Attila Kiss

Attila Kiss
Budapest University of Technology and Economics · Department of Nuclear Energetics

PhD

About

42
Publications
8,030
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166
Citations
Introduction
I hold a PhD in Physical Sciences/MSc in Mechanical Engineering. I am assistant professor at BME NTI. I am engaged in contributing national & international (e.g.: EU) R&D projects & in teaching of (under)graduate students. My main research fields are experimental & numerical (CFD & sub-channel) analyses on thermal hydraulics in SCWRs. I have 15+ years of experience in CFD & thermal hydraulics. I was substitute representative of EURATOM in the SCWR Th. & Safety Prj. Man. Board of GIF (2019-2022).
Additional affiliations
January 2017 - February 2017
Budapest University of Technology and Economics
Position
  • Professor (Assistant)
September 2009 - February 2016
Budapest University of Technology and Economics
Position
  • Research Assistant

Publications

Publications (42)
Article
Inherently poorer moderation in SCWRs due to average density lower than in LWRs and the resulted spectral shift can be useful when we apply thorium fuel cycle instead of uranium-plutonium one, according to an on-going study in BME NTI. Upon this conclusion, a thorium fueled SCWR design (Th-SCWR) has been proposed by BME NTI. In current feasibility...
Article
The application of relatively simple and cheap wrapped wire spacer in the European supercritical water-cooled reactor (HPLWR) has been proposed in order to provide enhanced heat transfer in the fuel assembly without unacceptable penalty in pressure loss. The wires cause twisting flow in the fuel assembly, which means the coolant flows not only stra...
Technical Report
FOREWORD The supercritical water cooled reactor (SCWR) is an innovative concept that operates at a pressure higher than the thermodynamic critical point of water, allowing the core outlet coolant temperature to be much higher than that of the current generation of WCRs. The key technological advantages of the SCWR include its high thermal efficien...
Article
Full-text available
The application of relatively simple and cheap wrapped wire spacer in the European supercritical-water-cooled reactor has been proposed in order to provide enhanced heat transfer in the fuel assembly without unacceptable penalty in pressure loss. The wires cause twisting flow in fuel assembly, which means the coolant flows not only straight in the...
Thesis
Full-text available
In this dissertation, I present my doctoral research which was about thermal hydraulic investigations of the coolant (supercritical (pressure) water, SCW) flow in Supercritical Water-cooled Reactor (SCWR) relevant geometries. This research was started during the elaboration of my MSc thesis (February-June 2006). At the beginning, my former Supervis...
Article
Two computational fluid dynamic (CFD) benchmarks have been performed to assess the prediction accuracy and sensitivity of CFD codes for heat transfer in different geometries. The first benchmark focused on heat transfer to water in a tube (first benchmark), while the second benchmark covered heat transfer to water in two different channel geometrie...
Conference Paper
Full-text available
Two blind Computational Fluid Dynamic (CFD) benchmarks have been performed to assess the prediction accuracy of current CFD codes used by the participants against heat transfer data in different geometries. CFD calculations have been performed by the participants for tube (1st benchmark) and two different channel geometries (2nd benchmark). In the...
Article
The thermal hydraulics of supercritical water under forced-, mixed convection and natural circulation conditions is not fully understood. In order to study the thermal hydraulic behaviour of this fluid under natural circulation conditions a small size, closed experimental loop has been designed and built. The thermal hydraulic phenomenon occurring...
Conference Paper
Full-text available
The wrapped wire spacer has been considered as an alternative spacer device in Generation IV reactor concepts just like in the European SCWR, in the HPLWR concept. In the wrapped wire spacer concept practically each fuel rod gets a wire wrapped around it. Thus on one hand radial velocity components, strong mixing (heat, momentum and mass transfer),...
Article
Full-text available
A konvencionális erőművi technológiában bevett gyakorlatnak számító kapcsolt energiatermelés hamarosan létrejöhet nukleáris hőforrással is. Ennek megvalósítására jelenleg is kutatások folynak a negyedik generációs reaktorok közé tartozó magas hőmérsékletű reaktor (HTR) koncepció alkalmazásával. Ezzel a reaktorral akár 1000 °C-os kilépő primerköri h...
Article
Full-text available
Heat transfer in supercritical water reactors (SCWRs) shows a complex behavior, especially when the temperatures of the water are near the pseudocritical value. For example, a significant deterioration of heat transfer may occur, resulting in unacceptably high cladding temperatures. The underlying physics and thermodynamics behind this behavior are...
Article
The Supercritical Water Reactor (SCWR) is one of the six reactor concepts being investigated under the framework of the Generation IV International Forum (GIF). One of the major challenges in the development of a SCWR is to develop materials for the fuel and core structures that will be sufficiently corrosion-resistant to withstand supercritical wa...
Article
The Supercritical Water Reactor (SCWR) is one of the six reactor concepts being investigated under the framework of the Generation IV International Forum (GIF). One of the major challenges in the development of a SCWR is to develop materials for the fuel and core structures that will be sufficiently corrosion-resistant to withstand supercritical wa...
Conference Paper
Full-text available
Heat transfer in supercritical water reactors (SCWR) shows a complex behavior, especially when the temperatures of the water are near the pseudo-critical value. For example, a significant deterioration of heat transfer may occur, resulting in unacceptably high cladding temperatures. The underlying physics and thermodynamics behind this behavior is...
Article
Full-text available
