March 27, 2017

Indian Submarine Propulsion Reactor Needs - Arihant, Aridhaman & Chakra II

Photo of  "S-1" land based prototype reactor at Kalpakkam for India's Advanced Technology Vessel (ATV) (Arihant) Program. S-1 went critical on November 11, 2003, was declared operational on September 22, 2006 and photographed (above) in early August 2009. Kalpakkam is an Indian nuclear enclave 45 km south of Chennai, on India's lower east coast. Kalpakkam is shorthand for the longer, more formal, name of the nuclear enclave which is the Indira Gandhi Centre for Atomic Research (IGCAR) (Photo courtesy The Hindu).

[Update as at March 27, 2017] The Submarine Matters article below was originally published in October 2015 - which explains why the comments below it are of October 2015. The article is suggested reading before I publish an overt update on India's nuclear submarine program on March 30 or 31, 2017.

Please connect with Submarine Matters US and France in Talks with India to Assist India's Nuclear Submarine Program, September 29, 2015.


The land based prototype reactor at Kalpakkam was designated "S-1" in India's Advanced Technology Vessel (ATV) (Arihant) Program, 
"S-2" - was INS Arihant itself with its 83 MW 1st or 2nd generation reactor
"S-3" is INS Aridhaman the first true SSBN (yet to be launched) which will have a more powerful 2nd or 3rd generation reactor.

The Indian indigenous nuclear submarine program, that produced the Arihant, continues under some  secrecy. Secrecy is not total because Kalpakkam and its parent organisation, the Bhabha Atomic Research Centre (BARC), need to demonstrate to politicians and the public that the large amounts of taxpayers money is spent wisely with progress made in the nuclear projects.   

•  Work on the Indian nuclear sub program dates from the 1970's and was referred to as the Advanced Technology Vessel (ATV) Project .

•  The prototype nuclear propulsion plant at Kalpakkam (photo) was developed under the program "Plutonium Recycling Project" or "PRP" under direction of BARC or Bhabha Atomic Research Center (BARC). Kalpakkam nuclear enclave is 45 km south of  Chennai on the lower east coast of India.  

•  The 
Kalpakkam-Arihant prototype plant went critical on November 11, 2003 and after further development was declared operational on September 22, 2006. It was only shown to the press once, in early August 2009, about one week after the July 26, 2009 launch of the Arihant itself. Apparently only one photo (above) was cleared for distribution. 

•  Most sources list the prototype and the Arihant reactors as being rated at 82.5 MW. 
There are around 13 fuel assemblies with each assembly having 348 fuel pins.

Major components of Arihant's reactor were made by Indian companies, including:
-  the reactor vessel, made of special grade steel by Heavy Engineering Corporation, Ranchi. 
-  steam generator by Bharat Heavy Electricals Limited (BHEL) and 
-  Pressure valves were made by Audco India, Chennai.


There is a great deal of difference between a nuclear propulsion reactor in a submarine and a land-based atomic power station to produce electricity. While a land-based atomic power plant gets backup from other power stations on the electrical grid, a submarine nuclear propulsion reactor only has some weak diesel engines for emergency backup. A propulsion reactor has to be miniaturised to fit into the confined space of a submarine and be lightweight but strong enough to endure the shock due to moderately powerful underwater explosions. The reactor must also withstand the pitch and roll of a submarine. The reactor must also be capable of rapidly accelerating and decelerating the submarine - unlike a land-based power plant which ramps up gradually.

The Arihant's 83 MW reactor went critical after many sea trials. Extrapolating from known data on Russian submarines and their reactors - the Akula class has a 190 MW reactor but turbines that are rated at just 32MWGoing by the roughly 20 percent power rule here, the turbines on the Arihant are likely to be around 15 MW, or about 20,000 horsepower. Rating them at higher than that doesn't seem to make much sense, and the figures placing them at 47,000 hp (on wiki right sidebar) seems ludicrous - that sort of power would propel the Arihant's estimated 6,000 tons (surfaced) (perhaps 7,000 tons submerged) bulk past 37 knots (like a high speed SSN). A lower power rating and a speed in the SSBN range of 24 knots seems far more likely. A ballistic missile submarine isn't meant to sprint across the oceans - it's meant to be a ghost, running silent and deep, popping up to deliver its apocalyptic cargo when the time calls.

Arihant, with its 83 MW reactor, must be considered an interm and experimental test bed. The 83 MW reactor is not powerful enough for the second of class INS Aridhaman SSBN. Aridhaman, to carry a larger missile load, may weigh around 8,000 tons (surfaced). So a more powerful reactor, approaching Chakra II's 190 MW reactor, may be India's objective. 


A major reason for India funding Chakra II (ex Nerpa Akula's) completion and 10 year lease is Indian interest in developing a reactor with something approaching 190 MW.  It is logical to assume that India has a prototype 190 MW reactor at Kalpakkam with Russian advisers for technology transfer. The Akula SSNs, like Chakra II, use the OK-650 reactor rated at 190 MW. It uses a low end 20%-45% HEU reactor. The OK-650 may have been first used 1980 and is still being placed on new Russian submarines - such as 2 on the Borei SSBN in 2009. The OK-650 and other 190 MW Russian submarine reactors are made by the OKBM Afrikantov company.

