Nuclear propulsion gives ballistic missile submarines significant strategic and tactical advantages. So, facing a nuclear armed North Korea, South Korea is displaying the signs of seeking such a capability. Nuclear propulsion provides for much more rapid discrete movement and much longer term discrete/submerged operation.
On Oct 25, 2019
I wrote the article South Korea Looking at France’s
Barracuda SSN or Just the K15 Reactor. It is significant that France’s
K15 reactor, that powers its Barracuda
(Suffren-class) SSN, uses Low Enriched Uranium (LEU) of 7.5% (see page 66 here). LEU is more acceptable, from a nuclear proliferation politico-legal viewpoint, than HEU - as higher percentages of HEU (40% in the tamper secondary stage at a minimum) can be used for nuclear weapons.
So it comes as less of a surprise that a South
China Morning Post (SCMP) article, dated October 6, 2020 https://www.scmp.com/week-asia/politics/article/3104424/south-koreas-request-submarine-nuclear-fuel-us-denied-report
reported:
“Citing an unidentified diplomatic source in
Washington, [South Korean news site DONG-A
ILBO] said South Korea [in September 2020] briefed the US side on
its plan to develop [SSBNs] and expressed its wish to be supplied with low-enriched uranium from the US
to use as fuel for the subs.” But “its
initial request has been turned down by Washington” due to the US-SK
Agreement for Peaceful Nuclear Cooperation (aka “123 Agreement”)
Providing context for this South Korean LEU request, SCMP
further reported,
October 6, 2020:
“As
part of its programme to build up its military capabilities over the next five
years, South Korea’s defence ministry in August [2020] unveiled a plan to
develop three 3,600-4,000-tonne submarines, [what I termed “KSS III Batch
III”s in
2019] which would be capable of carrying more ballistic missiles than the
existing [KSS III] 3,000-tonne submarines.
The
defence ministry is keeping open the possibility that the new subs could be
powered by nuclear fuel instead of diesel fuel, although a ministry spokesman
said that details “have not yet been fixed as to the propulsion methods of the
submarines”
COMMENT
As the US Trump Administration has rejected South Korea’s enriched Uranium request just weeks before the US November 3, 2020 Elections, it is possible South Korea is waiting on whether any incoming Biden Administration might reverse the LEU rejection decision.
LEU and other aspects of a nuclear propelled ballistic missile submarine (SSBN) capability are interlinked. South Korea could only develop a submarine reactor and an SSBN design from scratch with great difficulty. So it is more likely South Korea would seek the elements of an SSBN deterrent system from a combination of countries.
Failing US LEU approval South Korea might:
- again discuss with Russia, as South Korea did in 2017, a naval reactor design.
- renew what likely have been discrete talks with France on K15 reactor design and Barracuda variant as an SSBN and also French sourced or designed LEU for a K15 reactor. In terms of SLBMs South Korea would also be aware France, in the 1960s, helped Israel develop the Jericho ballistic missile for nuclear warhead delivery system. This was while France, in the 1950s/60s, was also building Israel's Dimona/Negev Reactor Center for nuclear explosives, including the Plutonium Reprocessing Plant.
OR
- South Korea could enrich its own LEU. In 2000 South Korea laser enrich uranium to 77%. Enriching its own Uranium is the only way South Korea can guarantee supply. However to do so South Korea would still politically need US permission and need US influence over the IAEA and other non-proliferation forums. The US can always remove its armed forces from South Korea, if US policies are not heeded.
South Korean risks, policies and technical transitions to develop nuclear tipped SLBMs will be the subject of a future article.
LEU subs are not a good idea imho though the Chinese and French set store by it and the US seems to favor downblending HEU into LEU for future subs..
