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Updated September 29, 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.
SSN(X) Program
When procured at a rate of two boats per year, VPM-
equipped Virginia-class SSNs have an estimated
Program Designation
procurement cost of about $3.4 billion per boat.
In the designation SSN(X), the “X” means that the exact
design of the boat has not yet been determined.
For additional information on Navy submarines, the
Virginia-class SSN program, and the Columbia-class SSBN
Procurement Schedule
program, see CRS Report RL32418, Navy Virginia (SSN-
Under the Navy’s FY2020 30-year (FY2020-FY2049)
774) Class Attack Submarine Procurement: Background
shipbuilding plan, the first SSN(X) would be procured in
and Issues for Congress, by Ronald O'Rourke, and CRS
FY2031, along with a single Virginia-class boat. In FY2032
Report R41129, Navy Columbia (SSBN-826) Class Ballistic
and FY2033, the final four Virginia-class boats would be
Missile Submarine Program: Background and Issues for
procured, at a rate of two per year. Procurement of follow-
Congress, by Ronald O'Rourke.
on SSN(X)s, at a rate of two per year, would then begin in
Submarine Construction Industrial Base
FY2034. The 30-year plan’s sustained procurement rate of
two SSNs per year would achieve a force of 66 SSNs —the
U.S. Navy submarines are built by General Dynamics’
Navy’s current SSN force-level goal—in FY2048.
Electric Boat Division (GD/EB) of Groton, CT, and
Quonset Point, RI, and Huntington Ingalls Industries’
A long-range Navy shipbuilding document released by the
Newport News Shipbuilding (HII/NNS), of Newport News,
Trump Administration on December 9, 2020, proposed a
VA. These are the only two shipyards in the country
new SSN force-level goal of 72 to 78 boats. To meet this
capable of building nuclear-powered ships. GD/EB builds
goal by the latter 2040s, it projected an SSN procurement
submarines only, while HII/NNS also builds nuclear-
rate of three boats per year during the period FY2035-
powered aircraft carriers and is capable of building other
FY2041, and two and two-thirds boats per year (in annual
types of surface ships.
quantities of 2-3-3) during the period FY2042-FY2050. A
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Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
long-range Navy shipbuilding document released by the
class SSNs and, in modified form, is to be used for
Biden Administration on June 17, 2021, proposed a new
building Columbia-class SSBNs), or whether individual
SSN force-level goal of 66 to 72 boats and envisaged
SSN(X)s should instead be completely built within a
increasing the SSN procurement rate years from now to
given shipyard (the separate-yard approach used for
something more than two boats per year.
building earlier Navy SSNs and SSBNs).
Design of the SSN(X)
Regarding the third issue above, a January 2020
The Navy states that the SSN(X)
Department of Energy (DOE) National Nuclear Security
Administration (NNSA) report to Congress on the potential
will be designed to counter the emerging threat
for using LEU for the SSN(X) that was provided by the
posed by near peer adversary competition for
Navy to CRS in unclassified form stated:
undersea supremacy. Unlike the VIRGINIA Class
It is not practical to substitute LEU into existing
Submarine, which was designed for multimission
naval fuel systems or to design a VIRGINIA Class
dominance in the littoral, SSN(X) will be designed
Submarine (VCS) replacement [i.e., the SSN(X)]
for greater transit speed under increased stealth
around an unproven advanced LEU fuel concept.
conditions in all ocean environments, and carry a
Developing a newly designed submarine capable of
larger inventory of weapons and diverse payloads.
later acceptance of an LEU reactor core would also
It will also be designed to retain multi-mission
involve insertion of substantial margin (e.g.,
capability and sustained combat presence in denied
increased hull size) that would be difficult to
waters, with a renewed priority in the anti-
estimate accurately at present and costly to
submarine warfare (ASW) mission against
implement. If future United States policy requires a
sophisticated threats in greater numbers.
shift to LEU, at least 15 years of advanced fuel
(Budget-justification book for FY2022 Research,
development and significant investment would be
Development, Test, and Evaluation, Navy account,
required. This development timeline makes it
Vol. 3 [Budget Activity 5], p. 1301.)
impractical to design a lead ship VCS replacement
with an LEU reactor while meeting the Navy’s
A Navy official stated in July 2021 that the Navy wants the
schedule.
SSN(X) to incorporate the speed and payload the Navy’s
fast and heavily armed Seawolf (SSN-21) class SSN design,
FY2022 Funding Request and
the acoustics (i.e., quietness) and sensors of the Virginia-
Congressional Action
class design, and the operational availability and service life
The Navy’s proposed FY2022 budget requests $98.0
of the Columbia-class design. (Justin Katz, “SSN(X) Will
million in research and development funding for the
Be ‘Ultimate Apex Predator,’” Breaking Defense, July 21,
SSN(X) program, including $29.8 million in Project 2368
2021.)
(SSN[X] Class Submarine Development) within Program
Potential Procurement Cost
Element (PE) 0604850N (SSN[X]), which is line 154 in the
Navy’s FY2022 research and development account, and
An April 2021 Congressional Budget Office (CBO) report
$68.1 million in Project 2370 (Next Generation Fast Attack
states that in constant FY2021 dollars, the SSN(X)’s
Nuclear Propulsion Development) within PE 0603570N
average unit procurement cost is estimated at $5.8 billion
(Advanced Nuclear Power Systems), which is line 48.
by the Navy and $6.2 billion by CBO—figures that are
substantially higher than the $3.4 billion unit procurement
The House Armed Services Committee’s report (H.Rept.
cost of a VPM-equipped Virginia-class SSN.
117-188 of September 10, 2021) on the FY2022 National
Issues for Congress
Defense Authorization Act (NDAA) (H.R. 4350)
recommended approving both of these funding requests.
Issues for Congress include the following:
The Senate Armed Services Committee’s report (S.Rept.
ï‚· whether the Navy has accurately identified the
117-39 of September 22 [legislative day, September 21],
SSN(X)’s required capabilities and accurately analyzed
2021) on the FY2022 NDAA (S. 2792) recommended
and incorporated the impact that various required
increasing line 154 by $25.8 million for “Navy UFR
capabilities can have on the SSN(X)’s cost;
[unfunded requirement]—SSN(X) non-propulsion
ï‚·
development.” (Page 446)
the potential impact of the SSN(X) program on funding
that will be available for other Navy program priorities;
The House Appropriations Committee’s report (H.Rept.
ï‚· whether it would be technically feasible for the SSN(X)
117-88 of July 15, 2021) on the FY2022 DOD
to be powered by a reactor plant using low-enriched
Appropriations Act (H.R. 4432) recommended reducing
uranium (LEU), rather than the highly enriched uranium
line 154 by $4.98 million for “excess to need” (page 270)
(HEU) used on other Navy nuclear-powered ships, and
and line 48 by $18.082 million for a “Classified
if so, what impact using LEU in the SSN(X) would have
adjustment” that may or may not be related to the SSN(X)
on nuclear arms control and nonproliferation efforts and
program (page 266).
SSN(X) costs and capabilities; and
ï‚·
Ronald O'Rourke, Specialist in Naval Affairs
whether each SSN(X) should be built jointly by GD/EB
and HII/NNS (the approach used for building Virginia-
IF11826
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Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress


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https://crsreports.congress.gov | IF11826 · VERSION 10 · UPDATED

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