Covered up by the Soviet authorities for decades, this remains one of the worst nuclear disasters in history. The location, at Mayak nuclear fuel reprocessing plant, being kept secret due to it’s use in the Russian nuclear weapons program, only much later was the full extent of it known. Despite occurring back in 1957, documents detailing it were only declassified in 1990, due partly to Soviet pride, though just as much to avoid worries about nuclear power programs in general. I personally only found out about it be looking up the scales of nuclear disasters on Wikipedia.
It shows just how vulnerable spent nuclear fuel is if left uncooled- in this case, carelessly left alongside potentially explosive materials (ammonium nitrate). Amazingly, not only were the nearby inhabitants kept there for a time, and in fact some are still living near the area, but the most intensely radiated region was used as a ‘live’ military training ground. Due to wind currents, the contaminated area was truly colossal, with 800 square km still off-limits today, though the most affected area was closer to the site. It shows that with nuclear fuel storage, there is no room for negligence or a lack of accountability. With the fuel rods producing heat for generations, it is a long-term problem, without any satisfactory solution yet being found.
More details can be found in this declassified document-
Even grimmer is this site, from a filmaker who visited the region, forgotten by the world, where there have been not one, but cumulatively three nuclear disasters-
It should be added here that nothing remotely like this is likely to happen in Japan, as there is not the potential for such a tremendous explosion (which was a chemical and not a nuclear explosion, anyway). Having so many people on site and so much international attention is also a good thing. Yet it highlights the long-term dangers of nuclear waste, wherever it is, the problems associated not being limited to reactors themselves. Right now we can’t really live without nuclear power, though it makes sense to search for safer alternatives, that don’t produce so much radioactive materials. I’m not convinced ‘renewables’ can make enough power on their own economically, but it makes sense to use them where possible, which is something Germany is having a lot of success with and with newer technology emerging, they could be even more effective in the years to come.