This paper describes the first steps of the realization of a natural circulation loop cooled by supercritical water. The thermal hydraulics of supercritical water is not fully understood. The thermal hydraulic phenomenon in the loop is intended to be measured by thermocouples, absolute and differential pressure transducers, flow meter and simultane...
Conference Paper
Full-text available
Three dimensional CFD simulations have been performed for supercritical water flow within a fuel bundle with 4 rods in a square arrangement. To ensure spacing between the rods, the design of the bundle uses thin wires wrapped clockwise around each rod. This geometry is presently investigated in the framework of EU supported FP-7 project of SCWR Fue...
Conference Paper
Full-text available
This paper describes the first steps of the realization of a natural circulation loop cooled by supercritical water. The thermalhydraulics of supercritical water is not fully understood. The thermalhydraulic phenomenon in the loop is intended to be measured by thermocouples, absolute and differential pressure transducers, flow meter and simultaneou...
Conference Paper
Full-text available
The supercritical pressure water is considered as the coolant in the primary loop of the presently developed Generation IV Supercritical pressure Water-cooled Reactors (SCWRs). The thermal hydraulics of this coolant is not fully understood though it is essentially needed for basic design and nuclear safety reasons. During the last decade, it has be...
Conference Paper
Full-text available
The supercritical pressure water is considered as the coolant in the primary loop of the presently developed Generation IV Supercritical pressure Water-cooled Reactors (SCWRs). The thermal hydraulics of this coolant is not fully understood though it is essentially needed for basic design and nuclear safety reasons. During the last decade, it has be...
Conference Paper
Full-text available
This paper describes the first steps of the realization of a natural circulation loop cooled by supercritical water. The thermalhydraulics of supercritical water is not fully understood. The thermalhydraulic phenomenon in the loop is intended to be measured by thermocouples, absolute and differential pressure transducers, flow meter and simultaneou...
Conference Paper
Full-text available
Three dimensional computational-fluid-dynamics simulations are performed for the fluid flow within a 40 rod fuel bundle in a square arrangement with a central moderator channel. To ensure spacing between the rods the design of the bundle uses thin wires wrapped counter-clockwise around each rod. This geometry is presently investigated in the framew...
Conference Paper
Full-text available
As recent studies prove in contrast to “classical” dimensional analysis, whose application is widely described in heat transfer textbooks despite its poor results, the less well known and used discriminated dimensional analysis approach can provide a deeper insight into the physical problems involved and much better results in all cases where it is...
Conference Paper
Full-text available
Three dimensional computational-fluid-dynamics simulations are performed for the fluid flow within a 40 rod fuel bundle in a square arrangement with a central moderator channel. To ensure spacing between the rods the design of the bundle uses thin wires wrapped counter-clockwise around each rod. This geometry is presently investigated in the framew...
Article
Computational fluid dynamics (CFD) codes have become promising tools for the investigation of thermal hydraulics in revolutionary reactor concepts in the last decade. In Reynolds-averaged Navier-Stokes calculations, the CFD codes (for example, the ANSYS CFX code used here) use turbulence modeling, wall functions, and other approaches. Therefore, th...
Conference Paper
Full-text available
The increasingly used supercritical pressure water (SCW) is a special coolant for conventional fossil fired power plant and newly intended to use for Supercritical pressure Water cooled Reactors (SCWRs) in the near future. Five experimental cases have been selected to serve as test cases for CFD validations using Reynolds Averaged Navier-Stokes (RA...
Conference Paper
Full-text available
Three dimensional computational-fluid-dynamics simulations are performed for the fluid flow within a 40 rod fuel bundle in a square arrangement with a central moderator channel. To ensure spacing between the rods the design of the bundle uses thin wires wrapped counter-clockwise around each rod. This geometry is presently investigated in the framew...
Conference Paper
Full-text available
The Supercritical or High-Performance Light-Water Reactor (HPLWR) is presently being investigated in Europe, Japan and other countries. In the cooling channels of the reactor core water at supercritical pressure of 25 MPa is strongly heated above the pseudo-critical temperature of 385°C. For the understanding of the flow and heat transfer in the co...
Conference Paper
Full-text available
The Supercritical or High-Performance Light-Water Reactor (HPLWR) is presently being investigated in Europe, Japan and other countries. In the cooling channels of the reactor core water at supercritical pressure of 25 MPa is strongly heated above the pseudo-critical temperature. For the understanding of the flow and heat transfer in the cooling and...
Conference Paper
Full-text available
CFD codes become promising tools for the investigation of thermohydraulics in revolutionary reactor concepts in the latest decade. In RANS (Reynolds Averaged Navier-Stokes) calculations the commercial CFD codes (for example the ANSYS CFX) use turbulence modelling, wall functions and other approaches. Therefore the accuracy of CFD codes for water fl...
Article
Full-text available
Three dimensional computational-fluid-dynamics simulations are performed for the fluid flow within a 40 rod fuel bundle in a square arrangement with a central moderator channel. To ensure spacing between the rods, the design of the bundle uses thin wires wrapped counter-clockwise around each rod. This geometry is presently investigated in the frame...
Article
Validation of the ANSYS CFX commercial CFD code for calculating the supercritical pressure water flow and also the meshing parameters' sensitivity study of the corresponding model are presented in this paper. Measurement data for heat transfer to supercritical water in a vertical smooth-bore tube published by Swenson and et al. were compared with R...

