Condition monitoring of electrical equipment in nuclear power plants

This paper presents the results of a review of maintenance methods that may be considered for condition monitoring of equipment in a nuclear power plant. Some of these methods are presently being used on instruments and equipment whose performance is governed by the plant technical specifications. Other methods are being used to monitor the condition of heavy power production equipment in the plant. From a survey of eight utilities which have or will soon have operating generating stations it was found that eM was not being used on light equipment or environmentally qualified equipment. An exception is the monitoring of drift in pressure transmitters by some utilities. An explanation for the lack of widespread use of condition monitoring (CM) is the uncertainty over the cost effectiveness and reliability of the test methods to yield unambiguous information. A purpose of CM is to optimize the preventive maintenance program by adjusting the tests performed and the schedule to the unique requirements of the equipment. By showing the changing condition of the equipment with time, CM may also be able to predict when certain criteria will be reached in the future. CM programs to demonstrate the ability of certain tests to show a correlation between degradation and the measured parameter and to establish criteria for judging the condition of the equipment could help remove some of the ambiguity that now exists.