Technical Review of On-line Monitoring Techniques for Performance Assessment. Volume 2: Theoretical Issues

摘要

IN 1995 the U.S. Nuclear Regulatory Commission (NRC) published a summary of the state-of-the-art for the area of on-line monitoring prepared by the Analysis and Measurement Services Corporation as NUREG/CR-6343, On-Line Testing of Calibration of Process Instrumentation Channels in Nuclear Power Plants. The conclusion of this report was that it is possible to monitor calibration drift of field sensor and associated signal electronics and determine performance of the instrument channels in a nonintrusive way. In 1998, the Electric Power Research Institute (EPRI) submitted Tropical Report (TR) 104965, On-Line Monitoring of Instrument Channel Performance for NRC review and approval. This report demonstrated a nonintrusive method for monitoring the performance of instrument channels and extending calibration intervals required by technical specifications (TS). A safety evaluation report (SER) was issued in 2000 in which NRC staff concluded that the generic concept of on-line monitoring (OLM) for tracking instrument performance as discussed in the topical report is acceptable. However, they also listed 14 requirements that must be addressed by plant-specific license amendments if the TS-required calibration frequency of safety-related instrumentation is to be relaxed. The SER did not review or endorse either of the two methods addressed in the topical report. This report, published in three volumes, provides an overview of current technologies being applied in the United States for sensor calibration monitoring. Volume 1: State-of-the-Art, provides a general overview of current sensor calibration monitoring technologies and their uncertainty analysis, a review of the supporting information necessary for assessing these techniques, and a cross reference between the literature and the requirements listed in the SER. This volume entitled Volume 2: Theoretical Issues, provides an independent evaluation of the application of the most commonly employed OLM methods.