India Navy Nuclear Submarines (SSBN & SSN)

[Raptor]

First three Navy nuke attack submarines to be 95% Made in India


The Cabinet Committee on Security is considering the Navy proposal worth over Rs 50,000 crore for indigenously building three nuclear attack submarines which would be built by the Defence Research and Development Organisation (DRDO) in Visakhapatnam.


Manjeet Negi
New Delhi
June 13, 2021UPDATED: June 13, 2021 15:42 IST
First three Navy nuke attack submarines to be 95% Made in India
The Indian Navy proposal to have six indigenous nuclear attack submarines was one of the first few major defence modernisation proposals to have been cleared by the Narendra Modi government soon after it came to power in 2014. (File photo/Representational Image)
In a major boost to the government's bid to indigenise the defence sector, the first three nuclear attack submarines planned to be built by the Indian Navy would be 95 per cent made in India.

The Cabinet Committee on Security is considering the Navy proposal worth over Rs 50,000 crore for indigenously building three nuclear attack submarines which would be built by the Defence Research and Development Organisation (DRDO) in Visakhapatnam. In a separate project, Arihant class nuclear-powered submarines are being built with the capability of launching ballistic missiles.

“The nuclear attack submarine project would be a big boost for the indigenous submarine capability as 95 per cent of it would be made in India. This would provide a big boost to the domestic defence sector including both private and public sector,” a top government source told India Today TV.

The project would also be very helpful for the economy as it is expected to generate a large number of jobs in the defence sector, sources said. The Navy and DRDO would first get a clearance for three of these boats and will have the option of building three more after the completion of this project.

The Indian Navy proposal to have six indigenous nuclear attack submarines was one of the first few major defence modernisation proposals to have been cleared by the Narendra Modi government soon after it came to power in 2014.

Despite some delays, India has been making big headways in the field of indigenous submarine building capability. The first Arihant class boat was commissioned a few years ago and the second one INS Arighat is also undergoing sea trials and is expected to be commissioned in near future.

India has plans to build 24 submarines, including six with nuclear attack capabilities, which would give it long legs to operate in the Indian Ocean region and will help it to keep its adversaries in check at long distances.

The first six conventional boats are already under construction in Mumbai under the Kalavati class project while the tender for the next six with greater capability would be issued soon after recent clearance by the Defence Ministry. There is a plan to build six more conventional submarines under Project 76 but it will take a long time to be initiated.

India is also leasing nuclear attack submarines since the 1990s which have helped it remain current on the operations of such boats.

First three Navy nuke attack submarines to be 95% Made in India

The Cabinet Committee on Security is considering the Navy proposal worth over Rs 50,000 crore for indigenously building three nuclear attack submarines which would be built by the Defence Research and Development Organisation (DRDO) in Visakhapatnam.

www.google.com

@Nilgiri @crixus @Zapper @Test7 @T-123456 @Kartal1 @Cabatli_53

 

[Gessler]

I don't think this was posted in the thread before, so doing it now.

Artwork credit: H.I. Sutton @ Navalnews.com

 

[Nilgiri]

https://twitter.com/i/web/status/1412482207726329856

 

[Gessler]

https://twitter.com/i/web/status/1412482207726329856

By the way, the fact that they can support multi-round ejection from the get go is encouraging as this would mean having an easier time converting these boats into SSGNs once the S5-class take over as deterrence platforms.

A silo that can take 3 x 0.74m K15 SLBMs should be able to take at least 5-6 x 0.52m Nirbhay SLCMs. That would give about 20-24 cruise missiles per boat. Not unlike the 6-round Tomahawk VLS on Virginia-class subs.

 

[Gessler]

Use this thread to post all news, updates & discussions regarding the various nuclear submarine programs of the Indian Navy, including:

Arihant-class SSBN
S-4* SSBN
S5-class SSBN
Project-75A/Project-76 SSN
Past & future leased Russian SSNs

@Nilgiri @Cabatli_53 @T-123456 @Vergennes @Kartal1 @Anmdt @trishna_amrta @kumata @Gautam @Isa Khan @Raptor @Fuzuli NL @UkroTurk 🚬 @Test7 @AlphaMike @Bogeyman

I have posted some excerpts to kick this off...​

 

[Gessler]

I will start off by posting excerpts from an interesting conversation I had a while ago regarding the various concerned programs, I'll be adding various links & pictures that weren't originally part of the convo in order to add more context for a forum audience. For better intake of info in a crisp, bite-sized format I'll be dividing it into 3 parts.

