The best part about studying radioactivity is how predictable it is and how easy it is to detect. It's part of how we are able to date the age of earth using Uranium isotope ratios. Decay occurs at predictable rates. The entire earth's crust is contaminated with nuclear byproducts which allow us to learn a great deal about it's formation even a couple billion years later.
Fossil reactors are just an example of the nuclear world we live on. There are also countless other nuclear materials in the earth's crust. It's part of why we have to test for nuclear contamination of our wells.
The destruction of one of these reactors a mile deep would be a blip on the radioactive material being unearthed. We would have to be careful not to place them next to existing aquifers, but they would be way more safe than surface plants which already have an amazing track record.
Fossil reactors are just an example of the nuclear world we live on. There are also countless other nuclear materials in the earth's crust. It's part of why we have to test for nuclear contamination of our wells.
The destruction of one of these reactors a mile deep would be a blip on the radioactive material being unearthed. We would have to be careful not to place them next to existing aquifers, but they would be way more safe than surface plants which already have an amazing track record.