe and

reliable operation.

In addition to the support provided by DOE, the Navy also budgets about

$200 million in operation and maintenance funds to provide essential

technical and logistical support for its operational reactors. The types of

activities include routine maintenance and engineering support, inspection

and refurbishment of reactor plant components, safety surveillance at

shipyards, and power plant safety assessments.

Our cost estimate was based on allocating a portion of the annual cost for

these activities to a nuclear carrier. For the DOE-funded activities, we

allocated 5 percent of DOE’s average funding between fiscal year 1991 and

1997 and 2.08 percent of the Navy’s average funding between fiscal year

1994 and 1996 for Navy support activities (see table 3.13).

Table 3.13: Cost to Provide Nuclear

Support Activities to a Nuclear Carrier Fiscal year 1997 dollars in millions

Annual

cost

Percent

allocated

Allocated

annual cost

Life-cycle

cost

Energy-funded $731.0 5.0a $36.6 $1,828

Navy-funded 208.4 2.08b 4.3 217

Total $2,045

Note: Numbers may not add due to rounding.

aDOE activities were allocated on the basis of a nuclear carrier’s demand for power in relationship

to other nuclear ships in the Navy’s fleet. (See app. I for additional information regarding the

relative demand for power nuclear ships.)

bThe Navy-funded activities were allocated based on our analysis of the number of reactor plants

supported by these funds.

Source: Our analysis of DOE and Navy data.

Page 93 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Nuclear Carriers Are

More Costly to

Inactivate and

Dispose of Than

Conventional Carriers

Nuclear carriers are significantly more expensive to inactivate and dispose

of than conventional carriers. The cost to inactivate and dispose of a

nuclear carrier is estimated at $887 million. In addition, it will cost the

Navy an estimated additional $13 million to provide long-term storage18 of

the spent nuclear fuel (SNF) after it is removed from the carrier’s reactor

plant. On the basis of Navy data, we estimate that the cost to inactivate

and dispose of a conventional carrier is $52.6 million.

Carrier Disposal Cost A conventional carrier can be placed in the reserve fleet or retained as a

mobilization19 asset at the end of its service life. When the Navy no longer

needs a conventional carrier, it can transfer the carrier to the Maritime

Administration, sell the carrier to a private firm or foreign government, or

sell the carrier for its scrap value. Our estimate of $52.6 million to

inactivate and dispose of a conventional carrier is based on Navy data and

includes the cost to place the carrier in reduced mobilization status, 

3 years maintenance in a reduced mobilization status, and final disposal

cost less scrap value.

These are not realistic options for a nuclear aircraft carrier because of its

nuclear propulsion systems. A nuclear ship is constructed with a nuclear

power plant inside a section of the ship called the reactor compartment.

The components of the nuclear power plant include a high-strength

reactor vessel, heat exchangers (steam generator), and associated piping,

pumps, and valves. Each reactor plant contains over 100 tons of lead

shielding, part of which is made radioactive by contact with the

radioactive material. At the end of its useful service life, the nuclear carrier

and its radioactive materials must be disposed of.

Although a nuclear carrier has never been disposed of, the basic steps

necessary to dispose of a carrier would be similar to those performed on

nuclear submarines and surface ships. The first step is defueling the

reactor plant. The highly radioactive SNF is removed from the reactor and

sent to the Naval Reactor Facility, located at DOE’s Idaho National

Engineering and Environmental Laboratory for examination and

temporary storage. (Disposition of spent nuclear fuel is discussed later in

this chapter.) Next, piping systems, tanks, and vessels are drained; the

radioactive systems are sealed; and the reactor compartment is sealed and

enclosed in a high integrity steel package. Reactor compartments removed

18Radioactive materials will need safe storage for thousands of years. Our estimate is based on the

radioactive materials storage requirement during the first 100 years after a carrier is commissioned.

19The Navy keeps three carriers in Mobilization B status. When a carrier is taken out of active service,

it is placed in a Mobilization B status; the oldest carrier in Mobilization B status is then disposed of.

Page 94 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

from submarines have been transported by barge from Puget Sound Naval

Shipyard to DOE’s Hanford, Washington, site for final burial.

The Navy provided us with a cost range of between $818.6 million and

$955.5 million to dispose of the first Nimitz-class nuclear-powered carrier.

We used the mid-point cost in our analysis—$887 million. Most of the cost

can be attributed to defueling and removing contaminated nuclear

equipment and material. This estimate did not include the cost associated

with storing the SNF or any cost associated with maintaining oversight of

the reactor plant’s burial site in Hanford.

Spent Nuclear Fuel Storage Spent nuclear fuel (SNF) will be removed from the carrier’s reactor plant

twice during the Nimitz-class carrier’s service life—at its midlife and at

inactivation. Because it is highly radioactive, SNF will need to be safely

stored for thousands of years. Based on estimates recently provided in

DOD’s official comments on our draft report, the Naval Nuclear Propulsion

Program now estimates it will cost about $13 million to safely store the SNF

during the first 100 years after a nuclear-powered carrier is

decommissioned using a new dry storage method (see table 3.14). We

were unable to verify the accuracy and completeness of this estimate but

we do know that the new method promises to be significantly less

expensive than the method formerly used, called the wet storage method.

Table 3.14: Navy Cost Estimate for the

Dry Storage of a Nuclear-Powered

Carrier’s Spent Nuclear Fuel

Fiscal year 1997 dollars in millions

Cost

Initial cores

Hardware per ship set of cores $ 4.8

Operational costs for 75 years of dry storage 1.8

Replacement cores

Hardware per ship set of cores 4.8

Operational costs for 50 years of dry storage 1.7

Total cost $13.0

Note: Numbers may not add due to rounding.

Source: Naval Nuclear Propulsion Program.

The Navy has been temporarily storing its SNF using a wet storage method.

Under this method the nuclear propulsion program stores the fuel in

special pools located at DOE’s Idaho National Engineering and

Page 95 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

Environmental Laboratory. The water in the pools serves the dual purpose

of acting as the barrier for the radiation and dispersing the heat in the SNF.

Using this method, DOE estimated that it would cost about $306 thousand

to receive and place the Nimitz-class cores into the storage pools and an

additional $1.144 million for each year the cores are stored. The storage

cost begins to accumulate after the first cores are removed during the

carrier’s refueling complex overhaul near its 25th year of service. The

storage cost will double when the replacement cores are removed upon

carrier inactivation. Temporary storage costs for naval SNF are likely to

change as the Navy transitions20 to the dry storage method. Table 3.14

reflects the anticipated savings from adopting the new method of spent

nuclear fuel storage.

Ultimately, SNF will have to be permanently disposed of, which will present

an extremely difficult challenge because it will remain dangerous for

thousands of years. The national strategy focuses on disposal of SNF

generated by civilian nuclear power plants and high-level waste in a

geologic repository. DOE is responsible for developing an underground

repository. However, DOE does not expect that the repository will be

operational until about 2010,21 more than 10 years behind that envisioned.

Thus, estimating the cost is complicated because the current repository

plans were not based on disposing defense-grade SNF, such as that from

naval reactor plants, but on the high-level waste that is generated from

reprocessing defense-grade SNF. Thus, we did not estimate final disposal

costs for the carrier’s SNF but instead focused on the current storage

practices.

Agency Comments

and Our Evaluation

DOD partially agreed with our life-cycle analysis. DOD agreed that a

thorough understanding of total life-cycle costs is key to allocating scarce

resources. However, DOD disagreed that comparing the life-cycle costs of

conventionally powered carriers such as the U.S.S. John F. Kennedy with

Nimitz-class nuclear-powered carriers was appropriate because of

differences in the age, size, and capabilities of the carriers.

DOD agreed that the life-cycle cost of nuclear-powered carriers is greater

than conventionally powered carriers but that the premium is not as large

20In October 1995, the state of Idaho, the Navy, and DOE reached an agreement regarding the shipment

and storage of SNF in Idaho. As a result, all SNF located at DOE’s Idaho site will be placed in dry

storage by 2023 and all SNF will be removed from Idaho by 2035.

21Nuclear Waste: Foreign Countries’ Approaches to High-Level Waste Storage and Disposal

(GAO/RCED-94-172, Aug. 4, 1994) and Nuclear Waste: Comprehensive Review of the Disposal Program

Is Needed (GAO/RCED-94-299, Sept. 27, 1994).

Page 96 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

as estimated by us. DOD did not agree with our approach of making

cost-per-ton comparisons between nuclear-powered Nimitz-class carriers

and conventionally powered carriers such as the Kennedy. DOD believed

that it would be more appropriate to compare conventionally and

nuclear-powered carriers with equivalent capabilities.

While the nuclear-powered Nimitz-class carrier and the conventionally

powered Kennedy-class carrier are not identical, we chose to compare

them because the Kennedy was the last and largest conventionally

powered carrier built, it employs an airwing of comparable size to that of

the Nimitz-class carriers, and there was adequate historical data available.

Further, both classes of carriers have performed the same missions for

more than two decades.

Our estimate of the difference in costs between the two types of carriers is

greater than DOD’s estimate primarily because of differing methodologies.

Our acquisition cost estimate was based on a cost-per-ton methodology,

which is an accepted method for estimating these costs and has been used

by the Navy and others. The actual acquisition cost for the Kennedy,

adjusted for inflation, is virtually the same as the acquisition costs used in

our estimate. According to the Navy, it estimated the cost for a “new”

conventionally powered carrier with the capabilities of the newest

Nimitz-class carriers and assumed the conventionally powered carrier

would have a larger displacement than a Nimitz-class carrier. It stated that

the conventionally powered carrier’s cost was based on actual manhours

adjusted to reflect manhour and material growth over 30 years. Navy

officials told us they assumed the conventionally powered carrier would

be constructed at Newport News Shipbuilding and therefore used that

company’s cost factors (for example, labor rates, overhead rates, and

material rates). In addition, because the Navy did not include the cost of

the Kennedy’s SLEP when it calculated the average cost for a CV SLEP, its

estimate was greater than ours.

Our operating and support costs were based on historical data for the

conventionally powered Kennedy-class and the nuclear-powered

Nimitz-class. The DOD estimate is based on estimates of a much larger

conventionally powered carrier as discussed above. We also used different

methodologies for estimating indirect costs (see app. VII, comments 33, 34,

and 35). The Navy chose to estimate personnel cost using its Manpower

Billet Cost Factor Model. This model is intended to estimate the full

manpower cost, including indirect cost, such as training. We did not use

this model because much of the nuclear training costs are not captured by

Page 97 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 3 

Life-Cycle Costs for Nuclear-Powered

Aircraft Carriers Are Greater Than for

Conventionally Powered Carriers

that model. Instead, we used validated historical costs to estimate direct

personnel costs. We separately estimated training pipeline cost using a

methodology developed by the Navy’s Center for Cost Analysis.

The Navy also used a different method for allocating the annual cost of

DOE’s laboratories that support its nuclear fleet. We allocated this cost

based on the demand/consumption of nuclear power. Finally, the Navy’s

new estimate to inactivate and dispose of the CVN is nearly 40 percent less

than the estimate used in our analysis. We did not use the Navy’s newer

estimate because no evidence was provided or found to support the

significant reductions in cost to the original estimate provided to us.

DOE concurred with DOD’s comments addressing estimates of costs

associated with nuclear reactor plant support activities and the storage of

SNF. These comments and our evaluation of them are discussed in

appendix VII.

Page 98 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

Homeporting Navy ships overseas enables the United States to maintain a

high level of presence with fewer ships because the need for a rotation

base to keep forces deployed is smaller. The homeporting of a

conventionally powered carrier at Yokosuka, Japan, provides a level of

presence that would otherwise require six nuclear-powered carriers

homeported in the United States. However, the Navy has been replacing

conventionally powered carriers with nuclear-powered carriers. If this

trend continues, the Navy will eventually have to either

• establish a nuclear-capable maintenance facility and related infrastructure

in Japan to accommodate a nuclear-powered carrier to be homeported

there or

• expand the force to include the additional nuclear-powered carriers that

would be needed to keep the same level of presence, but with ships

deploying from the United States.

Alternatively, the Navy could either construct a new conventionally

powered carrier or accept a lower level of presence.

While it would be several years before the carrier force would have

undergone a complete transition to nuclear propulsion, it will also take

several years to implement any of the strategies that will allow the United

States to maintain a long-term continuous naval carrier presence in the

Pacific region.

Conventionally

Powered Carrier

Force Structure Has

Been Declining

The conventionally powered carrier force has declined from nine carriers

in fiscal year 1991 to the current force of four conventionally powered

carriers.1

 By fiscal year 2008, current Navy plans project there will be one

conventionally powered carrier in the force. Three of the current carriers

are in the active force and one is assigned to the reserve force. One of the

active carriers, the U.S.S. Independence (CV-62), is homeported at

Yokosuka, while two, the U.S.S. Kitty Hawk (CV-63) and the

U.S.S. Constellation (CV-64), are periodically deployed overseas.2

 The

fourth, the U.S.S. John F. Kennedy (CV-67), is considered an operational

reserve carrier. It provides Navy and Marine Corps aviators carrier landing

training and qualification, participates in exercises, and can be deployed to

1

There were nine conventionally powered carriers in the Navy’s force structure from fiscal year 1981

through fiscal year 1991.

2

The U.S.S. Kitty Hawk (CV-63) is scheduled to replace the U.S.S. Independence (CV-62) in fiscal year

1998 as the permanently forwardly-deployed carrier in Yokosuka. The U.S.S. Independence

(CV-62) will be decommissioned.

Page 99 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

fill gaps in overseas presence and help meet crisis response needs. Table

4.1 shows the four carriers now in the force, their last full year of active

service, and their age at the end of their estimated service life.

Table 4.1: Conventionally Powered

Carrier Force—Last Full Year in Active

Service Carrier Year

Ship age

(in years)

U.S.S. Independence (CV-62) 1997 39

U.S.S. Kitty Hawk (CV-63) 2007 47

U.S.S. Constellation (CV-64) 2002 41

U.S.S. John F. Kennedy (CV-67) 2017 43-50

Source: Navy.

As recently as 1994, the U.S.S. Kennedy was scheduled for

decommissioning in fiscal year 2011. However, current long-range Navy

carrier construction plans indicate it will be decommissioned in fiscal 

year 2018, thus adding 7 years to its service life. The remaining service life

of the Kennedy will depend on several factors, including whether it

undergoes extensive major maintenance and modernization, whether it

deploys regularly in support of the active force, or whether it is primarily

used as a training carrier. Unlike many of the other conventionally

powered carriers, the Kennedy did not receive an extensive service life

extension overhaul that would have added 15 years of service life.

Benefits of

Homeporting a

Carrier in Japan

A conventionally powered carrier has been permanently forward deployed

and homeported in Japan since 1973. This carrier provides full-time

presence in the Pacific region without the need for long transit times and

can respond to a crisis in the region in a matter of days. Providing

continuous forward presence is a clear advantage to having an aircraft

carrier and its battle group permanently forward deployed in Japan.

Additionally, the government of Japan makes significant contributions for

the yen-based costs of maintaining U.S. forces in Japan.

The United States and Japan share the cost of basing U.S. forces in Japan

through the Special Measures Agreement. Japan also pays for new

facilities and improvements the United States uses through the Japanese

Facilities Improvement Program. The Program, begun in 1979, is a cost

and burden-sharing program funded and administered by the Japanese

government. It is not required or protected by any treaty or agreements

between the United States and Japan. According to Pacific Command and

Page 100 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

Pacific Fleet officials, the Program could fund construction of the

additional maintenance facilities to permanently homeport a

nuclear-powered carrier in Japan.

Japan contributes more than 70 percent of the total yen-based cost of

stationing U.S. forces there (more than $5 billion in 1995). These

contributions include aircraft carrier maintenance and repairs performed

by the Japanese work force at the U.S. Naval Ship Repair Facility,

Yokosuka. Currently, these facilities have no nuclear repair capability. If

the carrier now homeported in Japan were to return to a U.S. homeport,

the United States would incur all maintenance costs. For nuclear-related

maintenance to be conducted at the U.S. Naval Ship Repair Facility,

Yokosuka, several infrastructure improvements would be required and the

maintenance would be performed by U.S. shipyard workers at U.S.

expense.

Homeporting a

Nuclear-Powered

Carrier in Japan Could

Be Difficult and

Costly

Homeporting a nuclear-powered carrier permanently at Yokosuka would

require a major base reorganization, including nuclear-propulsion

maintenance and support facilities, upgraded utilities, and dredging of the

harbor and approach to accommodate a deeper draft ship. It would also

require additional family housing and support facilities. Although funds

could be obtained through the Japanese Facilities Improvement Program,

the approval process could be lengthy. The Department of State noted that

the entry into Japanese ports of nuclear-powered vessels remains sensitive

in Japan and that there would have to be careful consultations with the

Government of Japan should the U.S. Government wish to homeport a

nuclear-powered carrier in Japan.

Facilities and Port

Improvements

The Navy’s requirements for additional facilities to support a

nuclear-powered carrier homeported at a base that supports

conventionally powered carriers are described in the Navy’s March 1995

report entitled Nimitz-Class Aircraft Carrier Homeporting Cost

Comparison Between NAS (Naval Air Station) North Island and NSY

(Naval Shipyard) Long Beach. Each facility’s requirements will differ

based on what exists at the facility. The facilities and port improvements

being made to accommodate the homeporting of a nuclear-powered

carrier at Naval Air Station, North Island in San Diego, which is already

capable of homeporting conventionally powered carriers, illustrates what

improvements may be needed to expand the maintenance, harbor, and

Page 101 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

infrastructure capabilities of the conventionally powered carrier homeport

in Yokosuka, so that it could accommodate a nuclear-powered carrier.

The facilities planned for the nuclear-powered carrier homeport at the

North Island Naval Air Station are similar to those at Puget Sound Naval

Shipyard. The North Island facilities include an aircraft carrier wharf, a

controlled industrial facility, a ship maintenance facility, and a

maintenance support facility. Other projects at North Island include the

dredging of the harbor channel and a turning basin for the ship. Also,

upgraded power would be required at the ship berthing. The controlled

industrial facility and ship maintenance facility provide depot-level repair

and maintenance of nuclear propulsion plant systems and components.

