Why does some nuclear radiation take thousands of years to decay and some only a decade or so?

Question

I’ve been researching nuclear energy and radiation in an effort to understand it. I don’t understand why I’m seeing a lot of info saying a nuclear bomb’s radiation dies out in about 10 years, but a nuclear reactor explosion like Chernobyl will take thousands of years. What’s the difference?

EDIT: Okay, so what I’m seeing is I didn’t account for the differences in types and sheer amounts of fuel for each kind of reaction. I’m not a chemist or physicist or anything. I just like learning stuff. 😁

These explanations make a lot of sense, so to those of you who didn’t answer the wrongway and provided helpful and educational responses, thank you.

In: Chemistry

Answer 1

2 factors –

One is different types of radioactive atoms are more radioactive and so decay faster.

Two is reactors use a lot more radioactive material – a bomb might contain tens of kgs while Chernobyl had 192 tons of nuclear fuel in it.