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Updated May 24, 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
Congress approved $1 million in initial research and
component suppliers, an additional source of work is the
development funding for the SSN(X) program in FY2021.
Navy’s nuclear-powered aircraft carrier construction
An issue for Congress for FY2022 and subsequent years is
program.
whether to 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
Source: Cropped version of photograph accompanying Dan Ward,
have been procured through FY2021. Most Virginia-class
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
caption states that it shows USS Minnesota (SSN-783) under
additional, 84-foot-long, mid-body section equipped with
construction in 2012, and credits the photograph to the U.S. Navy.
four large-diameter, vertical launch tubes for storing and
launching Tomahawk cruise missiles or other payloads.
When procured at a rate of two boats per year, VPM-
SSN(X) Program
equipped Virginia-class SSNs have an estimated
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
If the SSN(X) program follows the pattern of previous
projected an SSN procurement rate of three boats per year
Navy submarine acquisition programs, the SSN(X)
during the period FY2035-FY2041, and two and two-thirds
program’s annual research and development funding
boats per year (in annual quantities of 2-3-3) during the
requests in coming years would increase to tens of millions
period FY2042-FY2050.
of dollars per year, and eventually to hundreds of millions
of dollars per year. In addition to funding in PE 0604850N,
Design of the SSN(X)
funding for developing the SSN(X)’s reactor plant might be
The Navy states that the SSN(X)
provided through PE 0603570N (Advanced Nuclear Power
Systems), the PE that has been used in the past for funding
will be designed to counter the emerging threat
the development of reactor plants for other Navy nuclear-
posed by near peer adversary competition for
powered ships.
undersea supremacy. Unlike the VIRGINIA Class
Submarine, which was designed for multi-mission
Issues for Congress
dominance in the littoral, SSN(X) will be designed
Issues for Congress include the following:
for greater transit speed under increased stealth
conditions in all ocean environments, and carry a
whether the Navy has accurately identified the
larger inventory of weapons and diverse payloads.
SSN(X)’s required capabilities and accurately analyzed
While SSN(X) will be designed to retain multi-
and incorporated the impact that various required
capabilities can have on the SSN(X)’s
mission capability and sustained combat presence
procurement cost
in denied waters, renewed priority of the anti-
and life-cycle operation and support (O&S) cost;
submarine warfare (ASW) mission against
the potential impact of the SSN(X) program—given the
sophisticated threats in greater numbers will
design’s currently estimated unit procurement cost and
influence the design trade space. SSN(X) will be
potential future Navy funding levels—on funding that
required to defend against threat UUVs [unmanned
will be available for other Navy program priorities;
underwater vehicles], and coordinate with a larger
contingent of off-hull vehicles, sensors, and
whether it would be technically feasible for the SSN(X)
friendly forces.
to be powered by a reactor plant using low-enriched
(Budget-justification book for FY2021 Research,
uranium (LEU), rather than the highly enriched uranium
Development, Test, and Evaluation, Navy account,
(HEU) used on other Navy nuclear-powered ships, and
if so, what impact using LEU in the SSN(X) would have
Vol. 3 [Budget Activity 5], p. 1365.)
on (1) nuclear arms control and nonproliferation efforts,
The Navy is examining three broad design options for the
(2) the SSN(X)’s operational capabilities, and (3) the
SSN(X)—a design based on the Virginia-class SSN design,
SSN(X) program’s schedule, technical risk, and
a design based on the Columbia-class SSBN design, and a
development, procurement, and life-cycle operation and
brand new design. An industry official stated that the
support (O&S) costs; and
SSN(X) might have a beam (i.e., hull diameter) greater than
that of the Virginia-class design (34 feet), and closer to that
whether each SSN(X) should be built jointly by GD/EB
of the Navy’s Seawolf-class SSN design and Columbia-
and HII/NNS (the approach that has been used for
class SSBN design (40 and 43 feet, respectively).
building Virginia-class SSNs and, in modified form, is
to be used for building Columbia-class SSBNs), or
Potential Procurement Cost
whether individual SSN(X)s should instead be
Based on the Navy’s desired capabilities for the SSN(X),
completely built within a given shipyard (the separate-
the Navy and the Congressional Budget Office (CBO)
yard approach used for building earlier Navy SSNs and
expect the SSN(X) to be substantially more expensive to
SSBNs).
procure than the Virginia-class design. An April 2021 CBO
report on the December 9, 2020, 30-year Navy shipbuilding
Regarding the final issue above, the Navy and Congress
document states that in constant FY2021 dollars, the
chose the joint-production strategy for the Virginia-class
SSN(X)’s average unit procurement cost is estimated at
program as a means of preserving two U.S. submarine
$5.8 billion by the Navy and $6.2 billion by CBO.
construction shipyards during an expected period of
relatively low annual submarine procurement rates. For the
Funding
SSN(X) program, factors to consider include the expected
Funding for the SSN(X) program is currently provided in
future submarine procurement rate; the impact that shifting
the Navy’s research and development account, and
back to separate-yard production might have on the Navy’s
specifically in Project 2368 (SSN[X] Class Submarine
ability to use competition in awarding SSN(X) construction
Development), which is the only project within Program
contracts; and the feasibility and cost of shifting back to
Element (PE) 0604850N (SSN[X]). In the Navy’s FY2021
separate-yard production after more than 20 years of joint
budget, PE 0604850N was line 150 in the Navy’s research
production.
and development account. For FY2021, the Navy requested
$1 million for PE 0604850N. Congress, as part of its action
Ronald O'Rourke, Specialist in Naval Affairs
on the Navy’s proposed FY2021 budget, approved this
request.
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
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
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https://crsreports.congress.gov | IF11826 · VERSION 2 · UPDATED