A benchmark exercise on the use of CFD codes for containment issues using best practice guidelines: A computational challenge

Toward a CFD-grade database addressing LWR containment phenomena

“…For these simulations, the GOTHIC, CFX-4 and CFX-5 codes have been used, using the standard k-ε turbulent model. It can be observed that the radial positions of the maximum temperature predicted by GOTHIC are close to the experimental ones (different markers at the same distance from the wall for the experimental data indicate repetition runs for the same test) at the early times selected, and in the range of those predicted by CFX using various meshes (the complete set of results, with all CFD codes used in the benchmark is given by Andreani et al, 2008). …”

“…The analytical activities were performed with CFD codes and with advanced Lumped Parameter codes. These analytical activities provided a contribution toward the assessment of strengths and drawbacks of different codes in analyzing the phenomena occurring in these PANDA tests (OECD 2007;Royl et al 2008Royl et al , 2009Andreani et al 2008, 2010a, Bentaib et al 2009. A number of simulation challenges were identified in relation to: gas transport and stratification for the case of high flow exit elevations; prediction of peak gas temperature (mainly in the near-wall plume test series); stratification disruption and erosion for the case of the three gas test; and condensation/condensate transport and re-evaporation phenomena.…”

Interaction of a light gas stratified layer with an air jet coming from below: Large scale experiments and scaling issues

“…Cleaver et al (1994) studied this phenomenon for a methane release in an enclosure and demonstrated that stable stratification did not occur if: Peterson (1994) developed a similar criterion with a slightly different constant c because of partially confined conditions. Finally, in the nuclear containment thermal-hydraulics issues, Andreani et al (2008) illustrated the set-up of a stratified atmosphere with an horizontal steam jet. Now, we consider that the stratified layer is already set-up inside the containment and a vertical air jet is coming from below.…”

Development of Best Practice Guidelines for CFD in Nuclear Reactor Safety

“…Useful results can be obtained from single phase CFD models of the gas mixture as long as special models track removal of steam and hydrogen from the system. Before application to VVER this modeling approach was validated against the HYJET [18] and SETH [19] tests and results from HYMI [20] and ISP 47 [21] exercises. Lessons on nodalization and model selection learned from validation were carried into the final containment analyses.…”