Using Statistical Process Control Methodology to Improve the Safe Operating Envelope

Abstract

Failure limits used to assess impairments from Operating Manual Tests (OMT) are often established using licensing limits from safety analysis. While these determine that licensing conditions are not violated, they do not provide pro-active indications of problems developing with system components. This paper discusses statistical process control (SPC) methods to define action limits useful in diagnosing system component problems prior to reaching impairment limits. Using data from a specific OMT, an example of one such application is provided. Application of SPC limits can provide an improvement to station operating economics through early detection of abnormal equipment behaviour.