In his talk in IISc for which I took notes Chidambaram said
.. if 1 Kg of Pu is fully used up in a nuke - the yield will be 16KT (less if less is used up, of course). If 1 Kg of Deuterium is used up fully - you get a yield of 80kT, and if 1 kg of Lithium Deuteride is fully used up in a fusion bomb the yield will be 50 kT.
Now on page 419 of "Weapons of Peace" Raj Chengappa says that 6 "perfect spheres" of Plutonium were sent to Pokhran, each weighing "around three to eight kilograms depending on the test they were meant for"
Using Chidambaram's own words and assuming that the largest Pu ball - of 8 kg was used in S1 - we should have got a fission explosion of (16 x 5) = 80 kt. If only 50% was used up it should have given 40 kt. If 20% was used up it would have given 16 kt.
However if a 3 kg ball was used in S1 we should have got 48 kt fission @ 100 %, 24 kT @ 50% and 10 kt @ 20 %.
PKIyengar spoke of 400 grams of LiD being used up. Using to the data given by R Chidambaram and the 400 gram figure by PKIyengar - the fusion yield alone should have been 20 kilotons
Now guess which ball was used? How much it weighed. What was the efficiency of fission? How much fusion?
Here is what PKI and Kalam said in 2000
No comment on N-test results: Kalam
From R. Suryamurthy
Tribune News Service
NEW DELHI, Aug 1 — The Principal Scientific Adviser, Dr A.P.J. Abdul Kalam, today refused to comment on doubts expressed by a leading member of the scientific community on the country’s May 1998 nuclear tests.
"I will not comment. I do not have access to the data. So I will not comment," Dr Kalam said when asked to react to the doubts expressed by the former Chairman of the Atomic Energy Commission, Dr P.K. Iyengar.
Dr Iyengar had said scientific data indicated that the core of the hydrogen bomb had burnt only partially during the nuclear test. The bomb design included two components — a boosted fission device (a small atomic bomb) that triggered the secondary core of the hydrogen or fusion bomb.
The boosted fission device released about 20 kilotons (kt) of energy that triggered the fusion core that produced another 20 kt, giving a total yield of 40 kt. This indicated that only about 400 gm of the fusion device had burnt.
Dr Iyengar had also said that larger megaton devices could not be made with such devices. India needed to test more hydrogen and neutron bombs with complete burning of the core before signing the comprehensive test ban treaty.
He had said more tests would be needed to try out different designs like boosted fission devices, the stage II fusion device and the neutron bomb which India was yet to test.