Limitorque Operators - An Exercise in Optimized Reliability

Abstract

Electrically operated valves are widely used in nuclear power generating stations (NGSs) world-wide. Their reliability is of crucial importance, especially in safety systems such as emergency coolant inject ion (ECI) systems. High failure rates in Ontario Hydro NGSs and NGSs in the United States has brought into focus the express need to study in detail reliability issues associated with these valves. The experience gained in this study at the Ontario Hydro Pickering NGS-A is discussed in this paper.