Key Topic Outstanding Know-How & Sustainable Innovations Technical Session: Reactor Physics, Thermo and Fluid Dynamics

摘要

The Technical Session about Neutron Flux Oscillation Phenomena was chaired by Joachim Herb (Gesellschaft für Anlagen und Reaktorsicherheit (GRS) GmbH) and well attended by approx. 50 listeners. It comprised of three keynotes and two technical presentations. The main topics were the significant changes of the neutron flux noise levels in different German and foreign pressurized water reactors (PWRs). For about ten years an increase in neutron noise levels has been observed in German PWRs. During the following five years the noise levels have been decreasing again. In principle, a correlation of the neutron noise levels to the use of certain fuel element types was observed and the phenomenon of neutron flux oscillations had been known since decades. Nevertheless, no self-consistent physical theory exists so far, which can explain the observed changes and the absolute levels of the observed neutron flux noise levels. Therefore, safety authorities, technical support organizations (TSO), utilities as well as research organizations showed increased interest in this topic during the last years. The results of the corresponding work as well as an outlook into soon-starting research projects were given in this session.