Hydraulic behaviour of a partially uncovered core
A critical review of experimental data and theoretical models relevant to the thermohydraulic processes in a partially uncovered core has been performed. Presently available optimised thermohydraulic codes should be able to predict swell level elevations within an error band of +-0.5m. Rod temperature rising velocities should be predicted within an error bandwidth of +-10%, provided the correct rod heat capacity is given. A general statement about the accuracy of predicted rod temperatures is not possible because the errors increase with simulation time. Highest errors are expected for long transients with low heating rates and low steam velocities. As a result, three areas for additional research are suggested: - a high-pressure test at 120 bar to complete the void correlation data base, - a low steam flow/low power experiment to improve heat transfer correlations, - a numerical investigation of three-dimensional effects in the reactor core with unequally heated rod bundles. For the present state of 1-dimensional experiments and models, suggestions for a satisfactory modelling have been derived. Further work could improve the modelling capabilities and the code reliability for some limiting cases such as high pressure boil-off, low-power long-term steam cooling, and unequal heating of neighbouring bundles.
Bibliographic Reference: EUR 12406 EN (1989) 80 pp., FS, ECU 7.50
Record Number: 199010289 / Last updated on: 1994-12-01
Original language: en
Available languages: en