The total area required for these facilities is the equivalent to 4-1/2 football

fields. The projects at North Island are estimated by the Navy to cost about

$260 million.

According to facilities and logistics officials from the Pacific Command,

Pacific Fleet, and Navy headquarters, in addition to the nuclear

maintenance facilities, other improvements would be needed at Yokosuka

to support a homeported nuclear-powered carrier. For example, a larger,

stronger pier would be needed to accommodate the larger, heavier

nuclear-powered carrier and cranes for pier-side maintenance. Also,

upgraded and expanded electrical power supplies would be needed to run

the reactor coolant pumps while the ship is berthed. Additional

substations would be required for redundancy, and commercial power

would also have to be upgraded. Access to controlled pure water would

also be required.

According to these officials, Nimitz-class aircraft carriers need harbors

and pierside-areas dredged to 50 feet or more, compared to a 45-foot depth

for conventionally powered carriers. The harbor and pier side at Yokosuka

would need to be blasted and dredged, because of the rock bottom, to

accommodate a nuclear-powered carrier. Other improvements could

include modifications to the drydock and associated equipment. However,

the Navy has not conducted a survey to identify specific drydock

improvements needed to support a nuclear-powered carrier at Yokosuka.

Limited Space for

Additional Facilities

The Navy restricts access to nuclear propulsion system components to

U.S. citizens, even though some of the components are the same used in

conventionally powered ships. Restrictions on access to nuclear

propulsion components require separate facilities for nuclear maintenance

Page 102 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

and general ship repair. However, according to Pacific Command officials,

there is little room at Yokosuka for additional maintenance facilities. Thus,

providing additional maintenance facilities would require replacing

existing structures; however, Yokosuka’s existing conventional carrier

maintenance facilities are spread over several buildings throughout the

facility.

According to Department of State officials, there may be space constraints

at Yokosuka that could make the homeporting of nuclear-powered aircraft

carriers difficult. The port of Yokosuka is congested. The city of Yokosuka

is adjacent to the base, which also limits expansion.

Family Housing and Other

Personnel Support

Facilities Already Stressed

Family and bachelor housing shortages are severe at Yokosuka. According

to the Deputy Chief of Staff, Shore Installation Management, U.S. Pacific

Fleet, the base needs over 1,200 additional units. The planned homeporting

of additional and larger surface combatants at Yokosuka will increase the

need for additional housing. For example, homeporting a nuclear-powered

carrier could add about 200 families. The housing situation could be

further exacerbated with the addition of hundreds of U.S. workers to work

on nuclear-related equipment during maintenance periods. The additional

personnel would add to the requirement for commissaries and recreation

and other support facilities.

Lengthy Approval Process According to Pacific Command officials, facility improvements at

Yokosuka could be funded through the Japanese Facilities Improvement

Program. However, obtaining approval is a lengthy process. For example,

a family housing project took 10 years to obtain approval and funding.

Pacific Command officials estimated it could take between 7 to 15 years to

obtain approval for nuclear-powered carrier homeporting facilities

improvements.

Other Overseas Homeports The Navy’s 1994 Naval Forward Presence Report stated that forward

homeporting a nuclear carrier overseas is problematic because of

potential host nation opposition as well as the complexity of

nuclear-related maintenance that might require the ship to return to the

United States for repairs. The report estimated that the establishment of a

nuclear-capable maintenance facility at an overseas location would be

expensive and politically unacceptable.

Page 103 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

Providing Regional

Presence With

Carriers Homeported

on the West Coast

The Pacific Command’s policy requires continuous presence of an aircraft

carrier in the Pacific region. The carrier now permanently forward

deployed in Japan provides this level of presence. Based on our analysis

using the Navy’s Force Presence Model and data, we found the single,

conventionally powered carrier permanently forward deployed in Japan

provides forward presence coverage in the Pacific region that would

require six nuclear-powered carriers homeported at West Coast ports of

the United States. Reducing regional presence requirements to 75 percent

still would require four nuclear-powered carriers in an all nuclear-powered

force.

The requirement for an increased number of nuclear-powered carriers

when based out of the United States is a function of deployment cycle

policies and requirements, including a maximum 6-month deployment, the

need for post deployment shipyard maintenance, predeployment training

and exercises, and the deployment transit distance and speed. (See chs. 1

and 2 for a more complete discussion.) However, the Navy currently does

not have the infrastructure to support additional nuclear-powered carriers

at West Coast homeports.

Agency Comments

and Our Evaluation

DOD partially concurred with the discussion of the difficulties associated

with homeporting and maintaining a nuclear-powered carrier in Japan.

According to DOD, infrastructure changes would not be as significant as we

portray because the non-propulsion plant maintenance would continue to

be supported by Ship Repair Facility, Yokosuka. DOD said that if a

nuclear-powered carrier was homeported in Japan, maintenance plans

could be modified to improve the ability of the ship’s force to maintain the

propulsion plant, augment the ship’s force with “fly-away” teams, and

periodically return the ship to the United States for depot-level

maintenance and replace it with another carrier. DOD agreed that some

changes in base support infrastructure would be required if a

nuclear-powered carrier was homeported in Japan.

Our discussion of the implications of homeporting a nuclear-powered

carrier in Japan was based, in part, on the Navy’s current maintenance

strategy. We note the Navy has not modified that strategy. Further, we

note that significant changes in base support infrastructure would be

required to accommodate a nuclear-powered carrier homeported in Japan.

We note that the Navy made significant and costly infrastructure changes

at North Island Naval Air Station when it decided to homeport a

nuclear-powered carrier there.

Page 104 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Chapter 4 

Implications of an All Nuclear-Powered

Carrier Force on Naval Presence in the

Pacific

The Department of State noted in its only comment on the draft report that

the entry of nuclear-powered vessels into Japanese ports remains sensitive

in Japan and there would have to be careful consultations with the

government of Japan should the U.S. government wish to homeport a

nuclear-powered carrier in Japan.

Page 105 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

The Defense Appropriations Act of 1994 Conference Report directed us to

study the cost-effectiveness of nuclear-powered aircraft carriers. 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 that includes the cost 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. An evaluation of aircraft carrier

and/or industrial base issues was not included in our scope of work.

In performing our analysis, we reviewed policy directives, planning

guidance, strategies, threat assessments, operational histories, statistics,

schedules, studies, and assessments on conventionally and

nuclear-powered carriers. We reviewed and conducted analyses using the

Navy’s Force Presence Model to gain an understanding of the various

factors that affect the required numbers of carriers to achieve various

overseas presence levels, and examined the Navy’s assessments of aircraft

carrier requirements for presence. We also reviewed several Department

of Defense (DOD) and Navy studies, for example, the Naval Forward

Presence Report; several historical cost-effectiveness studies, including

Nuclear Power for Surface Warships, the Sea-Based Air Platform

Cost/Benefit Study, and the Carrier 21 Study; the Report on the Bottom-Up

Review; defense guidance; and other documents relevant to understanding

how assumptions on key operational and cost factors affect plans,

programs, and operations. We consulted with officials of the Joint Staff,

the Office of the Secretary of Defense, the Navy, and the Center for Naval

Analyses to develop and concur with our proposed measures of

effectiveness—peacetime presence, crisis response, and war-fighting. In

addition, we met with agency officials to obtain information on new

technologies and system improvements and future aircraft carrier

requirements, capabilities, and operations.

To understand how the Navy has and is using its carrier force during

peacetime, crises, and war, we discussed past and current naval

operations with U.S. Atlantic Fleet and U.S. Pacific Fleet officials. We also

talked with officials of the Joint Staff and the Atlantic, Pacific, and Central

Commands to obtain their perspectives on how the conventionally and

nuclear-powered carriers support their strategies, plans, and operations.

Page 106 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

We met with battle group commanders and carrier commanders and their

staffs from both conventionally and nuclear-powered carriers and

examined briefings on recent deployments to understand the role, use, and

missions of the conventionally and nuclear-powered carriers. In addition,

we toured both conventionally and nuclear-powered carriers to discuss

ship and air wing operations and capabilities with the ships’ and air wings’

commanders and staff. We also met with the Combat Logistics Fleet

Commander for the Atlantic Fleet, the Combat Logistics Fleet Chief of

Staff for the Pacific Fleet, and the commanding officer of the

U.S.S. Sacramento, a fast combat support ship that directly supports the

battle group.

To gain an understanding of nuclear propulsion cost, technology, and the

nuclear fuel cycle, we talked with officials of the Naval Nuclear Propulsion

Program and visited facilities and laboratories dealing with naval nuclear

propulsion research and development, test, and evaluation; training; fuel

processing; and radioactive waste management.

We talked with experts and academicians from both public and private

organizations to obtain additional perspectives covered in our visits with

U.S. military and defense officials. We performed our fieldwork from

February 1995 to February 1997 at the following locations :

Washington, D.C., area

• Office of the Secretary of Defense

• The Joint Staff

• Office of the Chief of Naval Operations

• Naval Nuclear Propulsion Program

• Bureau of Naval Personnel

• Deputy Chief of Naval Operations (Plans, Policy, and Operations)

• Deputy Chief of Naval Operations (Logistics)

• Air Warfare Division, Deputy Chief of Naval Operations (Resources,

Warfare Requirements, and Assessments)

• Assessment Division, Deputy Chief of Naval Operations (Resources,

Warfare Requirements, and Assessments)

• Naval Sea Systems Command

• Aircraft Carrier Program Management Office

• Cost Estimating and Analysis Division

• Engineering Directorate

• Naval Center for Cost Analysis

• Ships History Branch, Naval Historical Center

Page 107 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

• Defense Intelligence Agency

• Commission on Roles and Missions of the Armed Forces

• Headquarters, Department of Energy

• Headquarters, Department of State

• Institute for Defense Analyses

• Center for Naval Analyses

Norfolk, Virginia, area

• Headquarters, U.S. Atlantic Command

• Headquarters, U.S. Atlantic Fleet

• Naval Air Force, U.S. Atlantic Fleet

• Naval Surface Force, U.S. Atlantic Fleet

• Carrier Group Eight (Theodore Roosevelt Battle Group) (commanding

officer/battle group staff)

• Carrier Group Six (America Battle Group) (commanding officer)

• U.S.S. America (CV-66)

• U.S.S. Theodore Roosevelt (CVN-71)

• Commanding Officer, U.S.S. George Washington (CVN-73)

• Commanding Officer, Logistics Group Two

• Naval Doctrine Command

• Naval Safety Center

• Supervisor of Shipbuilding, Conversion, and Repair (Newport News)

• Newport News Shipbuilding and Dry Dock Company

Tampa Bay, Florida, area

• Headquarters, U.S. Central Command

• Headquarters, Navy Central Command

Seattle, Washington, area

• Commander, Naval Surface Group Pacific Northwest

• Commander, Task Force 33

• Commander, Logistics Group One

• Planning, Engineering, Repairs, and Alterations, Carriers (PERA/CV), Naval

Sea Systems Detachment

• Puget Sound Naval Shipyard

• U.S.S. Abraham Lincoln (CVN-72) (commanding officer and staff)

• U.S.S. Sacramento (AOE-1) (commanding officer and staff)

Page 108 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Alameda, California, area

• Carrier Group Three (Lincoln Battle Group) (commanding officer/battle

group staff)

San Diego, California, area

• Naval Air Force, U.S. Pacific Fleet

• Naval Air Station North Island

• U.S.S. Kitty Hawk (CV-63) (commanding officer, air wing, and department

heads)

• U.S.S. Constellation (CV-64) (executive officer, air wing, and department

heads and chief of staff, Cruiser-Destroyer Group One)

Honolulu, Hawaii, area

• Headquarters, U.S. Pacific Command

• Headquarters, U.S. Pacific Fleet

• Pearl Harbor Naval Shipyard

• Former Commanding Officer, U.S.S. John F. Kennedy (CV-67) (Deputy

Commander, U.S. Pacific Fleet)

Other Locations

• Department of Energy

• Pittsburg Naval Reactors Office, West Mifflin, Pennsylvania

• Bettis Atomic Power Laboratory, West Mifflin, Pennsylvania

• Schenectady Naval Reactors Office, Schenectady, New York

• Knolls Atomic Power Laboratory, Niskayuna, New York

• Kesselring Prototype Reactors Site, West Milton, New York

• Department of Energy-Idaho Operations Office, Idaho Falls, Idaho

• Idaho National Engineering and Environmental Laboratory, Idaho Falls,

Idaho

• Chief of Naval Education and Training, Pensacola, Florida

• TradeTech, Denver, Colorado

• The Uranium Exchange Company, New Fairfield, Connecticut

Page 109 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Aircraft Carrier

Maintenance Analysis

Our comparison of operating and maintenance time encompassed the

aircraft carriers of the Forrestal- (except for U.S.S. Independence),

Kitty Hawk-, Kennedy,- and Nimitz-classes. We excluded the U.S.S.

Midway and the U.S.S. Coral Sea because they were designed and built

during World War II and we believed their age made them

unrepresentative. Additionally, the U.S.S. Midway was homeported in

Japan during part of the period and, thus, was not subject to the normal

maintenance cycle—the same reason we excluded the U.S.S.

Independence. We also excluded the U.S.S. Enterprise because, as the first

nuclear-powered carrier, it was a unique design and, thus, we believed its

data would not be comparable to the ships of the Nimitz-class.

Our comparisons also only include that time the carriers spent undergoing

regular depot-level maintenance in a shipyard. Our data also represents

the collective experience of the two ship types, not per ship-type averages.

That is, we determined the total number of days all conventionally and

nuclear-powered carriers were (1) in service during the time period, (2) in

a shipyard undergoing depot-level maintenance, and (3) available for

operating with the fleet. Our results are based on those totals by

propulsion type, not on individual ship, ship class, or ship type averages.

We revised our methodology for adjusting service life extension program

(SLEP) time as follows. Three conventionally powered carriers, CV-60,

CV-66, and CV-67, underwent complete comprehensive overhauls during

the period. The mean length of those overhauls was 436 days. Four

ships—CV-59, CV-63, CV-64, and CV-67—underwent SLEP during the time

period. Using the original start date of each ship’s SLEP, we substituted a

436-day overhaul for each SLEP. We further modified each ship’s remaining

schedule by eliminating the Post Shakedown Availability/Selected

Restricted Availability scheduled after the SLEP and scheduled the next SRA

18 months after the SLEP’s completion. We then moved each ship’s

remaining schedule forward to compensate for the reduced length of the

availability. We also added an additional SRA and sufficient operating time

to CV-59’s schedule to allow it to reach its actual deactivation date of

September 15, 1992.

As in our earlier calculations, when calculating depot-level maintenance

time for the period October 1, 1997, through December 31, 2007, we

excluded the Enterprise and the conventionally powered carriers

homeported in Japan. We also excluded the Ronald Reagan since it will be

under construction for about half the period.

Page 110 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Conventionally and

Nuclear-Powered

Aircraft Carrier Cost

Model

We developed a life-cycle cost model to estimate the life-cycle costs for

both a nuclear and a conventionally powered aircraft carrier. For the

nuclear ship, we used data available for the Nimitz-class carrier (CVN-68

class). We selected the Kennedy-class1

 as the comparable conventional

carrier for several reasons. The U.S.S. John F. Kennedy (CV-67) was the

last and largest conventional carrier built, it employs an airwing of

comparable size to that of the Nimitz-class, and there were adequate

historical data available.

Our life-cycle cost model includes the cost of nuclear fuel as part of the

investment activity: acquisition, refueling complex overhaul (RCOH), and

inactivation. Operating and support costs were generally based on

historical data for the two ship classes. Our model also included an

assignment of indirect cost when the cost was determined to be

significant. In each case, we did not determine the incremental or marginal

cost of a support activity, but we did allocate a portion of the total annual

cost as an indirect cost for the carrier. All costs are expressed in constant

fiscal year 1997 dollars, except as noted. As discussed later in this

appendix, we also performed a present value analysis to identify any

potential differences when the time value of money was considered.

Ship Acquisition Costs We developed our own estimate for the cost to acquire a conventional

carrier based on the historical acquisition cost per ton to build aircraft

carriers. Our methodology was similar to one used in our earlier study2

and by the Center for Naval Analyses in some preliminary work it did for

the Navy as it began to assess its future carrier needs. We determined a

ratio between the acquisition cost per ton of the U.S.S. John F. Kennedy

(CV-67) and the U.S.S. Nimitz (CVN-68). This ratio was then applied to the

Navy’s projected acquisition cost per ton of the CVN-76 to provide an

estimated acquisition cost per ton for a new conventionally powered

carrier. The resulting cost per ton was then multiplied by the Kennedy’s

displacement to provide a rough order of magnitude acquisition cost.

While there are many unknowns involved in estimating the current cost to

acquire a ship (conventionally powered carrier) that has not been built for

over 25 years, our estimate was based on the best available information we

could obtain. For the nuclear carrier, we multiplied the displacement

weight for the CVN-76, the most recently authorized Nimitz-class carrier,

by the average acquisition cost per ton for the Nimitz-class carriers built.

1

For our analysis, the Kennedy-class includes the CV-63, CV-64, CV-66 carriers that are similar in size,

displacement, and crew size and other ship characteristics.

2

Navy’s Aircraft Carrier Program: Investment Strategy Options (GAO/NSIAD-95-17, Jan. 1995).

Page 111 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Although research, development, test, and evaluation and military

construction costs are normally included in developing an acquisition cost

estimate, in contrast to the more limited procurement estimate, our

estimate did not include several nuclear-related military construction costs

because they were not included in the Selected Acquisition Reports for the

Nimitz-class. For example, the costs of nuclear maintenance facilities for

the nuclear-powered carriers to be homeported in San Diego, California,

have not been captured.

Operating and Support

Costs

Ship operating and support costs were generally based on the 10-year

average cost for the CV-67 and CVN-68 class carriers during fiscal years

1985 through 1994, which were obtained from the Navy’s Visibility and

Management of Operating and Support Cost (VAMOSC) Management

Information System database. Several operating and support cost

categories were modified or added because data were not fully captured

by the system. The categories we adjusted included personnel, depot

maintenance, fossil fuel, indirect training, fossil fuel delivery, and nuclear

support structure.

