Building up on its capability to operate over 20 nuclear reactors for half a century now, India is progressing towards its own 700 MW Pressurised Heavy Water Reactor (PHWR) – which is slated for a trial run soon and is expected to go critical later this year.

India’s atomic power plant operator Nuclear Power Corporation of India (NPCIL) has undertaken construction of 700 MW PHWRs – two each in Gujarat and Rajasthan; and the project is progressing well. The PHWRs have the advantage that they can be refuelled while at full power, making them more efficient.

“Following import of two boiling water reactors (BWR) from the US and two CANDU reactors from Canada, India built pressurized heavy water reactors (PHWR), using its own technology. All these units are performing well,” M.R.Srinivasan, member of Atomic Energy Commission and Founder-Chairman of Nuclear Power Corporation of India (NPCIL) told The first nuclear reactor to undergo trial run will be the one at Kakrapar Atomic Power Station (KAPS) in Gujarat.

Two-and-a-half months following the hydro-tests in May-June this year, there will be hot-conditioning of the unit. The systems will be drained and dried before carrying out the fuel loading expected in October this year. Thereafter the reactor will go critical – starting its first nuclear fission process) in November 2017. The unit is estimated to start commercial operations by early next year.

India had got its two boiling water reactors (BWR) from the US and first CANDU or PHWR in 1950s from Canada. Unlike the BWR, the PHWR does not use a single large reactor vessel and the nuclear core is used in hundreds of pressure tubes. These Canadian-built PHWR used natural Uranium (U-235) oxide as fuel and used heavy water (D2O) as moderator. India, however, is seeking to develop a sodium-cooled fast reactor and use Thorium as the fuel.

“India is developing sodium cooled fast reactors for the second stage of the program. In due course of time, India hopes to use thorium as a source of energy for which Uranium 233 produced in second stage reactors would be the starting fuel. In the near term the emphasis will be on building PHWRs and LWRs (Light Water Reactors such as the Russian VVER),” Srinivasan said outlining the vision of India’s nuclear energy development programme.

So far NPCIL has been building 220 MW and 540 MW PHWRs and it is the first time it is attempting to build a 700 MW nuclear reactor. But, Srinivasan contends that India has placed “special emphasis on operator training and strict regulatory oversight to achieve this successful record” and operating its fleet (now numbering 22 reactors) in a safe manner over the past nearly 50 years speaks of its safety records. The project cost of building two units at KAPS is approximately Rs. 11,500 crores but drawing for its experiencing in using coal-based power, India says nuclear power is economically competitive.

“India hopes to expand the nuclear power capacity substantially to reduce carbon emissions. Indian experience indicates that nuclear power is competitive with coal based power, where the power station is located some 800 km from the coal mines,” Srinivasan added.