ReplyDeleteHALEU (>10% to < 18%) could be a good compromise and might help avoid the struggles faced by the French with the Barracuda K-15 reactor. Usually 7% or 5% LEU is not suitable as a fuel for fast attacks from what I have read (The Shang 93G class or Barracuda could be used as exceptions to argue to the contrary, I suppose)
Hi GhalibKabir
ReplyDeletehttps://www.world-nuclear.org/information-library/non-power-nuclear-applications/transport/nuclear-powered-ships.aspx explains that LEU for the K15 is cheaper as it is dual military-civilian use "However, the enrichment level for newer French naval fuel has been dropped to 7.5% U-235, the fuel being known as 'Caramel', originally developed for research reactors and providing the possibility for greater fuel density, so helping to minimize the increased size of an LEU-fuelled core."
BUT "It needs to be changed every [7 to] ten years or so, but avoids the need for a specific military enrichment line, and some reactors will be smaller versions of those on the Charles de Gaulle. In 2006 the Defence Ministry announced that Barracuda class submarines would use fuel with "civilian enrichment, identical to that of EdF power plants," about 5% enriched..."
The need for 3 or 4 refuels might cause French subs to be withdrawn at critical times.
Yes "HALEU (>10% to < 18%) could be a good compromise and might help avoid the struggles faced by the French with the Barracuda K-15 reactor." but it would no long be dual-use cheaper.
It is puzzling that China has gone the LEU for submarine route. I wonder if China has HEU fuel for submarine in development - to keep up with US/UK advances?
Cheers
I think the French had difficulty operating their military enrichment facility and hence could not justify HEU cores. Also the strategic goals of France and budget did not permit or necessitate a HEU core. So I think they are going with a 7.5% LEU reactor. Hence their LEU to HEU and back to HEU journey occured.
ReplyDeleteThe Chinese I think had to learn everything from limited public data on the 5% LEU fueled Ice breaker Lenin and they followed french difficulties with enrichment closely in the 60s. This led to LEU design on the lines of the French (an Integrated PWR).
http://fissilematerials.org/blog/2017/05/chinese_naval_reactors.html
http://www.nea.gov.cn/2011-11/30/c_131278758.htm
However, from what I do read on various fora, it is not at all convincing that all the Type 93s are LEU fueled... the chinese have been capable of HEU core making since the 80s and given the massive enrichment facilities at Lanzhou being used in the 80s heavily, I am sure they have even HEU for 6-10 n-subs every year.
I think it is very much in the realm of possibility that the chinese have quietly deployed HEU cores as their belligerence will necessitate using HEU submarines for power, speed and endurance. Plus HEU cores can be for the lifecycle of a sub unlike the Frenchies LEU ones.
Hi GhalibKabir [at October 16, 2020 at 8:45 PM]
ReplyDelete1. In addition to your points on French LEU and HEU I think French LEU for submarine was within the background that France decided to develope all its military nuclear elements independently of the US - unlike UK dependence on the US. This meant slower French nuclear weapon and land/submarine/carrier reactor developments within a budget much lower than the US/UK.
France had/has much 2-way budget sharing and joint nuclear research with Israel for SRBMs-MRBMs, air dropped weapons, land reactors, enrichment and past joint nuclear testing in the Sahara and then South Pacific.
Part of French independence from US help was because France not only wanted a deterrent against the Soviets, but also against notional NATO ally West Germany. France was tired of 3 German invasions since 1870 https://en.wikipedia.org/wiki/Franco-Prussian_War .
2. Russian help after Stalin's death for China quickly evaporated so China had to go the LEU submarine reactor route.
Thanks for http://fissilematerials.org/blog/2017/05/chinese_naval_reactors.html and
http://www.nea.gov.cn/2011-11/30/c_131278758.htm very interesting.
Yes China wants to keep up with US HEU (all of life fuel) sub reactor developments.
Cheers
Pete
ReplyDeleteS. Korea launches new 3,000-ton-class SLBM submarine
http://www.koreaherald.com/view.php?ud=20201110000384
Thank Anonymous
ReplyDeleteSouth Korea's announcement on the second 3,000 ton submarine launch also court my eye, at https://www.koreatimes.co.kr/www/nation/2020/11/205_299175.html
I'll do an article on that on Monday. Also including the nuclear propulsion for future South Korea subs issue.
Cheers
Pete