Part-1: The outline of the SSN program and where it fits into the broader picture

(NOTE: Alpha = The Project-75A SSN)

I'm skeptical about the figures of Alpha tonnage/displacement floating around in the media. I suspect those displacement figures of approx 6,000 tons (not only mentioned by Hindustan Times but many others as well) are from the same erroneous sources that also claimed that the S-3 boat (INS Arighat, the sister of S-2 INS Arihant) would be considerably bigger and carry 8 missile silos. But satellite images of the Ship Building Centre (SBC) harbour at Visakhapatnam (Visak, most commonly pronounced & spelled Vizag) prove that both Arihant & Arighat are the same length & size, and carry the same number of missile tubes - Four.

Google Maps show Indian Nuclear Submarines berthed alongside

In a rare occurrence, the Google maps has captured the images of two Indian strategic submarines berthed alongside in a

frontierindia.com

The S-2 INS Arihant (pennant after commissioning SSBN-80) and the S-3 INS Arighat berthed beside each other, measuring the same size

Now don't get me wrong - I still am inclined to believe that the 4th nuclear boat to be built by SBC (known in the media as the S-4* or S-4 Star) would indeed be considerably bigger than the Arihant-class, satellite images of a new submarine dockyard shelter constructed at Vizag which is up to 40m longer than Arihant's shelter substantiate the theory that a new, bigger boat is around the corner - and it definitely can't be the S-5 yet. So it has to be the rumoured S-4* SSBN, with perhaps 8 silos.

Nuclear expert Hans M. Kristensen's observation of the same summarized in his tweet, though he speculates this to be intended for the S-4 itself (3rd nuclear boat), not the S-4*:

https://twitter.com/i/web/status/1370325335435309058

Personally, I would think all three Arihant-class SSBNs will be of the same dimensions, it would not make any sense to have the last boat in class to be substantially different than the others. The S-4* on the other hand might make sense as both a test platform for new, larger equipment that may eventually find use on the still larger S-5 class down the line, once the systems mature after at-sea testing on this boat. The Arihants would have to be at sea (or in refit), delivering on the deterrence role, you can't ask them to come off their vitally important duties to function as test platforms for new stuff - the S-4* might make a lot of sense in that respect.

Fan-made CGI by Twitter user Harshal Pal of the rumoured S-4* SSBN. The INS Aridhaman name was originally believed to be for the S-3 boat, but later reneged and called INS Arighat instead

Another reason to be skeptical about the Alpha's displacement figures would be that pretty much all available sources (unless I'm misremembering) quote the Arihant-class boats' surfaced displacement as approx. 6,000 tons (and estimated around 7,000 submerged). So if the Alpha indeed turns out to be an 'Arihant without silos' as some are speculating, then there's no way it'll also be 6,000 tons surfaced. Has to be 5,000 or so, but even that is speculation at this point considering no one has seen any details of the SSN program.

So personally I'll hold my horses for now regarding the displacement figures.​

 

[Gessler]

Part-2: Regarding the possible use of the SSNs in a land-attack role as SSGNs

Regarding the use of VLS system to launch SLCMs from the Alphas - I don't think they will go down that way. Allow me to explain my point of view.

In the 2030s, when the S-5 SSBNs start becoming available for carrying forward the role of what the Royal Navy calls Continuous At-Sea Deterrence or CASD (I'm using that expression because the hydrodynamic testing model of S-5 has it's bow planes attached to the hull roughly at the same spot where the Vanguard-class SSBN has them, instead of on the conning tower like Arihant, though the similarities are likely to end there) ....

Hydrodynamic testing model of a next-generation submarine with a very visible missile compartment. Understandably, this can only be considered one of many such models undergoing testing at the facilities of Vizag-based Naval Science & Technology Laboratory (NSTL)

...anyway, as each new S-5 becomes available to take over the CASD role, a corresponding Arihant-class boat would in all likelihood be retired from performing any form of deterrence role***, after which it would probably be subjected to a scheduled refit & refueling of the reactor. So what will the Indian Navy do with these boats then? They would still have at least 10-15 more years of service life left.

My guess: they will convert them into performing a role that is somewhat less demanding (on the part of keeping at least one boat operational at all times) - into an SSGN role. When the Arihants are subjected to refit & refueling, the nuclear armed K-4 intermediate-range ballistic missiles can be swapped out and replaced with up to 5 or 6 Nirbhay-type SLCMs per silo. The Arihant's silos were designed to accept either one K-4 or three smaller K-15 per tube so we know it is designed to support the multi-round ejection systems needed for such 'pack' VLS.

One of the Arihant's missile tubes at dry dock - this particular tube is visibly in a triple-pack configuration for 3 x K15 short-range SLBMs

The K-15 missile has a diameter of 0.74m compared to 0.52m for the Nirbhay, so it can potentially pack 5 or 6 Nirbhays in those tubes I'm guessing, for a total of 20-24 vertically-launched cruise missiles per boat (someone needs to do the math on that diameter, either way very similar to the 6-round Tomahawk VLUs on some Virginia-class boats).

