India Begins Commercial Operation of First Domestically Designed 700-MWe PHWR Nuclear Reactor

India has begun commercial operation of its first domestically designed 700-MWe pressurized heavy water reactor (PHWR) at the Kakrapar nuclear power plant in Gujarat, state-owned Nuclear Power Corp. of India Ltd. (NPCIL) reported on Aug. 30.

Commercial operation of  Unit 3 at Kakrapar Atomic Power Project, which is located near the city of Vyara in the state of Gujarat, began on June 30, nearly three years after the unit achieved first criticality. Unit 4, a twin 700-MWe unit, is at an “advanced stage of commissioning,” with a target to begin commercial operation in March 2024, the government entity noted. Kakrapar already houses two 220-MWe PHWR reactors completed between 1993 and 1995, 

Government data suggests its first-of-a-kind 700-MWe reactor project at Kakrapar fell eight years behind schedule and experienced cost overruns, which pushed up costs from original estimates of INR 11,459 crores ($1.4 billion) to INR 19,220 crores ($2.3 billion). Kakrapar 3’s commercial operation, however, marks a significant milestone for India, positioning the reactor as the “front-runner” in a series of 16 indigenous 700-MWe PHWRs, which are at various stages of implementation,” NPCIL said.

India has a 6.3-GW operating nuclear fleet comprised of 17 PHWR nuclear reactors, and two VVER pressurized water reactors (PWRs, at Kundankulam in Tamil Nadu). Two boiling water reactors (BWRs) at Tarapur Atomic Power Station in Maharashtra state and one PHWR (Unit 1 at the Madras Atomic Power Station in Tamil Nadu) are currently in suspended operation.

It also has eight nuclear reactors under construction. Along with Kakrapar 4 in Gujarat, these include two other 700-MW PHWRs at the  Rajasthan Atomic Power Station and four PWRs at the Kudankulam Nuclear Power Plant. NPCIL last week noted that 15 700-MWe PHWR reactors “are at different stages of implementation.” A prototype fast-breeder reactor (PFBR),  spearheaded by India’s national nuclear research arm, Bharatiya Nabhikiya Vidyut Nigam Ltd. (BHAVINI), is also reportedly at an advanced stage of integrated commissioning in Kalpakkam, Tamil Nadu. The government anticipates completing construction of these projects by 2027.

The first phase of the Kakrapar Atomic Power Station in Gujarat, India, Units 1 and 2, which was completed between 1993 and 1995, comprised two 220-MWe domestically designed pressurized heavy water reactors (PHWRs). The second phase, Units 3 and 4, comprises two 700-MWe PHWRs. Unit 3 began commercial operation on June 30, 2023, and Unit 4 is slated to reach that milestone in March 2024. Source: DAE (GODL-India), GODL-India

Nuclear Self-Reliance: India’s Quest for Energy Independence

India’s development of a domestically designed PHWR began in the late 1960s. Excluded from the the Nuclear Non-Proliferation Treaty and subject to a 1974 trade embargo for acquiring nuclear weapons capability, the country set out on a three-stage closed fuel-cycle program. The program champions self-reliance through the development of domestic technology that reduces its reliance on imported uranium and strives to make more substantial use of thorium, of which India has more abundant reserves.

The first stage of the program involves building indigenously engineered PHWRs fueled by natural uranium to generate electricity and plutonium. The second stage will use fast-neutron reactors fueled by plutonium to breed U-233 from thorium. In the third stage, using wholly indigenous technology, the country plans to use advanced heavy-water reactors fueled with U-233 obtained from the irradiation of thorium in PHWRs and fast reactors.

“As India has a declared ‘closed fuel cycle’ policy, reprocessing of spent fuel is at the center of India’s nuclear program, not only from the perspective of the waste management but also for recovery of fissile material to use it in next stage reactors,” the government recently noted. “With India now having safeguarded reactors using natural as well as enriched uranium as fuel, reprocessing of both types of fuels and development of associated technologies is an ongoing research and innovation area.”

India’s first 220-MW PHWR reactor at Rajasthan Atomic Power Station, built in 1972, was modeled on the Douglas Point reactor in Canada—Canada’s first full-scale nuclear power plant and the second CANDU PHWRunder a joint Indo-Canadian nuclear cooperation. Its first two PHWR units using a domestically developed standardized 220-MWe design were implemented at the Narora Atomic Power Station in 1989. The design was eventually scaled up to 540-MWe by utilizing excess thermal margins and demonstrated at the Tarapur station in 2005.

The 700-MWe PHWR design that is now operational at Kakrapar 3 reportedly retains the features of standardized Indian PHWR units, which include two diverse and fast-acting shutdown systems, a double containment of reactor building, a water-filled calandria vault, an integral calandria-end shield assembly,  and zirconium alloy pressure tubes. The design, however, also incorporates some novel features to the Indian PHWR design, including partial boiling at the coolant channel outlet, interleaving of primary heat transport system feeders, passive decay heat removal system, regional over-power protection, a containment spray system, mobile fuel transfer machine, and a steel liner on the inner containment wall.

