India's Arihant-class SSBN Progress

Submarine Matters has been covering India’s first SSBN, INS Arihant’s progress since Arihant's launch on July 26, 2009 at Shipbuilding Centre (SBC) Visakhapatnam (aka Vizag) on India’s eastern coast. SBC Vizag builds India’s SSBNs and will be building its future SSNs. 

Arihant’s reactor went critical on August 10, 2013. Arihant is the lead submarine of the Arihant-class of four small SSBNs.    

Ghalib Kabir wrote the information below on June 20, 2023: 

The Indian Naval establishment has crossed a milestone in its N-Sub program with INS Arihant entering into its first refuel and deep maintenance cycle in November 2022. 

American nuclear reactor specialist, Peter Lobner, has produced a huge Marine Nuclear Power 2018 study. See page 152 of one of his 100+MB PDF documents) which reports Arihant's reactor:

-  [separately designated] Compact Light-water reactor (CLWR-B1)  

-  is rated at 82.5 MWt

-  with maximum propulsion power of 11.9 MW (aka 11.9 MWe) being about 16,000 shp. 

-  this HEU reactor is “about 30% U-235” [not 40% U-235 mentioned in other sources]

-  with a core in “13 fuel assemblies with each assembly having 348 fuel pins”.

Arihant’s 2 year deep maintenance and refueling program would give the Indian Navy first hand experience with spent fuel extraction, then nuclear fuel reloads and  subsequent reprocessing of the extracted fuel.

Above is an overhead photo of INS Arihant in dry dock at SBC Vizag for deep maintenance/refueling. It has been there since November 2022 and probably remains there. (Photo & captions courtesy Damien Symon @detresfa_   https://twitter.com/detresfa_/status/1612808236469727233 )
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[Submarine building and reactor development experience was partly gained by 600 Indian technicians being trained in Russia, with their families for a long-term stay, page 154, Lobner].

It is critical now that operational expertise is extending to maintaining and refueling nuclear submarines locally in India.

Even from above it is obvious Indian designers benefitted from the Russian Kilo SSK design. This is clearly visible in the forward arrangement of Arihant, resembling an enlarged Kilo (not to mention the Russian 'show me' based learnings too).

The 7 bladed high-skew propeller is also visible. The missile silo section is covered....I hope the K series missile silos are being swapped out from the current K-15 SLBMs to the longer range K-4 MRBM/IRBMs (the K-4s are apparently in production phase). 

Ghalib Kabir
June 20, 2023