Nirbhay subsonic long-range (~1500km est.) cruise missile, first tested in 2012-13 and shown here in a ground-launch configuration with the test launcher in background. A submarine-launched LACM deriving from this program is said to be in development

So, better to not encumber the Alphas with the additional weight & power requirements needed to fulfill an SSGN role - better to let them be as light & sleek as possible for reasons of speed, stealth as well as reactor efficiency, all critical for a hunter-killer SSN.

( Will explain my view on the subject I've marked with '***' in a separate post )​

 

[Gessler]

Part-3: Regarding the size & scope of Indian CASD arsenal, and the compulsion for converting Arihants into SSGNs

Here you go regarding '***'

Considering India does not have stockpiles of hundreds & hundreds of nukes, we might not even have the number it would be needed to simultaneously arm Three or Four S-5 class as well as Three Arihant-class (discounting the S-4*). So it would have to be an inevitability to bring the Arihants off the line as deterrence platforms once the S-5s start coming in...

HI Sutton's depiction of the S-5 SSBN, based on the hydrodynamic model shown above, shown here with 12 tubes in 6x2 configuration

...keeping in mind the fact that the S-5 class will probably have 12 missile tubes storing K-5 or K-6 intercontinental SLBMs (which will most definitely have Multiple Independently-targeted Re-entry Vehicles or MIRVs). Each S-5 boat, even if we assume a relatively modest MIRV capacity of 3 RVs per missile, would be carrying 36 nuclear warheads. Three such boats, if we assume each has it's own permanently assigned load of missiles, would require 108 warheads. If we're talking four boats (following the UK & France pattern of SSBN numbers) that goes to 144 warheads. That's close to the total stockpile that most experts assume India to have currently (~150 warheads).

If we assume 4 MIRVs per SLBM (like the slide I've linked below, shown by DRDO's then-chairman Dr. VK Saraswat at IIT-Bombay university) then it would be 48 warheads per sub, and 144 for Three boats and 192 for Four boats. With a quoted throwaway weight of 2 tons, likelihood is high for there to be indeed 4 x 500kg MIRVs per K-5/K-6.

A public release-approved indication or roadmap depicting the technologies under development to achieve a contemporary SLBM capacity needed to ensure survivable deterrence into the future (early/mid-2010s iteration of the design)

Personally I'd definitely assume India has more than 150 nukes even currently, the delays of Plutonium deliveries to the PFBR prototype also point at the possibility of the Pu going to fill other, more pressing & strategically important requirements, like perhaps building more bombs. By the time the S-5s come online, I'd certainly expect us to have more than 150.

However - it must be remembered that India, with two nuclear-armed hostile neighbours who share land borders, certainly has no plans of giving up it's land-based rail & road-mobile nuclear deterrent like UK & France have done. This portion of the triad will continue to be armed in the form of Agni-4, Agni-5 and the in-development Agni-6 with MIRVs. The Agni-6 is reportedly designed to have a throw weight of 3 tons, so we're again looking at a significant MIRV payload (again, refer to the slide I've linked below, from same source at IIT-Bombay presentation).

Public release-approved depiction of next-generation land-based nuclear deterrence (right), shown compared with the existing technology of the time in the form of the Agni-5 (left)

And we won't be giving up the Air-launched deterrent either (like UK has done), the presence of nuclear gravity bombs as well as the ongoing development of a nuclear-capable Liquid-Fuel Ramjet (LFRJ) ALCM intended for the Indian Rafales (very similar to the French ASMP-A missile) indicate that this leg of the triad is here to stay as well.

REVEALED: India's Naval Anti-Ship Missile Breaks Cover At #DefExpo2020 - Livefist

A missile system that India's DRDO mentioned for the first time in 2018 has broken cover at the ongoing Def Expo show in Lucknow. The 55-km range helicopter launched Naval Anti-Ship Missile (NASM-SR) has been detailed for the first time since the project was sanctioned in 2017, and has since…

www.livefistdefence.com

A first-generation (1980s) Indian air-dropped nuclear device, equipped with a SAFF (Safing, Arming, Fuzing, Firing) system. The current air-deliverable deterrence (of the gravity bomb variety) is believed to be third-generation. Annotations by GODOFPARADOXES on Twitter.

