Unprotected transients

Abstract

As indicated in the two previous chapters, there are several features that combine to make a SFR system safe and reliable. Only when a major off-normal condition is encountered, combined with a postulated failure of the Plant Protective System (PPS), can serious accident consequences be predicted. Even then, it has been demonstrated that a properly designed SFR can survive unprotected transients without damage to the fuel or other barriers to radiation release. With this background, it is useful to address accidents in three categories as follows: Protected transients. An event initiator occurs, such as a component failure, failure of a safety grade system (other than the reactor PPS), or an external event, followed by activation of the plant protection system to shut down the reactor.