T-sar Bomba
The bhangmeter results and other data suggested the bomb yielded around 58 Mt (243 PJ), which was the accepted yield in technical literature until 1991, when Soviet scientists revealed that their instruments indicated a yield of 50 Mt (209 PJ). In theory, the bomb would have had a yield in excess of 100 Mt (418 PJ) if it had included the uranium-238 fusion tamper which figured in the design but which was omitted in the test to reduce radioactive fallout.