One of the intended applications of the LFRJ program, shown here in an anti-shipping configuration by 3D artist Kuntal Biswas. The LFRJ platform is intended to branch off into many applications including AShM, LACM, STAR (Supersonic Target) and a nuclear delivery system on the lines of ASMP-A

What all this means is that we'll be needing a significant number of warheads (at least 100) outside of CASD as well. And this just goes to show that there's no way we can continue operating Arihants as nuclear-armed SSBNs even after S-5s come in. We just won't have enough nukes for them, and that's just part of the reason compelling us to convert the Arihants into conventionally-armed SSGNs in the 2030s - poised to be the ideal platform for cruise missile strikes on likes of Karachi's naval facilities/airbases or any Chinese naval presence at Gwadar in the event of open hostilities.​

 

[Gessler]

I will start off by posting excerpts from an interesting conversation I had a while ago regarding the various concerned programs, I'll be adding various links & pictures that weren't originally part of the convo in order to add more context for a forum audience. For better intake of info in a crisp, bite-sized format I'll be dividing it into 3 parts.

Part-1: The outline of the SSN program and where it fits into the broader picture

(NOTE: Alpha = The Project-75A SSN)

I'm skeptical about the figures of Alpha tonnage/displacement floating around in the media. I suspect those displacement figures of approx 6,000 tons (not only mentioned by Hindustan Times but many others as well) are from the same erroneous sources that also claimed that the S-3 boat (INS Arighat, the sister of S-2 INS Arihant) would be considerably bigger and carry 8 missile silos. But satellite images of the Ship Building Centre (SBC) harbour at Visakhapatnam (Visak, most commonly pronounced & spelled Vizag) prove that both Arihant & Arighat are the same length & size, and carry the same number of missile tubes - Four.

Google Maps show Indian Nuclear Submarines berthed alongside

In a rare occurrence, the Google maps has captured the images of two Indian strategic submarines berthed alongside in a

frontierindia.com

View attachment 27089
The S-2 INS Arihant (pennant after commissioning SSBN-80) and the S-3 INS Arighat berthed beside each other, measuring the same size

Now don't get me wrong - I still am inclined to believe that the 4th nuclear boat to be built by SBC (known in the media as the S-4* or S-4 Star) would indeed be considerably bigger than the Arihant-class, satellite images of a new submarine dockyard shelter constructed at Vizag which is up to 40m longer than Arihant's shelter substantiate the theory that a new, bigger boat is around the corner - and it definitely can't be the S-5 yet. So it has to be the rumoured S-4* SSBN, with perhaps 8 silos.

Nuclear expert Hans M. Kristensen's observation of the same summarized in his tweet, though he speculates this to be intended for the S-4 itself (3rd nuclear boat), not the S-4*:

https://twitter.com/i/web/status/1370325335435309058

Personally, I would think all three Arihant-class SSBNs will be of the same dimensions, it would not make any sense to have the last boat in class to be substantially different than the others. The S-4* on the other hand might make sense as both a test platform for new, larger equipment that may eventually find use on the still larger S-5 class down the line, once the systems mature after at-sea testing on this boat. The Arihants would have to be at sea (or in refit), delivering on the deterrence role, you can't ask them to come off their vitally important duties to function as test platforms for new stuff - the S-4* might make a lot of sense in that respect.

View attachment 27090
Fan-made CGI by Twitter user Harshal Pal of the rumoured S-4* SSBN. The INS Aridhaman name was originally believed to be for the S-3 boat, but later reneged and called INS Arighat instead

Another reason to be skeptical about the Alpha's displacement figures would be that pretty much all available sources (unless I'm misremembering) quote the Arihant-class boats' surfaced displacement as approx. 6,000 tons (and estimated around 7,000 submerged). So if the Alpha indeed turns out to be an 'Arihant without silos' as some are speculating, then there's no way it'll also be 6,000 tons surfaced. Has to be 5,000 or so, but even that is speculation at this point considering no one has seen any details of the SSN program.

So personally I'll hold my horses for now regarding the displacement figures.​

Later on, other points of view (backed up by good sources) have emerged that the intention was always for 2 x smaller boats with 4 silos and 2 x larger boats with 8 silos. Will have to be seen, but it's also highly possible that the new infrastructure at SBC Vizag may indeed be for the S-4 itself, not necessarily S-4*.

Also, ya'll must be wondering - why is the first boat in class, INS Arihant, called S-2?

Why not call it S-1 to make everything simpler? Well, the reason is the "S-1" did actually exist - it was sort of a 'mock-up submarine' that was designed to enable shore-based testing of the CLWR-B1 pressurized water reactor before putting it on a sea-going vessel.

The first criticality of the marine-rated CLWR-B1 was achieved on the "S-1" platform. The first crews were also trained on it in the operation of a marine PWR.

