Why can’t we dump nuclear waste in the same place we mine nuclear fuel?


Why can’t we dump nuclear waste in the same place we mine nuclear fuel?

In: 691

Old mining shafts are the most common places to store nuclear waste, so we kind of do that.

Its just that these shafts have to be checked and prepeared because if there is for example leaking water, it could radiate whole lakes and countries.

There are relatively reasonable methods to dispose of nuclear wastes, in fact quite a few of them. None of them really very new either.

The problem is not technology, it is political.

If someone takes a decidedly anti-nuclear position, they aren’t particularly interested in seeing practical solutions weakening their arguments. So it becomes an eternal round of demonstrating methods, only to be met with conspiracy theories and accusations of lies and demands of perfection beyond feasibility. And this is a tough battle that few governments were interested in confronting – so it simply becomes gridlock and eternal arguments.

Uranium ore is radioactive, but it is not quite the same amount of radiation. You need to refine and process in such a way that makes the material volatile enough to produce power. You can find uranium ore on the surface of a mountain if you know where to look and hiking around it is harmless.

As others have said you don’t find uranium ore in huge chunks and even those are not highly radioactive. Once the the highly concentrated/enriched uranium has been used in a reactor it becomes highly radioactive and cannot be simply put back into a mine or pit. That’s also just the uranium, a lot of the other parts of the reactor are now contaminated and must be stored properly.

Not all uranium is the same. Spent uranium fuel is “spent” because all the fissile uranium has decayed already. Fissile uranium is U^238 which means there are 92 protons and 146 neutrons in this isotope of uranium. This is the most common form of uranium [*in* Earth about 99.3%](https://www.radioactivity.eu.com/site/pages/Uranium_238_235.htm#:~:text=The%20half%2Dlife%20of%20uranium,and%20only%200.70%25%20uranium%20235). Enriching uranium gets you to a higher ratio of U-235 to U-238.

The fissile kind of uranium is U^235 which means 92 protons and 143 neutrons in the nucleus. [This isotope is fissile because when it is hit by a neutron the now U^236 fissions into barium-141 and krypton-92](https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_General_Chemistry_%28Petrucci_et_al.%29/25%3A_Nuclear_Chemistry/25.08%3A_Nuclear_Fission).

As the fissile uranium is used in fission less of U-235 exists in the fuel and eventually there’s a point of diminishing returns and at this point most of the fuel is U-238. So at this point the spent material no longer has sufficient U-235 to be useful for fission and is instead used in [military applications as armor piercing rounds, tank armor](https://www.epa.gov/radtown/depleted-uranium).