Of nuclear submarine powers India may still have reactors less advanced than China's but ahead of Brazil. The most advanced remains the US. USS Nautilus was launched in January 1954 and its reactor went critical in December 1954, under two years after the land based prototype went critical. The US provided the UK with its best reactors and helped the UK build copies. France may have received direct US-UK assistance or they tacitly permitted "espionage" by France.


As at September 2015 India appears to be encouraging Russia, France and the US to compete in providing nuclear submarine assistance to India. Russia is an overt provider of assistance while France and US may claim that are not actually assisting in Indian submarine reactor development.

Biswajit Pattanaik advised in Comments [Oct 2, 2015 8:42PM] India may want a reactor similar to the K15, 150 MW that France has in the Barracuda SSN. Years ago a retired Indian Navy Admiral said the Navy asked BARC to develop a 190 MW with HEU for possible use for the 2nd Vikrant class aircraft carrier and future SSBNs and SSNs that will appear after 2025 time frame. Biswajit understands India is seeking French assistance to increase the life of the Indian reactor from the current 5-8 years to around 10-15 years. India may also be talking to French reactor builder AREVA about converting the K15 from LEU to a new HEU type reactor. 

Ultimately India would be very interested in developing a reactor approaching the capabilities of the US Virginia class's ninth generation S9G reactor which uses higher HEU of 90+ % and lasts the lifetime of a submarine (33 years).


Sources used include:

 -  Atomic Power Review, August 11, 2013:

-  On the Wings of a White Swan, also August 11, 2013, and 

-  "Warhawk, Jun 23, 2014"



Biswajit Pattanaik said...

Hi Pete,

A great article.Full of useful info & facts plus some good insights.

Keep up the good work.

Regarding INS Arihant's reactor capacity of 83MWe,when India started the ATV project;the Govt. & IN wanted an SSN.But after the Pokhran-II nuclear tests from 11–13 May 1998 & subsequent change in India's Nuclear doctrine of No-First Use;the ATV Program was morphed into a SSBN program to reflect this doctrine & to provide the country with a 2nd Strike Nuclear capability.That's why the Arihant class SSBN have such a low powered reactor on board because it was orginally headed for a SSN program.

On India's Nuclear Doctrine Policy....

India has a declared nuclear no-first-usepolicy and is in the process of developing a nuclear doctrine based on "credible minimum deterrence." In August 1999, the Indian government released a draft of the doctrine which asserts that nuclear weapons are solely for deterrence and that India will pursuea policy of "retaliation only". The document also maintains that India "will not be the first to initiate a nuclear first strike, but will respond with punitive retaliation should deterrence fail" and that decisions to authorise the use of nuclear weapons would be made by the Prime Minister or his 'designated successor(s)'.

Interestingly India's nuclear doctrine calls for a No-First Use of Nuclear weapons only on non-nuclear weapon states.But it may or can use its nuclear weapons on a nuclear power state as first strike weapon.Whether the nature of nuclear attack was a miniaturised version or a"big" missile or a small nuclear attack or not, India will retaliate massively to inflict unacceptable damage.Plus if Indians Militarily or Civilians are attacked with Nuclear/Biological/Chemical/Radiological weapons anywhere in the world (knowingly by the conerned state),India will respond with its nuclear weapons irrespective of the fact whether it is nuclear-weapon or non-nuclear weapon state.



Peter Coates said...

Thanks Biswajit

Certainly India's nuclear doctrine makes chilling reading, including:

"Plus if Indians Militarily or Civilians are attacked with Nuclear/Biological/Chemical/Radiological weapons anywhere in the world (knowingly by the conerned state),India will respond with its nuclear weapons irrespective of the fact whether it is nuclear-weapon or non-nuclear weapon state."

Hopefully the India PM will have considerable discretion. Countering the Assad regime's use of Sarin with a nuclear weapon would certainly be decisive.



Biswajit Pattanaik said...

Hi Pete,

He...he...he..... ☺ :-) chilling reading,don't worry about that;the Indian politicians haven't yet get that rigid spine to take such bold decision.The main aim of such doctrine is to deter any such possibilty & that's the only use of such doctrine so no need to worry about it(& less so against a non-nuclear weapon state).And India is not the only country with such doctrine all of the other nuclear weapon states also have similar doctrine regarding the same.

And all the nuclear weapon states also know there is no such thing as No-First-Use of nuclear weapons between them.It will be foolhardy to belive that India will alone adhere to such non-senseical thing.Every other nuclear weapon state have almost the same nuclear doctrine barring some differences.

The main aim of having nuclear weapon is to deter any misadventures.Nuclear weapons aren't meant to be used in war they are here for physiological pressure.Only once in our mankind we had seen use of nuclear weapons by the USA on the Japanese.And i hope that it stays the same way for the rest of the future of the mankind.