The 83 MWt CLWR-B1 Pressured Water Reactor on shore. Reactors of this design equip all Arihant-class boats. A larger 190 MWt CLWR-B2 is under development for future nuclear submarine propulsion​

 

[Nilgiri]

@Gessler

I have two threads for SSBN and SSN programs (they are under strategic forces/ programs section):

Navy - Indian SSBN Programs

Well, its about time I feel to start a thread for SSBN (Arihant class) program of Indian Navy. I have put this thread in strategic forces for now given the overall higher relevance to that paradigm. To start, here is brief and interesting introduction+context+analysis on it given by a retd...

defencehub.live

Navy - Indian SSN Programs

@Gautam

defencehub.live

Both are also pinned so they appear in the main section pinned.

What do you propose is best organisation for it? combine all into one big thread and have it here (Navy section) or combine this with that one there somehow?

 

[Gessler]

@Gessler

I have two threads for SSBN and SSN programs (they are under strategic forces/ programs section):

Navy - Indian SSBN Programs

Well, its about time I feel to start a thread for SSBN (Arihant class) program of Indian Navy. I have put this thread in strategic forces for now given the overall higher relevance to that paradigm. To start, here is brief and interesting introduction+context+analysis on it given by a retd...

defencehub.live

Navy - Indian SSN Programs

@Gautam

defencehub.live

Both are also pinned so they appear in the main section pinned.

What do you propose is best organisation for it? combine all into one big thread and have it here (Navy section) or combine this with that one there somehow?

@Gessler

I have two threads for SSBN and SSN programs (they are under strategic forces/ programs section):

Navy - Indian SSBN Programs

Well, its about time I feel to start a thread for SSBN (Arihant class) program of Indian Navy. I have put this thread in strategic forces for now given the overall higher relevance to that paradigm. To start, here is brief and interesting introduction+context+analysis on it given by a retd...

defencehub.live

Navy - Indian SSN Programs

@Gautam

defencehub.live

Both are also pinned so they appear in the main section pinned.

What do you propose is best organisation for it? combine all into one big thread and have it here (Navy section) or combine this with that one there somehow?

Combine everything and have it here in Navy section.

 

[Nilgiri]

Thought of submitting these parts above as an article for the forum (like you did with the orbital rockets)? @Gessler

 

[Gessler]

Thought of submitting these parts above as an article for the forum (like you did with the orbital rockets)? @Gessler

If you think its worthwhile, go ahead.

 

[Gessler]

Some thoughts, possibilities & hypotheses surrounding the SSN program & its reactor and design choices:

https://twitter.com/i/web/status/1444631861502767109

 

[Nilgiri]

Will be interesting to follow @Vergennes @Gessler @Gautam et al.

Overall I feel the AUKUS-SSN development will help augment the Franco-Indian strategic partnership, and both sides should look to expand and develop it more.

India's Project 78A SSN Construction Programme Being Accelerated With French Partnership & Mentoring

Official Statement: France’s President Emmanuel Macron dialled India’s PM Narendra Modi on September 21, 2021 to talk about strengthening c...

trishul-trident.blogspot.com

Official Statement: France’s President Emmanuel Macron dialled India’s PM Narendra Modi on September 21, 2021 to talk about strengthening cooperation in the Indo-Pacific and also boost, as Macron’s office said in a statement, India’s strategic autonomy. Macron assured Modi of France’s continued “commitment to the strengthening of India’s strategic autonomy, including its industry and technology base, as part of a close relationship based on trust and mutual respect”.

Translation: An apex-level agreement has been reached under which France and India will officially announce their decision to cooperate in both military-technical and military-industrial matters related to Project-78A—the Indian Navy’s (IN) plan to procure six indigenously-built nuclear-powered attack submarines. What will come next is the inking of a government-to-government agreement between India’s Ministry of Defence and France’s Direction Générale de L'Armement (DGA, or Directorate General of Armaments) that will formalise such cooperation. It will also officially enable France to supply the enriched uranium fuel for the India-built pressurised water reactors (of Russian design) for the entire service-lives of the six SSNs.

Principal beneficiaries of this G-to-G agreement at the industrial-level will be France’s NAVAL Group and THALES, while on the Indian side the prime industrial contractor will be Larsen & Toubro. While the six SSNs will have the same double-hulled design as that of the three nuclear-powered SSBNs now being procured from L & T by the IN, they will have reduced submerged displacements (about 4,800 tonnes, as opposed to the SSBN’s 6,000 tonnes), and will incorporate (just like the French Navy’s Barracuda-class SSNs) a hybrid propulsion system that will provide electric propulsion for economical cruise speeds and turbo-mechanical propulsion for higher speeds. In addition, each of the SSNs are likely to incorporate a pumpjet propulsor that combines a shrouded rotor and a stator within a duct to significantly reduce the level of radiated noise and avoid cavitation.

