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Updated August 2, 2021
Navy Next-Generation Attack Submarine (SSN[X]) Program:
Background and Issues for Congress
Introduction and Issue for Congress
In addition to GD/EB and HII/NNS, the submarine
The Navy wants to begin procuring a new class of nuclear-
construction industrial base includes hundreds of supplier
powered attack submarine (SSN), called the Next-
firms, as well as laboratories and research facilities, in
Generation Attack Submarine or SSN(X), in FY2031. The
numerous states. Much of the material procured from
SSN(X) would be the successor to the Virginia-class SSN
supplier firms for the construction of submarines comes
design, which the Navy has been procuring since FY1998.
from sole-source suppliers. For nuclear-propulsion
The Navy’s proposed FY2022 budget requests $98.0
component suppliers, an additional source of work is the
million in research and development funding for the
Navy’s nuclear-powered aircraft carrier construction
SSN(X) program. An issue for Congress is whether to
program.
approve, reject, or modify the Navy’s funding requests and
acquisition strategy for the SSN(X) program.
Figure 1. Virginia-Class Attack Submarine (SSN)
Submarines in the U.S. Navy
The U.S. Navy operates three types of submarines—
nuclear-powered ballistic missile submarines (SSBNs),
nuclear-powered cruise missile and special operations
forces (SOF) submarines (SSGNs), and nuclear-powered
attack submarines (SSNs). The SSNs are general-purpose
submarines that can perform a variety of peacetime and
wartime missions.
Virginia-Class Program
Since FY2011, Virginia-class SSNs (Figure 1) have been
procured at a rate of two boats per year, and a total of 34
have been procured through FY2021. Most Virginia-class
Source: Cropped version of photograph accompanying Dan Ward,
boats procured in FY2019 and subsequent years are to be
“Opinion: How Budget Pressure Prompted the Success of Virginia-
built with the Virginia Payload Module (VPM), an
Class Submarine Program,” USNI News, November 3, 2014. The
additional, 84-foot-long, mid-body section equipped with
caption states that it shows USS Minnesota (SSN-783) under
four large-diameter, vertical launch tubes for storing and
construction in 2012, and credits the photograph to the U.S. Navy.
launching Tomahawk cruise missiles or other payloads.
When procured at a rate of two boats per year, VPM-
equipped Virginia-class SSNs have an estimated
SSN(X) Program
procurement cost of about $3.4 billion per boat.
Program Designation
For additional information on Navy submarines, the
In the designation SSN(X), the “X” means that the exact
Virginia-class SSN program, and the Columbia-class SSBN
design of the boat has not yet been determined.
program, see CRS Report RL32418, Navy Virginia (SSN-
774) Class Attack Submarine Procurement: Background
Procurement Schedule
and Issues for Congress, by Ronald O'Rourke, and CRS
Under the Navy’s FY2020 30-year (FY2020-FY2049)
Report R41129, Navy Columbia (SSBN-826) Class Ballistic
shipbuilding plan, the first SSN(X) would be procured in
Missile Submarine Program: Background and Issues for
FY2031, along with a single Virginia-class boat. In FY2032
Congress, by Ronald O'Rourke.
and FY2033, the final four Virginia-class boats would be
procured, at a rate of two per year. Procurement of follow-
Submarine Construction Industrial Base
on SSN(X)s, at a rate of two per year, would then begin in
U.S. Navy submarines are built by General Dynamics’
FY2034. The 30-year plan’s sustained procurement rate of
Electric Boat Division (GD/EB) of Groton, CT, and
two SSNs per year would achieve a force of 66 SSNs —the
Quonset Point, RI, and Huntington Ingalls Industries’
Navy’s current SSN force-level goal—in FY2048.
Newport News Shipbuilding (HII/NNS), of Newport News,
VA. These are the only two shipyards in the country
A long-range Navy shipbuilding document released by the
capable of building nuclear-powered ships. GD/EB builds
Trump Administration on December 9, 2020, proposed a
submarines only, while HII/NNS also builds nuclear-
new SSN force-level goal of 72 to 78 boats. To meet this
powered aircraft carriers and is capable of building other
goal by the latter 2040s, it projected an SSN procurement
types of surface ships.
rate of three boats per year during the period FY2035-
FY2041, and two and two-thirds boats per year (in annual
https://crsreports.congress.gov
Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
quantities of 2-3-3) during the period FY2042-FY2050. A
potential future Navy funding levels—on funding that
long-range Navy shipbuilding document released by the
will be available for other Navy program priorities;
Biden Administration on June 17, 2021, proposed a new
SSN force-level goal of 66 to 72 boats and envisaged
whether it would be technically feasible for the SSN(X)
increasing the SSN procurement rate years from now to
to be powered by a reactor plant using low-enriched
something more than two boats per year.
