Pre-test prediction of FIX II intermediate break experiment with THYDE-P1

This report contains the results from the pre-test prediction calculation of FIX II Intermediate Break Experiment with the THYDE-Pl computer code. The experiment simulated the conditions corresponding to an intermediate size break loss-of-coolant accident (LOCA) in one of the recirculation lines of a boiling water reactor (BWR) with external pumps. The test was the first LOCA experiment in the FIX II facility and was chosen as the OECD CSNI International Standard Problem No. 15. Although an extensive verification calculations have been performed with THYDE-Pl for pressurized water reactors (PWRs), the present calculation is the first application to BWR. The major purposes of the present calculation are to verify the applicability of THYDE-Pl to BWR and to indentify the model deficiencies for further code modification. After the experimental data being released, the predicted results with THYDE-Pl have been compared with the experimental data. The comparison shows that the present calculation has adequately predicted the important phenomena observed in the experiment. (author)