It was in 1984 that construction began of India’s Rattehalli Rare Materials Plant (RMP), located near Mysore in Karnataka State, which is a pilot-scale gas centrifuge uranium enrichment plant with several hundred gas centrifuges, and is capable of producing several kilograms of highly enriched uranium (HEU) each year. Construction of the pilot-scale gas centrifuge enrichment facility at began in 1987, took four years to complete, and began operating in 1991. The plant is operated by Indian Rare Earths Limited (IREL), which is a subsidiary of India’s Department of Atomic Energy (DAE). The DAE first confirmed the existence of the plant in 1992. Items that the IREL initially imported to outfit the RMP, such as vacuum pumps, vacuum furnaces, machine tools, vacuum bellows-sealed valves, and canned motors for centrifugal pumps, were subsequently indigenised. Thereafter, work began on producing low enriched uranium (LEU) for submarine-based pressurised water reactors (PWR) at a large uranium enrichment centrifuge complex, the Special Material Enrichment Facility (SMEF), in Challakere Taluk, Chitradurga District of Karnataka. Between 2009 and 2010, an area of approximately 10,000 acres in the Chirtradurga District of Karnataka was diverted for various military-technical and military-industrial purposes. Within this area, 1,410 acres in Ullarthi Kaval and 400 acres in Khudapura were allocated to the DAE’s Bhabha Atomic Research centre (BARC) for the purpose of developing the SMEF. In 2011, India announced publicly her intention to build this industrial-scale centrifuge complex in Challakere Taluk, Chitradurga District (Karnataka). This site has since been dedicated to the production of both highly enriched uranium (HEU) and LEU for military and civilian purposes, although industrial-scale production has yet to commence. BARC has been allotted many more acres in Ullarthi Kaval compared to Khudapura (1,410 versus 400 acres respectively).

Despite such investments, the fuel for powering the INS Arihant S-73’s (India’s first in-country built SSBN) PWR (and for the INS Arighat as well) had to be obtained from Russia. The PWR for this SSBN is the third-generation OK-700A/VM-4SG model, generating 89.2mW thermal (29.73mW electric) and producing 18,000hp when using 44% enriched uranium. The PWR was developed by the OJSC N A Dollezhal Scientific Research & Design Institute of Energy Technologies (also known as NIKIET) and which is now part of JSC Atomenergoprom. Such PWRs were series-produced in Izhorsky Zavod, at Kolpino, near St Petersburg, and at the Nizhny Novgorod Machine-Building Plant (Afrikantov OKBM). In India, JSC Atomenergoprom authorised the DAE to licence-produce such PWRs. Such PWRs have a total technical service life of 35 years and require refueling after 17 years. The reactor core of such PWRs comprises between 248 and 252 fuel assemblies. Each fuel assembly contains tens of fuel rods, and these vary from the traditional round rods to more advanced flat fuel-rods. The point of the flat fuel-rod is to enlarge the surface of each fuel-rod so as to improve the thermal efficiency. Most of the uranium fuel assemblies are clad in zirconium. The fuel assemblies in the middle of the reactor core (weighing about 115kg) are enriched to 22% U-235, while the outermost fuel assemblies are enriched as much as 45%.


It remains to be seen whether France will assist India in developing a fourth-generation variant of the OK-700A/VM-4SG PWR that will feature a higher reactor density (capable of using France-supplied uranium enriched to more than 60%), resulting in a higher power output close to 40mWe and becoming a lifelong PWR that does not require refuelling thrughout its service-life.

 

[Gessler]

Will be interesting to follow @Vergennes @Gessler @Gautam et al.

Overall I feel the AUKUS-SSN development will help augment the Franco-Indian strategic partnership, and both sides should look to expand and develop it more.

India's Project 78A SSN Construction Programme Being Accelerated With French Partnership & Mentoring

Official Statement: France’s President Emmanuel Macron dialled India’s PM Narendra Modi on September 21, 2021 to talk about strengthening c...

trishul-trident.blogspot.com

Official Statement: France’s President Emmanuel Macron dialled India’s PM Narendra Modi on September 21, 2021 to talk about strengthening cooperation in the Indo-Pacific and also boost, as Macron’s office said in a statement, India’s strategic autonomy. Macron assured Modi of France’s continued “commitment to the strengthening of India’s strategic autonomy, including its industry and technology base, as part of a close relationship based on trust and mutual respect”.

Translation: An apex-level agreement has been reached under which France and India will officially announce their decision to cooperate in both military-technical and military-industrial matters related to Project-78A—the Indian Navy’s (IN) plan to procure six indigenously-built nuclear-powered attack submarines. What will come next is the inking of a government-to-government agreement between India’s Ministry of Defence and France’s Direction Générale de L'Armement (DGA, or Directorate General of Armaments) that will formalise such cooperation. It will also officially enable France to supply the enriched uranium fuel for the India-built pressurised water reactors (of Russian design) for the entire service-lives of the six SSNs.

