Chernobyl is not the same as a nuclear weapon strike.
Nuclear power production produces large quantities of fission products, and those products are stockpiled inside the core. So you end up with high quantities of Strontium 90 and Cesium 135, since these are long lived, while nuclear weapons will instantly release large ammounts of short lived particles which quickly decay away to background. Activated Argon has a half life of 14 hours, and so will be back to background levels after about a week. The primary radiation source for plant workers is actually the reactor coolant while at power, as it generates a highly energetic gamma and has a half life of only 8 seconds. Of course this means that one minute after shut down the primary coolant loses 98% of its activity. So since power reactors tend to generate more power, but over a dramatically longer period of time, they are more dangerous since they generate more long term radiological threats than a weapon would.
There is also the issue of the type of bomb. If they are true hydrogen bombs, then they would be cleaner than a conventional fission bomb, and dramatically cleaner than a boosted fission bomb. Since the majority of the energy from the blast comes from the fusion of light nuclei which creates much less dangerous radionuclides that tend to also be shorter lived. There is also the potential for elements transmutation and 'burning' from neutron relases which will cause a varied radiological release compared to a nuclear plant. Then again, I was in power production, not weapons design, those production rates might be documented, I know Xenon curves and other fission product production rates are heavily documented for reactor ops because some of them have a notable effect on rod height required for criticality.
In conclusion, the game automatically upgrades the bombs to the best available type (which doesn't make sense, but it's a game). So if they were dirty bombs, then the long term damage would be worse than hydrogen, however the effect on infra and IC and pop is much worse that it should be for a nuke waste bomb. Reading the HoI2 wiki nuclear weapons page they do vary the province effects. And on further examination the numbers match up closely, though probably not perfectly. I think my biggest problem is the waste bomb, which for all intents and purposes is basically like a biological weapon similar to anthrax. Which we're banned from talking about, or modding into the game, even though it is already built into the game.
I'm not sure why you would make that assumtion. The first bombs dropped on Japan were very low yield in the 10-30 kT range. Unless both sides have access to hydrogen bombs, if you only had standard fission bombs at the time then the yields were likely only about 1 Mt.
The link given does OK for thermal effects (doesn't account for terrain or height of airburst). Take a look at wikipedia, they've got some decent info about fallout.
