Operation and maintenance of the 250 kW TRIGA Mark II reactor at the J. Stefan Institute

During the last two years the reactor was in operation without any longer shut-down. Only a small bending of the regulating control rod was noticed. This failure was repaired. One of the major problem, but not connected to the operation of the reactor, is the delivery of the new FLIP fuel elements. Since the beginning of operation, the reactor has been at full power about 24-00 hours per year, or 220 hours per month, which means that the utilization of the reactor in Ljubljana is relatively very high. One of the reasons for this high utilization is the quite extensive production of radioactive isotopes, especially short lived, for various consumers and the irradiation of samples for our nuclear chemistry division. Problems with rotary specimen rack occurred and a new rotary specimen rack was installed. During the last years some of the original instrumentation of the reactor was substituted because of ageing of the electronics or to improve the operational capabilities of the reactor