On-line success path monitoring: aid to restoring and maintaining plant safety

This report provides the basic methodology and the results of a conceptual evaluation of a technique of success path based functional recovery guideline support. The method for Success Path Monitoring (SPM) developed in this report is intended to enhance the relationship that currently exists between a Safety Parameter display system (SPDS) and symptoms by providing an operating crew the link needed to successfully identify problems impacting safety, select appropriate corrective procedures, and verify the success of mitigating actions. The 1979 accident at Three Mile Island (TMI) demonstrated that this type of information was needed as the resources available at that time to the operating crew were not adequate for their decision making.