Reactor primary coolant pump coupling has overspeed release - fired by small charges producing limited damage

摘要

A main coolant circulating pump for the primary circuit of a nuclear reactor has its rotor driven by an electric motor through a coupling with overspeed release. The releasable coupling comprises bolts interconnecting the driving and the driven sides. These bolts contain an explosive charge connected to a detonator which is fired if the coupling overspeeds. Pref. a number of bolts around the circumference of the coupling are all connected in a series to a single detonator. To prevent overspeeding of the motor e.g. if a burst occurs in a coolant circuit. The coupling does not release heavy components if the charges are fired; therefore damage from flying debris is avoided.