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Activity name  COPSAR - Containment Pressure Suppression Systems Analysis for Boiling Water Reactors
Project summary  

SRV sparger tests with combined steam injection through the sparger head and LRR will be carried out in 2016 with PPOOLEX to provide closures for the EMS model development for spargers by KTH. The aim is to define momentum fields in the pool caused by injection of steam through the small holes directed radially at the sparger head and vertically in the LRR.

Experiments on mixing efficiency due to water injection through RHR nozzles will be continued in 2016 in order to further extend and validate the EHS and EMS models. A thermally stratified condition will be first created with small steam injection through the SRV sparger. Single phase water injection through the RHR nozzles will then be used to mix the pool. The effect of flow rate and water temperature on mixing efficiency will be studied. The PIV measurement system will be used for determining flow fields during the mixing phase.


KTH will perform pre-test analysis and simulations for selection of operational regimes and test procedures, and post-test analysis and validation with EHS/EMS models implemented in GOTHIC against PPOOLEX tests with (i) combined sparger head and LRR injection and (ii) RHR nozzles. Further development of EHS/EMS models for spargers and RHR nozzles will be pursued to simulate dynamics of the pool mixing and stratification. The models will be validated against respective separate effect tests.


CFD simulations of PPOOLEX experiments on SRV spargers and RHR nozzles are performed. Detailed model of the sparger geometry is constructed in the CFD model. A sub-model for the condensation of clouds of small vapour bubbles is used in the ANSYS Fluent code. The thermal stratification of the pressure suppression pool during steam injection into the pool is studied with CFD calculations. Suitable time interval of stratification and mixing experiment of PPOOLEX is calculated. The CFD model provides detailed information of the energy and momentum sources in the vicinity of the sparger, which can be used in the development of the EMS/EHS model for the GOTHIC code at KTH. The CFD calculations provide information on the mass and heat sources from the pool surface to the gas space of the wet well that can be used in the modelling of wet well spray experiments. The results are compared to the results obtained in the PPOOLEX experiments and to the results of GOTHIC calculations performed at KTH.

Lead organisation  Lappeenranta University of Technology, Finland
Contact person  Markku Puustinen,, +358 40 152 9528


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