Resumen
Fukushima Daiichi is the most recent in a series of major power reactor accidents. With Three Mile Island and Chernobyl, Fukushima Daiichi offers another event in which severe fuel damage occurred, fission products were released to the environment, and public evacuations were implemented. Improvements in plant and regulatory performance are required to eliminate major reactor accidents. These events are minimized by protecting the three fission product barriers and focusing attention on preserving these structures. Protection of fission product barriers is a necessary and sufficient requirement to limit the radiological aspects of a power reactor accident.