SYSTEMS INTERACTION STUDY OF A WESTINGHOUSE PWR.

This paper presents methods and findings of a systems interaction study of Indian Point 3. The study was carried out in support of the resolution of Unresolved Safety Issue A-17 on Systems Interactions. Fault tree methods were employed. Among the study's findings is a single active failure in the low pressure injection function; this discovery led to a plant modification. The purpose of this paper is to report methods and findings of a systems interaction study conducted at Brookhaven National Laboratory in support of the resolution in Unresolved Safety Issue (USI) A-17. In addition to providing support to the staff in resolving USI A-17, the project discovered an important new class of failure modes which led the utility to implement a hardware modification. Below, the scope of the project is indicated, key features of the method are highlighted, principal findings are discussed, and comments are offered on the usefulness of this type of study.