India’s Department of Atomic Energy (DAE) told the Deccan Herald on 18 April that the middle of 2018 was now being looked at as a more realistic target for commissioning the 500MWe Prototype Fast Breeder Reactor (PFBR) under construction at the Madras Atomic Power Station in Kalpakkam.

The Indira Gandhi Centre for Atomic Research (IGCAR) began to design the sodium-cooled fast reactor in 1980 and construction began in 2004 by BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Ltd), a government enterprise set up under DAE to focus on FBRs. It was originally expected to be commissioned in September 2010, which was later rescheduled to September 2014 and then to September 2016. In October 2016, the Atomic Energy Commission announced that it would be commissioned in 2017, with six more breeder reactors planned. However, criticality has now been delayed until October 2017, for commissioning the following year.

The PFBR is seen as launching the second stage of India's three-stage nuclear power programme as envisioned by Homi Bhabha, the father of Indian nuclear programme. The long-term goal is to develop an advanced heavy-water thorium cycle to make use of India’s abundant resources of thorium. The first stage uses pressurised heavy water reactors (PHWRs) fuelled by natural uranium, and light water reactors, which produce plutonium in addition to their prime purpose of electricity generation. Stage two uses fast reactors burning the plutonium with a blanket around the core having uranium as well as thorium, so that further plutonium is produced as well as uranium-233. In stage three, advanced heavy water reactors (AHWRs) will burn thorium-plutonium fuels to breed U-233 which can eventually be used as a self-sustaining fissile driver for a fleet of breeding AHWRs.

The PFBR is a pool-type reactor with 1750t of sodium as coolant. It will initially burn mox fuel. It has a blanket with uranium and thorium to breed fissile plutonium and U-233. It has two primary and two secondary loops, with four steam generators per loop. It is designed for a 40-year operating life at 75% load factor. Two more such 500MWe fast reactors have been announced for construction at Kalpakkam, but slightly redesigned by the Indira Gandhi Centre to reduce capital cost. Then four more are planned at another site.

DAE officials said the main reason for the delay is the over-cautious attitude of scientists because of the nature of the technologies involved. “The policy adopted is that we will be slow and steady, but sure. That is the way, it is going on. If some problem comes in rushing through it, then it will be questioned all over the world,” DAE secretary Sekhar Basu wrote to a panel of the lawmakers, who reviewed the PFBR project.

The caution may arise from India’s past experience with its small, pilot-scale Fast Breeder Test Reactor (FBTR). The budget for the FBTR was approved by DAE in 1971, with a planned commissioning date of 1976. It finally  attained criticality in 1985, and it was eight more years before its steam generator began operating. The final cost was more than triple the initial estimate. Its operation  has been interrupted by several accidents and the associated delays have been long. As of 2013, the FBTR had operated for only 49,000 hours in 26 years, or barely 21% of the maximum possible operating time.