NPCIL noted that Kakrapar 3’s successful commercial operation has “advanced safety features, which are comparable to the best in the world.” Its design, construction, commissioning, and operation by Indian engineers and scientists and domestic supply of components and equipment “is a shining example” of Atmanirbhar Bharat, Prime Minister Narendra Modi’s 2020-raised campaign for national self-reliance.

Nuclear’s Key Benefit in India: Economically Competitiveness

Nuclear power may play an important role in India’s 2021-declared goal to achieve net-zero greenhouse gas (GHG) emissions by 2070, NPCIL has noted. The country has so far committed to increasing its share of non-fossil electricity generation capacity to 50% by 2030, accounting for 500 GW. However, this could require an annual capacity addition increase of nearly 39 GW per annum until 2030, compared to 12.8 GW per annum achieved in the period 2016–2022, according to Columbia’s Center on Global Energy Policy.

India’s Long-Term Low-Carbon Development Strategy submitted to the United Nations Framework Convention on Climate Change in November 2022 envisions a “three-fold” increase in nuclear capacity by 2032. While nuclear power produced just 3% of the country’s total power generation in 2021, the country anticipates its nuclear capacity could ramp up progressively from the current 7.5 GWe (including suspended reactors) to 22.5 GWe by 2032, NPCIL said.

A primary driver for the planned expansion is to secure a “clean and [environmentally] friendly source of baseload electricity generation, which is available 24×7,” NPCIL said. According to industry observers, however, nuclear power also offers a smaller land use footprint and remarkably competitive economic benefits. An analysis published by think-tank Observer Research Foundation (ORF) in May 2023 posits that the cost of firm power from Tarapur, India’s oldest nuclear generator is about INR 2 ($0.02)/kWh. That’s “lower than the lowest tariff for solar power, which is intermittent,” it notes. The cost of power from newer plants like Kudankulam is in the range of INR4-6 ($0.05–$0.07)/kWh, which is comparable to power from some thermal power plants and hybrid solar-pumped hydropower combinations.

“In India, specific generation, a parameter that signals economic efficiency of power generation (gigawatt hours of power generated for a megawatt of capacity) was highest for nuclear power at 6.35 compared to 4.74 for coal-based power, the second highest in 2020-21,” ORF added. “The specific generation of nuclear power has been consistently higher than the average specific generation value over the last two decades.”

Mobilizing Investment Is a Challenge

Getting new nuclear power plants built, however, is challenging given a“difficulty in mobilizing investment,” ORF notes. DAF in 2020 said the 1,400-MW expansion at Kakrapar (for Units 3 and 4) bore a sanctioned (approved) cost of INR 16580 crore ($2.2 billion) compared to INR 39849 crore ($5.3 billion) for new LWRs at Kudankulam 3 and 4, a combined 2,000 MW. Citing 2018 assumptions from the federal Central Electricity Authority (see Annexure 11.1), ORF suggests the capital cost of a PHWR nuclear power plant in India hovered at about INR 117 million ($1.41 million)/MW in 2021-2022 and could be INR 142 million ($1.7 million)/MW in 2026-27.

“The average capital cost of nuclear power is in the same range as that of large hydro-power projects or LNG (liquefied natural gas) liquefaction plants but it is far more difficult to raise capital for nuclear power plants as they are exposed to unique risks (low probability but high-risk events such as natural disasters, terrorist attacks, nuclear proliferation problems),” ORF said. “In addition, there are issues like long lead times, risk of construction problems, delays and cost overruns and the possibility of future changes in policy or technology.”

India is in tandem considering small modular reactors (SMRs). Dr. Jitendra Singh, Minister of State Science and Technology, on Aug. 2 told Lok Sabha, India’s lower parliamentary house, that while “augmentation of nuclear power capacity through large size reactors” is “a primary goal,” the government is “exploring options of collaborating with other countries” to take up “indigenous development” of SMRs. In November 2022, the minister said India was focused on SMRs of up to 300 MW.

The country is also mulling bold changes to the Atomic Energy Act 1962 that could lift a ban on foreign direct investment (FDI) in the nuclear energy sector. A panel assembled by think tank Niti Aayog has put forth the recommendation. “State-run [NPCIL] and [BHAVINI] currently dominate nuclear power generation in India,” noted law firm King Stubb & Kasiva in a recent blog post. Allowing FDI in the nuclear energy sector could furnish India with new capital prospects, advanced technology, and expertise—and ultimately bring it closer to its goal of generating 9% of its power from nuclear energy by 2047, the firm noted.

However, the prospect “is not without its complexities and challenges,” the law firm noted. “The Civil Liability for Nuclear Damage Act 2010, aimed at addressing liability concerns related to nuclear incidents, may require further clarification, especially concerning its application to emerging nuclear technologies like small modular reactors and advanced reactors. The role of private and foreign companies as Nuclear Power Plant (NPP) operators necessitates thorough evaluation, involving the establishment of new protocols and regulatory frameworks to ensure safe and efficient operation.”

Sonal Patel is a POWER senior associate editor (@sonalcpatel@POWERmagazine).

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