Research - Takács Antal
Before 1998 I have dealt with the physics of thermalhydraulical phenomena, their modelling. Later I got practice in using the Finnish TH system code SMABRE, the francia-német ESCADRE severe accident code package and the FLUENT CFD code. I participated in the evaluation of PMK-experiments. In evaluation of critical DNBR in VVER-440 core I had an insight in the usage of the COBRA subcjannel code. I had participated in evaluating the Smolin and Bezrukov VVER-specific critical heat flux correlations. My hydraulical calculations meant a contribution to a VVER-440/V213 specific thermalhydraulical data base for later TH system calculations of the Paks NNP.
CATHARE2 Activity Related to VVER-440/V213
I have been responsible for CATHARE TH calculations at Thermalhydraulics Department since 1998.
During the past 20 years firstly a 2-loop model of a unit of Russian type VVER-440/V213 nuclear plant (PWR) was elaborated for CATHARE2 code. Later on this preliminary model formed the base of developing a more detailed 6-loop model of the plant. The advantage of this extended model is its ability to reflect and describe the asymmetrical behavior of loops in different transient scenarios. The development of the 6-loop model started in 1999.
The development consisted of two major steps:
- the extension of the nodalization to 6 loops,
- the separation of the transient trip logics corresponding to the 6-loop geometry.
The core physics is described by a 0D core kinetics.
The nodalization may contain 0D (VOLUME), 1D (AXIAL), connection (TEE) and 3D (THREED) elements connected by junctions.
The development work was done parallely to validation of the input model by calculations and benchmarks with other codes results.
In the meanwhile several PMK2 transients have been calculated and experiences were introduced and benefited in the 6-loop plant model.
Presently we have a model capable to calculate several scenarios like transients without loss of coolant (inadvertent main coolant pump trip, inadvertent reactor scram, inadvertent closure of MSIVs,...), small break or large break LOCAs, SGTR, steam line break, etc. Please find more details in my Publications list.
The development and validation work work has been supported by the Hungarian Atomic Energy Agency.
Peculiarities in hydrodynamics
1 Peculiarities at microgavity on N. Bondarin spaceman's photo:
- the water droplet stays on the leaf
- the droplet is spherical
- the bubble remains inside the droplet