Conclusions

The RIC mobile internal instrumentation system benefits from extremely favorable feedback from around a thousand reactor-years of experience.

In functional terms, it is highly resolving and achieves a remarkable level of precision. In July 1979, during zero-power physical tests on the Bugey 5 unit, a particular anomaly was detected in consumable poison rods made of Pyrex (borated silica glass). These rods were manufactured in two parts, which had separated during transport, leaving a void that caused a flux peak in the middle of the core. Similarly, the detection of a slight asymmetry in power distribution (x, y ) during start-up of the 1,300 MW stage, now observed on all units, is to the credit of the RIC system. This asymmetry, due to slight geometric variations affecting the core during operation, is now taken into account in studies. The only drawback is the...