March 9th, South Korea will elect a new president. One of the things the new president will determine is whether or not to push Washington to support South Korea’s development and fueling of a nuclear submarine. The Progressive candidate, Lee Jae-myung, intends to press the United States to cut a submarine technology transfer deal for South Korea just like Washington did for Australia. In a recent interview, Mr. Lee noted, “It is absolutely necessary for us to have those subs.”
But is it? Mr. Lee’s key opponent, Yoon Suk-yeol, says no and he’s got a point. In fact, if South Korea is serious about neutralizing the surface and underwater naval threats in the closed seas surrounding it, it would be far better served by investing in advanced nonnuclear anti-submarine and anti-surface capabilities.
This is detailed in an NPEC-commissioned study the Naval War College Review just published. Authored by James Campbell Jr., of Naval Sea System Command, “Seoul’s Misguided Desire for Nuclear Submarines,” sets out how poorly a nuclear submarine would perform in the closed Yellow, East China, and East Seas that surround it. To accomplish the key patrolling missions of tracking and containing North Korean naval threats and helping the United State and Japan monitor the first island chain, building and deploying nuclear submarines is vastly more expensive and far less effective than investing in more appropriate, advanced, nonnuclear naval systems.
These systems include upgrading South Korea’s air-independent propulsion submarines, its anti-submarine aircraft, and its naval surface combatants. Washington and Tokyo should also collaborate to upgrade, share, and analyze acoustic and non-acoustic anti-submarine sensor information. Finally, Seoul should invest in new anti-submarine technologies including airborne and underwater drones, anti-submarine wave runners, artificial intelligence-enhanced anti-submarine systems, and the like.
Japan should also focus on the development of such systems as its major contribution to Western Pacific security is to monitor and contain both Chinese and North Korean surface and subsurface naval threats to the first chain of islands connecting Japan, Taiwan, and the Philippines. For this mission, from the local bases in South Korea and Japan, nonnuclear submarines and other nonnuclear systems will perform far better dollar for dollar than nuclear submarines. Australia, which is thousands of miles from these waters, is a different matter. It requires platforms that can quickly travel significant distances and stay on station for extended periods. For this purpose, nuclear submarines make sense.
All of this pertains to nonproliferation. To prevent the further spread of nuclear weapons, it’s essential that the US, UK, and Australia raise the nonproliferation standards to restrict the spread of uranium enrichment and the highly enriched fuels needed to propel nuclear submarines. NPEC supports having Australia and as many other countries as possible legally forswear enriching uranium or recycling plutonium as the UAE and Taiwan have already made such commitments. Short of that, and at the very least, South Korea and Japan should focus on anti-submarine warfare investments that make military sense, and that’s not nuclear submarines.
By James O. Campbell, Jr.
In 2017, President Moon Jae-in endorsed the development and acquisition of a nuclear submarine for the Republic of Korea (ROK—South Korea). South Korean proponents of nuclear submarines favor the program for two technical reasons. First, nuclear submarines can stay underwater for months, rather than the days or weeks of which conventional diesel-electric submarines are capable. Second, nuclear submarines can maintain speeds of up to forty knots at depth, whereas nonnuclear submarines have difficulty sailing much above twenty knots at depth for any significant duration, and must surface frequently to recharge their batteries—which makes them easier to detect. These two attributes, South Korean nuclear-submarine proponents argue, make nuclear submarines ideal for detecting and neutralizing the ballistic-missile submarines of the Democratic People’s Republic of Korea (DPRK—North Korea).1
Since Moon’s 2017 endorsement, South Korean interest in developing an indigenously designed nuclear submarine only has grown. Recent press reports indicate the intention of the ROK Navy (ROKN) to modify three KSS-III submarines (of the Dosan Ahn Chang-ho class) into four-thousand-ton nuclear-powered submarines.2
Doing so would constitute a major commitment. Not only would the addition of nuclear power to the final three submarines in the class impact the defense budget severely, but South Korea also would have to find a reliable, long-term fuel supplier. South Korea has nuclear-fuel purchase agreements with the United States, but for civilian applications only. In press reports, unnamed military sources assert that once the United States agrees to supply low-enriched uranium for naval use, the development process will be a breeze.3 This claim glosses over the complexities associated with and the many difficulties involved in building nuclear submarines
1. Kim Tong-Hyung, “SKorea Scrambles to Improve Weapons Following NKorea Test,” AP News, 5 September 2017, apnews.com/
2. Jung Da-min, “Korea Accelerates Submarine Development Project,” Korea Times, 11 November 2020, koreatimes.co.kr/; Seoc Woo Kim, Jungmin Kang, and Frank von Hippel, “South Korea’s Risky Quest to Build Nuclear-Powered Attack Submarines,” Bulletin of Atomic Scientists, 18 November 2020, bulletin.org/; Sanghoon Kim, “Time for South Korea to Build Nuclear Submarines?,” National Interest, 22 August 2020, nationalinterest.org/.
3. Sang-Ho Yun, “S. Korean Military Announces Plan to Develop 3 4,000-Ton Submarines,” Dong-A Ilbo, 11 August 2020, www.donga.com/.
To read the entire paper, click here.