We adjusted the VAMOSC baseline data for direct personnel, depot

maintenance, and fuel costs. We modified the personnel cost to capture

the cost of accrued retirement by adding an additional 30.6 percent, the

percentage for DOD’s contribution to its retirement fund for fiscal 

year 1997. We estimated depot maintenance costs using the Navy’s

notional maintenance plans for each carrier over its lifetime. We did not

use the historical depot maintenance costs captured by the Navy’s VAMOSC

database for several reasons. First, the cost data collected for the nuclear

carriers reflected maintenance performed under the Engineered Operating

Cycle (EOC) strategy. Since the Navy is changing its maintenance strategy

for nuclear carriers and does not intend to use the EOC strategy in the

future, we were not confident that the historical costs would provide the

best basis for estimating life-cycle depot maintenance costs. We were also

concerned that the VAMOSC data, which captured costs for fiscal

years 1985-94, would lead to over- or underestimating costs because of the

carrier types’ average age. Thus, our estimated maintenance cost was

determined by the number, type, and cost for the notional maintenance

expected over each of the carrier’s life time. Using the Navy’s notional

plans, we determined the number and type of depot maintenance periods

that would occur over each of the carrier type’s 50-year service life. To

estimate the cost for each type of depot maintenance period, we multiplied

Page 112 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

the number of labor workdays3 expected for each type of maintenance

times the Navy’s composite labor workday rates4

 for public and private

shipyards. We estimated additional maintenance costs for materials,

centrally procured equipment, spare parts, and other miscellaneous items

based on our analysis of historical costs for these items.

Nuclear fuel cost was provided by the Naval Sea Systems Command’s

Nuclear Propulsion Directorate. For this analysis, the direct nuclear fuel

cost included the procurement of the initial and replacement fuel cores,

the uranium used in the cores, and the cost to install and remove the initial

and replacement cores. Our estimated cost for fossil fuel was based on the

historical average number of barrels a conventionally powered carrier

used and the average price per barrel between fiscal year 1991 and 1995

paid by the Navy.

We also modified the VAMOSC baseline data to account for several indirect

operating and support cost categories that are affected because of the

difference in propulsion systems. These categories include indirect cost

for training, fossil fuel delivery system, and nuclear power supporting

activities. Indirect cost estimates are generally based on an allocation of

the annual cost.

The indirect training cost was based on the personnel training requirement

needed to support the specific enlisted ratings in the engineering

department of the U.S.S. John F. Kennedy (CV-67) and the engineering and

reactor departments of the U.S.S. Nimitz (CVN-68). We selected four

ratings (machinist’s mates, electrician’s mates, electronics technicians and

boiler technicians) because the requirements for rating skills were most

affected by the type of propulsion plant. The training requirement for

these skills was determined by the number of required billets, annual crew

turnover, and attrition rates. Using Navy provided crew turnover and

attrition rates and the cost per student for initial and specialized skills

training, we developed the cost per student for specialized training

received at the moored ships and prototypes. Our estimated cost per

student was based on 26 weeks of pay and allowance per student plus an

allocated portion of the total cost for instructors and base support

personnel and operation and maintenance funding for these facilities.

Training cost was estimated by multiplying the annual training

3

The Navy provided labor workdays estimated for both depot maintenance and fleet modernization for

each type of depot maintenance period.

4

The Navy provided composite public and private shipyard rates that reflected the average labor and

overhead cost of work performed.

Page 113 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

requirement by the applicable initial and specialized training cost per

student.

Indirect fossil fuel delivery cost was based on the Navy’s method of

determining the fully burdened cost for each barrel of fuel delivered to its

fleet of ships. Our methodology allocated a portion of the Navy’s total

annual cost to operate and maintain its fleet supply activities, service craft,

and oilers5

 to each barrel of fuel delivered. For example, the Navy spends

about $54 million to operate and support its fleet industrial centers. Since

these centers store other fuels, we allocated about 42 percent, or

$22.7 million, based on the proportion of fossil fuel to total fuel issued at

each center. The $22.7 million was then divided by 10.5 million, the total

number of barrels of fossil fuel issued by the Fleet Industrial Supply

Centers, to produce an estimated delivery cost per barrel. A similar

method was used to allocate the annual cost to operate and support Navy

and Military Sealift Command oilers to each barrel of fuel delivered.

The estimated indirect nuclear support activities cost was based on an

allocation of the total costs for these activities. The Navy-funded activities

support operational reactor plants and the funding level are directly

influenced by the number of plants being supported. There are eight

operating reactor plants types, one of which is for the Nimitz-class.

Therefore, we allocated 12.5 percent of the Navy’s average funding for the

Nimitz-class carriers. Since there are six Nimitz-class carriers in the force,

one-sixth (or 2.08 percent) of the funding was used to estimate the cost of

this support activity for one nuclear-powered carrier. The estimated

indirect cost for DOE-funded nuclear supporting activities was allocated

based on the nuclear carriers’ demand for power (or energy needs). Based

on our analysis of uranium consumed and shaft horsepower needs of the

nuclear fleet, we determined that the nuclear carrier accounted for about

five percent of the total uranium consumed and shaft horsepower required

by naval nuclear ships. We allocated 5 percent of the average funding

between fiscal year 1991 and 1997 for Energy’s Naval Nuclear Propulsion

Program as our estimated annual cost of these support activities.

Inactivation and Disposal

Costs

Our estimate to inactivate and dispose of a conventional carrier was based

on the Navy’s estimated cost to place the carrier in reduced mobilization

status, 3 years maintenance in mobilization status, and final disposal cost

5

This includes the AO, AOE, and AOR class ships as well as oilers operated by the Military Sealift

Command.

Page 114 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

less scrap value. We estimated scrap value based on scrap sales of naval

ships during fiscal years 1993 and 1995.

Our estimate to inactivate and dispose of a nuclear carrier was based on

data provided by the Navy and the DOE. The Navy provided a cost range to

inactivate and dispose of a carrier. We used the mid-point estimate. In its

official comments on our draft report, DOD provided a new estimate for the

receipt and annual storage of the spent nuclear fuel (SNF) from a

Nimitz-class carrier. This estimate, which is based on the dry storage

method, is much less expensive than the estimate for the wet storage

method. We were unable to verify the accuracy or the completeness of the

new estimate but have included it since the dry storage method is

generally much less expensive than the wet method. The dry storage

estimate does not include costs for the new dry storage facility or fuel

characterization. SNF storage costs include the storage costs of spent

nuclear fuel for the first 100 years after a carrier is commissioned. We

assumed the initial SNF cores would be removed at a carrier’s midlife and

sent to storage in its 25th year of service and remain there for 75 years and

the replacement cores would be removed at the end of the carrier’s service

life and sent to storage near its 50th year of service and remain there for 

50 years.

Effects of Pricing

Alternatives for Fossil and

Nuclear Fuel

The cost of fuel has been of interest throughout the debate over nuclear

versus conventional propulsion. Because of the interest, we analyzed the

affect of different pricing strategies on the cost of the conventional and

nuclear carriers.

Fossil Fuel Crude oil prices were fairly stable during the 1950s and 1960s. Prices rose

significantly as a result of the oil crises of 1973 and 1979-80, although they

did not remain at these peak levels. Figure I.1 shows the price of crude oil

and the price the Navy paid for fossil fuel, as well as the major events

affecting U.S. crude oil prices. Table I.1 shows the affect on life-cycle costs

for a carrier if the cost of fossil fuel were double the current price.

Page 115 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Figure I.1: Crude Oil, Fossil Fuel, and Major Events Affecting U.S. Crude Oil Prices

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 

Fiscal Year

Navy Price History Crude Domestic First Purchase Price 

1971:

Begin

Crude Oil

Price

Controls

1973-1974:

First Oil Crisis:

Arab Oil

Embargo

1979-1980:

Second Oil Crisis:

Iranian Revolution

1981:

End of Crude Oil

Price Controls

1990-1991:

Persian Gulf War

Price per barrel in

fiscal year 1997

dollars

Sources: Navy and Energy Information Administration.

The cost estimate of $48 million for the uranium used in a Nimitz-class

carrier over its lifetime was provided to us by the Navy. The estimate

reflected the cost incurred by DOE when the uranium for the Navy was

produced6

 sometime during the late 1980s.

6

Natural uranium undergoes a number of processes before it is a usable fuel: mining and milling,

conversion, and enrichment. All domestic enrichment services were handled by the DOE until 1993,

when these operations were transferred to the United States Enrichment Corporation.

Page 116 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Table I.1: Comparison of Life-Cycle

Costs for the Conventionally Powered

Carrier and the Nuclear-Powered

Carrier Using Different Fuel Price

Scenarios

Fiscal year 1997 dollars in millions

CV cost if

fuel = $29.52

CV cost if

fuel = $59.04

CVN cost if

fuel = $48 mil

CVN alternative

fuel = $101 mil

Investment $2,916 $2,916 $6,441 $6,494

Direct operating and

support

Personnel 4,636 4,636 5,206 5,206

Fuel 738 1,476 0 0

Maintenance 4,130 4,130 5,746 5,746

Other 933 933 724 724

Indirect operating and

support 688 688 4,290 4,290

Disposal 53 53 1,031 1,031

Life-cycle cost $14,094 $14,831 $23,438 $23,492

Annual cost $282 $297 $469 $470

Note: Numbers may not add due to rounding.

Source: Our analysis.

DOE stopped all production at its plants capable of producing

defense-grade uranium7

 in 1991 because there was a surplus of

defense-grade uranium as a result of nuclear weapon agreements.

Defense-grade uranium could be blended down to enrichment levels

suitable for use in commercial reactors and sold to the private sector. The

value of the uranium if sold and not used in a naval reactor is considered

an opportunity cost. The uranium from one Nimitz-class carrier has an

estimated market value, or opportunity cost, which is more than twice that

of our estimate.

Methodology for Allocating

Indirect Costs for

Nuclear-Powered Ships

Using a Demand for Power

Factor

Naval propulsion plants use a pressurized water reactor design that has

two systems: a primary system and a secondary system (see fig. I.2). The

primary system circulates water in a closed loop consisting of the reactor

vessel, piping, pumps, and steam generators. The heat produced in the

reactor is transferred to the water. The heated water passes through the

steam generators where it gives up its energy. The primary water is then

pumped back to the reactor to be reheated.

7

The difference between fuel used in commercial reactors and for naval reactors is the degree to which

the uranium has been enriched. Commercial grade uranium is enriched to about 3-4 percent U-235

where defense grade uranium is enriched to above 90 percent. Uranium used to fuel a naval reactor is

a defense grade uranium.

Page 117 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Figure I.2: Diagram of a Pressurized Water Reactor

Source: Navy.

Nuclear and conventional propulsion systems of similar capacity have

many common features. Both require heat to produce steam to drive

turbines and generators. In the case of a nuclear system, the fissioning of

uranium within the reactor replaces the burning of fossil fuel to generate

the necessary heat. Inside a reactor, the uranium fuel is assembled in such

a way that a controlled chain reaction can be achieved. Control rods can

be inserted into or withdrawn from the reactor to create the necessary

power level needed. Over time, the uranium is burned and eventually it

must be replaced.

Size, weight, and operations influence a ship’s demand for power as well

as the propulsion plant and fuel that supply the power. For example, a

Nimitz-class carrier, weighing nearly 100,000 tons, requires far more shaft

Page 118 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

horsepower from its propulsion plant than is necessary for a submarine or

surface ship that weighs about 8,000 tons. Similarly, there is a difference in

the amount of nuclear fuel that is burned. We calculated the weighted

average for each nuclear ship’s demand for power, as measured by: shaft

horsepower requirements and uranium burn. We found that one

Nimitz-class carrier’s demand for power is about equal to that of eight

SSN-688s. As shown in figure I.3, in 1995, nuclear carriers accounted for

about 35 percent of the nuclear power used by the fleet and are expected

to account for nearly 60 percent by 2015 based on current force plans.

Page 119 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Figure I.3: Demand for Power by

Nuclear-Powered Ships Based on

Force Structures in Fiscal Years 1995,

2000, and 2015

Fiscal year 1995

Fiscal year 2000

Fiscal year 2015

SSBNs (15.00%)

CVN-65 (5.00%)

CVN-68 (30.00%)

CGNs (6.00%)

SSNs (44.00%)

SSBNs (17.00%)

CVN-65 (5.00%)

CVN-68 (41.00%)

CGNs (3.00%)

SSNs (34.00%)

SSBNs (13.00%)

CVN-68s (60.00%)

SSNs (27.00%)

Sources: Our analysis and Navy and Jane’s Directory of Fighting Ships 1994-1995.

Page 120 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Present Value Analysis Because investment alternatives normally incur different costs over

different time streams it is our policy to compare the alternatives on an

equal economic basis using a technique called present value analysis. This

analysis, which converts costs occurring at different times to a common

unit of measurement, is predicated on the theory that costs incurred in the

future are worth less than costs incurred today. Present value analysis also

provides a means to transform a stream of costs to a single number so it

can be compared to another. Caution should be exercised when

discounted dollars are used in performing analyses because discounted

numbers are artificially small and can invite misinterpretation both in

absolute amount and in comparing alternatives, especially in programs

with very long time periods. A concern expressed about long duration

projects is that normal discount rates virtually eliminate from

consideration any values occurring beyond 25 years into the future. The

expenditure streams in our analysis are about 60 years for the

conventionally powered carrier and more than 100 years for the

nuclear-powered carrier.

Our present value analysis used budgetary profiles we developed for each

carrier type. The budget profiles included the major investment costs

(initial acquisition, midlife modernization, inactivation, and disposal) as

well as annual operating and support costs. The timing of the budget

profiles was based on the assumption that both carriers would be

commissioned in the same year and have 50-year service lives. The

notional procurement profile of a nuclear carrier includes advance

procurement of long lead nuclear components 2 years prior to full funding

of the ship, and the construction period is estimated to be 1 year longer

than for a conventional carrier. As a result, the nuclear-powered carrier’s

investment profile begins 3 years earlier than for a conventional carrier.

We also used annualized operating and support costs. The budget profiles

were then converted into projected outlay profiles using the Navy’s official

outlay rates.

While a performing present value analysis is a generally accepted practice,

there is no generally agreed upon discount rate. However, there is

agreement that a range of rates should be used to determine the

investment’s relative sensitivity to changes in rates. Our policy, in general,

is to use the interest rate on marketable Treasury debt with maturity

comparable to that of the program being evaluated (adjusted to reflect

expected inflation when using constant dollars). We calculated the present

value of the two carrier types using three different discount rates—our

rate, the Office of Management and Budget rate, and the Congressional

Page 121 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix I 

Ojectives, Scope, and Methodology

Budget Office rate. As table I.2 shows, regardless of the discount rate used,

the nuclear carrier’s present value was at least 57 percent more than the

present value of the conventional carrier.

Table I.2: Discounted and Undiscounted Life-Cycle Costs for a Conventionally and Nuclear-Powered Carrier

Dollars in billions

Carrier option Outlays

Our rate

(4.43a percent)

OMB rate

(3.6 percent)

CBO rate

(2.8 percent)

Conventional $14.1 $4.9 $5.8 $6.9

Nuclear 22.2 8.2 9.5 11.1

Difference $8.1 $3.3 $3.7 $4.2

Percent difference 57% 67% 64% 61%

Note 1: Numbers may not add due to rounding.

Note 2: CBO is Congressional Budget Office. OMB is Office of Management and Budget.

aRate of return for 30-year treasury bonds minus the most recent estimate of inflation by Wharton

Econometric Forecasting Associates.

Source: Our analysis.

Page 122 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix II 

Conventionally Versus Nuclear-Powered

Cost-Effectiveness Debate—the Rationale

for Nuclear Power

For fiscal year 1963, DOD requested a conventionally powered carrier. A

prolonged debate to change the propulsion of the carrier, later named the

U.S.S. John F. Kennedy (CV-67), to nuclear power, followed. The campaign

to support nuclear power was led by the Chairman of the Joint Committee

on Atomic Energy, the Secretary of the Navy, and the Chief of Naval

Operations. Opposition to nuclear-powered carriers eventually weakened,

and all aircraft carriers since have been nuclear-powered, beginning with

the U.S.S. Nimitz (CVN-68) in the fiscal year 1967 program. Including the

U.S.S. Enterprise (CVN-65), a total of eight nuclear-powered carriers have

been built and two more are under construction.1

In an April 1963 memorandum to the Secretary of Defense, the Secretary

of the Navy concluded that “nuclear propulsion permits a significant

increase in the beneficial military results for a given expenditure and that

we must exploit and take maximum advantage of it. . .and that all new

major warships should be nuclear-powered.” The Navy staff’s

comparative analyses showed that the costs of a nuclear task force would

be about the same as a nonnuclear task force with its fuel replenishment

and escort ships. The advantages of nuclear propulsion in surface

warships were summarized in an enclosure to the memorandum:

“As a nation with an overseas strategy, nuclear propulsion in our combatant surface ships

adds an essential new dimension to their versatility and effectiveness in war or deterrence

of war. Increased 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.”

The specific advantages accruing to nuclear propulsion, according to the

Navy study, were

• virtually unlimited high-speed endurance;

• optimized prepositioning of (nuclear) fuel (the reactor cores reduce the

quantity and total costs of conventional fuel which must be prepositioned

and protected);

• reduced vulnerability to atomic fallout because nuclear-powered ships do

not depend on a constant intake of large amounts of air for boilers;

• increased shipboard electric power for new radars, sonars, and missile

systems that would otherwise reduce the operating range of

conventionally powered ships; and

• elimination of stack gases.

1

The Harry S. Truman was commissioned in July 1998.

Page 123 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix II 

Conventionally Versus Nuclear-Powered

Cost-Effectiveness Debate—the Rationale

for Nuclear Power

In the language of the memorandum the meaning of “virtually unlimited

high-speed endurance” was elaborated

• Nuclear-powered forces can be sent at high sustained speeds to distant

areas of operations and arrive ready to go into action—they do not have to

refuel before engaging the enemy.

