India's Reliance on Variants of Russian Submarine Reactors

India has, since the 1950s [A], been talking about building nuclear attack submarines (SSNs). Their principal mission would be to scour the seas for enemy (mainly Pakistani and Chinese attack) submarines before and during India’s Arihant class SSBN nuclear deterrent patrol activities. India’s SSNs would particularly be a counter to China’s growing numbers of SSNs visiting the Indian Ocean. 

A major technical hurdle for India is improving reactor output from the 83 to 90 MW achieved on the Arihant class small SSBNs to 150 to 190 MW required for India's future 13,000 ton S5 class SSBNs and the SSNs.

India's highest priority may be building an Indian variant of INS Chakra's/Akula's Russian 190 MW OK-650B/OK-650M reactor.

[A] Drawing from this August 2014 Submarine Matters’ report:

India plans to build 6 SSNs “to be constructed at Visakhapatnam. Few details, no date milestones. This [1990s Federation of American Scientists] report indicates India has been interested in building or buying 6 SSNs since the 1950s, with Russian assistance, for fleet protection, mainly against Chinese subs. India financed the completion of INS Chakra (ex Nerpa) (a Russian Akula 2) - is long leasing it - and commissioned it into the Indian Navy in 2012. Since commissing Chakra has been almost invisable. It may not be operational but rather a full test model for examination and trials by the India Navy, DRDO and India's nuclear reactor sector. It is likely any Indian built SSN would draw heavily on Akula 2 technology and be built with Russian assistance."

Inspired by Manu Bubby of India’s The Economic Times, June 24, 2019, most excellent report and a mainly subsequent Wikipedia report:

India approved the construction of 6 SSNs [1] in February 2015.[2] These will be Indian designed and built with a lot of help from the Russian research and on-site advisers...at India’s Visakhapatnam Main Naval Base East shipyard. Expertise gained in the construction of the Arihant class SSBNs (which I suspect use variants of the Russian VM-4 or VM-5 reactor ) will be transferred to the SSN project.[5] Since India is a traditional user of Russian nuclear submarines (with INS Chakra (2011) on lease) the new domestically built submarines would be third class of SSN operated by Indian navy after leased Charlie-class submarine and Akula-class submarines.[3] All six submarines are expected to be constructed in India [ie. none in Russia] under India’s  “Make in India” Program.[1][4]

The submarines will be powered by a conventional PWR reactor being developed by Russia and India's BARC. The new reactor will likely be in the 150-190 MW range (likely variant of Russia's 190 MW OK-650B/OK-650M reactor). This will be much more powerful than the under-powered 83 MW Russian-BARC reactor used in the Arihant-class (INS Arihant and INS Arighat so far) SSBNs.[3]

On June 24, 2019 , it was reported [5] that ₹100 crores = 100 x 10,000,000 = 1 Billion Indian Rupees = only US$14.4 million has been allocated for the initial phase of the project. With such small infusions of money since the project began in 1950s-2015 “development work would stretch beyond 2025”. Unsurprisingly the SSNs will use pressure hull steel permitting them to dive deeper than the Arihants. A scaled down model of the SSN is scheduled to begin testing soon.

References (courtesy Wikipedia)

[1]"India to Build 6 Nuclear-Powered Submarines - Navy Chief". Sputnik International. Sputnik. 4 December 2015.

[2] "Government clears construction of 7 stealth frigates, 6 nuclear-powered attack submarines". The Economic Times. 18 February 2015. Retrieved 19 April 2015.

[3] "Watch Out, China: India Is Building 6 Nuclear Attack Submarines". The National Interest. 18 February 2015. Retrieved 19 April 2015.

[4] "India finalizing plans to order three more Scorpene submarines". The Times of India. Retrieved 2015-12-04.

[5] Pubby, Manu. "Work begins on India’s next gen nuclear-powered submarines" The Economic Times. 24 June 2019

FURTHER COMMENT

India's rather relaxed, underfunded SSN program, might commission the first basically Russian Husky (concept sketch above) derived "indigenous Indian" SSN/SSGN by 2050, if Pakistan and China are lucky.

Pete