March 28, 2024

France’s Future SSBN “SNLE 3G” Starts Production

 Offline inimitable submarine commenter Shawn Chung commented:

 (with a nice MS paint graphic from HI Sutton below)

https://www.navalnews.com/naval-news/2024/03/france-cuts-steel-on-its-first-next-gen-ssbn-snle-3g/

Confirmation that France's SNLE 3G future SSBN project has begun comes hot on the heels of the French built future Dutch Orka announcement

According to a 2021 article, the first of four 15,000+ ton displacement SNLE 3G submarines is to be commissioned in 2035, when the Le Triomphant has been in commission for close to 40 years (actually ok for a boomer - USS Ohio will be in service for 44 years when she decommissions in 2026), but considering the last Suffren SSN (1/3rd the displacement of the SNLE-3G) is predicted to take 8 years to build, expecting to launch the first SSBN in 'the early 2030s' is overly ambitious.  

Artwork (which can be expanded) of possible SNLE-3G future French SSBN design (Courtesy H I Sutton of Covert Shores via Naval News, March 20, 2024)
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Pete Comment

A major part of the SNLE 3G project will be the development of France's third? generation submarine reactor called the "K22". This will have an output of 220 MW(th = thermal) which will represent a major increase in power over the Triomphant class' K15 (150 MW(th)) reactor. 

While the USN, and partly the UK RN, rely on the US' massive nuclear propulsion industrial base to develop new reactor technology, France's much smaller base has no such advantage. This means considerable risk is involved in France developing the K22, which may result in delays in SNLE 3G completion.

Like the US Columbia-class, the SNLE 3Gs will probably utilise electric drive, rather than mechanical reduction gears) for quieter/stealthy operation.

9 comments:

  1. In addition to its dealings with Brazil, France is also in talks to
    get involved in India's SSN program:

    https://idrw.org/india-and-france-to-soon-forge-cooperation-on-nuclear-attack-submarine-program/

    ReplyDelete
  2. Sutton drawing is not the reality. Precise one is not yet made !!!!

    ReplyDelete
  3. Hi Pete
    I am not sure the K22 is a key problem
    It has been tested in a shore pilot plant since the new RÉS facility became « hot «  in 2018 in Cadarache
    My undertandind is that the engineering was completed in 2023 and actual forging has started in IndretThe reactor is also needed for the PA NG(aircraft carrier, 2 reactors, construction start due 2 in 2025 in St Nazaire
    The K22 is an extrapolation of the K15, 50 % morepower or probably a 25 % increase in size
    More interesting on the NG vidéo is the computerized thick steel plates water jet cutting in a swimming pool sized facilty (very high precision and no thermal stresses

    ReplyDelete
  4. Hi Pete,

    Regarding: "While the USN, and partly the UK RN, rely on the US' massive nuclear propulsion industrial base to develop new reactor technology, France's much smaller base has no such advantage."

    I believe this is part of the reason why the French always decided to stick with LEU reactors for their strategic submarine/aircraft carrier programs instead of HEU, which would have required further investments.

    Cheers

    ReplyDelete
  5. Hi Pete

    I do not think that the K22 is a major risk any more
    It is an extrapolation (about 25% larger in dimensions ) of the K15 with identical fuel cycle and infra (robots for loading , inspection ect)
    ,
    With the new onshore "hot" plant(RES in Cadarache .that diverged in 2018..) the criticak design has been tested since 2018,the engineering has been completed in 2023 and my undertanding is that forging elements is taking place
    The K22 is also needed for the PA NG (new aircraft carrier , construction starting next year)
    This is well documented in Technicatome , CEA, Naval G ..publications and on Parlement key people hearings/presentations .Not telling everythyng is obvious but not "misrepresentation" under oath,,
    The Fr N /deterrent programm was never secret (and is not),except for the details as this is perceived as a mean of getting political support, of attracting talents ..and communicating to "whoever" that the "deterrence is real"

    On the video , the most novel part for me was the computerized thick very large steel plates precise cutting , by high pressure water jet, in a swimming pool sized facility.

