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Highly-reliable triple modular redundant system NURECS-MarkⅢ

“NURECS-Mark Ⅲ” is Hitachi’s latest control system to support stable nuclear power plant operations with high reliability.

NURECS-MarkⅢ : uclear High Reliability Control System - Mark Ⅲ

High reliability

The controller has triple modular redundancy. Each controller performs asynchronous independent calculations. Since control output is determined by three-system majority logic, normal operations can be continued, even if malfunction occurs in one controller.

Failure resistance

All NURECS-Mark II system components are multiplexed, not just the controllers. This includes power supply, input-output and other equipment to assure high failure resistance. Also, fallback operation is possible with a single controller.


Troubleshooting can be done efficiently, thanks to failure information stored in memory and displays of each state and abnormal condition. Each component is multiplexed to enable replacements of malfunctioning components during operation.