A new report released by the U.S.-based Institute for Science and International Security (ISIS) claims that India’s nuclear program is one of the largest in developing nations. The think tank estimates that by the end of 2014, India had enough weapon-grade plutonium to possess a nuclear stockpile of up to 125. The report considered the country’s weapon-grade plutonium to estimate its nuclear arsenal.

India Has One Of The Largest Nuclear Programs: US Think Tank

70% of India’s weapon-grade uranium is in nuclear weapons

The resulting estimate has a median of 138 nuclear weapons equivalent. However, the country’s actual stockpile built from weapon-grade plutonium could be much less. ISIS says it is “reasonably safe to assume” that only 70% of India’s stock of weapon-grade uranium is in nuclear weapons. Thus the predicted number of nuclear weapons from plutonium is about 100, with a range of 75-125.

The report was co-authored by David Albright and Serena Kelleher-Vergantini. Albright had led numerous anti-India campaigns and opposed the Indo-US nuclear deal a decade ago. The authors estimate that New Delhi has developed 100-200 kg of weapon-grade uranium for nuclear weapons. Reiterating that India has produced highly enriched uranium, ISIS admitted that this estimate was “highly uncertain.”

India may have used civil reactors to produce weapon-grade plutonium

The report added that India also possesses some thermonuclear weapons that rely on both weapon-grade uranium as well as plutonium. For its nuclear weapons effort, the country separates plutonium produced in a set of dedicated, small reactors and a smaller amount produced in nuclear reactors. India also has a rapidly growing centrifuge program that could produce large amounts of highly-enriched uranium for nuclear warheads and nuclear-powered submarines.

A large chunk of India’s weapon-grade plutonium comes from the Dhruva and Cyrus reactors located at the Bhabha Atomic Research Center (BARC) near Mumbai. Citing an unnamed US official, ISIS said India used its civil nuclear reactors after the 1998 tests to “surge” weapon-grade plutonium production for its weapons program. It may have further produced weapon-grade plutonium for nuclear weapons in its civil nuclear reactors, adds the report.