Peter Coates said...

Hi Biswajit

Thats a relief. My faith in deterrence and MAD is almost restored.

But then doubtors might say:

1. what about crazy religious zealots with itchy buttton fingers, who don't fear destruction?

2. states like North Korea whose people may be so brainwashed that some take the death of Kim III as the apocalyptic death of a God with nothing except button pushing as solace? or the biggee...

3. Miscalculation and panic in large militaries. A classic case being Soviet submarine B-59 in the Cuban Missile Crisis pondering whether to unleash a nuclear warhead torpedo at the sub's US Navy tormentors?



Biswajit Pattanaik said...

Hi Pete,

😊...I am glad that your faith in deterrence and MAD is almost restored.

Yes,there will always be some execptions.

1)Yeah,those are the danger lots always having some kind of itching problems**ahem...ahem...*ahem...Pakistan is one of those states.And given their past records regarding nuclear proliferation it doesn't aspire any confidence either.And among all the nuclear weapon states it is the most unstable;plus quite a few crazy religious zealots with itchy buttton fingers reside their or are under the patronage of that Govt.

2)The less said about that country the better.I mean it has to be one the most craziest nation in the world.That country is totally out this galaxy.

3)Yeah,that was one scary for sure.Hope something similar doesn't happen in the future.Those Communist ruled countries had some serious problem with their functioning.
Plus the Chinese SSBNs carry their SLBMs without its Nuclear warhead the reason being the CCP Politicians don't have enough belief/trust on their naval personnel(PLAN).Plus the Chinese aren't the 9 feet tall giant which most of the general public of the world belives.



GhalibKabir said...

a minor quibble with Biswajit's comments. The Arihant has 85 MWt reactor (40% HEU based fuel) and not a 85 MWe, the 85 MWt translates into a modest 16.5-17 MWe. As I understand on land based reactors the rule of thumb is 3 MWt equals 1 MWe while in a naval reactor 5/6 MWt equals 1 MWe. That makes sense as the OK650 and K15 Russian and French reactors are rated 190 MWt and 150 MWt respectively but shaft electrical rating is 32 MWe for the K15 and between 32 and 38.5 MW for the 650 (closer to 32, but Chinese sources say closer to 38).

Peter Coates said...

Hi GhalibKabir

Thanks for going through estimates and units of measure so thoroughly.

I think India has taken much longer than it expected getting Arihant's reactor up to "speed" - sufficient to commission Arihant.

I'm assuming there are many Russian advisers in Arihant, assisting with the reactor and other aspects.



Anonymous said...

Hi Pete

Japan and India signed civil nuclear agreement [1] in Tokyo, yesterday. JPN Ministry of Foreign Affair (MOFA) released details of the agreement [2, 3, 4]. This agreement is essential for introduction of Japanese nuclear generation system into India who suffers from serious shortage of power. Selling US-2 [5] is under review [2].

This agreement will be contribute to corporation of maritime security by India and Japan, and uranium export from AUS. PM Abe succesivly provides diplomatic achievement. He will meet Mr. Trump next week and President Putin in December.

[1] (Japan and India sign civil nuclear agreement, BBC, NOV/12/.2016)
[2] (JPN)
[3] (text of the agreement, ENG)
[4] (text of note on the agreement, ENG)


Peter Coates said...

Hi S

Hopefully India will PAY for Japanese provided nuclear reactors and services like a commercial customer without the usual POST AGREEMENT INTER-GOVERNMENTAL HAGGLING that India's politicians indulge in.

France has long suffered such post-Agreement haggling regarding its Scorpene and Rafale sales to India.

I'm aware that India was concered that countries providing/building/operating nuclear reactors in India should be prepared to pay unlimited public liability/compensation in case of nuclear accidents in India. Has that issue been resolved by Japan?



Peter Coates said...

As I was saying [13/11/16 3:54 PM] India usually indulges in POST AGREEMENT INTER-GOVERNMENTAL HAGGLING over arms deals.

Historians will recall the Japan was to sell US-2i amphibious aircraft to India about 2 years ago. However as of Oct-Nov 2016: "India-Japan Military Aircraft Deal Faces Further Delays [because] India’s MOD is seeking clarification over the Indian Navy’s requirement for 12 amphibious aircraft from Japan."

"So far the Indian MOD has only indicated that it would like to purchase two US-2i aircraft in fly-away condition, whereas the remaining ten (sources say that the Indian Navy requirement is pegged at 12-18 aircraft) should be built in India under Indian Prime Minister Narendra Modi’s ‘Make in India’ initiative. ShinMaywa, however, thinks that license-building ten US-2i is impracticable and too costly given the small number of aircraft." see

Looks like Japan will either:

- have to bribe all the usual Indian politicians and defence officials to accept the deal (but Japan doesn't bribe) OR

- Japan will end up effectively donating the aircraft to an India that refuses to pay.

Ganesh Dore said...

Next up .. would be pump drive propulsion with nuclear power generation and direct electric motor drive. I think the Boren class is pump drive via steam turbine.