Abstract
In the PHARE project "Hydrogen Management for the VVER440/213" (HU2002/000-632-04-01), CFD calculations with GASFLOW 2.1, FLUENT 6.1.22 and CFX-5.7.1 were performed for the Paks NPP modeling a defined severe accident scenario involving hydrogen release. The purpose of this work was to demonstrate the use of CFD codes to model a containment undergoing a severe accident.
With growing experience in performing such analyses the results can support the formation of a sound basis for assessing the risk of losing containment integrity as a result of hydrogen deflagrations. As an effective mitigation measure in such a situation, the implementation of catalytic recombiners is planned in the Paks NPP. In order to support these plans both unmitigated and recombiner-mitigated simulations were performed. These are described and selected results are compared. The codes CFX and FLUENT needed to be extended by wall and bulk steam condensation models to be able to simulate all relevant processes during the given accident.
The parallel use of several CFD codes for the same accident scenario was chosen to reduce uncertainties in the results by revealing margins of major findings. Previously it was considered impractical to use CFD codes to simulate a full containment subject to a severe accident and extending over many hours. This was due to prohibitive computing times and missing physical capabilities.
This work demonstrates, supported by developments in CFD codes and improvements in computer power, that these calculations have now become feasible
With growing experience in performing such analyses the results can support the formation of a sound basis for assessing the risk of losing containment integrity as a result of hydrogen deflagrations. As an effective mitigation measure in such a situation, the implementation of catalytic recombiners is planned in the Paks NPP. In order to support these plans both unmitigated and recombiner-mitigated simulations were performed. These are described and selected results are compared. The codes CFX and FLUENT needed to be extended by wall and bulk steam condensation models to be able to simulate all relevant processes during the given accident.
The parallel use of several CFD codes for the same accident scenario was chosen to reduce uncertainties in the results by revealing margins of major findings. Previously it was considered impractical to use CFD codes to simulate a full containment subject to a severe accident and extending over many hours. This was due to prohibitive computing times and missing physical capabilities.
This work demonstrates, supported by developments in CFD codes and improvements in computer power, that these calculations have now become feasible
| Original language | English |
|---|---|
| Title of host publication | Proceedings |
| Subtitle of host publication | 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12 |
| Publisher | American Nuclear Society (ANS) |
| ISBN (Print) | 978-0-89448-057-7 |
| Publication status | Published - 2007 |
| MoE publication type | A4 Article in a conference publication |
| Event | 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12 - Pittsburgh, United States Duration: 30 Sept 2007 → 3 Oct 2007 |
Conference
| Conference | 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12 |
|---|---|
| Country/Territory | United States |
| City | Pittsburgh |
| Period | 30/09/07 → 3/10/07 |
Keywords
- severe accident
- CFD code
- hydrogen
- mitigation
- PAR