Thorium

Small thorium nuclear reactors are fail safe. In order to understand this consider burning wood chips in a stove. You add the chips and nothing happens until you use a match to lite the wood. The fire then continues as long as you keep adding chips. If you stop adding chips the fire goes out. In thorium reactors the fuel, thorium, is mixed with melted salt much like table salt. At this point nothing happens because thorium cannot start a chain reaction without the match which is Uranium 233. When the U 233 is add to the fuel mixture the chain reaction begins and will continue as long as you keep adding fuel ( thorium with melted salt). If you stop adding fuel the reaction stops and the reactor shuts down. This is called walk away safety because if the power to the plant is disrupted the reactor shuts down. In addition small thorium reactors do not use water to cool. Using water means high pressure but thorium works at ordinary atmospheric pressure. No chance of an explosion and thus no need for a containment vessel. Thorium reactors produce far less waste products and can use up existing stored waste from regular uranium power plants.