Maintenance Operation on AGN-201 "COSTANZA" Nuclear Research Reactor of Palermo University

During operations with AGN-201 "COSTANZA" nuclear research reactor of Palermo University a failure of a compensated boron-lined ionization chamber provided with a measurement channel was highlighted. A maintenance program aimed to verify the operative conditions of all measurement systems was then started. It was easy to identify as cause of the malfunction a seepage of water inside the container of a Westinghouse WL 6377 ion chamber due to a lack of watertight closure. This can be attributed to corrosion of the container due to parasitic currents circulating between the container, the chamber and the reactor tank that acts as electrical ground of the system. In this work we refer over maintenance operations and on the protective devices adopted to avoid corrosion phenomena due to parasitic currents among various parts of the reactor. This maintenance experience can be reference for similar actions on other research reactors with a long operative life. (author)