MOC for instrumentation and control systems of nuclear power plants

Context and challenges

The project for this client, a major player in the nuclear industry, concerns Maintenance in Operational Condition (MOC) for its systems, in particular the KIT N1.
This system is in fact a processor that ensures acquisition of the majority of digital (On-Off) and analogue (ANA) signals in a nuclear plant unit in order to make them available to the supervision systems for operational support.

For example, the standard KIT N1 configuration for a 900 MW plant unit is 157 acquisition PCB, 32 digital inputs and 24 acquisition units with 60 ANA inputs, for a potential total of 5,024 digital inputs and 1,440 ANA inputs.
Every KIT N1 at all 54 of the 900 and 1300 MW nuclear power plant units requires maintenance operations.

Since 1991, the client has entrusted Assystem with the task of ensuring Maintenance in Operational Condition (MOC) for all the KIT N1 systems.