The Turbine Protection System (TPS) provides an additional independent protection function for the steam turbine and generator. The TPS detects undesirable operating conditions and initiates trips to avoid damaging the steam turbine. The Mitsubishi TPS is implemented with a digital nuclear Instrumentation and Control (I&C) platform MELTAC.
The Mitsubishi TPS is composed of two Turbine Trip subsystems A and B; Each subsystem is comprised of two controllers; Each controller is comprised of two standby redundant CPU and associated I/O. Each controller operates independently. One controller from each subsystem interfaces with Train A or Train B. Each Train in turn controls two valves in series.
The Mitsubishi TPS realizes high reliability and maintainability by adapting four controllers which operate independently.
- The four controllers operate independently to ensure improved system reliability and maintainability
- Through the two 1-out-of-2 train control configuration, each valve is separately operable. So valve testing can be performed during plant operation without losing the trip function.
Feed Water Pump Turbine Protection System
Mitsubishi also provides a Feed Water Pump Turbine (FWPT) Protection System. The Mitsubishi FWPT Protection System is implemented with MELTAC, and realizes high reliability and maintainability.