	Background

The U.S. strategic nuclear deterrent is spread among three legs, as  depicted in figure 1. Currently, 14  Ohio class SSBNs provide the sea-based strategic deterrent. A reliable TRA illuminates concerns and  serves as the basis for realistic discussions on how to mitigate potential  risks as programs move from the early stages of technology  development. These efforts include the  integrated power system, nuclear reactor, propulsor/coordinated stern,  stern area system, and common missile compartment. However, the Navy  identified only two of the submarine’s technologies as “critical” in the  program’s 2015 TRA, thereby underrepresenting the technology risk in  the program. Moreover, there is no requirement that the Navy report to  Congress on its progress in developing and testing the technologies until  after the program completes its production readiness review in May 2020  after the Navy requests another $8.7 billion in funding for the construction  of the lead submarine. The status of these  technologies is discussed in detail below. The Navy Has Not Appropriately Identified Technologies as Critical, Which Underrepresents the Program’s Technical Risk

While the Navy conducted the 2015 Columbia class TRA in accordance  with a DOD-approved plan, it did not follow our identified best practices  for identifying all critical technology elements (CTE), resulting in an  underrepresentation of the technical risk facing the program. Required Report to Congress on Technology Efforts Will Not Occur Until after Lead Ship Authorization

As the Columbia class program moves into its detail design and  construction phase, it will be more than 2 years before the next  requirement for a formal DOD report to Congress on the progress of the  technology efforts. Congress will be asked to approve  lead ship construction absent key information on the maturity of the  critical technologies that, at present, are not up to the maturity levels that  would provide assurance they will work as intended. Further, the Navy faces an aggressive production schedule in  order to deliver the lead submarine by fiscal year 2031, which will be  required to prevent a gap in U.S. nuclear deterrent capabilities. As a result, a portion of the submarine had to be redesigned at additional  cost. This means that it is more likely than not that actual costs to  research, develop, and buy the submarines will exceed the Navy’s $128  billion estimate. Given the risks facing the program and the significance of potential delays  or cost growth, we believe this program warrants increased attention to  and scrutiny over what we consider to be its critical technologies  (inclusive of the program’s stated technology development efforts),  several of which remain immature. Matter for Congressional Consideration

In our draft report we had suggested a matter for congressional  consideration related to additional Navy reporting on the Columbia class  technologies, but we have since removed it because the recently passed  National Defense Authorization Act (NDAA) for 2018 includes Navy  reporting requirements for the Columbia class program that would  achieve the intent of our matter. To assess the status of key Columbia class technologies, we reviewed  the Navy’s technology development plan and the planned technical  approach and the status of key prototyping efforts to all of the systems  that comprise the program, focusing on the technology readiness level of  the major components that are key to enabling program success and that  are key cost and schedule drivers. We also compared technology  development efforts with program requirements and with GAO’s identified  best practices for shipbuilding programs. To assess the risks, if any, with the Navy’s planned approach for design  and construction, we compared the status of design maturity with Navy  and shipyard plans to identify any delays, and compared planned design  maturity and schedule projections with those of prior U.S. submarine  efforts (the Virginia, Seawolf, and Ohio classes) to assess realism of  Columbia class estimates. This evaluation leverages, among other things, prior GAO work on cost  estimating and the Navy’s acquisition of lead ships. These  practices align with GAO’s identified best practices in shipbuilding—stable  requirements, design maturity at construction start, and manufacturing  readiness.
Why GAO Did This Study

The Navy's Columbia class ballistic missile submarines will replace the 14 Ohio class that currently provide the sea-based leg of the U.S. nuclear triad, slated to begin retiring in 2027. The first Columbia must begin patrols in 2031 to prevent a gap in deterrent capabilities; the class will ultimately carry up to 70 percent of the nation's strategic nuclear capability. The program is a top Navy priority with an expected cost of $267 billion over its life cycle, including $128 billion to research, develop, and buy 12 submarines.
House Report 114-102 included a provision for GAO to examine the Columbia class program. Among other things, this review examines (1) the status of key Columbia class technologies; and (2) potential risks with the Navy's planned approach for design and construction.
GAO reviewed the Navy's technology readiness assessment, technology development plan, and the status of key prototyping efforts, and compared efforts with GAO's identified best practices for shipbuilding programs and technology readiness assessments. GAO also assessed the status of design maturity and the Navy's acquisition strategy and interviewed relevant officials.

What GAO Found

Additional development and testing are required to demonstrate the maturity of several Columbia class submarine technologies that are critical to performance, including the Integrated Power System, nuclear reactor, common missile compartment, and propulsor and related coordinated stern technologies (see figure). As a result, it is unknown at this point whether they will work as expected, be delayed, or cost more than planned. Any unexpected delays could postpone the deployment of the lead submarine past the 2031 deadline.
Further, the Navy underrepresented the program's technology risks in its 2015 Technology Readiness Assessment (TRA) when it did not identify these technologies as critical. Development of these technologies is key to meeting cost, schedule, and performance requirements. A reliable TRA serves as the basis for realistic discussions on how to mitigate risks as programs move forward from the early stages of technology development. Not identifying these technologies as critical means Congress may not have had the full picture of the technology risks and their potential effect on cost, schedule, and performance goals as increasing financial commitments were made. The Navy is not required to provide Congress with an update on the program's progress, including its technology development efforts, until fiscal year 2020—when $8.7 billion for lead ship construction will have already been authorized. Periodic reporting on technology development efforts in the interim could provide decision makers assurances about the remaining technical risks as the Navy asks for increasing levels of funding.
Consistent with GAO's identified best practices, the Navy intends to complete much of the submarine's overall design prior to starting construction to reduce the risk of cost and schedule growth. However, the Navy recently awarded a contract for detail design while critical technologies remain unproven—a practice not in line with best practices that has led to cost growth and schedule delays on other programs. Proceeding into detail design and construction with immature technologies can lead to design instability and cause construction delays. The Navy plans to accelerate construction of the lead submarine to compensate for an aggressive schedule, which may lead to future delays if the technologies are not fully mature before construction starts, planned for 2021.

What GAO Recommends

GAO had suggested a matter for congressional consideration related to additional reporting on the Columbia class technologies, but removed it because of recent legislation that implements this requirement. Department of Defense comments on the draft were incorporated as appropriate in this report.