The reliability of the Sizewell `B´ reactor protection system

The two constituent components of the Sizewell B nuclear power station reactor protection system, the primary protection system and the secondary protection system have been subjected to separate reliability assessments and have been shown to meet the reliability requirements specified. The reliability claimed for the systems is not limited by the assessed random failure rates but by the common mode failure rates assigned to the systems. The reliability assessments of the two systems demonstrates that the reactor protection system as a whole has an acceptable reliability for its function