It was modeled on the Canadian Chalk River National Research X-perimental (NRX) reactor.
[4] The 40 MW reactor used natural uranium fuel, while using heavy water as a moderator.
Nonetheless, CIRUS produced some of India's initial weapons-grade plutonium stockpile,[6] as well as the plutonium for India's 1974 Pokhran-I (Codename Smiling Buddha) nuclear test, the country's first nuclear test.
CIRUS was shut down in September 1997 for refurbishment and was scheduled to resume operation in 2003.
Even if the reactor has a life of twenty more years, India had declared that this reactor would be shut down by 2010 in accordance with the Indo-US nuclear accord reached between Indian Prime Minister Manmohan Singh and US President George W.