There are two types of nuclear reactors that are used to generate power globally, liquid cooled and gas cooled. The liquid cooled design is the most common in the US. The gas cooled design is used in Europe. When the liquid cooled design fails as with 3 Mile Island, Chernobyl, and the disaster in Japan, the reactor melts down. This can be averted by using a gas cooled design which takes days to reach criticality as opposed to the minutes of a liquid cooled design. The gas cooled design also doesn't produce as much irradiated waste as the design is simpler and much safer. The liquid cooled design is antiquatied and dangerous. The technology is proven to be perilous time and time again. The gas cooled design is more efficent and exponentially safer to run and maintain.



