İNERMA, 1 - 03 October 2015
Nuclear energy is an inevitable source of energy to supply 13% of the World’s electricity. On the other hand, severe accidents experienced so far, Three Miles Island, Chernobyl, and Fukushima raised questions for the safety aspects of these reactors. The design of nuclear reactors is such that radioactivity release is avoided and radioactivity is confined within the system even in a severe accident case. In order to assure this, there are multiple barriers against the release of the radioactive species. The first barrier is the fuel pellet itself. It is surrounded by a zirconium alloy cladding which serves as a second barrier in light water reactors. There are a couple of more barriers until the containment building which covers all the nuclear components. As long as the integrity of the fuel pellet and pin is preserved, the release can be significantly avoided. Recently, new fuel design alternatives are proposed to provide strong resistance against disintegration in severe accident conditions. These are called “Accident Tolerant Fuel”. This article discusses alternative accident tolerant fuels and their design features. An assessment is made in comparison with conventional nuclear fuel with respect to safety features.