Update of BWR [boiling water reactor] owner's group stability initiatives

On March 9, 1988, a dual recirculation pump trip occurred at LaSalle County Station Unit 2, which ultimately resulted in thermal-hydraulic neutron flux oscillations. Because cycle-specific calculations had led to the belief that such oscillations were not likely, the LaSalle operators were not fully prepared to quickly respond to the event. As a result, the oscillations were automatically terminated by a high-flux scram. Although no safety limits were approached and no damage to the fuel or plant occurred or was expected, several concerns related to the understanding of instability phenomena, the adequacy of existing nuclear instrumentation to detect and suppress oscillations, and the reliability of predictive calculations were raised. This paper discussed General Electric Company boiling water reactor owner's group (BWROG) activities that address these concerns, including BWROG efforts to identify the need for and development of a long-term stability solution