Reliability Analysis of a Nuclear Reactor Fuel Charging System

A fuel charge/discharge system for a nuclear reactor with on-load fuel changing is considered. The system consists of two fuel charging (fc) machines which operate in parallel. When both fc machines have been down for more than 28 days the reactor becomes subcritical and shuts down spontaneously. Using conditional probability arguments and renewal theory it is shown how reliability measures of a two unit redundant system can be extended to obtain the expected frequency and duration of reactor shut-downs due to fc system failures.