    ReplyDelete
  6. Thanks Anonymous at 3/28/2024 2:33 PM - FRANCE HELPING INDIA'S SSN PROJECT?

    For https://idrw.org/india-and-france-to-soon-forge-cooperation-on-nuclear-attack-submarine-program/

    India has for decades relied on Soviet, then Russian, nuclear submarine (including reactors) transfer of technology with help by Russian Advisers (currently based in India).

    France should be mindful that its nuclear sub including reactor cooperation with India comes with the certainty that French design secrets shared with India would be forwarded to Russia.

    Also French SSN + reactor advisors in India will be approached for recruitment by Indian "agents" working for the Russians, or by Russian advisors or "diplomats" themselves.

    Cheers Pete

    ReplyDelete
  7. Thanks Anonymous at 3/28/2024 9:47 PM and Anonymous at 3/29/2024 8:58 AM

    FOR INFO ON THE STATUS OF FRANCE'S NEW SUBMARINE REACTOR, THE K22

    I will turn your comments into an article next week.

    Regards Pete

    ReplyDelete
  8. Hi again Anonymous at 3/28/2024 9:47 PM and Anonymous at 3/29/2024 8:58 AM

    Looking at the diagram at https://www.graphicnews.com/en/pages/45643/military-brazil-france-submarine-programme

    It is difficult to believe that a Rubis sized 48 MW(th) reactor could be expected to power the future SSN Brazillian Alvaro Alberto SSN displacing 6,000 tonne (presumably submerged).

    Perhaps the 48 MW is electrical "(e)" output?

    The Alvaro Alberto will be at least 700 tonnes larger than a Suffren-Barracuda SSN - with the Suffren using a 150 MW(th) K15 reactor.

    More info see https://gentleseas.blogspot.com/2014/01/brazil-future-ssn-dcns-assistance.html

    Can you tell me more about Brazil's future SSN reactor?

    Or what reactor power the 6,000 tonne Alvaro Alberto would require?

    Regards Pete

    ReplyDelete
  9. Hi Gessler at 3/28/2024 9:57 PM

    Your comment is mostly true. France eventually decided on LEU for sub reactors due to economics and new nuclear inventions. See https://uploads.fas.org/2016/12/Frances-Choice-for-Naval-Nuclear-Propulsion.pdf

    "In 1996, France decided to stop enriching uranium to HEU levels for weapons purposes [A secret - France by 1996 then mainly relied on Pu and Tritium for an all 2-stage thermonuclear weapon arsenal]. If the Navy had wanted to use HEU fuel, it would have had to invest significant money to have its own HEU enrichment facility. By choosing to only use LEU fuel with enrichments much less than 20 percent in the fissile isotope uranium-235, France has SAVED MONEY by purchasing from the commercial market. Moreover, France’s decision to use LEU fuel for naval propulsion has not degraded the operational performance of the ships."

    But earlier France's first SSBNs, the Redoubtable-class (from the 1960's) only used HEU - see

    "The French Government decided — unlike other countries, which started using nuclear submarines — to start with SSBNs. Those submarines were equipped with nuclear plants identical to the PAT. As France had meanwhile completed an enrichment plant, the SSBN cores used from the start of the nuclear propulsion program HEU in the form of metallic alloy.

    Yet, very soon after the start of the first SSBN, the scientists working in CEA (the French Atomic Energy Commissariat) who were in charge of developing nuclear propulsion, realized that they could use LEU, in dioxide form, to produce cores which would provide energy to the SSBNs four to five times (20 to 25 years) greater than with the first generation of cores. This was possible, on the one hand, because the conception of the first generation cores included high margins and, on the other hand, because SSBNs are low consumers of energy due to the nature of the slow, steady speed of patrolling. The nuclear plants of the
    SSBNs of “Le Redoutable” class could use interchangeably “metal” cores (first generation) or “oxide” cores (second generation).

    After this experience, the French Navy decided to adopt cores using low-enriched uranium dioxide for all the following classes of nuclear ships: SSN Rubis class, SSBN Le Triomphant class, SSN Barracuda class, and CVN Charles de Gaulle."

    Regards Pete

    ReplyDelete

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