While an increased level of defence-industrial collaboration with France is to be expected post-AUKUS, considering India now remains the only big player left in the IOR with which large-scale maritime cooperation remains possible, the level of French participation in the SSN (or the S-5 SSBN**) programs will be determined by what stage of design/development we currently are at with regard to those programs.

If we are past the point of design freeze on either, the cooperation would have to be very minimal - or at least reserved for later 'Flights'/classes, considering the timelines in question.

We need SSNs ASAP, and may not be in a position to go back to drawing board at this point - that needs to be kept in mind.

** Which we know to have been subjected to hydrodynamic testing at least as of 2019. No reason to believe SSN wasn't.

View attachment 33171


Principal beneficiaries of this G-to-G agreement at the industrial-level will be France’s NAVAL Group and THALES, while on the Indian side the prime industrial contractor will be Larsen & Toubro. While the six SSNs will have the same double-hulled design as that of the three nuclear-powered SSBNs now being procured from L & T by the IN, they will have reduced submerged displacements (about 4,800 tonnes, as opposed to the SSBN’s 6,000 tonnes), and will incorporate (just like the French Navy’s Barracuda-class SSNs) a hybrid propulsion system that will provide electric propulsion for economical cruise speeds and turbo-mechanical propulsion for higher speeds. In addition, each of the SSNs are likely to incorporate a pumpjet propulsor that combines a shrouded rotor and a stator within a duct to significantly reduce the level of radiated noise and avoid cavitation.

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While any French help in better testing/refinements of the products at hand would always be welcome (Naval Group has some of the best testing facilities in Europe), again this would depend on where we are with regard to indigenous programs.

We know that R&D on Pumpjet propulsors for Torpedos was ongoing since early-2000s.

Plus we have tender documents announcing contract for fabricating a 35MW Electric Drive motor - which spins a Pumpjet. Unclear if this is for SSBN or SSN (likely the former, considering even the Barracuda only has a 20MW motor), but if its being done for one, would almost certainly be done for the other as well.

https://twitter.com/i/web/status/1320175768438190080

It was in 1984 that construction began of India’s Rattehalli Rare Materials Plant (RMP), located near Mysore in Karnataka State, which is a pilot-scale gas centrifuge uranium enrichment plant with several hundred gas centrifuges, and is capable of producing several kilograms of highly enriched uranium (HEU) each year. Construction of the pilot-scale gas centrifuge enrichment facility at began in 1987, took four years to complete, and began operating in 1991. The plant is operated by Indian Rare Earths Limited (IREL), which is a subsidiary of India’s Department of Atomic Energy (DAE). The DAE first confirmed the existence of the plant in 1992. Items that the IREL initially imported to outfit the RMP, such as vacuum pumps, vacuum furnaces, machine tools, vacuum bellows-sealed valves, and canned motors for centrifugal pumps, were subsequently indigenised. Thereafter, work began on producing low enriched uranium (LEU) for submarine-based pressurised water reactors (PWR) at a large uranium enrichment centrifuge complex, the Special Material Enrichment Facility (SMEF), in Challakere Taluk, Chitradurga District of Karnataka. Between 2009 and 2010, an area of approximately 10,000 acres in the Chirtradurga District of Karnataka was diverted for various military-technical and military-industrial purposes. Within this area, 1,410 acres in Ullarthi Kaval and 400 acres in Khudapura were allocated to the DAE’s Bhabha Atomic Research centre (BARC) for the purpose of developing the SMEF. In 2011, India announced publicly her intention to build this industrial-scale centrifuge complex in Challakere Taluk, Chitradurga District (Karnataka). This site has since been dedicated to the production of both highly enriched uranium (HEU) and LEU for military and civilian purposes, although industrial-scale production has yet to commence. BARC has been allotted many more acres in Ullarthi Kaval compared to Khudapura (1,410 versus 400 acres respectively).

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Despite such investments, the fuel for powering the INS Arihant S-73’s (India’s first in-country built SSBN) PWR (and for the INS Arighat as well) had to be obtained from Russia. The PWR for this SSBN is the third-generation OK-700A/VM-4SG model, generating 89.2mW thermal (29.73mW electric) and producing 18,000hp when using 44% enriched uranium. The PWR was developed by the OJSC N A Dollezhal Scientific Research & Design Institute of Energy Technologies (also known as NIKIET) and which is now part of JSC Atomenergoprom. Such PWRs were series-produced in Izhorsky Zavod, at Kolpino, near St Petersburg, and at the Nizhny Novgorod Machine-Building Plant (Afrikantov OKBM). In India, JSC Atomenergoprom authorised the DAE to licence-produce such PWRs. Such PWRs have a total technical service life of 35 years and require refueling after 17 years. The reactor core of such PWRs comprises between 248 and 252 fuel assemblies. Each fuel assembly contains tens of fuel rods, and these vary from the traditional round rods to more advanced flat fuel-rods. The point of the flat fuel-rod is to enlarge the surface of each fuel-rod so as to improve the thermal efficiency. Most of the uranium fuel assemblies are clad in zirconium. The fuel assemblies in the middle of the reactor core (weighing about 115kg) are enriched to 22% U-235, while the outermost fuel assemblies are enriched as much as 45%.

