PM Modi Today Hailed The 'Criticality' Of Kakrapar Atomic Power Plant-3. What Does This Mean?

Prime Minister Narendra Modi took to Twitter this morning (22 July) to congratulate Indian nuclear scientists for achieving ‘criticality’ of the homegrown Kakrapar Atomic Power Plant-3.

The Prime Minister said this development was a “trailblazer” for similar achievements in the future within the prism of self-reliance.

Union Home Minister Amit Shah chimed in on Twitter, too, dubbing this a “Big Day in India’s Nuclear history”.

The Kakrapar Atomic Power Plant-3, KAPP-3 in short, is the indigenous, single-largest nuclear reactor in the country with a production capacity of 700 MW.

More of this kind is set to follow – KAPP-4 is in the works already – in the future.

The “kind” referred to here is the pressurised heavy water reactor (PHWR).

And to “achieve criticality” is to fire up a controlled, self-sustaining nuclear fission chain reaction.

The Department of Atomic Energy said this was achieved for the first time today at 09.36 am.

The PHWR is a type of nuclear reactor that uses heavy water, or deuterium oxide, as coolant and moderator.

The reactor is fuelled by natural uranium.

PHWRs were developed in Canada, which drew experience from working with wartime allied countries in the 1940s.

It was known as CANDU. In 1956, Canada supplied a 40 MW CANDU reactor to India and the United States supplied the heavy water for it.

India’s first PHWRs were built in Rajasthan with the help of the Canadians, who had supplied all the main equipment. Rajasthan Atomic Power Station’s 220 MW reactor RAPS-1 was the first.

More of the Indian hand in equipment was found in building RAPS-2. After Pokhran-1 in 1974, the Canadians withdrew support and India had to take matters in its own hands, which it did.

“From the third PHWR unit (Madras Atomic Power Station, MAPS-1) onwards, the evolution and indigenisation of the design began with the objective of keeping abreast with evolutionary changes taking place worldwide and of meeting new safety criteria,” writes Dr Srikumar Banerjee.

Ever since, India has invested in the design and development of these reactors, thanks to the work of Bhabha Atomic Research Centre (BARC) and Nuclear Power Corporation with the help of industry partners.

They have been able to move up capacity from 100 MW, 200 MW, 220 MW, and 540 MW before reaching 700 MW.

India’s KAPP-3 unit is of the Mark V-type category in the progress of its PHWR design.

India’s reactor of choice has been the PHWR because it allows for optimum utilisation of the limited uranium resources, provides a higher plutonium yield – for the second stage fuel, and availability of indigenous technology.

Sometimes, the case is made against PHWR for the high cost of heavy water.

But these reactors produce more energy per kilogram of mined uranium as compared to the alternative, the LWR.

The low absorption of neutrons in the PHWR variety also helps avoid the need for enriched fuel.

At the end of 2019, Union Minister Jitendra Singh had said that the Department of Atomic Energy will commission one nuclear reactor every year from 2020 onwards.

The third unit of the Kakrapar atomic power station was to be the first in this plan.

KAPP-4 nuclear reactor is scheduled for commissioning somewhere in the middle of 2021, after which the commissioning of RAPP-7 nuclear reactor in Rajasthan's Rawatbhata is set for 2022.

It’s unclear how much, if any, delay will be caused on account of the ongoing pandemic.

Even KAPP-3 was scheduled for commissioning a little earlier in the year, April 2020.

Presently, 22 nuclear reactors, with a cumulative installed capacity of 6,780 MW, are operational in India under the ambit of NPCIL.

As India moves towards cleaner sources of energy, nuclear power plants can replace plants fuelled by coal and other polluting fuels.

Currently, only about 3 per cent of India’s electricity comes from nuclear fuel.

Under the Paris climate change accord, India has committed that by 2030, at least 40 per cent of its electricity will be generated from non-fossil sources.

To replace coal-using thermal plants with nuclear power plants, India needs to get many more of these reactors going.

The country’s plan to ramp up nuclear output to 32,000 MW by 2032 can go a long way.

For KAPP-3, the next step would involve another round of tests, called Phase B commissioning, after which regulatory clearances will be sought and the reactor will be plugged into the grid for power generation.

The Kakrapar Atomic Power Station, situated in Surat, Gujarat, comprises two units of indigenous 220 MW PHWRs.

Commercial operation of these units commenced in May 1993 and September 1995 respectively.

They had a few months separating the stages of achieving criticality and going into commercial production.