Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf1 Publication
Validation of Trio_U for Transient Accident Scenarios Numerical Studies of the ROCOM Buoyancy Driven Test Case Simulating ECC Injection During Natural Convection in PWR
Höhne, T.; Bieder, U.
For the validation of the Trio_U code an experiment with constant flow rate in one loop (magnitude of natural circulation) and 10% density difference between ECC and loop water was taken. For this study a LES approach was used for mesh sizes between 340000 1.7 mil-lion control volumes. As a result in the experiment as well as in the calculation the ECC water only partly mixes with ambient coolant in the cold leg. A stratified flow is developing during the injection. In the downcomer a momentum driven flow field is still present at the begin-ning, after this the ECC water propagates downwards the downcomer below CL 1. Trio_U calculations show a good qualitative agreement with the experiment, while at local positions some differences in the concentration field occur.
The obtained results can be used for further studies of the core behaviour using coupled thermo-hydraulic-neutron-kinetic code systems.
Keywords: Turbulence; boron dilution transients; LES; TRIO_U
Note technique SMTH/LDTA N° 2003-079, CEA Grenoble, August 2004