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

The operational data in the years 1972-1973 and up to October 1974 are presented. A general trend observed in the past two years is a slow aging of the electronic equipment. Problems with the recorder were experienced and a new recorder will be installed at the end of 1974. The other equipment performs without troubles. Because of the substantial elongation of the fuel elements, 5 FLIP fuel elements were inserted. Extensive measurements of the neutron flux distribution were performed. The measurements of power noise of the reactor have shown that the different inlet systems for the cooling water produce different power noise. The diffusor mixes the water very extensively, therefore vibration of the regulating rods is suspected. The diffusor of the inlet system for cooling water was exchanged with the short pipe. (U.S.)