The Bhabha Atomic Research Centre (BARC) is currently developing a powerful 200 MWt (Megawatt thermal) reactor to significantly enhance the endurance of the Indian Navy's future submarines. This initiative is a significant step in strengthening India's strategic deterrence capabilities and promoting self-reliance in defense technology.
Advancements in Reactor Technology
The new reactor, a major upgrade from the 83 MW reactors used in the INS Arihant and INS Arighat, is being developed for the S-5 class nuclear-powered ballistic missile submarines (SSBNs) and nuclear-powered attack submarines (SSNs). The third submarine in the Arihant class, INS Aridhman, is currently undergoing trials. This development signifies a move towards fourth-generation naval reactors, with the CLWR-B2 representing a clear evolution from the CLWR-B1 reactor currently deployed on India's Arihant-class and S4-class SSBNs.
One of the key improvements in the CLWR-B2 is the elimination of the need for a land-based prototype reactor. The technologies and reactor architecture for the B2 variant are heavily based on the already proven CLWR-B1 platform, with enhancements in thermal efficiency, safety mechanisms, and miniaturization.
Strategic Implications
The development of this indigenous nuclear reactor is a landmark achievement for India's defense infrastructure, signaling a new phase in the nation's technological and strategic evolution. By increasing the number of nuclear-powered submarines, India can ensure the survivability of its nuclear arsenal in case of a first-strike attack from a potential adversary.
The new reactor will provide a major operational advantage to newer submarines, such as greater endurance and longer submergence time. This is particularly crucial given the evolving geopolitical dynamics in the Indo-Pacific region and the increasing challenges posed by neighboring countries. The enhanced power output will enable submarines to operate more efficiently and for extended periods without surfacing, thereby improving stealth and operational capabilities.
Submarine Capabilities
The Indian Navy has ambitious plans for its submarine fleet, including the construction of six SSNs under Project 75 Alpha. The S-5 class SSBNs will be significantly larger than the Arihant-class submarines and are expected to carry 12 to 16 intercontinental-range ballistic missiles (ICBMs), greatly enhancing India's second-strike nuclear deterrence capability. The SSNs, meanwhile, will serve as hunter-killers, tasked with escort duties, ISR (Intelligence, Surveillance, and Reconnaissance) missions, and neutralizing enemy submarines and surface vessels in blue-water operations.
The development of the 190-MW reactor also has potential implications beyond submarines. A twin configuration of the reactor could provide the necessary power for a 70,000-ton nuclear-powered aircraft carrier, should the Navy decide to pursue this path in the future.
Pump-jet Propulsion
A significant upgrade accompanying the CLWR-B2 reactor is the incorporation of pump-jet propulsion systems on the S-5 class SSBNs and the two new SSNs. Pump-jet propulsion offers a considerable advantage in terms of acoustic stealth, reducing cavitation and making submarines harder to detect by enemy sonar.
Future Developments
While the initial plan was to develop a 190-MW reactor, there are ongoing discussions to potentially increase the power output to surpass the 200MW threshold. However, the integration of a larger reactor will depend on the submarine's internal capacity and potential structural modifications. As a result, the development and integration of a new reactor could take considerable time, possibly appearing in the second or third group of S5 Class submarines, post-2040.