I doubt it would be necessary much longer - like mentioned, the Challakere enrichment complex (which is a very large one, btw) should come fully online in the next few years and provide enough HEU fuel for the some 15-20 naval PWRs that India could ultimately end up operating.

But if for whatever reason that doesn't pan out, France can be a great stop-gap alternative (if for whatever reason Russia stops supplying).

It remains to be seen whether France will assist India in developing a fourth-generation variant of the OK-700A/VM-4SG PWR that will feature a higher reactor density (capable of using France-supplied uranium enriched to more than 60%), resulting in a higher power output close to 40mWe and becoming a lifelong PWR that does not require refuelling thrughout its service-life.

This would be considering we did not get the designs & engineering models for the 3rd Gen OK-650B 190mwT PWR used on Akula-class.

But there is some ambiguity here...

India signed a $900 million lease agreement for the K-152 Nerpa back in 2008-09 (and took delivery by 2012). Quite a hefty price - more than half of what it would have costed to build a new one. This submarine, the INS Chakra-II (Chakra-I was a Charlie-class SSGN leased back in 1988-91), came with the aforementioned OK-650B powerplant, and would have enabled Indian Naval engineers to get operational experience on this type of reactor - like how they did on the VM-4 PWR on the old Charlie, which eventually gave rise to India's own 83mwT CLWR-B1 PWR that went into Arihant-class SSBNs.

And then, in 2018 we have this report from BARC:

http://www.barc.gov.in/presentations/fddir18.pdf

So some form of shore-based test setup prototype of the CLWR-B2 (190mwT PWR purportedly based on the OK-650) was either under construction, or already under test operation as of 2018. That was 3 years ago.

(SBC, Vizag is the yard that builds the Arihant-class SSBNs and takes care of all related equipment needs).

If we make the assumption that Russia transferred the designs for the OK-650B during the initial contract agreement in 2008-09, it would be a fair logical reasoning to assume that 10 years later, a working example of an Indian-built version would be operational (or close to it), with whatever modifications were necessary.

So if we have a working CLWR-B2 as of today, there is no question of developing the VM-4SG into a 4th generation type - it would be pointless, rather develop the OK-650 design instead, which is approximately 20 years newer.

Which then beggars the question...if the OK-650B PWR design was already transferred back in 2008-09 in the $900mn deal (evidenced by the B2 PWR existing by 2018)...then what the HECK was transferred in the $3.3 BILLION deal for the Chakra-III signed in 2019 ??

The submarine supposedly being leased is the same class (infact, the Bratsk is a slightly older model) as the one leased back in 2012-2021, which costed less than 1/3 this amount. So its pretty evident that whatever is being paid for isn't just the submarine. And based on the cost, its something several orders of magnitude more advanced than the OK-650B.

This is from a NTI report in March 2016:

^^ That last paragraph is of interest. The 1.5 billion ballooned to more than double, and we only wonder if elements of the Yasen/Severodvinsk were transferred or not...along with some know-how/know-why regarding the 4th generation OK-650KPM/KTP-6 complex that went into the 885M Yasen-M.

The nuclear submarine cooperation between India & Russia goes very deep, so I won't be surprised. France can, however, still help a great deal when it comes to quietening the boat.

 

[Nilgiri]

Which then beggars the question...if the OK-650B PWR design was already transferred back in 2008-09 in the $900mn deal (evidenced by the B2 PWR existing by 2018)...then what the HECK was transferred in the $3.3 BILLION deal for the Chakra-III signed in 2019 ??

We tend to learn about details of provisions in these things much later.

The nuclear submarine cooperation between India & Russia goes very deep, so I won't be surprised. France can, however, still help a great deal when it comes to quietening the boat.

Yep I agree. There is also lot on the shipyard process side they can help with modernising and improving (especially in something so niche like submarines)...with eye on achieving next tier level of economy of scale.

The nuclear core assistance may be far more limited as that is more set in stone like you have pointed out. I doubt French would produce HEU just to export to us anyway.

 

[Gessler]

https://twitter.com/i/web/status/1451561743528824832

https://twitter.com/i/web/status/1451561761807556610

 

[Super falcon]

Indian sub fleet with nuke subs are game chnger which pak should also consider too

 

[SavageKing456]

https://twitter.com/i/web/status/1476052266067308546

great news coming