• Independent operations of nuclear ships can be conducted in those areas

where simultaneous deployment of the usual replenishment forces may

require an unacceptable amount of time or risk. The necessary logistic

support ships can start later and/or transit more slowly and still arrive in

time for replenishment of aviation fuel and ammunition.

• The requirement of oil-fueled forces to take into account the risk of loss of

fuel oil facilities either at the source or en route to the refueling

rendezvous is eliminated.

• Absence from the restrictions imposed by fueling requirements

significantly reduces the vulnerability of the force by eliminating the

requirement to slow down to conserve fuel and to refuel. These required

refuelings reduce the tempo of any offensive and defensive effort.

• The nuclear-powered forces require less overall replenishment and have

much greater freedom in the selection of location and time for the

replenishment rendezvous. Nuclear propulsion also reduces the size of the

logistic support force and its escorts.

• Nuclear-powered ships can be kept in an area of minimum vulnerability

with respect to the enemy submarine threat until required to move into

another action area. They can proceed at a high sustained speed using

such indirect routes and circumvention to increase enemy submarine

tasks as may be indicated by the overall tactical situation.

The Defense Secretary’s February 1963 memorandum also asked the Navy

to comment on specific topics. The Navy’s comments regarding worldwide

deployments, underway replenishments, future shipbuilding programs,

and force structure reductions are summarized below.

• Worldwide Deployments

• Nuclear propulsion will greatly facilitate fast initial reaction, rapid

transit, readiness for combat on arrival, and strike group operations

with reduced task group vulnerability and logistic support requirements.

• The improved efficiency of coverage of potential trouble areas

associated with nuclear-powered task groups can be capitalized on by

either (1) better coverage, using the same numbers of groups as with

conventional forces or (2) comparable coverage, using fewer groups.

Page 124 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix II 

Conventionally Versus Nuclear-Powered

Cost-Effectiveness Debate—the Rationale

for Nuclear Power

• The potential exists to compensate for the increased costs of individual

nuclear-powered ships by obtaining more effectiveness or by reducing

force levels as these nuclear ships are delivered to the fleet.

• As they are delivered to the fleet, the nuclear-powered ships will be

phased into those assignments where transit distances may be long and

logistic support somewhat limited. For example, a nuclear-powered task

group could perform a high speed transit of about 5,000 miles from 10 to

50 percent faster than a conventionally powered group, depending upon

the level of fuel support received by the conventionally powered carrier

groups.

• The costs of achieving this capability with a nuclear force would be

approximately the same as with a nonnuclear force with its fuel

replenishment and escort ships.

• Replenishment

• Underway replenishment is the most reliable and effective method of

restocking naval forces with large quantities of consumables in combat

or in peacetime deployment to remote areas. This kind of support,

however, cannot be relied on in armed conflict situations or in areas

characterized by inadequate or nonexistent bases.

• By eliminating the requirement for ship propulsion fuel, requirements

for replenishment of aviation fuel and ordnance will become the

controlling factors, varying directly with the level of aircraft activity

and/or combat operations.

• Design and operational evaluations will continue to be directed toward

minimizing dependence on nuclear-powered ships upon logistic support

by increasing consumables storage, such as was done in the case of the

CVAN-67 design for aviation fuel and ordnance.

• Future shipbuilding programs

• The application of nuclear propulsion is toward a goal of all nuclear

attack carrier groups. The greatest advantages of nuclear power accrue

when the entire task group is so equipped. However, the advantages to

screen ships themselves are significant. An alternative would be to use a

nuclear-powered carrier with a conventional screen; however, in this

case, the operational and logistics gains will be less if the

nuclear-powered carrier must function as a part-time oiler and is still

tied to the logistics of her escorts.

• Force reductions

• Nuclear-powered task groups will provide improved efficiency of

coverage of potential trouble areas. The benefits thereby can be

capitalized on, in part, by a reduction in carrier task groups or by

increased effectiveness.

Page 125 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix II 

Conventionally Versus Nuclear-Powered

Cost-Effectiveness Debate—the Rationale

for Nuclear Power

• A general transition to nuclear propulsion should permit some reduction

in total numbers of ships required to meet the Navy’s widespread,

worldwide commitments.

Page 126 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

The Navy operates a Combat Logistics Force fleet of about 40 ships that

resupply combatant ships at sea with several commodities. The ships carry

significant amounts of these commodities, for example, ship and aviation

fuel (DFM and JP-5, respectively), ordnance, and other supplies such as ship

and aircraft fuel, ordnance, and food (see table III.1), which enables

combatant ships to operate at sea almost indefinitely, if required, without

ever needing to go into ports to replenish their stocks. The force

represents additional days of sustainability for the naval force by serving

as an extension of the combatant ships’ bunkers, magazine and store

rooms.

Table III.1: Capacities of Selected

Combat Logistics Force Ships Class Speed Fuel a Ordnance Other supplies

(knots) (barrels) (tons) (tons)

(T-) AE-26 20 b 6,000 b

(T-) AFS-1 20 18,000 c 7,000

AO-177 20 150,000 625 420

(T-) AO-187 20 180,000 c d

AOE-1 30 177,000 2,500 750

AOE-6 30 156,000 1,800 650

Note: T-class Combat Logistics Force ships are operated by the Navy’s Military Sealift Command.

These ships use civilian, instead of military, crews but may have a small military detachment

aboard. A majority of the non-AOE class ships are now operated by the Military Sealift Command.

aReflects a combined total for DFM and JP-5.

bPrimary mission is ordnance replenishment. Limited quantities of fuel and other supplies are also

available.

cNo ordnance carried.

dPrimary mission is fuel replenishment. Limited capacity to carry other supplies.

Source: Navy.

A comparison of these capacities with average daily ship and aviation fuel

consumption and ordnance expenditures reflected in table III.2 shows that

daily fuel consumption represents only a small percentage of the fuel

capacity carried by Combat Logistics Force ships.

Page 127 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

Table III.2: Average Daily Fuel and

Ordnance Consumption Rates for

Selected Ship Classes

Ship class DFM (barrels) JP-5 (barrels) Ordnance (tons)

Carrier (CV) 2,700 6,500 70-150

Carrier (CVN) a 6,500 70-150

CG-47 725 a a

DD-963 710 a a

DDG-51 710 a a

aNo quantities shown.

Source: Center for Naval Analyses report.1

The conventionally powered cruisers and destroyers that are a part of

carrier battle groups are dependent on underway replenishment support

by Combat Logistics Force. Compared to a conventional carrier, they have

smaller fuel storage capacities and relatively high fuel consumption rates

at higher speeds. Table III.3 compares the approximate range and

endurance of these ships as well as of a conventional carrier.

1

Center for Naval Analyses Report 205, Sizing the Combat Logistic Force, June 1993. The Center for

Naval Analyses used 1990 and 1991 fleet data contained in the Navy Energy Usage Reporting System

for fuel consumption, and aircraft fuel and ordnance consumption based on the final days of Operation

Desert Storm.

Page 128 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

Table III.3: Battle Group Ship Range

and Endurance at Various Speeds Speed (knots) 18 22 26 30

CV

Range (nm) 8,600 7,800 6,300 5,100

Daily fuel consumption

(percentage of total load) 5 7 10 14

Days endurance 20 15 10 7

CG-47

Range (nm) 6,200 5,600 4,600 3,300

Daily fuel consumption

(percentage of total load) 7 9 14 22

Days endurance 14 11 7 5

DD-963

Range (nm) 5,100 4,800 4,200 3,300

Daily fuel consumption

(percentage of total load) 8 11 15 22

Days endurance 12 9 7 5

DDG-51

Range (nm) 4,300 4,000 3,500 2,800

Daily fuel consumption

(percentage of total load) 10 13 18 26

Days endurance 10 8 6 4

Note: Ranges rounded to nearest 100 nautical miles. Fuel consumption and days endurance

rounded to nearest whole number.

Source: Our analysis of Navy data.

As shown in table III.4, the other ships in the battle group require a higher

proportion of the fuel during a transit than a conventional carrier requires.

Thus, from a practical standpoint, the time penalty for refueling is more

associated with the rest of the battle group than with the conventional

carrier.

Page 129 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

Table III.4: Battle Group Propulsion

Fuel Underway Replenishment

Requirements During Transits Percent of total

Underway replenishment requirement

Transit distance (nm)

Transit

speed

Total

(barrels) CV

Remainder of

battle groupa

4,800—Norfolk, Va. to the Eastern Mediterranean Sea

20 52,370 0 100

24 91,953 43 57

28 106,286 37 63

8,600—Norfolk, Va. to the Persian Gulf via the Suez Canal

20 158,656 25 75

24 158,656 25 75

28 236,276 34 66

12,000—San Diego, Calif. to the Persian Gulf

20 229,564 34 66

24 250,609 32 68

28 342,562 35 65

a For this analysis, we used a battle group configuration that included one conventional carrier,

two CG-47 class cruisers, two DD-963 class destroyers, and two DDG-51 class guided missile

destroyers. This configuration is consistent with the Navy’s standard carrier battle group. We also

assumed that underway replenishments would occur when the ships’ fuel levels reached

30 percent of capacity and that the ships were then refueled to full capacity.

Source: Our analysis of Navy data.

The presence of a station ship2 in the battle group extends the group’s

range considerably compared to those shown in table III.3. Table III.5

reflects an AOE’s impact on the ability of notional conventional (CVBG) and

nuclear (CVNBG) carrier battle groups to reach their destinations. As in the

previous analyses, these battle groups consist of a carrier (CV or CVN),

two CG-47s, two DD-963s, two DDG-51s, and one AOE-1. As the table

shows, the capabilities of the two groups are about equal.

2

Station ships travel with carrier battle groups. They carry petroleum products, ordnance, and other

supplies and are generally replenished by shuttle ships operating from land-based facilities worldwide.

Page 130 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

Table III.5: Battle Group Comparative

Transit Capabilities With AOE Support

(illustrative transit destinations and

distances)

Transit distance (nm)

Transit

speed CVa CVNa

4,800—Norfolk, Va., to the Eastern Mediterranean Sea

20 Yes Yes

24 Yes Yes

28 Yes Yes

8,600—Norfolk, Va., to the Persian Gulf via the Suez Canal

20 Yes Yes

24 No Yes

28 No No

12,000—San Diego, Calif., to the Persian Gulf

20 No No

24 No No

28 No No

aA “Yes” indicates that the battle group completes the transit with at least 30 percent propulsion

fuel remaining, collectively.

Source: Our analysis of Navy data.

To further illustrate the information presented in table III.5, we compared

the estimated remaining fuel levels of these battle groups when they

reached their destinations, assuming that the battle groups sailed at a

constant speed of 20 knots. We assumed that the ships would be fully

refueled whenever they reached 30 percent of their fuel capacities. We

also assumed that the diesel fuel marine (DFM) carried by AOEs

represented 60 percent of their total fuel capacity.

For example, the distance from Norfolk to the Eastern Mediterranean Sea

is approximately 4,800 nautical miles and could be covered in about 

10 days. The conventional carrier would have arrived with over 40 percent

of fuel remaining and would not have needed refueling during the transit.

The carrier could steam another 2 days at a constant 20 knots before

reaching 30 percent of capacity (consuming about 6 percent of capacity

per day). Once refueled the carrier could operate about another 12 days at

a constant 20 knots before again reaching 30 percent. The destroyer and

cruiser escorts of both battle groups would arrive with between 53 and

90 percent of their fuel remaining, depending on the type of ship and

interval since their last at-sea refueling. The AOE supporting each battle

group would have about 54,000 barrels of ship fuel remaining when

Page 131 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

arriving on station, if no other Combat Logistics Force support was

provided.

In another instance, the distance from Norfolk to the Persian Gulf is

approximately 8,600 nautical miles and could be covered in about 18 days.

The conventional carrier would arrive in the Persian Gulf with about

65 percent of its fuel remaining, having been refueled once during the

voyage. We estimated that the carrier could operate another 6 days at

20 knots before reaching 30 percent fuel remaining. The AOE would have

enough capacity to refuel the DDG-51s twice but could only refuel the

CG-47s and DD-963s once, if not refueled itself during the voyage. The

DDG-51s would arrive in the Persian Gulf with about 80 percent fuel

remaining, while the CG-47s would have about 30 percent fuel remaining.

The DD-963s would not be able to reach the Persian Gulf. In this case,

either the AOE would need to be refueled or another oiler, such as a

T-AO-187, would need to accompany the battle group. In the latter case, all

combatant ships would reach the Persian Gulf with over 60 percent fuel on

board, and the oilers would have over 55,000 barrels remaining. On this

voyage, the carrier would require about 25 percent of the replenishment

fuel, while the escorts would require the remainder. The CG-47s and the

DDG-51s in a nuclear carrier battle group would arrive at nearly full fuel

capacity, having been replenished two and three times, respectively, while

the DD-963s would have about 65 percent fuel remaining. The AOE,

however, would essentially be empty. We believe that on a voyage of this

distance, either the AOE would be replenished itself at some point or

another oiler would accompany the battle group.

Additionally, the distance from San Diego to the Persian Gulf is about

12,000 nautical miles and could be covered in about 25 days at a sustained

speed of 20 knots. With the refueling support of one AOE and no

additional Combat Logistics Force ships, only the carrier in the

conventional battle group would reach the Persian Gulf. It would have

about 25 percent fuel remaining. None of the conventional battle group’s

escorts would reach the Gulf. In the case of the nuclear carrier battle

group, the CG-47s would arrive with about 40 percent fuel remaining, and

the DDG-51s would have about 15 percent fuel remaining. The DD-963s

would run out of fuel before reaching the Gulf. A voyage of this distance

would most likely require additional Combat Logistics Force support. If

another oiler, such as a T-AO-187, accompanies each battle group, all the

ships of both battle groups reach the Persian Gulf with no additional

support provided. The conventional carrier would arrive with about

70 percent fuel remaining, while the escorts would have from about 40 to

Page 132 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix III 

Underway Replenishment Extends the

Endurance of Carriers

85 percent fuel remaining. The conventional battle group’s two oilers,

however, would essentially be out of fuel, unless they were resupplied

during the voyage. In this example, the conventional carrier required about

35 percent of the battle group’s overall underway refueling requirement. In

the nuclear carrier battle group, the escorts would also have between 40

and 85 percent of their fuel remaining, and the two oilers would have

about 65,000 barrels remaining.

Page 133 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix IV 

Comparison of the Transit Time of

Conventionally and Nuclear-Powered

Carriers Responding to Selected Crises

We examined the movement of carriers that responded to several crisis

situations in this decade to compare the transit times of conventionally

and nuclear-powered ships. The crises examined were Iraq’s invasion of

Kuwait in 1990, U.N. operations in Somalia in 1993, threatening Iraqi troop

movements toward Kuwait in 1994, and operations in Bosnia in 1995. We

also examined the transits of carriers responding to the crisis caused by

Iraq’s violation of the “no-fly-zone” over southern Iraq in October 1997

and actions taken in January 1998 to maintain a two-carrier presence in

the Persian Gulf.

Operations Desert

Shield/Desert Storm

When Iraq invaded Kuwait on August 2, 1990, the nuclear-powered 

U.S.S. Eisenhower (CVN-69) was in port in Naples, Italy. The carrier

traveled about 1,040 nautical miles to Port Said, Egypt, from August 3-7, a

period of 5 days, and later moved through the Suez Canal into the Red Sea.

The conventional powered U.S.S. Independence (CV-62) was operating

near Diego Garcia in the Indian Ocean when the invasion began. The

Independence arrived in the Gulf of Oman on August 5th, covering about

2,200 nautical miles in 3 to 4 days. Considering the time taken to travel this

distance, the Independence would probably have made the voyage at a

sustained speed of between 24 and 32 knots.

Table IV.1 summarizes the transit times of six other carriers that sailed

from ports in the United States and Japan and participated in Desert

Storm.

Page 134 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix IV 

Comparison of the Transit Time of

Conventionally and Nuclear-Powered

Carriers Responding to Selected Crises

Table IV.1: Steaming Time/Speed of Carriers Deploying to Desert Shield/Storm

Depart Arrive Days

Carrier From Date At Date Distance Elapsed Underway

Net

speeda Remarks

Midway

(CV-41)

Yokosuka,

Japan

10/02/90 Gulf of Oman 11/01/90 6,495 30 24 11.3 3-day port visits at

Subic Bay and at

Singapore

Saratoga

(CV-60)

Mayport,

Fla.

08/07/90 Red Sea 08/22/90 5,867 15 14 17.5 Assumes a 1-day delay

to transit Suez Canal

Rangers

(CV-61)

San Diego,

Calif.

12/08/90 Strait of

Hormuz

01/15/91 11,666 38 33 14.7 5-day port visit at Subic

Bay; assumes no other

stops in route

America

(CV-66)

Norfolk, Va. 12/28/90 Red Sea 01/15/91 5,527 18 17 13.5 Assumes a 1-day delay

to transit Suez Canal

Red Sea 02/07/91 Persian Gulf 02/14/91 3,450 7 7 21.1

Kennedy

(CV-67)

Norfolk, Va. 08/15/90 Red Sea 09/14/90 5,527 30 27 8.5b 2-day port visit to

Alexandria, Egypt, also

assumes a 1-day delay

to transit Suez Canal

Roosevelt

(CVN-71)

Norfolk, Va. 12/28/90 Red Sea 01/14/91 5,527 17 16 14.4 Assumes a 1-day delay

to transit Suez Canal

Red Sea 01/14/91 Persian Gulf 01/21/91 3,540 7 7 21.1

aNet steaming speed was derived from the total elapsed days minus days spent in port and/or

awaiting to transit the Suez Canal, multiplied by 24 (hours), divided into the distance.

bThe Kennedy spent about 7 days in the Virginia Capes operating area conducting battle group

training and carrier landing qualifications before proceeding eastward. If this time is not counted

as days underway toward the Red Sea, then the ship’s transit speed was 11.5 knots.

Source: Our analysis of Navy data.

