U.S. assessment calls India's 1974 nuclear test a near failure
The documents, which were recently obtained from the U.S. Department of State under the Freedom of Information Act, offer no explanation as to why this conclusion was reached. The National Security Archive at the George Washington University obtained the assessment and said that it may refer to the extremely low explosive yield of the nuclear tests.
Operation Smiling Buddha, as it was codenamed, tested a thermonuclear device at India's Pokhran firing range in the state of Rajasthan. The U.S. documents said that the Indian government claimed the explosive yield of the device to be nearly 15 kilotons. Seismic detection systems, however, reported a much lower yield, somewhere between two and eight kilotons.
One possible explanation for the discrepancy is that Indian scientists may have expected more impressive results than the actual yield. The results of several other Indian nuclear tests were similarly over estimated.
The Federation of American Scientists claims that the underground 1974 test may have only been partially successful, but records a different kiloton estimate.
"The device was placed in a vertical shaft and detonated at a depth of 107 meters. It is reported that the American intelligence community estimated that the actual yield was in the range of four to six kilotons. The test produced a crater with a radius variously reported at between 47 and 75 meters, and a depth of about 10 meters," an FAS analysis said.