1. anonymous Sergey as a story source, without any verificable identity.
2. "he went drinking with a few military personnel", so it's retelling of rehearsal, even more trust.
3. "government plan was to mix the meat from Chernobyl-area cattle with the uncontaminated meat", that's seems plausible. contamination of meat was "up to 1,0*10-6 Ci/kg" (according to widely cited secret "annex 10 of protocol #32"), it's 300 times of banana equivalent.
from the same scary stories fansites, there were 34 Кtons of bad meat (it's one thousand of railway carriages btw). so not so dramatic, definitely not a near nuclear blast.
4. [computer was] "located in a building close to the railroad tracks". inverse-square law, walls, exposure time from a moving train etc. i would more believe in vibration caused by trains as a cause of problems.
5. the SM-1800 computer:
KR580VM80A cpu (8080 clone) is 6 mkm and 2 MHz (compare to modern 10 nm and 2 GHz),
K565RU3A ram (4116 analog, like in ZX Spectrum), and other components. even the computer case was solid metal.
i can not tell you precisely, but there should be a powerful source of radiation to crash such computer reproducibly.
so no, i don't buy it. sorry for hurting your radio- and russo-fobias.