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Cited By

Projects

Projects (4)
Project
My main research filed is the thermal hydraulics of supercritical water which coolant is intended to be used in the Generation IV type Supercritical-Water-Cooled Reactor (SCWR). This class (SCWR) has reached the status of Generation IV reactor family now instead of being only one reactor concepts. There are many different SCWR design concept around the world: in Europe (HPLWR), in Russia (Super-WWER), in China, in Japan, in Canada (SCWR-CANDU). We mainly focuses on the European concept, the High Performance Light Water Reactor (HPLWR). We have used numerical (CFD and system code) and experimental approaches since 2006 (start of this research).
Project
We have participated the SCWR Fuel Qualification Test project (SCWR-FQT) financed by the EU (2011-2014). The SCWR-FQT project is related to the HPLWR Phase 2 European project, executed between 2006 and 2010, focused on the design of the European supercritical water cooled reactor, HPLWR. The scope of the SCWR-FQT Euratom-China parallel project is to design an experimental facility for qualification of fuel for the supercritical water-cooled reactor. The facility is destined to be operated in the LVR-15 research reactor in Czech Republic in the future. All necessary documents required for licensing of the FQT facility by the Czech regulator shall be the outcome of this project. Pre-qualification of the FQT facility will be carried out in China. Testing of a limited amount of commercially available nuclear grade materials, which are candidates for fuel cladding, will be carried out within this project as well. The European-Chinese team behind this project has been formed during a meeting held in Rez, Czech Republic, in October 2009; the wider EU-China scientific collaboration, together with its legal aspects, has been discussed during the seminar held in Beijing in March, 2010. During this project, we have performed CFD analysis on the test section with 2 × 2 wrapped-wired rod bundle along three revolution of wires. The main focus of our contribution was on: Sub-task 2.2 c) Inflow and outflow effects Optimisation of the design of the inlet and outlet of the test section by means of CFD flow analysis are needed in order to assure a stable and uniform inlet flow distribution and to assure sufficient mixing at the outlet section of the test section. Sub-task 2.2 d) Heat transfer and flow distribution in recuperator and cooler CFD Thermal-hydraulic analyses of recuperator and cooler of active channel are needed to optimise the design of these components. The pressure, flow and temperature distribution will be analysed. The risk of boiling should be investigated for the cooler.
Project
We have participated the HPLWR Phase 2 EU financed project as active supporter (2007-2010). The HPLWR concept is the European SCWR design. We have performed CFD analysis on the flow field, pressure profile, inter-sub-channel mixing and temperature distribution of wire wrapped HPLWR fuel assembly along one revolution of wires.