nuclear meltdowns

Fission-energy is a form of ordered-energy from long-dead stars that's found in all atoms much heavier than Iron-58 and Nickel-62. The only way we know to release it is to exploit the neutron-mediated herd-behavior of certain big atoms like Uranium-235.

Fissioning releases that ordered-energy by breaking atoms almost randomly into two fragments with energies that correspond to heat at about 200MeV/(2k_B) ≈ 10¹²K. The resulting motion warms up the atom's surroundings, including any coolant being used to pull the heat out for use running an electric generator.

This is an abundant form of ordered-energy that doesn't create green-house gases. To the extent that we make it safe and sustainable, fission energy is an important part of our future.

One of the two fission fragments usually has an atomic weight between 75 and 105, the other an atomic weight between 150 and 130. One inconvenient truth is that these fragments have a mess of chemical & radioactive properties.

The other problem is that once you get a herd of such atoms to start fissioning, the process may be controlled only by aggressively cooling the herd. Otherwise it melts and allows the release of both heat and fragments to get out of hand.

This is not new, as meltdown of naturally-occurring reactions like this are present in the geological record. If you have ideas for designing reactors so that gravity helps melting to disperse the critical mass, this might come in handy for future reactor construction!

All told, we take our chances with all forms of ordered-energy both because: (a) we need it to survive and because (b) it is fun to waste. If one looks at the numbers, the ratio of benefit to both: (i) cost & (ii) risk for fission-energy is quite good in spite of our media's passion for sensationalizing it.

If it helps with the overall picture of regional land-use, therefore, folks who assume the risk of living near reactors should get a break. That's mainly because space nearby a reactor will most likely be fine, but might accidentally lose its property value and habitability for decades.