[clarionbell]

Think about it this way.

All of the uranium used as fuel came from the ground. Now, we will be putting smaller quantity of other, also radioactive, materials into ground. Lot of places have high natural levels of radiation[0], sometimes they even make it as a spa location[1].

People were living around radiation since before they were people. And they managed. We still do.

In the end the question is if we want some radioactive pollution that is easy to contain in the near term, or a lot more carbon pollution that is impossible to contain in the near term.

One is destroying the planet as we speak. The other might be a problem few centuries in the future, if there is one.

[0]https://en.wikipedia.org/wiki/Background_radiation#Areas_wit...

[1]https://en.wikipedia.org/wiki/J%C3%A1chymov#Spa

[ghostly_s]

It's really not that simple. Enriching the raw materials and subjecting them to fission results in a waste product with quite different characteristics than the input.

[niek_pas]

I know nothing about nuclear physics; could you elaborate? How are the input and output different?

[c1ccccc1]

Uranium 235 can decay by splitting into two smaller nuclei and releasing some free neutrons. Frequently those smaller nuclei are themselves radioactive. Uranium has a very long half life, on the order of billions of years, so the natural rate of decay is very low. This makes it relatively safe, since there is not too much radiation produced per second. Many of the product nuclei that can be formed have a much shorter half life. So they emit more radiation, though on the plus side they don't last as long. In nature, these smaller nuclei are still formed, but at a very low rate. In a nuclear reactor, the uranium is bombarded with a large number of neutrons, and it has a chance of splitting whenever a neutron hits it. So there's a high rate of decay, and as a result, once the fuel has been in the reactor for a while, it contains a large amount of those fission products. That's what makes the waste more dangerous: it has isotopes in it that decay faster and therefore emit more radiation per second than pure uranium.

[supert56]

This is a really helpful explanation. I didn't have a clue that the long half life actually results in lower levels of radiation.

[adrianN]

You can hold natural uranium in your hand for a long time before it becomes a health concern. It's toxicity (heavy metal!) is more dangerous than its radioactivity. You shouldn't try the same with spent fuel or you will lose you arm quickly.