Graph illustrating significant events per reactor for the period between 1989 and 2001. Graph starts with a spike in 1989 at just under 1 significant event per reactor then drops of significantly floating at between .06 and .04 events in 1990 and 1991, between .04 and .02 events from 1992 through 1995, and between .02 and .00 from 1996 through 2001.
Significant events meet specific criteria, such as degradation of important safety equipment. The NRC staff reviews operating events and assesses their safety significance. The number of significant events has declined since 1989.