Summary on the activity of working group
20th Symposium of AER on VVER Reactor Physics and Reactor Safety (2010, Hanasaari, Espoo, Finland)
Nuclear applications of three-dimensional thermal hydraulics
Abstract
Summary on the activity of working group G in 2010
Attila Asz?di, Coordinator of Working Group G
The AER Working G meeting was held on 31 May – 1 June 2010 in Balatonf?red, Hungary
together with Working Group C. The short summary of Working Group G presentations is the
following.
1. D. Tar (AEKI): Experimental Investigation of Coolant Mixing in VVER and PWR Reactor
Fuel Bundles by Laser Optical Techniques for CFD Validation
? PIV and LIF measurements of flow in a VVER-440 fuel assembly head at different
boundary conditions (five heating configuration)
? Test section: 1 m long rod bundle (36 heated rods, 72 kW total heat power) with
assembly head
? Presentation of some velocity and temperature fields in the assembly head
? Calculation of POD modes in 5?5 PWR rod bundle with spacer grids
2. B. Kiss, A. Asz?di (BME NTI): Benchmark Calculation with Improved VVER-440/213 RPV
CFD Model
? Detailed CFX model of VVER-440/213 reactor pressure vessels with a simplified core
? Transient calculations for starting up of the 6th main coolant pump
? Comparison between ATHLET and CFX results
? Development of hexahedral mesh for the downcomer
3. R. Szij?rt?, B. Yamaji, A. Asz?di (BME NTI): Study of Natural Convection Around a
Vertical Heated Rod Using PIV/LIF Technique
? Simultaneous measurements of velocity and temperature fields performed applying a
combined PIV and LIF setup to investigate natural convection around the vertical
heated rod.
? Local heat transfer coefficient calculated from measured data.
4. P. M?hlbauer (REZ): A Simplified Approach to VVER-440 Fuel Assembly Head
Benchmark
? Model for VVER-440 fuel assembly head without spacer grid
? Calculation of benchmark exercises with FLUENT code
? Unstructured mesh of about 14 million cells
? Presentation of calculated temperature and velocity distributions, thermocouple
signals
5. A. Shishov, O. Kudryavtsev, D. Posysaev (GIDROPRESS): VVER-440 Fuel Assembly
Head CFD benchmark ? Preliminary results
? Model for VVER-440 fuel assembly head
? Three hexahedral meshes of 10.5, 12 and 25 million cells
? Calculation of benchmark exercises with CFX code
? Presentation of calculated temperature and velocity distributions, thermocouple
signals
6. S. T?th, A. Asz?di (BME NTI): First Results of VVER-440 Fuel Assembly Head Benchmark
? Introduction of benchmark exercises
? First comparison of GIDROPRESS, REZ and VUJE results
? After discussions agreement with the participants: benchmark calculations should be
performed with and without central tube flow