A former top intelligence official has said India would have the capacity to make about 50 nuclear warheads a year as it would be able to retain six reactors outside safeguards envisaged under the India-US nuclear agreement.

• Indo-US nuke tango

"Under the deal, India shall retain six unsafeguarded reactors and shall have the capability of producing nearly 50 nuclear warheads per year," J K Sinha, former additional secretary in the Research & Analysis Wing of the Cabinet Secretariat, has said.

Sinha said the assurance of supply of nuclear fuel from the US as well as the Nuclear Suppliers Group would free India's existing capacity to produce highly enriched uranium and plutonium for its nuclear weapons programme.

• Support the N-deal

In an article in Indian Defence Review, Sinha said an estimate showed that "the exempted reactors would be able to produce 130 kg of weapon-grade plutonium per year. Considering that just three to five kg of plutonium-239 is enough to manufacture a bomb of the kind that was dropped on Hiroshima and Nagasaki," he observed that the destructive capacity of India's nuclear arsenal was "self-evident".

Maintaining that there should be no doubt that India would continue to produce fissile material for nuclear weapons, he said the entire Fast Breeder Reactor programme was out of the safeguards ambit.

"The potential of the FBR technology is huge for India's nuclear weapons programme and for power generation," he said.