You don't seem to understand fizzles. A fizzle would not be expected to release even a kiloton of yield. A fizzle is not merely some malfunction of the bomb tha

You don't seem to understand fizzles. A fizzle would not be expected to release even a kiloton of yield. A fizzle is not merely some malfunction of the bomb that causes it to achieve very low yield. Moreover, because of the two stage nature of thermonuclear weapons a fizzle of the primary would result in the secondary not going off at all. The nominal yield of the secondary, which makes up the vast majority of the explosive power of multi-megaton bombs, is thus not even remotely relevant. A fizzle in the Tsar bomba (a 100MT capable device) would not be expected to release 1MT of energy or even 1/10th that, it would still release likely very much less than even a single kiloton.