Investigation of nuclear concrete

Recent times, life extension of nuclear power plant (NPP) plays one of the crucial roles in energetics and especially in nuclear industry. Key members of NPP's long term operation are reactor pressure vessel (RPV) and its cavity (concrete shell surrounding nuclear reactor). There is big interest in prediction of the state of biological shielding concrete around RPV. Many countries all over the world solve more or less the same problem: how to predict its state? Recent article provides with an opportunity of biological shielding concrete non-destructive testing (NDT). Two NDT methods will be performed as a possible solution of the problem. Due to high radiation, mechanical manipulators have been applied in order to attach ultrasonic or acoustic-emission transducers onto concrete surface or steel liner surface. The results will show 1) the possibility of the measurement near nuclear reactor in its outage, 2) the testing of RPV cavity from Greifswald's NPP NORD 3) and also the measurement of concrete samples irradiated by neutron and gamma radiation in light water reactor LVR-15. All presented material leads to the same goal: prolong the durability of old nuclear power plants and/or access their reliability and/or guarantee their safety.