In this paper a Proxel-based reliability analysis for the safety mechanism of a hazardous nuclear power reactor, which failures may represent an imminent danger to the environment, is proposed. The system consists of multiple valves and pumps which are set up in a way to provide a redundant route for a high-pressure water flow. An existing larger model for the system is decomposed into three independent parts which are thought to be analysed with much less effort. A Boolean logic for combining the reliability of the subcomponents is derived from a Fault-tree like view on the system and later used to generate reliability information of the original system as a function of time.