INVESTIGATION OF FUEL-ROD BEHAVIOR UNDER EXTENDED-1 BURNUP CONDITIONSWITH ROFEM FUEL PERFORMANCE CODE

Extending burnup is a practical way to improve the economics of water- reactor operation, via enhanced fuel utilisation and reduced spent fue l volume. A dedicated fuel behaviour modeling computer code (entitled ROFEM-1B) has been developed in order to analyse high burnup fuel perf ormance. The code was benchmarked on an experimental data base which i nclude a significant number of irradiation experiments performed in TR IGA-INR Pitesti research reactor. Five fuel rod behaviour during irrad iation up to 50 MWd kg(-1)UO(2)(-1) burnup have been analysed by the c ode in the framework of the first phase of the international FUMEX cod e exercise co-ordinated by IAEA Vienna. The input experimental data pa ckage has been prepared by IFE-OECD Halden, Norway laboratory. In the second phase of the FUMEX exercise the participants have analysed eigh t simplified theoretical cases. The paper presents and discuss the res ults obtained with ROFEM-1B in this exercise and the comparison betwee n code predictions and experimental data. (C) 1997 Elsevier Science Lt d.