Thorium reactor on course

THE construction of the Advanced Heavy Water Reactor (AHWR) is all set to begin this year. The AHWR will use thorium, the "fuel of the future", which is in plenty in India, to generate 300 MWe of electricity up from its original design output of 235 MWe. The reactor will have a life of 100 years and may be built on the campus of the Bhabha Atomic Research Centre (BARC) at Trombay. Scientists and engineers at BARC have been working for several years on the development of the AHWR.

Expert committees of Nuclear Power Corporation of India Limited (NPCIL) have completed the peer review of the detailed project report. A team of persons other than designers, who were equally knowledgeable in reactor design, has reviewed the design.

Said Anil Kakodkar, Chairman, Atomic Energy Commission: "I asked them to carry out a review of its design because it has new, innovative concepts. We wanted to get an independent peer review done." The team had made some suggestions for improving further the economy and constructability of the reactor. "But the soundness of the design is not in doubt," said Kakodkar, whose dream project is the AHWR. "We want to do a similar review on safety. The first one was generic, dealing with constructability, economics, engineering and so on. We want now to do a more specific review of the safety of the reactor. For that we are compiling documents, and will present it to people," he added.

The construction of the AHWR will mark the beginning of the third phase of India's nuclear electricity generation programme. In the first phase, 12 Pressurised Heavy Water Reactors (PHWRs) were built and are operational in the country. They use natural uranium as fuel, and heavy water as both moderator and coolant. The second stage has begun with the construction of the Prototype Fast Breeder Reactor (PFBR of 500 MWe) at Kalpakkam, Tamil Nadu. The PFBR will use plutonium, a byproduct from the PHWRs, as fuel. The fuel for the AHWR will be a hybrid core, partly thorium-uranium 233 and partly thorium-plutonium. The three stages are interlinked. The AHWR will be a technology demonstrator for thorium utilisation.

The design philosophy of the AHWR is simple but challenging: enhanced safety at low cost. It will incorporate passive safety features, which do not require human intervention. It will have no circulating pumps. It is a system in which dependency on active components is minimised to a large extent. It has operator-forging characteristics.

B. Bhattacharjee, Director, BARC, said: "At the international level, the AHWR has been selected for a case study at the IAEA (International Atomic Energy Agency) for acceptance as per international standards for next generation reactors."