The technology and goals were actually very different. In the US, you had regulator-imposed general design criteria that said things like "thou shalt have a void-coefficient of reactivity that is negative" and "thy shutdown systems shall be fast acting" and "thou shalt have diverse and redundant safety systems" and "when the shit hits the fan, thou shalt contain thy fission products".
In Soviet Russia, reactor design imposes criteria on YOU! Design reactor for maximal plutonium production and easy removal of fuel ---> minimal containment, minimal redundant systems, positive void coefficient, control rods that have graphite followers. So, when you begin to lose control of the reactor and you insert control rods, the graphite followers go in first, spiking reactivity and power, which causes your coolant to flash to steam, increasing void fraction, and because your void coefficient is positive, power goes UP even more instead of going down, and then the few safety systems you have don't work because you shut them all down or they suck to begin with, and then reactor (not containment, REACTOR) goes boom and chunks of FUEL and FLAMING GRAPHITE are forcefully ejected into the air.
So, then, why did Fukushima fail so badly, even though it had fast-acting shutdown systems, a negative void coefficient, diverse and redundant safety systems, and a containment design that satisfied all of the regulations that existed at the time? That's the real story here, and its moral has a lot to do with the idea of "beyond design basis" accidents and designing to be more robust than required by regulation.