Graph illustrating safety systems actuations per reactor for the period between 1989 and 2001. Graph starts high in 1989 at just over 1.4 actuations then drops slowly floating between 1.2 and 0.8 from 1990 to 1993, between 0.6 and 0.2 from 1994 and 1998, and between 0.2 and 0.0 from 1999 to 2001.
Note: Safety systems mitigate off-normal events by providing reactor core cooling and water addition. Actuations of safety systems that are monitored include certain emergency core cooling and emergency electrical power systems. Actuations can occur as a result of "false alarms" such as testing errors or in response to actual events. The number of safety events system actuations has declined since 1989.