Methods used to assess the safety and reliability of a nuclear reactor rod control system

This paper describes the reliability techniques used to estimate the risk of fission product release from accidents caused by faults in the rod control system of a pressurized water reactor.These techniques include: a three-level reliability assessment using a functional event tree and two levels of fault tree to assess functional and system's reliability, an operator response model using event trees and a method of using the structure function of a reliability model to investigate possible common mode failure interactions.