Advanced nuclear power reactors

The nuclear power industry has been developing and improving reactor technology for five decades and is preparing for the next generations of reactors to fill orders expected in the next 10 to 15 years. Several generations of reactors are commonly distinguished. Generation I reactors were developed in 1950's and 60's. Outside the UK, none are still running today. Generation II reactors are typified by the present US fleet and most in operation elsewhere. Generation III (and 3+) are the advanced reactors discussed here. The first are in operation in Japan and others are under construction or ready to be ordered. Generation IV designs are still on the drawing board and will not be operational before 2020 at the earliest. Reactor suppliers in North America, Japan, Europe, Russia and South Africa have a dozen new nuclear reactor designs at advanced stages of planning, while others are at a research and development stage. About 85% of the world's nuclear electricity is generated by reactors derived from designs originally developed for naval use. These and other second-generation nuclear power units have been found to be safe and reliable, but they are being superseded by better designs