If building nuclear weapons South Korea would rate highly the ability to penetrate deep North Korean bunkers or missile silos. South Korea has no appropriate aircraft (no US B-2s, pictured) but does have ballistic missiles for delivery. (Courtesy FAS).
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Nuclear weapons cycle. Highly simplified but some major stages. Uranium enrichment can also go more directly - to shaping then placement in device/warhead.
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South Korea has wished to increase its “breakout capacity” (ability to build nuclear weapons) or actually build them for decades. Such weapons would mainly provide a deterrent against North Korean or perhaps Chinese or Russian nuclear strikes or invasions.
If nuclear war actually occurred South Korea would see the need to penetrate deeply dug North Korean command bunkers, ballistic missile silos and now SLBM submarines. On land such penetration is more easily accomplished using nuclear weapons rather than developing a very heavy bunker busting conventional bomb capability (which only the US possesses).
For decades the US has knocked back South Korea’s nuclear aspirations by pledging to provide extended nuclear deterrence. However South Korean anxiety remains that the US would not risk nuclear war – especially against China or Russia. North Korea’s SLBM program underlines that North Korea is deepening its nuclear weapon efforts rather than denuclearising its armed forces.
In terms of the three ingredients for nuclear capability (delivery systems, device and nuclear explosives) South Korea:
- has built a ballistic and cruise missile force capable of hitting any target in North Korea with a 500 kg warhead (see next article, later today).
- would have designs of nuclear weapons since the 1960s, supplemented in the 1990s by designs circulated by the A Q Khan network. South Korea may not have “cold tested” any device – certainly not hot tested – and may lack nuclear test results from any nuclear weapon nation.
- South Korea lacks the 100 kgs of nuclear explosives in the form of Plutonium 238 and/or HEU required to build a sufficient number of nuclear weapons.
To make up the explosive shortfalls South Korea needs the ability to reprocess spent fuel from its 23 nuclear power reactors or to enrich Uranium.
Since 1974, South Korea has signed a pact with the United States not to reprocess spent fuel. The pact (123 Agreement) expired March 2014, was immediately extended two years and is now due to expire in 2016. North Korea SLBM intentions have increased South Korea’s desire to have the right to reprocess if it wished. South Korea has proposed a technology known as pyroprocessingbut the US still opposes it as a type of reprocessing.
South Korea can point to the existence of permitted-legal Japanese reprocessing facilities. Japan’s reasons for reprocessing remain implausible given the highly uneconomic nature of reprocessing compared to other less expensive forms of disposal. Also Japan can buy fresh uranium cheaply at the low existing uranium prices (since the Fukushima disaster).
South Korea could also build nuclear weapons that solely rely on HEU or use HEU to boost Plutonium weapons. HEU might be produced by gas diffusion in centrifuges on a massive and obvious industrial scale. Alternatively laser enrichment technology is available that can enrich on a smaller less obvious scale.
The problems of South Korean testing and weaponisation-miniaturisation, in secrecy, are serious in the very small Korean Peninsula. South Korea might therefore have to obtain improved designs and test results (even if old) from a nuclear weapon nation or non-state actor.
CONNECT WITH
- South Korean Submarines, 3,000+ ton KSS-III, Nuclear PotentialApril 16, 2015 http://gentleseas.blogspot.com.au/2015/04/south-korean-submarines-3000-ton-kss.html
- Mark Holt, “U.S. and South Korean Cooperation in the World Nuclear Energy Market: Major Policy Considerations”, Congressional Research Service, June 25, 2013
https://www.fas.org/sgp/crs/row/R41032.pdf especially page 1.
Pete