4. Storing spent fuel has not been resolved. Scientifically? False. Politically? Not yet in all countries. The thing to understand is that "spent fuel" is not spent. Current common reactor designs can't use all the fuel put into them before the fuel is so polluted that it is unusable.  Simply putting fresh fuel in the reactor is cheaper than processing the now-unusable fuel into usable fuel.  Scientifically, it is simpler to change the design.  We've known about these designs for a long time - they "close the fuel cycle" (use all the fertile and fissile material put into the reactor).  So far, only politics has prevented these designs replacing the current designs.  Take the EBR II (available commercially as the PRISM).  This design,  shut down by Carter in 1994 for political reasons, famously ran a walk-away safety test in 1986.  The Russians brought the BN-800 into full production in August 2016. The company Transatomic power was set up with the express purpose of using "spent fuel".