The mini reactors still have the same unsolved problem like current technology. The waste needs to be stored somewhere for thousands of years and it must be ensured that it doesn't diffuse into ground water.<p>We can state with confidence that we will never solve this problem.<p>A pitch for thorium reactors on google techtalks argued how that type would produce waste that is safe after 500 years. But what could happen in an accident? The US thorium test reactor he talked about is arguably the biggest radioactive mess and will cost a lot of effort to decomission.<p>There are similar pitches for nuclear fusion systems which may work or may not work (ITER or some weird accelerator pulse based system in sodium gas !!!). One can argue that fusion will create LOTS of neutrons that will bombard and activate the surroundings and can easily create the same waste problem we have in fusion reactors.<p>One should argue that from now on every time someone brings up a new 'safe' nuclear reactor technology that they also talk about decommissioning costs: What is the price to put each gram of expected radioactive waste into a proton beam at CERN and transmute it into fast decaying products.<p>Alternatively they are free to propose lasers for transmutation or whatever is cheaper.<p>One can expect solar power to be the winner in any such comparison. The sun has been proven to be a safe place for a fusion reactor since the beginning of time.