Page 135 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix IV 

Comparison of the Transit Time of

Conventionally and Nuclear-Powered

Carriers Responding to Selected Crises

Comparison of the

Voyages of the Lincoln

and the America

Supporting U.N.

Operations In Somalia

(1993)

The U.S.S. Abraham Lincoln (CVN-72) operating in the Persian Gulf

supporting Operation Southern Watch was ordered to move to the coast of

Somalia to support U.N. operations on October 7, 1993. The Lincoln moved

through the Straits of Hormuz on October 8 and arrived off the coast of

Mogadishu, Somalia, 4 days later, on October 12th. We estimate that the

Lincoln would have traveled at a sustained speed of 19 knots to cover the

approximately 1,800 nautical miles from the Straits of Hormuz to Somalia

in 4 days. The Lincoln operated off the coast of Somalia until November 4,

1993.

The U.S.S. America (CV-66) was operating in the Adriatic Sea supporting

U.N. peacekeeping operations in Bosnia-Herzegovina, when ordered on

October 27, 1993, to relieve the Lincoln operating off the coast of Somalia.

The America traveled from the Adriatic Sea to the Mediterranean Sea

entrance to the Suez Canal, in about 2 days, covering a distance of about

1,040 nautical miles, which equated to a sustained speed of about 22 knots.

The America completed the Suez Canal transit on October 30th and

reached the coast of Somalia on November 4th. We estimate that if the

America traveled about 2,400 nautical miles from the Suez Canal to the

coast of Somalia in about 5 days, it could have done so at a sustained

speed of about 20 knots. We estimate that the America would have

completed the total trip with about 60 percent of its propulsion fuel

remaining if no refueling had taken place.

Comparison of the

Transit of the

Washington in

October 1994, and a

Transit of Similar

Length by America in

December 1995

When Iraq moved two divisions of the Republican Guard south of the

Euphrates River, toward Kuwait, in early October 1994, the President,

faced with the imminent possibility of another Iraqi invasion of Kuwait,

directed that U.S. forces be dispatched to the region. This effort was called

Operation Vigilant Warrior. Included among those forces was the

U.S.S. George Washington (CVN-73), the closest American aircraft carrier

to the Middle East, operating in the Adriatic Sea. Two other carriers were

also deployed at sea at that time but were much farther away; the

U.S.S. America (CV-66) was operating near Haiti, and the

U.S.S. Kitty Hawk (CV-63) was operating near Korea.

The George Washington battle group was ordered to move to the Persian

Gulf on the evening of October 7, 1994, and arrived in the Red Sea on

October 10th.1

 The George Washington, with one escort, continued to

1

Once in the Red Sea, attack aircraft from the U.S.S. George Washington, or any other carrier, could

have reached targets in southern Iraq with refueling by aerial tankers. Also, on October 10th, Saddam

Hussein announced that the Republican Guard divisions would withdraw, and they began to move

northward soon afterwards.

Page 136 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix IV 

Comparison of the Transit Time of

Conventionally and Nuclear-Powered

Carriers Responding to Selected Crises

proceed around the Arabian Peninsula, arriving in the Persian Gulf on

October 14th.2

 According to a Center for Naval Analyses study,3 the

George Washington averaged about 25.6 knots, excluding the time spent

waiting to transit the Suez Canal and actually transiting the canal.

By comparison, the U.S.S. America made a similar voyage, but in the

opposite direction, from the Persian Gulf to the Adriatic Sea in

December 1995. The America began the voyage on December 2nd,

transited the Suez Canal on December 9th, and was in position in the

Adriatic Sea on December 11, 1995, in time for the signing of the peace

agreement between the fighting Balkan factions. Assuming that this

voyage took 8 full steaming days, excluding the time associated with

transiting the Suez Canal, the America would have covered the nearly

4,200 nautical miles at a sustained speed of about 22 knots. If the America

had steamed at the same sustained speed (26 knots) as the

George Washington did during Vigilant Warrior, a speed within its

capability, it would have arrived with about 33 percent fuel remaining if

there was no refueling during the voyage. With one refueling, the

U.S.S. America would have taken about 2 hours longer than the

George Washington to cover the same distance but would have arrived

with full fuel tanks.

Comparison of the

Transit of the

Nimitz in October

1997, and a Similar

Transit by the

Independence in

January/

February 1998

On October 1, 1997, after Iraqi aircraft had violated the southern

“no-fly-zone,” the U.S.S. Nimitz (CVN-68) was ordered to proceed to the

Persian Gulf at best speed. The carrier had completed a port visit to Hong

Kong and was scheduled to visit Singapore before heading for the Persian

Gulf. According to the Navy, the Nimitz completed this 5,500 nautical mile

transit in 11 days at an average speed of advance of about

21 knots. Our review of transit data indicated the carrier spent about

39 percent of the voyage at 27 knots and above. The carrier’s longest

sustained steaming period at or above 27 knots was one 9-hour period. The

Navy reported that the Nimitz was able to conduct flight operations on 6 of

the 11 transit days. The carrier arrived in the Persian Gulf on October 11,

1997.

2

Several dozen Air Force tactical aircraft arrived in the theater about the same time as did the

U.S.S. George Washington. On October 8th, Air Force units at Langley Air Force Base, Virginia, and

Pope Air Force Base, North Carolina, were alerted to deploy, but their aircraft were held at their bases

pending final basing arrangements with Saudi Arabia. The Langley fighters arrived in Saudi Arabia on 

October 11th, while the Pope aircraft arrived on October 13th and 15th, after completing

approximately 17-hour flights.

3

Exploring Alternative Paths for Future Sea-Based TACAIR Platforms, Report CAB 95-62, July 1995.

Page 137 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix IV 

Comparison of the Transit Time of

Conventionally and Nuclear-Powered

Carriers Responding to Selected Crises

On January 23, 1998, the U.S.S. Independence (CV-62) was ordered to

transit from Japan to the Persian Gulf to replace the Nimitz, which was

scheduled to return to the U.S. for a scheduled comprehensive refueling

overhaul. Our analysis of transit data for the Independence indicated the

carrier averaged over 24 knots during the voyage and spent over

70 percent of the time at 27 knots and above. During various parts of the

transit, the ship sustained speeds of 27 knots and above for several lengthy

periods of time, including 42, 31, and 27 continuous hours. Our review of

transit data indicated that aircraft flew on at least 5 days of the transit, the

last period ending late in the evening of February 4, 1998, the night before

the ship entered the Persian Gulf. The ship slowed down to speeds of 14

knots or less to conduct fuel replenishments and make periodic course

and speed changes to conduct flight operations.

Page 138 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

An October 1995 report on the Naval Nuclear Propulsion Program

Classification Review included a discussion of the impact of nuclear

propulsion in the Gulf War. The report stated:

“During this war the U.S. had unchallenged use of the oceans. Over 85 percent of the war

supplies were transported by ocean, halfway around the world. Accomplishing this

required complete control of the sea. A few enemy nuclear-powered submarines could have

significantly disrupted our supply lines. Nuclear-powered submarines with their covert

capability provided platforms for launching cruise missile strikes without concern for

detection prior to launch. The nuclear-powered aircraft carriers provided U.S.

Commanders with platforms for aircraft strikes that could be located for sustained periods

in areas of the Middle East not available by land. If Iraq had obtained access to nuclear

propulsion technology and had developed nuclear-powered submarines, it would have

significantly impacted the course of the war.”

Our analysis of carrier operations and support during Operation Desert

Storm did not reveal any significant differences between the

nuclear-powered carrier U.S.S. Theodore Roosevelt (CVN-71) and five

conventionally powered carriers, including the World War II-vintage

U.S.S. Midway (CV-41), that could be attributed to nuclear propulsion.

Although aircraft from the Roosevelt flew more missions than any other

Desert Storm carrier, this was due to several factors independent of the

propulsion system, including the distance to targets and the number and

mix of aircraft aboard each carrier. When the number of assigned aircraft

is considered, the number of sorties generated by each carrier is almost

identical.

Our analysis also indicated that the Navy supported all six carriers in

essentially the same manner. Despite the nuclear carrier’s greater jet fuel

and ordnance capacity, and its reduced reliance on logistics support, the

Roosevelt did not operate for longer intervals between replenishment

actions than the conventional carriers. Instead, all of the carriers were

replenished at about the same frequency, well before fuel and ordnance

reached critical levels.

Missions Generated

by Each Carrier Were

Comparable for the

Regions in Which

They Operated

When Operation Desert Storm began on January 17, 1991, the Navy had

three conventional carriers, U.S.S. America (CV-66),

U.S.S. John F. Kennedy (CV-67), and U.S.S. Saratoga (CV-60), positioned in

the Red Sea and two conventional carriers, U.S.S. Midway (CV-41) and

U.S.S. Ranger (CV-61), in the Persian Gulf. The nuclear-powered

U.S.S. Theodore Roosevelt (CVN-71), sailing from the Red Sea to the

Persian Gulf when hostilities began, did not begin to strike targets until

Page 139 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

January 22nd. The Navy operated three carriers each in the Red Sea and

Persian Gulf for about 3 weeks until the America moved to the Persian

Gulf in mid-February 1991, shifting the number of carriers in each

operating area to two and four ships, respectively.

Navy fixed-wing carrier-based aircraft flew over 18,000 sorties during the

war, according to statistics developed by Center for Naval Analyses in an

analysis of Desert Storm carrier operations. Aircraft from the Red Sea

Battle Force flew nearly 6,200 sorties (one-third of the sorties), while

aircraft from the Persian Gulf Battle Force flew nearly 11,800 sorties. We

believe that the significant differences in the operations of the two battle

forces were largely driven by the ranges to their targets. The Red Sea

carriers were about 400 to 600 nautical miles away from their targets.

Their aircraft had to fly even greater distances to get to and from aerial

tanker positions and to use specific entry and exit corridors to reach the

targets. The Persian Gulf carriers, on the other hand, launched many

missions to the coastal region and were generally closer to their targets

than the Red Sea carriers. As a result, the Persian Gulf carriers generally

launched more sorties of shorter duration. As the war progressed, the

Persian Gulf carriers moved further north in the Gulf, reducing strike

ranges even more. The shorter distances allowed the carriers to shift into

cyclic operations and generate many more sorties in the same span of

time. In addition, the America’s move to the Persian Gulf increased the

number of carriers to four and added further to the total sorties generated

by those carriers.

Because of the extended ranges involved during attacks on Iraq,

carrier-based aircraft required refueling from land-based tankers. Aircraft

from the Red Sea carriers relied on land-based tankers for the duration of

the war. In the Persian Gulf, the carriers were initially positioned about

280 nautical miles southeast of Kuwait City. As the war progressed and the

threat of Iraqi air and missile attacks on the Persian Gulf carriers

diminished, the carriers moved farther north, reducing their dependence

on land-based tankers. By the start of the ground war in late February, the

carriers were positioned about 185 nautical miles southeast of Kuwait

City. After the carriers’ arrival in the northernmost operating areas, Navy

refueling aircraft provided all refueling for Persian Gulf naval air strikes.

The total sorties generated by each carrier, as well as the average number

of sorties flown during the war, are shown in table V.1. The Kennedy and

the Saratoga operated in the Red Sea during the entire period, while the

Midway, the Ranger, and the Roosevelt operated in the Persian Gulf. The

Page 140 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

America began the war in the Red Sea but moved to the Persian Gulf in

mid-February for the final stages of the war.

Table V.1: Average Sorties Per Day Per Carrier During Desert Storm (43 Days)

Midway

(CV-41)

Saratoga

(CV-60)

Ranger

(CV9-61)

America

(CV-66)

Kennedy

(CV-67)

Roosevelt

(CV-71) Total

Total sorties 3,019 2,374 3,329 2,672 2,574 4,149 18,117

Daily average 70.2 55.2 77.4 62.1 59.9 96.5 421.3

Source: Our analysis of Center for Naval Analyses data.

Number of Sorties

Generated by

Individual Carriers

Were Proportional to

the Size of Their Air

Wings

The number of aircraft assigned to each carrier varied considerably and

had a direct impact on the sorties generated by each carrier. When the

average number of sorties per assigned aircraft are compared, there is

little difference between carriers operating in the same area (see

table V.2). Although the U.S.S. Theodore Roosevelt (CVN-71) launched the

most sorties of any carrier (4,149), the ship, along with the

U.S.S. John F. Kennedy (CV-67), had the most aircraft assigned—78 aboard

each carrier. Since the Roosevelt operated in the Persian Gulf,

considerably closer to assigned targets than the Kennedy in the Red Sea, it

was able to generate more sorties. On the other end of the spectrum, the

World War II-vintage U.S.S. Midway (CV-41) had only 56 aircraft assigned

(nearly 30 percent less than the Roosevelt), the least of any carrier,

followed by the U.S.S. Ranger (CV-61) with 62 aircraft.

When sorties are compared based on the number of aircraft assigned, the

sortie generation rates are nearly identical between the carriers. The

significant differences are between the Red Sea and Persian Gulf carriers.

When carriers in the same region are compared, their sortie generation

rates are also almost identical. The Kennedy and the

U.S.S. Saratoga (CV-60), which operated in the Red Sea for all of Desert

Storm, each averaged 33 sorties per aircraft. The three full-time Persian

Gulf carriers, Midway, Ranger, and Roosevelt, each averaged about 53

sorties per aircraft.

Page 141 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

Table V.2: Comparison of the Average Number of Sorties Generated by Each Carrier

Midway

(CV-41)

Saratoga

(CV-60)

Ranger

(CV-61)

America

(CV-66)

Kennedy

(CV-67)

Roosevelt

(CVN-71) Total

Total sorties 3,019 2,374 3,329 2,672 2,574 4,149 18,117

Aircraft assigned:

F-14 0 20 20 20 20 20 100

F/A-18 30 18 0 18 0 19 85

A-6E 14 14 22 14 13 18 95

A-7 0 0 0 0 24 0 24

E-2 4 4 4 4 5 4 25

EA-6B 4 4 4 5 5 5 27

KA-6D 4 4 4 4 3 4 23

S-3B 0 8 8 8 8 8 40

Total 56 72 62 73 78 78 419

Average sorties

per aircraft 53.9 33.0 53.7 36.6 33.0 53.2 43.2

Source: Our analysis of Center for Naval Analyses data.

Carriers Operated on

a Rotating Basis

Although Navy aircraft flew sorties every day throughout Desert Storm,

none of the carriers operated around-the-clock. Instead, they rotated on an

operating schedule that enabled them to have intervals of off-duty time.

According to the Center for Naval Analyses data, the three carriers initially

operating in the Red Sea, the U.S.S. America (CV-66), the

U.S.S. John F. Kennedy (CV-67), and the U.S.S. Saratoga (CV-60), followed

a rotating schedule with two carriers conducting flight operations while

the third stood down for 2 days. When the America departed for the

Persian Gulf on February 7th, the remaining two carriers continued to

operate with periodic stand-down intervals. In the Persian Gulf, the

U.S.S. Midway (CV-41), the U.S.S. Ranger (CV-61), and the

U.S.S. Theodore Roosevelt (CVN-71) also followed a rotating operating

schedule. Each carrier conducted air operations for approximately 

15 hours during a 24-hour interval. During the remaining 9 hours of a

24-hour interval, one carrier suspended air operations. The Ranger’s and

Roosevelt’s on-duty periods occurred during opposite portions of the

24-hour interval—with 3 hours of concurrent operations during turnovers.

The Midway’s on-duty period was roughly centered on one of Ranger’s and

Roosevelt’s turnovers. The Center for Naval Analyses reported that there

were only 6 days during the war when all six carriers operated. The rest of

the time usually four or five carriers were on line while others stood down.

Page 142 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

Average Sorties Per

Operating Day Were

Not Significantly

Different Among the

Carriers

When daily sortie rates were based on the number of days each carrier

operated, there was a significant increase in average sorties. As shown in

table V.3, the U.S.S. Theodore Roosevelt (CVN-71) led all carriers,

averaging about 106 sorties per day. The smallest and oldest carrier, the

U.S.S. Midway (CV-41), averaged about 89 sorties, 17 less than the

Roosevelt, but did so with 22 fewer aircraft. When we factored in the

number of assigned aircraft to average number of sorties per operating

day, the Midway led all carriers. The Midway averaged 1.59 sorties per

aircraft per operating day, followed by the U.S.S. Ranger (CV-61) with an

average of 1.41 sorties, and the Roosevelt with 1.36 sorties.

Table V.3: Average Sorties Per

Operating Day Generated by Each

Carrier

Midway

(CV-41)

Saratoga

(CV-60)

Ranger

(CV-61)

America

(CV-66)

Kennedy

(CV-67)

Roosevelt

(CVN-71)

Total sorties 3,019 2,374 3,329 2,672 2,574 4,149

Aircraft assigned 56 72 62 73 78 78

Operating days 34 33 38 31 31 39

Average sorties per

operating day 88.8 71.9 87.6 86.2 83.0 106.4

Average operating

day sorties per

aircraft 1.59 1.00 1.41 1.18 1.07 1.36

Source: Our analysis of Center for Naval Analyses data.

Logistics Support Was

Comparable for All

Carriers

The Navy committed about 40 percent of its Combat Logistics Force

ships—combat stores ships, oilers, ammunition supply ships, and

multicommodity fast combat support ships—to Desert Storm. Each of the

carrier battle groups was assigned its own dedicated support ships, to the

extent possible, that remained on station with its battle group and enabled

frequent replenishment of fuel and ordnance. According to Center for

Naval Analyses, all carriers were replenished at about the same frequency,

approximately every 3 to 3-1/2 days. The Center for Naval Analyses

concluded that the increased capacity for ordnance and aviation fuel in the

nuclear design was not sufficient to untether the battle force from the

logistics pipeline. It also concluded that the hoped for increase in freedom

of operational employment for nuclear carriers was restricted by the fossil

fuel dependence of their accompanying surface combatants.