uranium (LEU), rather than the highly enriched uranium
(HEU) used on other Navy nuclear-powered ships, and
Design of the SSN(X)
if so, what impact using LEU in the SSN(X) would have
The Navy states that the SSN(X)
on nuclear arms control and nonproliferation efforts and
SSN(X) costs and capabilities.
will be designed to counter the emerging threat
posed by near peer adversary competition for
whether each SSN(X) should be built jointly by GD/EB
undersea supremacy. Unlike the VIRGINIA Class
and HII/NNS (the approach used for building Virginia-
Submarine, which was designed for multimission
class SSNs and, in modified form, is to be used for
dominance in the littoral, SSN(X) will be designed
building Columbia-class SSBNs), or whether individual
for greater transit speed under increased stealth
SSN(X)s should instead be completely built within a
conditions in all ocean environments, and carry a
given shipyard (the separate-yard approach used for
larger inventory of weapons and diverse payloads.
building earlier Navy SSNs and SSBNs).
It will also be designed to retain multi-mission
capability and sustained combat presence in denied
Regarding the third issue above, a July 2018 letter to
waters, with a renewed priority in the anti-
Congress from Naval Reactors (the office within the Navy
and the Department of Energy responsible for des igning
submarine warfare (ASW) mission against
Navy reactor plants) stated that “substantial technology
sophisticated threats in greater numbers. SSN(X)
development of an advanced naval fuel [using LEU] would
will be required to defend against threat UUVs
be needed to increase uranium loading in naval reactors
[unmanned underwater vehicles], and coordinate
while simultaneously meeting performance requirements of
with a larger contingent of off-hull vehicles,
U.S. Navy warships,” and that “initial ship concept design
sensors, and friendly forces.
studies [for the SSN(X)] would need to occur no later than
(Budget-justification book for FY2022 Research,
the mid 2020s, nearly a decade before sufficient advanced
Development, Test, and Evaluation, Navy account,
fuel information could be available to support reactor
design efforts.” The letter stated that “Naval R
Vol. 3 [Budget Activity 5], p. 1301.)
eactors
provided a report to Congress in July 2016 outlining a 15-
The Navy is examining three broad design options for the
year test and development effort that would need to be done
SSN(X)—a design based on the Virginia-class SSN design,
to support initiating a reactor design using advanced fuel.”
a design based on the Columbia-class SSBN design, and a
brand new design. An industry official stated that the
FY2022 Funding Request and
SSN(X) might have a beam (i.e., hull diameter) greater than
Congressional Action
that of the Virginia-class design (34 feet), and closer to that
The Navy’s proposed FY2022 budget requests $98.0
of the Navy’s Seawolf-class SSN design and Columbia-
million in research and development funding for the
class SSBN design (40 and 43 feet, respectively).
SSN(X) program, including $29.8 million in Project 2368
(SSN[X] Class Submarine Development) within Program
Potential Procurement Cost
Element (PE) 0604850N (SSN[X]), which is line 154 in the
Based on the Navy’s desired capabilities for the SSN(X),
Navy’s FY2022 research and development account, and
the Navy and the Congressional Budget Office (CBO)
$68.1 million in Project 2370 (Next Generation Fast Attack
expect the SSN(X) to be substantially more expensive to
Nuclear Propulsion Development) within PE 0603570N
procure than the Virginia-class design. An April 2021 CBO
(Advanced Nuclear Power Systems), which is line 48 in the
report on the December 9, 2020, 30-year Navy shipbuilding
Navy’s FY2022 research and development account.
document states that in constant FY2021 dollars, the
SSN(X)’s average unit procurement cost is estimated at
The House Appropriations Committee, in its report
$5.8 billion by the Navy and $6.2 billion by CBO.
(H.Rept. 117-88 of July 15, 2021) on the FY2022 DOD
Appropriations Act (H.R. 4432), recommended reducing
Issues for Congress
the Navy’s line 154 funding request by $4.98 million for
Issues for Congress include the following:
“excess to need” (page 270), and recommended reducing
the Navy’s line 48 funding request by $18.082 million for a
whether the Navy has accurately identified the
“Classified adjustment” that may or may not be related to
SSN(X)’s required capabilities and accurately analyzed
the SSN(X) program (page 266).
and incorporated the impact that various required
capabilities can have on the SSN(X)’s cost;
Ronald O'Rourke, Specialist in Naval Affairs
the potential impact of the SSN(X) program—given the
IF11826
design’s currently estimated unit procurement cost and
https://crsreports.congress.gov
Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permissio n of the copyright holder if you
wish to copy or otherwise use copyrighted material.
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