India's own 700 MW reactor goes critical at Kakrapar
India's own 700 MW reactor goes critical at Kakrapar. Photo: Wikipedia

India is the only country in the world this year, to have achieved criticality with its first indigenously built nuclear reactor, even as the coronavirus (COVID-19) pandemic rages worldwide, starting from its spread during the first quarter.

India’s own and first 700 MW pressurised heavy water reactor (PHWR) at the Kakrapar Atomic Power Project (KAPP) in Gujarat state achieved its first criticality, or controlled self-sustaining nuclear fission chain reaction, last week, the state-run Nuclear Power Corporation of India Ltd (NPCIL) has announced.

NPCIL Chairman S.K. Sharma said in a televised interview that work at the new-build Kakrapar reactor Unit 3 – globally the first to have attained criticality in 2020 – never witnessed a stoppage in this period, testifying to India’s build up of indigenous capability in this field. “We did not resort to total stoppage of work at any stage in the Kakrapar Unit 3 construction. While the COVID-19 pandemic has affected society and the economy and construction of this kind has specific challenges of a large workforce present in a confined space, we paid minute attention to detail like creating wash basins in all construction areas to maintain hygiene, among other steps,” Sharma said.

“Besides, we conducted a pandemic specific job hazard analysis, which has become an SOP (standard operating procedure). However, just the preparation of an SOP is not enough. Everyday, we conduct a pre-job hazard analysis, and as a result of all these precautions, no one among the Kakrapar construction workforce contracted the coronavirus,” he added.

Terming the criticality attained for KAPP unit 3 as a historic moment, the NPCIL head said it is the first of its kind 700 MW PHWR designed by Indian scientists and engineers. “This unit is unique in that it is our first

700 MW reactor equipped with equipment manufactured indigenously and erected by Indian contractors,” he said. “The mainstay of our nuclear programme, which is now more than half-a-century old, started with reactors with a capacity of 220 MW, which was subsequently increased to 540 MW, and now we have manufactured this 700 MW optimal capacity reactor as our mainstay,” he added.

This became the country’s 23rd completed reactor, while another 700 MW one at KAPP (Unit 4) is under construction. Elaborating on the near-decade long construction period for unit 3, Sharma said that achieving criticality for 700 MW capacity with totally indigenous capability is not simply a question of “multiplying megawatts” “The entire reactor has been redesigned, concepts have been changed, while the manufacturing of components has faced many challenges, which the local manufacturers have met very competently,” he said. “The new reactor is a first of its kind, and a huge learning curve was involved for the designers, the manufacturers, as well as the construction companies, so it took them more time than earlier”, he added.

Besides, he pointed out the delay caused by the 2011 nuclear accident in Fukushima (Japan) on account of the tsunami, which necessitated a review of safety measures. “We conducted a review of safety measures, paused work in Kakrapar, changed the design in line with the global reviews of safety measures, and, thereafter, incorporated these changes in design for Kakrapar 3 and 4,” he said.

According to Sharma, “safety is our first, second and third priority”. “A safe reactor is a productive reactor, since it is also a reliable reactor. We are employing all the latest, state-of the art safety features in our reactors and have incorporated a lot of both passive and active safety features in our design”, he said.

Noting that Indian reactors have not suffered the kind of accidents comparable to Fukushima, Chernobyl (ex-USSR), or Three Mile Island (US), Sharma said the NPCIL has ensured that India continues to maintain its spotless record on nuclear safety. KAPP-3 has several safety features like a steel-lined inner containment, passive decay heat removal system and a containment spray system, among others.

The fuel was loaded into the reactor in mid-March 2020 and the systems were checked even during the Covid-19 lockdown. According to the NPCIL, the power generation will be increased gradually while experiments and tests will also be carried out. After the satisfactory functioning of the systems and obtaining the required regulatory approvals, the power unit will be connected to the western grid in about 3-4 months time, Sharma added.

Noting that sustained campaigning has resulted in removing misgivings among the public about nuclear energy, which India requires to achieve its carbon emission control targets, Sharma expressed confidence that the nuclear power capacity in the country would increase in the coming years. On India’s expansion plans, he said six reactors, including Kakrapar-4, are at advanced stages of construction and would be completed by 2024, providing additional capacity of 4,800 MW.

“Four more reactors are ready to start construction very soon, which will provide 3,400 MW. Besides, the government has approved 10 more PHWRs,” he said. The NPCIL plans to set up sixteen 700 MW PHWRs in the country, for which the government has accorded administrative and financial sanction. India’s current nuclear power capacity stands at 6,680 MW.

On foreign collaborations, Sharma said that the units 1 and 2 (1,000 MW each) of the Kudankulam Nuclear Power Project (KNPP) in Tamil Nadu being built with Russian collaboration are already connected to the grid, while 40% construction has been completed for units 3 and 4 of equal capacity. Two additional 1,000 MW units at the KNPP have been agreed upon, the construction work for which is due start soon, he said. Besides, talks are at a final stage with the French state-run firm EDF for constructing two Generation-3 European Pressurised Reactors (EPR) reactors at Jaitapur in Maharashtra state, he added.