Nuclear Submarines: Safety Concerns and Solutions

Charlie Furrer
February 15, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018

Consistency Under Complexity

Fig. 1: The USS Guitarro moored in San Diego. (Source: Wikimedia Commons)

Building a machine as complex as a nuclear submarine presents massive technological challenges, and requires a vast distribution of effort to complete. Dozens of critical systems must work together to ensure both the safety of the crew and the efficacy of the nuclear submarine as a whole. This report will examine the management systems in place to ensure safe production of nuclear submarines and their reactors.

The Design Process: Checks and Balances

The production of a nuclear submarine is a massive undertaking that involves cooperation between branches of government, the navy, and contractors. According to Schank et al., the Navy must be confident that the new sub meets its stringent requirements. Therefore, it is either heavily involved in the design process - basically designing the entire machine - or it runs detailed periodic checkups on progress. [1]

>In building such a complex machine as a nuclear submarine, the critical functions like the habitability systems, etc. are all delegated to technical warrant holders that are responsible for the viability of their particular system. However, since there is generally not enough demand (or civilian expertise) in the military navigation, communication, and weapons systems, the Navy takes responsibility for these. Additionally, the Navy also takes on the design responsibilities associated with the nuclear power plant. [1] Because of the importance and complexity of the onboard nuclear systems, the Navy provides detailed schematics and instructions to the contractor, to be followed without deviation. [2] The Navy refers to these as ND drawings (i.e. non-deviation).

Fig. 2: The figure shows the development of the US Nuclear submarine program. [4] As the program matured and the design process was improved and streamlined, the Navy was able to develop better ships, faster. Notice that 17 submarines were constructed in 1964, at the peak of production. (Source: C. Furrer, after Polmar and Moore. [4])

Because production of nuclear reactors was such a new industry during the beginning of the US Nuclear Sub program, the Navy pioneered engineering codes and standards in the realm of the Nuclear power industry. [3] It often had to draw from multiple engineering standards when they existed, and create new ones as necessary.

But were these measures effective? To answer this question, we must examine the Navys response to failure, specifically, the events around the sinking of the USS Thresher in 1963.

The USS Thresher was a nuclear attack submarine designed to combat the growing threat of Soviet submarines during the Cold War. [4] In order to combat increasingly advanced, difficult to detect Soviet machines, the United States began accelerating the rate at which it produced its own nuclear submarines, including those in the same class as the Thresher (see Fig. 2). At peak production in 1964, the United States produced 17 new nuclear submarines. While the Nuclear Submarine program had matured since it first built the USS Nautilus was first built in 1954, one might be inclined to believe that it had not advanced far enough to keep up with the increased demand for 17 submarines in a single year - thus leading to lapse in safety measures in Thresher's production and ultimately its destruction. It was the first Nuclear Submarine to be lost at sea. One Hundred and Nineteen people died in total - 17 were civilians and 112 were Navy personnel. It was in response to this disaster that Admiral Rickover (head of the Naval Reactors group, responsible for the nuclear submarine program) began an overhaul of the program in regards to safety procedures. [4]

This overhaul started with an intense examination of the accident. The most likely cause of the Thresher's sinking involved a reactor shutdown and failure to effectively restore power. Some felt that the complex procedures around operating the reactor led to confusion in heat of the moment, and eventually caused the sinking. [3] Because of this, Admiral Rickover ordered a complete overhaul in the system that governed reactor startup - with the aim of reducing the time needed to restart it. [4] Also, the mechanisms controlling the emergency surfacing systems (the ballast blowing systems that allow the sub to quickly surface) were redesigned. These changes, along with others, became collectively referred to as SUBSAFE protocols. [4] They are still in use today.


Managing the design of nuclear power plants is an extremely difficult task. When combined with the complexities inherent in the design of a submarine, it becomes doubly so. To deal with this increased difficulty, the US Navy - a pioneer in the building of such submarines - delegates responsibility of many systems to contractors but controls design of the reactors itself. It has developed an extremely robust set of safety protocols and management techniques in order to insure the best possible construction. Since the sinking of the USS Thresher, the United States Navy has not lost another sub.

© Charlie Furrer. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] J. F. Schank et al., Sustaining U.S. Nuclear Submarine Design Capabilities (Rand Corporation, 2007), pp. 119-132.

[2] J. F. Shank et al. Learning from Experience: Volume II: Lessons from the U.S. Navy's Ohio, Seawolf, and Virginia Submarine Programs (Rand Corporation, 2011), p. 5-10.

[3] J. W. Crawford and S. L. Krahn, "The Naval Nuclear Propulsion Program: A Brief Case Study in Institutional Constancy," Pub. Admin. Rev. 58, no. 2, 159 (1998).

[4] N. Polmar and K. J.Moore, Cold War Submarines (Potomac Books, 2003).