South Korea's SS-084 may? be SSBN Prototype

Anonymous on December 21, 2023 commented :

"South Korea seems intent on getting SSNs as well. Not sure if Australia would be interested in getting involved in that program though:

https://www.navalnews.com/naval-news/2023/11/south-korean-admiral-claims-that-nuclear-powered-submarines-are-necessary/  "

Pete Comment

The future proliferation of submarine nuclear propulsion to Australia (under AUKUS SSN Pillar 1 or Tier 1) certainly removes the submarine nuclear propulsion taboo that held South Korea and Japan back.

I suspect South Korean (SK) talk of an "SSN, K-SSN, KSS-N, KSSX-N, and KXXN" are euphemisms for SK SSBNs. See Submarine Matters articles that use some of these terms since 2012.

My logic is SK SSNs might only impede North Korean, Chinese and Russian naval and civilian shipping movements and port access. SK SSNs would not constitute "deterrents" to those countries' populations, land and air operations or, most importantly, to those 3 countries' nuclear weapon establishments. Although any future SK SSNs could be threats to nuclear tipped SLBM launching North Korean  SSBs and Chinese and Russian SSBNs.

My logic also looks at SK's program of ever more capable conventionally propelled ballistic missile submarines (SSBs). They are the KSS-3s Batch 1s (SS-083, 085 and 086), Batch 2s (with SS-087 so far). SK tends to build 9 submarines of each class for its navy. Hence it built 9 Type 209s and then 9 Type 214s. So after it completes 6 diesel-electric KSS-3s (3 Batch 1s and 3 Batch 2s) there is likely to be 3 Batch 3s. They might be nuclear propelled.

Curiously there is no "SS-084" among the Batch 1s. To confirm no SS-084 see seaforces and militaryfactory and EuropeanSecurity&Defence. South Korean people please confirm this omission. If this is not a misprint I suspect SS-084 (which, at present, might be a hull only) may develop into an SSBN prototype or be the first
KSS-3 Batch 3.

Also note a potential Hanwha Ocean New Technology is its large "Nuclear Propulsion Ship" concept. A reactor to power a ship would have the beginnings of dual-use potential. While a large ship's reactor (with gradual acceleration and deceleration) would be large a marine reactor for an SSBN could also be large and configured for gradual acceleration and deceleration. In contrast a reactor for an SSN would need to be further miniaturised and would also need to cater for an SSN's rapid stop-start tactical motion needs and have other specialised features. 

For countries without the budget of superpowers it is easier to place a "largish" marine reactor into a large SSBN before you miniaturise it for a small SSN. French experience with the K15 marine reactor is a case in point. It was "largish" when  commissioned into the Triomphant SSBN in 1997 (or just before), 2 x K15s were probably even larger when they ran critical in the Charles de Gaulle aircraft carrier by 1999. But if the K15's size was the main impediment it took all of 20 years to miniaturise it into France's "small" Suffren Barracuda SSN when the K15 ran critical in 2019 or 2020. 

The KSS-3 ballistic missile of choice appears to be the Hyunmoo 4-4. If its potential targets are nuclear armed North Korea, China or Russia, then a Hyunmoo 4-4's only explosive option will eventually be a nuclear warhead deterrent. Forget warheads with only several tonnes of high explosive or chemical weapons - they are not in the typical nuclear 100+ kiloton league when it comes to destroying deep dug, air-conditioned against chemicals, bunker targets.

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I'll address Anonymous's Japanese SSN (or SSBN) issue later.