83 MW pressurised water reactor developed by BARC used in INS Arihant & INS Arighat

The Bhabha Atomic Research Centre (BARC) is advancing India's nuclear submarine capabilities by developing a new 190-MW submarine nuclear reactor. This reactor is designed to power both the P-77 nuclear attack submarines (SSNs) and the S-5 ballistic missile submarines (SSBNs), marking a significant upgrade from the 83-MW reactors used in India's first-generation Arihant-class submarines.

The 190-MW reactor is a scaled-up version of the earlier design, with variants tailored for different operational needs: one for the endurance-focused SSBNs and another for the dynamic power demands of SSNs.

While the initial batch of S-5 SSBNs will utilise the 190-MW reactor, there are indications that future variants might require even more powerful reactors, potentially exceeding 200 MW.

This increase in power is driven by the need to support advanced technologies and next-generation weapons systems that these submarines may integrate.

The development of more powerful reactors for future batches of Indian submarines will depend on technological advancements and the ability to integrate these systems without significant structural changes to the submarines.

How Will The New 190-MW Reactor Improve The Performance of The P-77 SSN And S-5 SSBN

The new 190-MW nuclear reactor developed by the BARC is set to significantly enhance the performance of both the P-77 nuclear attack submarines (SSNs) and the S-5 ballistic missile submarines (SSBNs).

For the P-77 SSNs, this reactor will provide a substantial increase in power compared to earlier models, allowing for improved speed, stealth, and overall operational capabilities. The reactor's design supports the integration of advanced technologies such as nuclear-electric propulsion (NEP), which could enable quieter operations and enhance the submarine's ability to conduct diverse mission sets, including anti-shipping and land-attack roles.

For the S-5 SSBNs, the 190-MW reactor will support the strategic deterrence mission by providing sufficient power for prolonged submerged operations, essential for maintaining a stealthy presence and ensuring the ability to launch nuclear missiles when needed.

The reactor's capacity is deemed sufficient for the initial batch of S-5 SSBNs, which are designed for slow and stealthy operations. However, future batches might require even more powerful reactors to support next-generation systems and technologies, potentially exceeding 200 MW.

The new reactor will bolster India's maritime capabilities by enhancing the endurance, speed, and technological sophistication of its nuclear submarines, positioning them as formidable assets in the region's naval landscape.

Key Technological Advancements In The New 190-MW Reactor Compared To The 83-MW Reactors

The new 190-MW nuclear reactor developed by the BARC represents a significant technological advancement over the existing 83-MW reactors used in India's Arihant-class submarines.

The most obvious advancement is the more than doubling of power output, from 83 MW to 190 MW. This increased power will allow submarines to operate more efficiently and for longer periods without surfacing, enhancing their stealth and operational capabilities.

The new reactor is designed in two variants: one for nuclear attack submarines (SSNs) that can handle dynamic power demands for rapid manoeuvres, and another for ballistic missile submarines (SSBNs) focused on steady, long-duration operations. This flexibility allows the reactor to support diverse mission profiles.

The 190-MW reactor offers an extended refuelling interval, potentially up to 10 years, which significantly enhances the operational endurance of submarines like the S5-class SSBNs. This means less frequent maintenance and longer deployment times.

Although specific safety features of the 190-MW reactor are not detailed, BARC's experience with earlier reactors and its focus on advanced designs suggest that the new reactor will incorporate improved safety and efficiency features, similar to those seen in other modern nuclear reactors.

The new reactor represents a major leap in India's nuclear submarine technology, enabling more powerful and enduring naval capabilities.

IDN