In February, prosecutors accused the director of Mayak, Russia's main waste processing plant in the Ural Mountains, of allowing tons of radioactive nuclear waste to flow into a nearby river.

NPR: Russia Plans Nuclear Power Expansion

The problem is that there was a previous plant there (processing material from the local tin ores) which left quite a bit of radioactive residue around the place.

FORBES: The Rare Earths Shortage Isn't Over Yet