Page 143 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

Fuel Replenishment

During Desert Storm

Was Comparable for

Nuclear- and

Conventionally

Powered Carriers

According to the Center for Naval Analyses, which published several

studies related to Desert Storm, the frequency that aviation fuel was

replenished was essentially the same for all carriers, including the

U.S.S. Theodore Roosevelt (CVN-71), even though nuclear-powered

carriers have about 1.7 million more gallons of aviation fuel storage

capacity. Table V.4 shows that aviation fuel was replenished about every

3 days for the carriers operating in the Persian Gulf.

Table V.4: Frequency of Aviation Fuel

Replenishment by Persian Gulf

Carriers During January and

February 1991

Midway

(CV-41)

Ranger

(CV-61)

America

(CV-66)

Roosevelt

(CVN-71)

Number of replenishments 19 41 6 12

Days in Persian Gulf 59 46 16 40

Replenishment frequency (days) 3.1 3.1 2.7 3.3

Source: Our analysis of Center for Naval Analyses data.

Similarly, in the Red Sea, the conventionally powered carriers operating

also received aviation fuel every 2 to 3 days. The Center for Naval Analyses

stated that, “In practice, ships are topped-off whenever other operational

demands make it possible.” It reported that from February 17-27, 1991, the

peak period of the air campaign, aircraft from the Roosevelt consumed an

average of over 4,930 barrels (207,060 gallons) of fuel daily, while

U.S.S. America (CV-66) aircraft consumed about 4,990 barrels

(209,580 gallons) daily. The amount of aviation fuel consumed daily

represented only a small percentage of each carrier’s JP-5 capacity.

Ordnance Was Also

Replenished

Frequently

According to Center for Naval Analyses, ordnance expenditures by the

Persian Gulf carriers averaged about 49 tons per day per carrier during the

entire war. This rate increased to 116 tons per day during the 4-day ground

offensive. Each Red Sea carrier averaged about 43 tons per day during the

war and 59 tons per day during the ground war. The smaller Red Sea

expenditure rates were probably due to the smaller number of sorties

flown as a result of the longer distances these aircraft had to fly to reach

their targets. Like fuel, ordnance was also replenished about every 3 days

for the Persian Gulf carriers and about every 1 to 2 days in the Red Sea,

even though the ordnance expended over a 2- to 3-day period was only a

fraction of the ships’ storage capacities. For example, according to Center

for Naval Analyses, the U.S.S. Theodore Roosevelt (CVN-71) was rearmed

seven times during the last 20 days of February 1991, receiving over 

Page 144 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix V 

Operations of Carriers in the Persian Gulf

War

1,600 tons of ordnance. During this period, the Roosevelt expended an

average of about 2 percent of the capacity (by weight) per day. The 

U.S.S. Ranger (CV-61) was also rearmed seven times over this interval,

even though only about 5 percent of its ordnance capacity was consumed

daily. Similarly, the U.S.S. Midway (CV-41) was rearmed nine times

between January 16 and February 16, 1991, even though only about

5 percent of its ordnance capacity was expended daily.

Page 145 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VI 

List of Aircraft Carrier Hull Numbers,

Names, and Authorization and

Commissioning and Decommissioning Dates

Fiscal yeara

Authorized Commissioned Decommissioned

Conventionally powered carriers

CV-59 U.S.S. Forrestal 1952 1955 1993

CV-60 U.S.S. Saratoga 1953 1956 1994

CV-61 U.S.S. Ranger 1954 1957 1993

CV-62 U.S.S. Independence 1955 1959 1998

CV-63 U.S.S. Kitty Hawk 1956 1961 2008

CV-64 U.S.S. Constellation 1957 1962 2003

CV-66 U.S.S. America 1961 1965 1996

CV-67 U.S.S. John F. Kennedy 1963 1968 2018

Nuclear-powered carriers

CVN-65 U.S.S. Enterprise 1958 1962 2013

CVN-68 U.S.S. Nimitz 1967 1975 2023

CVN-69 U.S.S. Dwight D. Eisenhower 1970 1978

CVN-70 U.S.S. Carl Vinson 1974 1982

CVN-71 U.S.S. Theodore Roosevelt 1980 1987

CVN-72 U.S.S. Abraham Lincoln 1983 1990

CVN-73 U.S.S. George Washington 1983 1992

CVN-74 U.S.S. John C. Stennis 1988 1996

CVN-75 U.S.S. Harry S. Truman 1988 1998

CVN-76 Ronald Reagan b 1995 2003

CVN-77 Unnamed 2001 2008

CVX-78 Unnamed 2006 2013

CVX-79 Unnamed 2011 2018

aFuture years are planning dates subject to nuclear fuel state, material condition of the ship, and

shipyard building schedules.

bUnder construction.

Page 146 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Note: GAO comments

supplementing those in the

report text appear at the

end of this appendix.

Page 147 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Page 148 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 22-23.

See comment 1.

Page 149 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 2.

Now on pp. 24-26.

See comment 3.

Page 150 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 4.

See comment 5.

See comment 3.

See comment 6.

Now on pp. 26-28.

See comment 7.

Page 151 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 8.

Page 152 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 34-36.

See comment 9.

Now on pp. 36-38.

See comment 10.

Page 153 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 11.

Now on p. 39.

See comment 12.

Page 154 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 39-40.

See comment 13.

See comment 14.

Page 155 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 41-44.

See comment 15.

Page 156 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 16.

See comment 17.

See comment 18.

Page 157 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 44-48.

See comment 19.

See comment 8.

Page 158 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 49-50.

See comment 20.

See comment 21.

See comment 22.

See comment 23.

See comment 24.

Page 159 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

See comment 25.

Now on pp. 51-54.

See comment 26.

Now on pp. 55-61.

See comment 27.

Page 160 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 63-64.

See comment 28.

Now on pp. 65-66.

See comment 29.

Page 161 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 67-68

See comment 30.

Page 162 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 68-69

and 127-133.

See comment 31.

Page 163 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 70-71.

See comment 32.

Now on pp. 98-103.

Page 164 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 73-75.

Page 165 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Page 166 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on p. 91.

See comment 33.

Now on pp. 89-90.

See comment 34.

Page 167 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 92-93.

See comment 35.

Page 168 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Now on pp. 93-94.

See comment 36.

Now on pp. 94-96..

See comment 37.

Page 169 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

The following are our comments on DOD’s letter dated March 30, 1998.

GAO Comments 1. We note that conventionally powered carriers have been upgraded with

new features. During their midlife modernization periods, the carriers

received extensive rehabilitation and upgrading of their hull, propulsion,

auxiliary machinery, electrical and piping systems, improved radars and

communications equipment, and aircraft launch and recovery systems.

Kevlar armor was added to vital spaces. As part of the Navy’s Fleet

Modernization Program, the fleet is continuously upgraded with new

weapons and electronics systems, as well as other features. For example,

one of the conventionally powered carriers, the

U.S.S. Constellation (CV-64), has received several upgrades to its aviation

maintenance equipment; intelligence, combat, engineering, and navigation

systems; and habitability, and it embarks the newest and most capable

aircraft that exist in the Navy. At the time of our visit to the U.S.S.

Kitty Hawk (CV-63), the commanding officer told us that it had the most

modern systems installed in the command, control, communications,

computers, and intelligence (C4I) area and that its joint force air

component commander (JFACC) is the model for West coast carriers.

Another conventionally powered carrier, the U.S.S. John F. Kennedy

(CV-67), was the first carrier to operationally deploy with two

state-of-the-art intelligence systems, the Battle Group Passive Horizon

Extension System and the Common High Bandwidth Data Link. The

conventionally powered carriers also are scheduled to receive cooperative

engagement capability1

 along with their nuclear-powered counterparts.

We disagree that a new design conventionally powered carrier would

necessarily result in a larger and heavier ship. The assumptions underlying

this statement disregard the space and weight made available through

adopting new technologies and the reduced personnel requirements for

the ship and its air wing. Personnel reduction goals for the next carrier

ship’s force are about 50 percent. Potential air wing reductions can be

illustrated by the personnel savings expected in replacing F-14A squadrons

with two-seat F/A-18E/F squadrons. An F-14 squadron generally requires

275 maintenance personnel, while an F/A-18E/F squadron will require

about 180, a reduction of about 35 percent. For an air wing of 2,480

persons, this could result in a reduction of about 870 persons.

Cumulatively, these reductions are expected to require less demand for

1

This capability is a computer-based system that permits simultaneous sharing of detailed targeting

data between ships or forces at extensive ranges within the littoral area, thereby increasing reaction

time and firing opportunities against enemy missile attacks.

Page 170 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

hotel services such as mess halls, berthing, laundry, and food stores and

free up space and weight for aviation fuel and ordnance.

2. We believe the measures of effectiveness we chose are appropriate for

comparing the two types of carriers. Our methodology for evaluating the

effectiveness of conventionally and nuclear-powered carriers uses

performance-based mission outcomes (national security objectives) as its

metric and is not engineering requirements derived (maximum speed or

load carrying capacity). We coordinated our measures of effectiveness

with Joint Staff, Office of the Secretary of Defense, and Navy officials. In

fact, some senior Navy officials said that they believed that our

methodology was sound.

3. We do not state that carriers operate exclusively with battle groups.

Rather, we state that a battle group’s composition can vary depending on

the mission need. For example, figure 1.1 and related text shows a CVN

“surging” from the Mediterranean Sea to the Gulf, with elements of its

battle group, including a supporting fast combat support ship. The carrier

left five of its battle group ships in the Mediterranean Sea, including a

nuclear-powered cruiser.

4. Our analysis of the ship deck logs for the U.S.S. Nimitz does not support

DOD’s statement. According to the logs, ships of the U.S.S. Nimitz battle

group passed through the Strait of Hormuz around 6:00 p.m. on March 12,

1996, while the U.S.S. Nimitz exited the Strait of Hormuz around 10:00 a.m.

on March 14, 1996, approximately a day and a half later. We note that

while the U.S.S. Nimitz and one escort remained in the Gulf, several other

ships of the separate Middle East Task Force operated in the Gulf. The

average transit speed of the U.S.S. Nimitz to the South China Sea was less

than 20 knots.

5. While we agree that conventionally powered carriers are more

dependent on battle group logistics support than nuclear-powered

carriers, we do not agree with DOD that fuel consumption concerns limit

conventionally powered carriers to the slower speeds of logistics ships.

We note that the AOE-class battle group supply ship can sustain speeds of

30 knots and thus will not limit the transit speed of the battle group. In

situations where an AOE is not available, the Combat Logistics Force can

resupply fuel oil with its worldwide network of prepositioned oilers.

Logistics force planners and operators told us they knew of no time when

a conventionally powered carrier could not obtain Combat Logistics Force

support during peacetime or crisis. Recently, the conventionally powered

Page 171 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

carrier U.S.S. Independence (CV-62) traveled from its homeport in

Yokosuka, Japan, to the Arabian Gulf at an average speed of 24 knots.

During the transit, the ship sustained speeds of at least 27 knots over

two-thirds of the time.

6. We added information on more recent carrier deployments to

appendix IV.

7. Our report states that the maintenance strategy, along with propulsion

type, affects the length of a carrier’s employment cycle. Although the

Navy’s guidance for accomplishing ship depot-level maintenance

availabilities nominally sets depot intervals, durations, and mandays by

ship class, the Navy has deviated from this guidance for conventionally

powered carriers and nuclear-powered cruisers that have been grouped by

type for at least the last 8 years. We note that nuclear propulsion

maintenance requires exacting and stringent environmental, health, and

safety standards. Our analysis shows that, under the Navy’s current

strategy, nuclear-powered surface ships have longer depot-level

maintenance periods than their conventionally powered counterparts. For

example, the typical post-deployment maintenance period for a

nuclear-powered carrier lasts 6 months and about 62 percent of the work

is related to the propulsion plant. The typical post-deployment yard period

for a conventionally powered carrier is about 3 months. The

nuclear-powered carrier spends more time undergoing propulsion plant

work than the conventionally powered carrier does for all its maintenance,

repairs, and modernization. A similar relationship exists between

conventionally and nuclear-powered surface combatants. Our analysis

also shows that a conventionally powered Aegis cruiser or Kidd-class

guided-missile destroyer spends about one-fourth the maintenance

mandays per deployment as a nuclear-powered cruiser. Furthermore, our

analysis shows that a conventionally powered surface combatant spends

about 16 percent of its time in depot-level maintenance compared to

around 25 percent for a nuclear-powered cruiser. As shown in table VII.1,

the nuclear-powered cruiser maintenance cycle is more like a

conventionally powered carrier than a conventionally powered cruiser in

terms of the time spent in maintenance (about 25 percent) and mandays of

work to perform the maintenance (about 38,000 mandays after a typical

deployment and over 300,000 mandays for a complex overhaul).

Page 172 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

Table VII.1: Maintenance Period Characteristics of Conventionally and Nuclear-Powered Surface Combatants and Aircraft

Carriers

Typical post-deployment

depot maintenance period Complex overhaul

Ship type

Cycle time in

maintenance (percent) Months

Mandays

(thousands) Months

Mandays

(thousands)

Surface combatant

Conventionally powered 16 2-3 10 8.0 48

Nuclear-powered 24 3-4 38 18.0 350

Aircraft carrier

Conventionally powered 25 3 45 12.0 376

Nuclear-powered 29 6 162 10.5 289

Source: Our analysis of Navy data.

8. The September 1997 Chief of Naval Operations memorandum stated that

to prevent confusion and misunderstanding, the OPNAV Notice 47002

 is

being revised to reflect these comments. The OPNAV Notice 4700 has not

been revised to reflect that information.

9. We included information on the arguments that led to the use of nuclear

propulsion for surface ships in the 1960s to provide important historical

context for the debate. We did not discuss the arguments that culminated

in approval of nuclear propulsion for the Nimitz-class because DOD was

unable to provide us with supporting documentation. However, we

understand that many of the arguments in favor of nuclear propulsion

were the same as those presented in the 1960s.

10. While DOD said that the risk and cost associated with developing the

new Aegis capability in parallel with the new design nuclear propulsion

plant were factors in its choice of choosing conventional power for Aegis

cruisers, it provided no evidence to support this belief. The Secretary of

Defense’s assessment was that “the military value of an all

nuclear-powered Aegis ship program does not warrant the increased costs

or, alternatively, the reduced forced levels.” DOD was unable to provide

support for its rationale for deciding to retire the nuclear-powered surface

combatants at an average age of 17 years. Instead, it provided Navy point

papers that noted adding the New Threat Upgrade (NTU) will provide

extremely capable anti-air warfare for 10 plus years—combat system

capabilities comparable to AEGIS ships and an engagement range greater

2

Chief of Naval Operations. OPNAV Notice 4700, Subject: Notional Intervals, Durations, Maintenance

Cycles, and Repair Mandays for Depot Level Maintenance Availabilities of U.S. Navy Ships.

Page 173 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

than AEGIS (until introduction of the Standard Missile (SM2) Block 4 to

AEGIS cruisers). The point papers also stated that the nuclear-powered

surface combatants are (1) superior to all surface combatants in tactical

mobility and (2) the only combatant escorts that do not constrain a CVN

battle group’s mobility, flexibility, and rapid surge capability—“an

essential element of the future force structure.”

11. We were asked to assess the cost-effectiveness of conventionally and

nuclear-powered carriers and did not perform any comparisons of the

advantages and costs of using nuclear power in surface ships versus

aircraft carriers.

12. Our congressional mandate was to review the cost-effectiveness of

conventionally versus nuclear-powered carriers, not to develop potential

designs for a new carrier or to evaluate the cost-effectiveness of such

designs. We do not agree that a cost-effectiveness analysis should assume

that the next conventionally or nuclear-powered carrier would have the

same capabilities and features, nor do we agree that the highest end

technology should be assumed in the analysis. Rather, the goal of

designing a new carrier is to build a system with the capability necessary

to meet U.S. national security objectives. We also note that the Center for

Naval Analyses used a methodology similar to ours in some preliminary

work it did for the Navy as the Navy began to assess its future carrier

needs. This historical perspective covered a wide range of peacetime

forward presence, crisis response, and war-fighting scenarios that both

types of carriers have faced for over two decades. We believe this provides

a sound foundation for evaluating the relative cost and effectiveness of

these two ship types.

Although DOD said that the current assessment of a new carrier design

would include various features, including new fossil fuel and

nuclear-powered designs, we note that in the 1998 Navy Posture

Statement, the Secretary of the Navy and the Chief of Naval Operations

state, “This next generation nuclear-powered aircraft carrier is scheduled

to begin construction in 2006. . .” and “CVX will be the most

technologically advanced nuclear-powered carrier the Navy has ever

developed.”

13. We believe the report adequately addresses the support required for

both types of carriers. For example, it specifically states that

nuclear-powered carriers can transit long distances faster because, unlike

conventionally powered carriers, they do not need to slow for underway

Page 174 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

replenishment of propulsion fuel. It also included a table comparing

nuclear and conventionally powered carrier transit times that highlights

refueling requirements for conventionally powered carriers. We note that

DOD’s comment that operational commanders task the closest or

next-to-deploy carrier rather than selecting a particular carrier is

consistent with our finding that the carrier’s type of propulsion is not a

critical factor in making employment decisions. We also note that the vast

majority of Navy ships are fossil fuel-powered, thereby necessitating a

continuous logistics presence. In fact, the Navy has specifically designed

and strategically located its logistics infrastructure to provide continuous

support to peacetime and wartime naval operations. Elements of the

logistics infrastructure include naval depots, inventory control points,

distribution centers and bases in the United States; advanced overseas

support bases located in or near the theater of operations; and a highly

mobile fleet of Combat Logistics Force ships that carry a broad range of

supplies. Logistics planning to provide that support is a continuous,

organized process, performed in parallel with naval operations planning.

A recent example that we believe demonstrates the timeliness and

effectiveness of the Navy’s worldwide logistics infrastructure was the

unanticipated deployment of the conventionally powered

U.S.S. Independence from Japan to the Persian Gulf in January 1998,

during a confrontation with Iraq, to relieve the U.S.S. Nimitz. On

January 21, 1998, the Secretary of Defense ordered the U.S.S.

