Moving to passive designs

Moving to passive designs

from Web Edition | Bulletin of the Atomic Scientists by Robert Rosner

For months, and perhaps years, lessons will be learned from the events at the Fukushima Daiichi nuclear power plant in Japan, which will serve as both a laboratory and a classroom. As the sequence of events leading to the accident continued through the accident response, at least one concept was made clear: When operating reactors, defense-in-depth -- the technical concept of multiple layers of safety backup systems -- must incorporate a series of active backup systems (meaning that they require human intervention) that must be operable to forestall single-point catastrophic failures.