Many things. I'd need more details on exactly what effects you are interested in to say.
You get a rather large explosion.
A giant nuclear explosion would happen and we would all die.
It would create a mini nuclear explosion.
No. Chernobyl is in Russia.
because the bomb was designed to make it so.
can't say exactly, but it would depend mostly on the yield and location of the explosion.
nuclear explosion?
No, but there would be more release of radioactivity because the reactor itself would probably be melted in the explosion.
Depends mostly on where you are relative to it and the yield. Other variables include:weatherterrainyour clothsif you are in a building, its constructionwere you near a windowetc.
When and what explosion? One of the nuclear test shots. If so which?Remember Chernobyl was not a nuclear explosion, it was a steam explosion and graphite fire.
The only nuclear explosions in Japan were the two in WW2, on Hiroshima and Nagasaki.However I believe you meant the Japanese nuclear reactorexplosion, which was not a nuclear explosion it was either a steam explosion and/or a hydrogen/oxygen chemical explosion. That occurred at Fukushima.
AnswerThere would be a gigantic explosion AnswerThe force of the actual explosion would depend entirely on the bomb. The material in the power plant would almost certainly not contribute to the force of the explosion in any way. Nuclear explosions are not merely a matter of achieving critical mass; the critical mass has to be maintained while the explosion takes place, which is not easy. The environmental damage done by the bomb would probably be worse than if it had gone off in some other place, because the radioactive material at the power plant would be scattered to some unpredictable extent.Nuclear power plants are never, or nearly never, built in cities because of the possibility of accident. A nuclear bomb hitting a nuclear power plant would possibly cause fewer fatalities than a bomb hitting a city.