I can't envision a remotely plausible scenario that could even come close to Chernobyl in terms of impact. Chernobyl had no containment structure at all and was running at full power (infact, beyond full power once the steam inside the reactor increased the rate of fission) at the time of the incident. The steam explosion was so powerful that it launched the 4 million pound reactor lid through the roof scattering bits of fuel all over the countryside and then letting the radioactive graphite from the reactor burn and send highly radioactive smoke up into the jetstream.
Chernobyl consisted of an unsafe reactor design with a positive void coefficient and a control rod design that locally increased power output as it was being inserted combined with terrible management and operators who did not understand why the reactors power output was low and a complete lack of a containment structure to top it all off.
I genuinely can't envision a scenario like that happening with other non-RBMK reactors. Even if the operators were intentionally trying to just do the most devastation physically possible, it's not like they're going to be able to do anywhere near the damage that Chernobyl did. Trying to compromise the containment structure is not a reasonable goal, they are just far too massive and at least in the U.S. they are designed to take a direct hit by a fully loaded passenger jet without rupturing. Let alone rupturing the massive thick hunk of steel that is the reactor vessel inside of it.
There's still a couple of retrofitted RBMK style reactors operating in Russia but supposedly those don't have the same void coefficient problem, have better management and operational practices, and have better safety systems than the original design. Even if you count those against the safety of new nuclear power plants we're still not as bad off as Chernobyl was.
