Experience of an on-line reactor noise monitoring system for the Borssele (PWR) power reactor

After an extensive experimental program in which reactor noise has been studied during eight fuel cycles of the Borssele reactor, an on-line real time reactor noise monitoring system has been developed to continuously follow reactor operation from a remote site connected to the reactor by a telephone line. This system has been developed to follow reactor noise signatures and to identify changes in total r.m.s. noise power, power spectral densities, and physical quantities such as core barrel motion amplitudes and directions and reactivity. The real-time monitoring system consists of two main parts. The first part is a specially built microprocessor controlled digitizing units and a MODEM to transfer the digitized data by means of a telephone link to a digital computer 200 kms away. The second part of the system is the on-line monitoring system with a host computer (PDP 11/34) and array processor (Floating Point System, AP 120-B) located at a research centre