New Delhi, March 6: After infusing 15 years of extra life into the ageing Cirus reactor, scientists at the Bhabha Atomic Research Centre (Barc) might soon have to prepare for a permanent shutdown.

According to some reports, one of India’s commitments under the Indo-US nuclear deal would be to decommission Cirus, which was built with Canadian help in the 1950s, began operations in July 1960 and was refurbished for a fresh lease of life in 2004.

Cirus has been the sole and single “blot” on India’s nuclear history. Canada had helped India on the condition that the 40MW Cirus research reactor and any of its products would be used only for peaceful purposes. But it is widely believed that plutonium from Cirus was used in India’s “peaceful nuclear explosion” of 1974, prompting Canada to cut off nuclear cooperation with India.

Last December, when the deal was under negotiation, Canadian officials had argued that Cirus should be classified as a civilian nuclear facility and opened up for international inspections.

But with Cirus located within the Barc complex at Trombay, safeguards would have meant allowing international inspectors access within a research facility where India insists it does not want any inspections.

India has thus apparently decided instead to decommission Cirus. “For many of us, Cirus has been a mother reactor,” said a top Barc scientist, who said he had no information about any impending decommissioning.

Virtually all senior officials in the atomic energy hierarchy have trained at Cirus, where they learnt about reactor operations, heavy water handling and investigating neutron behaviour around the core where uranium atoms split to produce plutonium and other fission products.

“Cirus has an emotional value,” the scientist said.

Scientists said the decommissioning would also hamper research activities and production of radioisotopes used in industry and to irradiate vegetables and treat cancer.

While the 100MW indigenous Dhruva commissioned in 1985 is the primary source of radioisotopes today, Cirus also accounts for a small fraction of radioisotopes.

During the early 1990s, Cirus showed signs of ageing ? the performance of the reactor began to decline and there were frequent outages and temporary shutdowns.

Following a technical evaluation, Barc decided to replace its degraded components and refurbish the reactor to extend its life for 10 to 15 years. The refurbishment was achieved at 5 per cent the cost of building a new reactor.

“We think it still has a life of at least about 10 years,” said a scientist. “Decommissioning would be like premature retirement.”