India's Project 78A SSN Construction Programme Being Accelerated With French Partnership & Mentoring

Official Statement: France’s President Emmanuel Macron dialled India’s PM Narendra Modi on September 21, 2021 to talk about strengthening cooperation in the Indo-Pacific and also boost, as Macron’s office said in a statement, India’s strategic autonomy. Macron assured Modi of France’s continued “commitment to the strengthening of India’s strategic autonomy, including its industry and technology base, as part of a close relationship based on trust and mutual respect”.

Translation: An apex-level agreement has been reached under which France and India will officially announce their decision to cooperate in both military-technical and military-industrial matters related to Project-78A—the Indian Navy’s (IN) plan to procure six indigenously-built nuclear-powered attack submarines. What will come next is the inking of a government-to-government agreement between India’s Ministry of Defence and France’s Direction Générale de L'Armement (DGA, or Directorate General of Armaments) that will formalise such cooperation. It will also officially enable France to supply the enriched uranium fuel for the India-built pressurised water reactors (of Russian design) for the entire service-lives of the six SSNs.

Principal beneficiaries of this G-to-G agreement at the industrial-level will be France’s NAVAL Group and THALES, while on the Indian side the prime industrial contractor will be Larsen & Toubro. While the six SSNs will have the same double-hulled design as that of the three nuclear-powered SSBNs now being procured from L & T by the IN, they will have reduced submerged displacements (about 4,800 tonnes, as opposed to the SSBN’s 6,000 tonnes), and will incorporate (just like the French Navy’s Barracuda-class SSNs) a hybrid propulsion system that will provide electric propulsion for economical cruise speeds and turbo-mechanical propulsion for higher speeds. In addition, each of the SSNs are likely to incorporate a pumpjet propulsor that combines a shrouded rotor and a stator within a duct to significantly reduce the level of radiated noise and avoid cavitation.

It was in 1984 that construction began of India’s Rattehalli Rare Materials Plant (RMP), located near Mysore in Karnataka State, which is a pilot-scale gas centrifuge uranium enrichment plant with several hundred gas centrifuges, and is capable of producing several kilograms of highly enriched uranium (HEU) each year. Construction of the pilot-scale gas centrifuge enrichment facility at began in 1987, took four years to complete, and began operating in 1991. The plant is operated by Indian Rare Earths Limited (IREL), which is a subsidiary of India’s Department of Atomic Energy (DAE). The DAE first confirmed the existence of the plant in 1992. Items that the IREL initially imported to outfit the RMP, such as vacuum pumps, vacuum furnaces, machine tools, vacuum bellows-sealed valves, and canned motors for centrifugal pumps, were subsequently indigenised. Thereafter, work began on producing low enriched uranium (LEU) for submarine-based pressurised water reactors (PWR) at a large uranium enrichment centrifuge complex, the Special Material Enrichment Facility (SMEF), in Challakere Taluk, Chitradurga District of Karnataka. Between 2009 and 2010, an area of approximately 10,000 acres in the Chirtradurga District of Karnataka was diverted for various military-technical and military-industrial purposes. Within this area, 1,410 acres in Ullarthi Kaval and 400 acres in Khudapura were allocated to the DAE’s Bhabha Atomic Research centre (BARC) for the purpose of developing the SMEF. In 2011, India announced publicly her intention to build this industrial-scale centrifuge complex in Challakere Taluk, Chitradurga District (Karnataka). This site has since been dedicated to the production of both highly enriched uranium (HEU) and LEU for military and civilian purposes, although industrial-scale production has yet to commence. BARC has been allotted many more acres in Ullarthi Kaval compared to Khudapura (1,410 versus 400 acres respectively).

Despite such investments, the fuel for powering the INS Arihant S-73’s (India’s first in-country built SSBN) PWR (and for the INS Arighat as well) had to be obtained from Russia. The PWR for this SSBN is the third-generation OK-700A/VM-4SG model, generating 89.2mW thermal (29.73mW electric) and producing 18,000hp when using 44% enriched uranium. The PWR was developed by the OJSC N A Dollezhal Scientific Research & Design Institute of Energy Technologies (also known as NIKIET) and which is now part of JSC Atomenergoprom. Such PWRs were series-produced in Izhorsky Zavod, at Kolpino, near St Petersburg, and at the Nizhny Novgorod Machine-Building Plant (Afrikantov OKBM). In India, JSC Atomenergoprom authorised the DAE to licence-produce such PWRs. Such PWRs have a total technical service life of 35 years and require refueling after 17 years. The reactor core of such PWRs comprises between 248 and 252 fuel assemblies. Each fuel assembly contains tens of fuel rods, and these vary from the traditional round rods to more advanced flat fuel-rods. The point of the flat fuel-rod is to enlarge the surface of each fuel-rod so as to improve the thermal efficiency. Most of the uranium fuel assemblies are clad in zirconium. The fuel assemblies in the middle of the reactor core (weighing about 115kg) are enriched to 22% U-235, while the outermost fuel assemblies are enriched as much as 45%.

It remains to be seen whether France will assist India in developing a fourth-generation variant of the OK-700A/VM-4SG PWR that will feature a higher reactor density (capable of using France-supplied uranium enriched to more than 60%), resulting in a higher power output close to 40mWe and becoming a lifelong PWR that does not require refuelling thrughout its service-life.