A reliability analysis of the Clinch River Breeder Reactor plant power transmission system

This thesis presents a reliability analysis of the hardware in the Power Transmission System of the proposed Clinch River Breeder Reactor Plant (CRBRP). The analysis evaluates the quantitative and qualitative reliability characteristics of the components in the system based on standard fault tree analysis techniques. A qualitative common cause failure analysis is also performed to identify potential sources of dependencies among component failures in the system.

The qualitative analysis of the system hardware produces 552 sets of three hardware failures which can cause a loss of offsite power to the CRBRP due to Power Transmission System failure. The qualitative common cause analysis shows that there are three events which can cause a loss of offsite power: lightning, external operator errors, and vibration in the control room.

Based on the assumptions for the qualitative analysis, which include neglecting common cause effects, the asymptotic value of the system unavailability due to hardware failures is 9.0 x 10^-8. Based on the uncertainty in the data, there is a 90 percent likelihood that this value lies between 1.8 x 10^-8 and 1.2 x 10^-6. The system is expected to experience 4.8 x 10^-4 failures per year as a result of hardware failures in the Power Transmission System. In short, the Power Transmission System failure causes will surely be dominated by events other than independent hardware failures but attempting treatment of these events now is premature.