Chidambaram pointed out that several papers had been written on the test results and had been peer-reviewed in reputed international journals.

Now, India also had the computer simulation capability to predict the yields of nuclear weapons-fission, boosted fission and two-state thermonuclear, of designs related to the May 1998 tests.

He pointed out that even Iyengar, who is now questioning the tests' outcome, had agreed with the yield of the tests. However, the conclusions drawn by him on the efficiency were 'purely speculative in nature', according to Chidambaram.

He wondered how, without the knowledge of the design, the nature of fission-fusion break-up and quantity of thermo-nuclear material, Iyengar could calculate the efficiency of fuel burnt as 10 percent.

'No one outside the design team had the data to calculate fission-fusion yield break-up or any other significant parameter related to fusion burnt,' he said.