Independence to depart for the Persian Gulf. The carrier got underway on

January 23, 1998, and conducted a high-speed transit to the Persian Gulf,

arriving on February 5, 1998. During the voyage, the carrier was

replenished by three separate Military Sealift Command tankers, already

prepositioned in the western Pacific and Indian Ocean areas. Crisis

logistics planning enabled the tankers to rendezvous with the carrier to

provide needed replenishment without hindering the carrier’s ability to

respond in a timely manner to fulfill its tasking.

14. Our analysis shows that a conventionally powered carrier steaming at

28 knots would cover 6,740 nautical miles (a distance equivalent to that

from Norfolk to the Red Sea) in about 9-1/2 days and arrive with 

77 percent of its propulsion fuel remaining. We project that the AOE-6

would still have over 11,700 barrels of DFM remaining to give to other ships.

(Our analysis assumed that the AOE-6 had a maximum capacity of 93,600

barrels of DFM. Of this amount, 30,950 barrels would be needed for the

Page 175 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

AOE-6’s own propulsion, leaving 62,650 barrels available to refuel other

ships—the carrier would need 50,893 barrels.)3

Our calculations were based on published fuel consumption rates from the

ships’ engineering manuals, fuel capacities from ship manuals, and the

distances cited in the example. We calculated burn rates based upon the

more demanding 28-knot transit vice DOD’s 26-knot rate and we assumed

that the carrier would be refueled when its DFM levels reached 70 percent

of its capacity. Our analysis is very conservative because our burn rates

assumed all eight boilers being on-line when only five boilers need to be

on-line to sustain a 28-knot speed for the U.S.S. John F. Kennedy (CV-67).

15. Subsequent to providing written comments on our draft report, DOD

provided adjusted maintenance data that showed conventionally powered

carriers were in depot- level maintenance about 32 percent of the time

(26 percent when adjusted for the Service Life Extension Program (SLEP)

and the Nimitz-class ships were in depot-level maintenance about

27 percent of the time.

After receiving DOD’s comments, we re-examined our methodology but

could not replicate DOD’s results. Our original results remained—each

carrier type spent about 30 percent of its “unadjusted” time from

October 1, 1984, to December 31, 1996, in depot-level maintenance

availabilities.4

 We also examined two other time periods to gauge the

variability of the results. According to our calculations, from October 1,

1982, through December 31, 1996, conventionally and nuclear-powered

carriers were in the shipyards for depot-level maintenance 31 percent and

30 percent of the time, respectively, while accounting for 30 percent of the

time for both carrier types from October 1, 1983, through December 31,

1996.

In our draft report, we stated that, after adjusting for the time they spent in

SLEP, the conventionally powered carriers collectively would have spent

about 23 percent from October 1, 1984, through December 31, 1996, in

depot-level maintenance—about 7 percent less than the nuclear-powered

carriers. After receiving DOD’s comments, we re-examined and modified

our methodology for making the SLEP adjustment. According to our revised

calculations, the conventionally powered carriers would have spent about

3

According to data DOD provided to us on April 2, 1998, Commander Logistics Group Two assumed a

26-knot or higher transit for 10 days, with the transferable propulsion fuel capacity from an AOE-6

class ship (2.1-4.0 million gallons of DFM).

4

See app. I for a more detailed explanation of our methodology for calculating the availabilities.

Page 176 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

24 percent of their time in depot-level maintenance, about 6 percent less

than the nuclear-powered carriers. Our adjustments have been

incorporated into the report, and our methodology for adjusting SLEP time

is discussed in appendix I.

We also examined the effect that refueling overhauls would have on the

time that the nuclear-powered carriers would spend in depot-level

maintenance. According to current maintenance schedules, starting in

mid-1998 and ending in mid-2007, one of the Nimitz-class carriers will be

almost continually undergoing a refueling overhaul, a situation analogous

to the conventionally powered carrier SLEPs in the 1980s and early 1990s

(the notional durations of both a refueling overhaul and a SLEP is 

32 months). We found, that from October 1, 1997, through December 31,

2007, the nuclear-powered carriers will spend about 32 percent of their

collective time undergoing depot-level maintenance in a shipyard—about

2 percent more than during the original time period. The two operating

conventionally powered carriers will spend about 19 percent of their time

undergoing depot-level maintenance in a shipyard during this period.

16. We agree that, within the time period we examined, six of nine

conventionally powered carriers were inactivated or were within 5 years

of inactivation and that these ships would have received less maintenance

and modernization. However, because of the timing of the inactivation

decision and the actual inactivation, there would have been insufficient

time to significantly decrease the amount of maintenance and

modernization on the ships prior to their inactivation. For example, the

decision to inactivate the Forrestal (CV-59), the Saratoga (CV-60), and the

Ranger (CV-61) was first reflected in documents supporting DOD’s Fiscal

Year 1992 Future Year Defense Plan. The Forrestal and the Ranger were

decommissioned in 1993 and the Saratoga was decommissioned in 1994.

These three ships underwent regularly scheduled, and in some cases,

extensive maintenance. For example, the Saratoga, underwent a

comprehensive 15.9 month overhaul starting in January 1988 that lasted

about 1-1/2 months longer than the average overhaul for all conventionally

powered carriers. It also underwent SRAs that were longer than average

SRAs in 1991 and 1993. Also, the Navy has approved modernization on

carriers that are within 5 years of inactivation. For example, as we

reported in 1997, the Navy plans to install an improved ship self-defense

system on the U.S.S. Kitty Hawk in 2003, 5 years before its inactivation.5

According to a carrier maintenance planning official, modernizations

5

Ship Self Defense: Program Priorities Are Questionable (GAO/NSIAD-97-195R, Aug. 15, 1997).

Page 177 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

necessary for safe and effective operation can be and are applied to a

carrier within 5 years of its inactivation, and the ship must be maintained

so that it can complete its deployments.

We agree that the Kitty Hawk/Kennedy-class carriers were older and may

have required more maintenance. Those carriers were, on average, three

times as old as the ships of the Nimitz-class, over the actual maintenance

periods we examined. Because older ships require more maintenance, the

data for the Kitty Hawk/Kennedy-class ships may reflect a lower

availability than would the same ships if they were of similar age to the

Nimitz-class.

17. Our work shows that nuclear-powered carriers spend more time in

maintenance than do conventionally powered carriers. A key reason for

the difference is propulsion plant work. According to the Navy’s standard

maintenance planning factors, a nuclear-powered carrier requires about

613,000 mandays of depot-level maintenance to complete three

deployments, about 32 percent more than the 466,000 mandays a

conventionally powered carrier requires. A carrier maintenance planning

official said propulsion plant maintenance accounts for about 44 percent

of the total repair mandays on both conventionally and nuclear-powered

carriers. Moreover, according to a Puget Sound Naval Shipyard carrier

maintenance report, in a nuclear-powered carrier’s predominate

post-deployment major maintenance period of 6 months, about 100,000 of

the 162,000 notional mandays of work would involve nuclear propulsion

plant work. Additionally, a document discussing the factors that must be

considered when planning aircraft carrier maintenance ranked propulsion

type as the second most important factor, after operational requirements.

18. DOD’s assessment of the role maintenance schedules play in a ship’s

employment cycle relates more to conditions in a crisis situation vice

normal peacetime operations. To illustrate, Navy doctrine, as outlined in

Naval Warfare Publication 1, Strategic Concepts of the U.S. Navy, states

that the length of the employment cycle for each ship class is based on the

depot-level maintenance requirements for that class of ship. A regular

maintenance program is essential so that operational commanders have

ships with the material condition and capabilities to fight and win wars.

Furthermore, Navy guidance contained in the Chief of Naval Operation’s

OPNAV Notice 4700, which provides definitive guidance concerning

depot-level maintenance availabilities, states that ships shall accomplish

depot maintenance availabilities at the notional intervals, durations, and

repair mandays set forth. It also states that the durations specified provide

Page 178 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

the best notional estimates for long-range programming. To ensure

compatibility with the ship’s employment schedule and to facilitate depot

work loading, it authorizes minor deviations from the notional depot

availability interval.

Commenting on the challenges of providing peacetime presence

requirements and the relationship of ship maintenance and deployment

schedules, the Commander in Chief, U.S. Pacific Fleet, recently stated,

“The degree of attention required to manage many operational variables—maintenance,

training, operating tempo (OPTEMPO), personnel percentage of time in homeport (PERSTEMPO),

personnel rotation, new contingencies—is growing, and we are often forced to make

tradeoffs...If scheduled maintenance for a ship gets delayed it directly impacts the

maintenance, training, or PERSTEMPO of other ships.” 6

The Eisenhower’s experience during Desert Shield illustrates the degree of

coordination between deployment needs and scheduled maintenance

periods. The Eisenhower was not retained in the theater during the initial

stages of uncertainty after the 1990 Iraqi invasion of Kuwait, but it

returned to Norfolk for a previously scheduled maintenance period.

19. DOD’s conclusion that the Navy will maintain a force of 12 carriers is

based on an analysis of naval force structure options that it performed

during its Quadrennial Defense Review (QDR). Using the Navy’s Force

Presence Model, DOD analyzed various aircraft carrier force structure

options and compared them to the forward presence currently provided in

the U.S. European Command, U.S. Central Command, and U.S. Pacific

Command areas of responsibility. DOD 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.

Our analysis of the comparative number of conventionally and

nuclear-powered carriers needed to meet overseas presence requirements

was based on the Navy’s Force Presence Model, which was also used in

the QDR. Specifically, we used standard assumptions relating to carrier

type maintenance cycle, average speed of advance, distance, PERSTEMPO

restrictions, and length of deployments. We did not postulate what future

carrier type maintenance cycles may or may not be in terms of mandays or

durations. Although the maintenance strategy for conventionally and

6

Statement of Admiral Archie Clemins, U.S. Navy, Commander in Chief, U.S. Pacific Fleet, before the

Subcommittee on Readiness, House Committee on National Security, Mar. 6, 1998.

Page 179 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

nuclear-powered carriers can be similar, the actual maintenance

requirements for nuclear-powered carriers are very different than those

for conventionally powered carriers. For example, carrier maintenance

experts have told us that if an oil-fired steam boiler carrier were moved

from its existing maintenance strategy, the EOC to an IMP type cycle, its

profile would probably consist of two 4-month PIAs followed by a 8-month

DPIA compared to the two 6-month PIAs followed by a 10.5-month DPIA for

the nuclear-powered carriers.

20. Our analysis was intended to present a notional comparison of the

differences in time between the two carrier types to cover the same

distances at the same speeds when factoring in the impact of underway

replenishment. We recognize that neither type would sustain high speeds

during an entire long-distance voyage. Both types of carriers adjust their

speed to control for the proper amount of wind-over-the-deck for air

operations; accomplish underway replenishment; conduct propulsion

plant drills, and rudder swing checks; and adjust to weather conditions.

Nevertheless, both types of carriers can steam at high speeds and have

demonstrated this capability for extended periods of time for many

consecutive hours and even days.

21. We do not agree with DOD’s figures on the amount of propulsion fuel

and AOE fuel capacity that would be required for a conventionally

powered carrier on a 4,800- and 12,000-nautical mile transit at 28 knots.

Based on fuel consumption rates that the Navy provided to us, we found

the following.

• A conventionally powered carrier steaming at 28 knots on a 4,800-nautical

mile transit would require approximately 1.9 million gallons of

replenishment fuel if it were refueled when its propulsion fuel reached 

60 percent of its usable capacity. When the AOE fuel requirements

(1.4 million gallons) for this voyage are added, a total of 3.3 million gallons

of propulsion fuel would be required. This is the equivalent of 0.6 of an

AOE based on an AOE’s total usable ship propulsion fuel (DFM) capacity of

5.2 million gallons. If the carrier and the AOE were accompanied by a

battle group of six fossil-fueled escorts (2 CG-47/52s, 2 DD-963s, and

2 DDG-51s), a total of about 7 million gallons of fuel would be required,

the equivalent of 1.3 Sacramento-class ships.

• A conventionally powered carrier on a 12,000-nautical mile transit

steaming at 28 knots would require approximately 4.75 million gallons of

replenishment fuel if it were refueled when its propulsion fuel reached 

60 percent of its usable capacity. When the AOE’s fuel requirements

Page 180 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

(3.3 million gallons) for this voyage are added to the carrier’s, a total of

8 million gallons of propulsion fuel would be required. This is the

equivalent of 1.5 AOE ships. If the carrier and the AOE were accompanied

by a battle group of six fossil-fueled escorts (2 CG-47/52s, 2 DD-963s, and 

2 DDG-51s), a total of about 17.6 million gallons of fuel would be required,

the equivalent of 3.4 Sacramento-class ships.

22. We based our transit time and fuel consumption comparisons on the

assumption that the conventional carrier would have eight boilers on line

for speeds of 28 knots or faster and four boilers for speeds below 28 knots.

This produced conservative estimates of transit time and fuel

consumption. However, as a Navy-provided document shows, the

Kennedy, for example, can maintain a speed of 28 knots with only five

boilers on line and 29 knots with six boilers on line, with sufficient steam

to operate the catapults in both cases. We believe that such operations

over an extended period of time would be more stressful than normal.

However, under these conditions, not all boiler rooms would have to be

continually manned and operating. Thus, boilers could be rotated off-line

for routine preventive or emergent maintenance. Additionally, the boiler

maintenance information DOD provided in response to our request that it

amplify its comments indicates substantive scheduled maintenance

actions are generally only required at quarterly intervals or longer. While

the watch-standing requirements would be greater when only four boilers

are operating, carriers are supposed to be manned at a sufficient level that

their endurance at a peacetime cruising level of readiness is not

constrained.7

Additionally, Fleet officials familiar with the operation of conventional

carriers told us that conventional carriers can operate for extended

periods at high speeds. We also noted that they have done so in the past.

For example, logs maintained by the Independence during its

January/February 1998 transit from Japan to the Arabian Gulf indicated

that the ship sailed at 27 knots or faster, generally on six boilers, for over

70 percent of the voyage. The Saratoga, when responding to Iraq’s invasion

of Kuwait in 1990, sailed at 25 knots or faster for extended intervals again,

generally with six boilers on line. As noted elsewhere in this report, this

was considered to be the fastest Atlantic Ocean crossing since World 

War II.

7

The document discussing the required operating capabilities of the aircraft carriers specifies four

readiness conditions for a carrier that is underway. These range from Condition I: Battle Readiness to

Condition IV: Peacetime Cruising Readiness. Our review of several extended transits indicates that the

carriers generally steam at Condition IV.

Page 181 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

23. We agree that conventionally powered carriers normally refuel when

their on-board fuel level reaches 50 percent to 60 percent of capacity.

However, the 30-percent minimum fuel level we used is consistent with the

provisions of various fleet operating instructions and is greater than that

allowed in some instances by those instructions. Therefore, we believe

that, in a time of crisis, it is reasonable to expect that reaching the

intended theater of operations would have priority over maintaining a high

fuel level.

24. For a slightly different perspective, compare the crisis response

transits of the U.S.S. Nimitz (CVN-68) and the U.S.S. Independence

(CV-62) in late 1997 and early 1998 (see app. IV).

25. We added information on more recent carrier deployments to 

appendix IV, as noted in comment 3. Further, our independent review of

Navy records in some cases differed from the facts the Navy provided. For

example, the Navy reported that

“In May 1992, EISENHOWER left the Arabian Gulf and transited to the Norwegian Sea

steaming 7000 miles at 30 knots average speed. As part of a joint exercise, EISENHOWER

sprinted ahead of schedule and launched simulated strikes into northern English air bases

earlier than anticipated. The Royal Air Force was taken by complete surprise thinking the

battle group was 300-400 miles further south.”

Our review showed that in May 1992, the U.S.S. Eisenhower was at its

homeport of Norfolk, Virginia, having completed a 6-month deployment on

April 2, 1992. Navy records also show that the Eisenhower transited the

Strait of Hormuz on February 4, 1992, and proceeded to operate in the

North Arabian Sea for 10 days before entering the Gulf of Aden on

February 15th. The ship operated in the Red Sea for 4 days, spent 3 days in

port in Jeddah, Saudi Arabia, then operated in the Red Sea for another 

3 days. The ship transited the Suez Canal on February 27, steamed through

the Mediterranean, and spent 5 days in port at Palma de Mallorca, Spain.

The Eisenhower passed through the Straits of Gibraltar on March 7th and

began operating in the exercise in the Norwegian Sea on March 11. The

actual period of time for the Eisenhower to travel from the Arabian Gulf to

the Norwegian Sea was approximately 35 days. Had the ship averaged 

30 knots, it would have covered 7,000 miles in 10.7 days, including a day to

transit the Suez Canal.

The Navy also said that

Page 182 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

“On 1 October 1997, NIMITZ was ordered to proceed from the South China Sea (Hong

Kong) to the Arabian Gulf at best speed. This 5500 nm transit was completed in 11 days for

an average SOA [speed of advance] of about 21 knots. Since NIMITZ was able to conduct

flight operations for 6 of the 11 transit days, NIMITZ arrived on station with its airwing fully

qualified on 11 October 1997.”

Our analysis of this transit indicated that the U.S.S. Nimitz averaged 

24 knots for the trip. As discussed earlier, the U.S.S. Independence

(CV-62) averaged the same speed when it made a similar voyage about

3 months later. The Nimitz spent 30 percent of the voyage at 30 or more

knots (38 percent at 27 knots and above), while its longest sustained

period of high-speed sailing was 9 hours.

In another example, the Navy stated that

“In March 1996, the NIMITZ battle group was ordered to move from the Persian Gulf to the

western Pacific (Taiwan Straits). The increased self-sustaining capability of a CVN allowed

NIMITZ to remain on-station in the Persian Gulf with only one of its (fossil fueled) escorts,

while the remaining ships in the battle group began the transit toward east Asian waters.

Five days later, NIMITZ departed the Gulf and while en route, refueled her remaining

escort and conducted proficiency flight operations prior to overtaking the rest of her battle

group as they entered the Taiwan Straits.”

Our analysis of this transit indicated that ships of the battle group passed

through the Strait of Hormuz approximately 40 hours (1.7 days) before the

U.S.S. Nimitz and its escort the U.S.S. Port Royal. The Nimitz averaged 

19.8 knots for the transit while spending less than 5 percent of the time at

speeds of 27 knots and above. The ship sustained speeds of 28-30 knots

one time for a 6.5-hour period.

