There is no comparison between the effects of the Chernobyl "meltdown" and a nuclear explosion (either fission or fusion). There was no "Mach wave" or overpressure produced at Chernobyl, no thermal radiation (i.e., heat) released to any great extent.

Except for the radiation release, and even that is in some ways not comparable, there is little to compare between, say, the BRAVO or TRINITY shots and either Chernobyl or Three Mile Island.

No, there is something.

Ain't none of them good.

(I refer you to, among other sources, DA Pamphlet 39-3, The Effects of Nuclear Weapons (April, 1962 et seq.) for, well, the effects of nuclear weapons. There are many studies done on the release of radiation from both Chernobyl and TMI.)