LWR fuel power transient testing at SCK•CEN

For many years, a lot of transient tests have been performed in the BR2 reactor at SCK•CEN with a Pressurized Water Capsule (PWC) embedded in the so-called Calibration and Cycling Device (CCD). The PWC/CCD device, aiming at performing fast power transients on fuel pins in BWR- or PWR-like conditions was put into operation in 1977, has been continuously improved and is still operational. In 2010, PWC/CCD has undergone its periodic (every 5 years) requalification. To optimally control the power ramp, the transient fuel tests are realized exclusively by the variation of the BR2 power: the fuel rod heating rate is adjusted by varying the BR2 reactor power during dedicated short reactor cycles. Some typical results obtained from transient tests illustrate the performances of this facility and the accuracy of the power determination.