In another instance, the Navy stated:

“On 23 January 1998, U.S.S. INDEPENDENCE (CV-62) was ordered to transit from Japan to

the Arabian Gulf to replace U.S.S. NIMITZ (CVN68), a transit similar to the October 1997

NIMITZ transit. INDEPENDENCE transited 6800 nm with USNS GUADALUPE (TAO

200) at an SOA of about 20 knots, arriving in the Straits of Hormuz on 6 February 1998.

INDEPENDENCE did not conduct flight operations en route. Therefore, upon arrival in the

Arabian Gulf, INDEPENDENCE required over 3 days of flight operations to qualify her

airwing.”

Our analysis of Navy transit data showed that the U.S.S. Independence

averaged over 24 knots for the entire voyage and spent over 70 percent of

Page 183 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

the time at 27 knots and above. During various parts of the transit, the ship

sustained 27 or more knots for several lengthy periods of time, including

42, 31, and 27 hours continuous hours. The U.S.S. Independence refueled

three times during the voyage from three separate T-AO-187-class oilers.

Since these oilers have a top speed of 20 knots, and the Independence

steamed at 27 knots most of the time, it is unlikely that any of the oilers

remained with the carrier during the entire voyage. Our review of ship logs

and other data indicated that Independence aircraft flew during at least 

5 days of the transit, with the last period ending after 11:00 p.m. on

February 4th, the night before the ship reached the Strait of Hormuz. Our

records indicate that the Independence passed through the Strait of

Hormuz shortly before noon on February 5, 1998.

26. We agree that the ability to surge is dictated by the scope and

complexity of the maintenance to be performed, which varies from

availability to availability. In fact, based on discussions with Navy officials

directly responsible for maintenance and actual maintenance data, we

found that due to the complexity of its maintenance, a nuclear-powered

carrier’s maintenance period cannot be shortened to the same degree as

that of a conventionally powered carrier. The report provides an example

for which the data show that a conventionally powered carrier would

require less time to surge from maintenance.

We based our analysis on data provided by the Naval Air Force, U.S.

Pacific Fleet, and developed by the Navy’s aircraft carrier repairs,

maintenance, and modernization planning organization. Officials from the

Naval Air Force, U. S. Atlantic Fleet reviewed and concurred with the

planning organization’s information. The data were also provided to the

Naval Sea Systems Command’s Aircraft Carrier Program Office prior to

our receipt. These commands are responsible for coordinating ship

maintenance and modernization.

Officials from the planning organization noted that a conventionally

powered carrier can be brought out of maintenance before all repairs are

completed and begin its transit while remaining repairs and maintenance

are performed. The nuclear propulsion plants require a more structured

approach because of nuclear maintenance requirements and radiological

safety concerns. Atlantic Fleet officials stated it would be easier to surge

the conventionally powered carrier because additional workers could

easily be assigned to complete the work more quickly by completing work

tasks in parallel. In contrast, nuclear-powered carrier work is sequential

and there are a finite number of nuclear-certified workers.

Page 184 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

27. We did not characterize the Persian Gulf War as the definitive wartime

scenario. The report states that the nature of Desert Storm—a major

regional conflict—portends the types of conflict in which U.S. forces

expect to be engaged in the foreseeable future. This statement is based on

our assessment of the QDR, Defense Planning Guidance, and other DOD

documents that include regional dangers among the threats facing U.S.

forces. For example, the QDR, in discussing the regional dangers

confronting the United States, states that Southwest Asia—especially Iraq

and Iran—is among the foremost threats of coercion and large-scale, cross

border aggression by hostile states with significant military power.

Furthermore, according to Defense Planning Guidance,

“The security environment between now and 2015 will also likely be marked by the

absence of a ’global peer competitor’ able to challenge the U.S. militarily around the world

as the Soviet Union did during the Cold War. . .the U.S. is the world’s only superpower

today, and it is expected to remain so through at least 2015.” 

We agree with DOD that the United States benefited from a local supply of

oil during the Gulf War. However, based on further analysis, we do not

believe this was a controlling factor in the outcome of the Gulf War, nor do

we believe it would be a significant factor in any of the threats facing the

Nation. The Navy has prepositioned large amounts of fuel oil throughout

the Central Command, Indian Ocean, and Western Pacific areas. We used

the Gulf War scenario to evaluate the effectiveness of conventionally and

nuclear-powered carriers in their war-fighting missions because it actually

occurred and involved the most extensive and extended combat use of

carrier aviation since the Vietnam conflict.

28. We agree that light wind conditions or the necessity to perform

downwind air operations can make sortie generation more difficult.

However, our review of carrier transit data indicates that conventionally

powered carriers, like nuclear-powered carriers, adjust their steaming

speeds to meet operational needs. If conditions and operations call for

higher speeds, the propulsion plant in the conventionally powered carriers

can quickly generate and sustain higher speeds to support flight

operations. Throughout this review, we repeatedly sought examples where

conventionally powered carriers were unable to meet operational needs.

Navy officials provided no examples.

29. We agree that the Naval Sea Systems Command (NAVSEA) letter states

that the nuclear propulsion system gives the nuclear-powered carrier an

edge. However, its detailed comparisons noted many similarities between

Page 185 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

various aspects of the two carrier types. Additionally, in discussing this

analysis with NAVSEA officials, they told us that neither type of carrier

possesses any inherent, overriding advantage over the other in its

susceptibility to detection or vulnerability. While there are some

differences between the two carriers, neither has a distinct advantage that

can be specifically attributed to the ship’s propulsion type. These

statements support our conclusion that the propulsion system does not

materially affect survivability. We also note that DOD’s response

commented on the CVN-71’s and later ships’ enhanced survivability to

antiship cruise missile attack compared to that of CV-67 and the earlier

CVN-68 ships. While engine room fires impair a carrier’s mobility, analyses

we reviewed discussed a carrier’s loss in terms of magazine detonation or

sinking due to uncontrollable flooding resulting from blast and

fragmentation damage. These analyses indicated that the degree and type

of magazine protection incorporated into the ship’s design is a greater

determinant of survivability than is propulsion and showed that the

conventionally powered carrier can have a higher probability of surviving

an antiship cruise missile attack than can a nuclear-powered carrier.

Furthermore, we continue to believe that while refueling does restrict a

carrier’s ability to maneuver, the need to replenish will be driven as much

by the need to replenish other ships of the battle group as by the carrier.

30. We disagree that a new design conventionally powered carrier would

necessarily result in a larger and heavier ship, as discussed in comment 1.

31. Increases in fleet oiler requirements because of conventional

propulsion in carriers may not be as great as postulated because, in

general, infrastructure requirements are seldom increased or decreased in

response to small changes in force structure. A 1992 Center For Naval

Analyses report on Combat Logistics Force ship requirements for battle

forces centered around conventionally or nuclear-powered carriers

concluded that nuclear propulsion for carriers alone had only a marginal

effect on the number of support ships needed to sustain battle forces in a

typical combat scenario. The scenario postulated a naval deployment to a

limited regional conflict in Southwest Asia with naval forces supported

from bases in the Western Pacific. This scenario was chosen because the

extreme distances involved would tend to highlight the differences

between the numbers of Combat Logistics Force ships needed to support

battle groups with nuclear-powered carriers and battle groups with

conventionally powered carriers.

Page 186 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

The report also found that on an individual basis, a conventionally

powered carrier needs only one-half more of an oiler than a

nuclear-powered carrier used in a similar fashion (or, for a force of 12

carriers, an additional 6 fleet oilers). The report noted that earlier studies

of Combat Logistics Force requirements used much higher estimates for

ship propulsion fuel. This fact may contribute to the view that the

nuclear-powered carrier offers a freedom from oilers not possible with

conventionally powered carriers. The report also noted that, in practice,

carriers, regardless of propulsion type, are replenished whenever

operational demands make it possible, typically during rest periods

between major flight operations, which normally occur every few days.

As we note in appendix V, the Center for Naval Analyses concluded that

the “increased capacity for ordnance and aviation fuel in the CVN

[nuclear-powered carrier] design is not sufficient to untether the force

from the [logistic] 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.” Another important

factor that could affect the ultimate size of the oiler infrastructure is the

Navy’s general need for a global array of fuel replenishment ships and

depots. We note that the Navy requires a worldwide supply system

because the ship battle force is mostly a conventionally powered ship

force (253 of 349 ships as of April 14, 1998).8

 Appendix III shows that

escort ships of a conventionally powered carrier battle group generally

needed from two-thirds to three-quarters of the total battle group’s overall

underway replenishment fuel requirement.

32. In response to our requests, DOD provided no specific examples where

a conventionally powered carrier’s inability to accelerate actually caused

the situations it mentioned to occur. As stated in the report, ship

personnel are aware of wind conditions during flight operations and can

adjust the ship’s speed, as necessary, to respond to varying landing

conditions in a timely manner. Our review of data gathered during specific

ship transits revealed numerous examples where dramatic speed and

directional changes were made by conventionally powered carriers in

short periods of time to respond to operational needs. We identified two

instances during the recent high-speed transit of the

U.S.S. Independence (CV-62) from Japan to the Persian Gulf where aircraft

8

The Ship Battle Forces consists of Battle Forces, Mobilization Forces, Category A Assets, Strategic

Forces and Support Forces. The Battle Forces include aircraft carriers, surface combatants,

submarines, amphibious warfare ships and mine warfare ships in an active status. Combat logistics

ships, both active and those under the Military Sealift Command (MSC) and Naval Fleet Auxiliary

Force, are also included.

Page 187 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

experienced single-engine emergencies. With the exception of a minor

speed change in one instance, no other speed or directional changes were

made, and both aircraft were recovered safely.

33. Our estimate did not include an allocation of acquisition cost of the

fuel delivery costs because we did not have comparable acquisition cost

data for facilities (i.e., Department of Energy (DOE) laboratories) that

supported the delivery of nuclear power to the Navy’s fleet. We view these

as sunk costs because they tend to be invariant with the size and mix of

the forces. We excluded acquisition costs for all supporting activities and

functions whether they supported conventionally or nuclear-powered

carriers or both types of carriers.

34. Our pipeline training cost estimate is greater because it includes a

more complete universe of costs that are required to provide a steady

supply of trained nuclear propulsion plant personnel. In its comments, the

Navy estimates training pipeline costs at about $13.4 million, which is

based on an allocation of the $142 million it spends annually on nuclear

training. However, budget data indicate that the Navy spends nearly

$195 million annually for student, instructor, operations, and support

personnel and over $80 million in operations and maintenance funds for its

moored ships; the latter amount does not include operations and

maintenance funds for classroom training at the Nuclear Power School.

Our estimate was based on applying the annual per student training cost,

which includes all applicable personnel and operations and maintenance

costs, to the estimated annual training requirement to support one

nuclear-powered carrier.

35. We allocated the cost of DOE’s nuclear support activities based on the

benefit received by the nuclear-powered ships. Since the purpose of the

Naval Nuclear Propulsion Program is to ensure safe and efficient

production of energy, we allocated the program costs according to the

amount of energy consumed. This methodology is in accordance with The

Federal Accounting Standards Advisory Board (FASAB), which

recommends that indirect costs be assigned or allocated based on the

consumption or demand for the activity. Moreover, several DOE and Navy

officials suggested this was the best allocation methodology. This

methodology is also consistent with the way fossil fuel support activities

are allocated based on fuel usage. We overstated the costs for nuclear

support activities in our draft report, but we adjusted these costs in the

final report.

Page 188 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VII 

Comments From the Department of Defense

36. Our carrier disposal costs are based on an estimate provided by the

Navy in fiscal year 1994 and updated in fiscal year 1996. In its comments,

DOD provided a new estimate for the inactivation and disposal costs of a

Nimitz-class carrier. We did not use the newer estimate, which was about

40 percent less than the 1996 estimate, because the Navy did not provide

any evidence that would support significant changes to the 1996 estimate.

Most of the reductions in its new estimate are attributed to a large learning

curve and to new technologies.

Officials from the Navy’s principal shipyard for nuclear plant inactivation

and disposal, the Navy’s carrier maintenance experts, and the cost

estimating community have told us that it is highly unlikely that any

significant cost reductions can be obtained from learning in an episodic

activity such as the refueling or inactivations of a Nimitz-class carrier.

Large scale activities such as these with intervals of about 4 years do not

lend themselves to learning curve reductions on the scale that is included

in DOD’s new estimate.

Further, over the past 20 years, the methods and technologies have

remained fairly constant. The Navy was unable to provide any examples of

technologies that could result in potential cost reductions ranging from 

20 to 40 percent. Moreover, according to a recent Navy report, “although

delaying disposal could potentially allow the development of some new

technology to deal with the disposal of radioactivity, there is nothing

presently on the horizon that would hold the promise of a more cost

effective, environmentally safe disposal method for reactor departments.”9

37. In our draft report, our estimate for spent nuclear fuel (SNF) was based

on a “wet storage” method. The Navy told us that it plans to store SNF using

a different method referred to as dry storage. We modified the report

accordingly.

9

Department of the Navy. Final Environmental Impact Statement on the Disposal of Decommissioned,

Defueled Cruiser, Ohio Class, and Los Angeles Class Naval Reactor Plants (April 1996).

Page 189 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Appendix VIII 

Major Contributors to This Report

National Security and

International Affairs

Division, Washington,

D.C.

Richard J. Herley, Assistant Director

Roderick W. Rodgers, Evaluator-in-charge

Kenneth W. Newell, Sr. Evaluator

Joseph P. Raffa, Sr. Evaluator

Madelon B. Savaides, Sr. Evaluator

Tim F. Stone, Sr. Evaluator

Norfolk Field Office Brenda Waterfield, Sr. Evaluator

Mary Jo LaCasse, Evaluator

Office of the Chief

Economist,

Washington, D.C.

William McNaught, Assistant Director

Harold J. Brumm, Senior Economist

Several other persons assisted during the assignment, including Edna Thea

Falk, Rick Yeh, and Steve Katz. Mark Wielgoszynski provided advice in

defining the methodology and approach and reviewed the draft report.

Data analysis quality assurance checks were performed by Ricardo

Aguilera, Anthony DeFrank, Fred Dziadek, Bob Kenyon, Marc Schwartz,

and Dale Wineholt.

Page 190 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Related GAO Products

Surface Combatants: Navy Faces Challenges Sustaining Its Current

Program (GAO/NSIAD-97-57, May 21, 1997).

Nuclear Waste: Impediments to Completing the Yucca Mountain

Repository Project (GAO/RCED-97-30, Jan. 17, 1997).

New Attack Submarine: Program Status (GAO/NSIAD-97-25, Dec. 3, 1996).

Defense Infrastructure: Budget Estimates For 1996-2001 Offer Little

Savings for Modernization (GAO/NSIAD-96-131, Apr. 4, 1996).

Marine Corps: Improving Amphibious Capability Would Require Larger

Share of Budget Than Previously Provided (GAO/NSIAD-96-47, Feb. 13, 1996).

Future Years Defense Program: 1996 Program Is Considerably Different

From the 1995 Program (Letter Report GAO/NSIAD-95-213, Sept. 15, 1995).

Nuclear Carrier Homeporting (GAO/NSIAD-95-146R, Apr. 21, 1995).

Navy’s Aircraft Carrier Program: Investment Strategy Options

(GAO/NSIAD-95-17, Jan. 1995).

Nuclear Waste: Comprehensive Review of the Disposal Program Is Needed

(GAO/RCED-94-299, Sept. 27, 1994).

Nuclear Waste: Foreign Countries Approaches to High-Level Waste

Storage and Disposal (GAO/RCED-94-172, Aug. 4, 1994).

Future Years Defense Program: Optimistic Estimates Lead to Billions in

Overprogramming (GAO/NSIAD-94-210, July 29, 1994).

Navy Modernization: Alternatives for Achieving a More Affordable Force

(GAO/T-NSIAD-94-171, Apr. 26, 1994).

Navy Carrier Battle Groups: The Structure and Affordability of the Future

Force (GAO/NSIAD-93-74, Feb. 25, 1993).

Navy Maintenance: Overseas Ship Repairs and Associated Costs

(GAO/NSIAD-93-61, Nov. 13, 1992).

Nuclear Submarines: Navy Efforts to Reduce Inactivation Costs

(GAO/NSIAD-92-134, July 21, 1992).

Page 191 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Related GAO Products

Nuclear-Powered Ships: Accounting for Shipyard Costs and Nuclear Waste

Disposal Plans (GAO/NSIAD-92-256, July 1, 1992).

(701030) Page 192 GAO/NSIAD-98-1 Nuclear Carrier Cost-Effectiveness
Ordering Information

The first copy of each GAO report and testimony is free.

Additional copies are $2 each. Orders should be sent to the

following address, accompanied by a check or money order

made out to the Superintendent of Documents, when

necessary. VISA and MasterCard credit cards are accepted, also.

Orders for 100 or more copies to be mailed to a single address

are discounted 25 percent.

Orders by mail:

U.S. General Accounting Office

P.O. Box 37050

Washington, DC 20013

or visit:

Room 1100

700 4th St. NW (corner of 4th and G Sts. NW)

U.S. General Accounting Office

Washington, DC

Orders may also be placed by calling (202) 512-6000 

or by using fax number (202) 512-6061, or TDD (202) 512-2537.

Each day, GAO issues a list of newly available reports and

testimony. To receive facsimile copies of the daily list or any

list from the past 30 days, please call (202) 512-6000 using a

touchtone phone. A recorded menu will provide information on

how to obtain these lists.

For information on how to access GAO reports on the INTERNET,

send an e-mail message with "info" in the body to:

info@www.gao.gov

or visit GAO’s World Wide Web Home Page at:

http://www.gao.gov

PRINTED ON RECYCLED PAPER
United States

General Accounting Office

Washington, D.C. 20548-0001

Official Business

Penalty for Private Use $300

Address Correction Requested

Bulk Rate

Postage & Fees Paid

GAO

Permit No. G100