Vibration measurements in PWR obrigheim by use of in-core accelerometers

Two accelerometers were inserted into the reactor of the NPP Obrigheim (Germany), one into the core and the other above the core. The amplitude of different components vibrations (fuel element (FE), reactor pressure vessel-core barrel (RPV/CB) and the instrument string-instrument tube (IS/IT) system) were measured. Neutron-mechanical scale factors (SFs) were calculated for the in-core detectors.