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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 subsequent 30-year Navy shipbuilding document that the
capable of building nuclear-powered ships. GD/EB builds
Trump Administration released on December 9, 2020—a
submarines only, while HII/NNS also builds nuclear-
document that can be viewed as the Trump
powered aircraft carriers and is capable of building other
Administration’s final published vision for future Navy
types of surface ships.
force structure and/or a draft version of the FY2022 30-year
shipbuilding plan—proposed a new SSN force-level goal of
https://crsreports.congress.gov
Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
72 to 78 boats. To meet this goal by the latter 2040s, it
Issues for Congress
projected an SSN procurement rate of three boats per year
Issues for Congress include the following:
during the period FY2035-FY2041, and two and two-thirds
boats per year (in annual quantities of 2-3-3) during the
whether the Navy has accurately identified the
period FY2042-FY2050.
SSN(X)’s required capabilities and accurately analyzed
and incorporated the impact that various required
Design of the SSN(X)
capabilities can have on the SSN(X)’s procurement cost
The Navy states that the SSN(X)
and life-cycle operation and support (O&S) cost;
will be designed to counter the emerging threat
the potential impact of the SSN(X) program—given the
posed by near peer adversary competition for
design’s currently estimated unit procurement cost and
undersea supremacy. Unlike the VIRGINIA Class
potential future Navy funding levels—on funding that
Submarine, which was designed for multimission
will be available for other Navy program priorities;
dominance in the littoral, SSN(X) will be designed
for greater transit speed under increased stealth
whether it would be technically feasible for the SSN(X)
conditions in all ocean environments, and carry a
to be powered by a reactor plant using low-enriched
larger inventory of weapons and diverse payloads.
uranium (LEU), rather than the highly enriched uranium
It will also be designed to retain multi-mission
(HEU) used on other Navy nuclear-powered ships, and
capability and sustained combat presence in denied
if so, what impact using LEU in the SSN(X) would have
waters, with a renewed priority in the anti-
on nuclear arms control and nonproliferation efforts and
SSN(X) costs and capabilities.
submarine warfare (ASW) mission against
sophisticated threats in greater numbers. SSN(X)
whether each SSN(X) should be built jointly by GD/EB
will be required to defend against threat UUVs
and HII/NNS (the approach that has been used for
[unmanned underwater vehicles], and coordinate
building Virginia-class SSNs and, in modified form, is
with a larger contingent of off-hull vehicles,
to be used for building Columbia-class SSBNs), or
sensors, and friendly forces.
whether individual SSN(X)s should instead be
(Budget-justification book for FY2022 Research,
completely built within a given shipyard (the separate-
Development, Test, and Evaluation, Navy account,
yard approach used for building earlier Navy SSNs and
Vol. 3 [Budget Activity 5], p. 1301.)
SSBNs).
The Navy is examining three broad design options for the
Regarding the third issue above, a July 2018 letter to
SSN(X)—a design based on the Virginia-class SSN design,
Congress from Naval Reactors (the office within the Navy
a design based on the Columbia-class SSBN design, and a
and the Department of Energy responsible for designing
brand new design. An industry official stated that the
Navy reactor plants) stated that “substantial technology
SSN(X) might have a beam (i.e., hull diameter) greater than
development of an advanced naval fuel [using LEU] would
that of the Virginia-class design (34 feet), and closer to that
be needed to increase uranium loading in naval reactors
of the Navy’s Seawolf-class SSN design and Columbia-
while simultaneously meeting performance requirements of
class SSBN design (40 and 43 feet, respectively).
U.S. Navy warships,” and that “initial ship concept design
studies [for the SSN(X)] would need to occur no later than
Potential Procurement Cost
the mid 2020s, nearly a decade before sufficient advanced
Based on the Navy’s desired capabilities for the SSN(X),
fuel information could be available to support reactor
the Navy and the Congressional Budget Office (CBO)
design efforts.” The letter stated that “Naval Reactors
expect the SSN(X) to be substantially more expensive to
provided a report to Congress in July 2016 outlining a 15-
procure than the Virginia-class design. An April 2021 CBO
year test and development effort that would need to be done
report on the December 9, 2020, 30-year Navy shipbuilding
to support initiating a reactor design using advanced fuel.”
document states that in constant FY2021 dollars, the
SSN(X)’s average unit procurement cost is estimated at
Regarding the fourth issue above, the Navy and Congress
$5.8 billion by the Navy and $6.2 billion by CBO.
chose the joint-production strategy for the Virginia-class
program as a means of preserving two U.S. submarine
FY2022 Funding
construction shipyards during an expected period of
The Navy’s proposed FY2022 budget requests $98.0
relatively low annual submarine procurement rates. For the
million in research and development funding for the
SSN(X) program, factors to consider include the expected
SSN(X) program, including $29.8 million in Project 2368
future submarine procurement rate; the impact that shifting
(SSN[X] Class Submarine Development) within Program
back to separate-yard production might have on the Navy’s
Element (PE) 0604850N (SSN[X]) and $68.1 million in
ability to use competition in awarding SSN(X) construction
Project 2370 (Next Generation Fast Attack Nuclear
contracts; and the feasibility and cost of shifting back to
Propulsion Development). The SSN(X) program is also
separate-yard production after more than 20 years of joint
leveraging Virginia-class research and development work
production.
funded through Project 1947 (New Design SSN HM&E
[hull, mechanical, and electrical]) within PE 0604558N
Ronald O'Rourke, Specialist in Naval Affairs
(New Design SSN). (New Design SSN here refers to the
Virginia-class SSN.)
IF11826
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
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