References of "Leyer, Stephan 50003662"
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See detailPrevention of Electrostatic Charge Generation in Filtration of Low-Conductivity Oils by Surface Modification of Modern Filter Media
Staudt, Johannes; Duchowski, Johan; Leyer, Stephan UL

in Tribology Transactions (2020)

The electrostatic charging behavior of filter elements operating in various hydraulic and lubricating fluids has been re-examined from the perspective of fundamental material properties of the two ... [more ▼]

The electrostatic charging behavior of filter elements operating in various hydraulic and lubricating fluids has been re-examined from the perspective of fundamental material properties of the two materials participating in the event. In contrast to the previously proposed mechanisms that focused predominantly on fluid and material conductivities, new evidence strongly suggests that the relative placement of the substrates in the triboelectric series must be taken into account. The positions occupied in the triboelectric series account for the donor/acceptor tendencies exhibited by the materials when brought close together in close proximity ( 10 nm). Nevertheless, this behavior is only an outward manifestation of the deeper underlying characteristics that include material surface energies and, looking even deeper, the associated electron work functions of the interacting materials. Herein we provide several examples of the enhanced understanding of the electrostatic charging/discharging (ESC/ESD) phenomena as they occur in the course of filtration of hydraulic and lubricating fluids through modern filter elements constructed of synthetic glass fiber and polymer materials. [less ▲]

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See detailModelling of Passive Heat Removal Systems: A Review with Reference to the Framatome BWR Reactor KERENA: Part II
Manthey, René; Viereckl, Frances; Moonesi Shabestary, Amirhosein et al

in Energies (2019)

Passive safety systems are an important feature of currently designed and constructed nuclear power plants. They operate independent of external power supply and manual interventions and are solely driven ... [more ▼]

Passive safety systems are an important feature of currently designed and constructed nuclear power plants. They operate independent of external power supply and manual interventions and are solely driven by thermal gradients and gravitational force. This brings up new needs for performance and reliably assessment. This paper provides a review on fundamental approaches to model and analyze the performance of passive heat removal systems exemplified for the passive heat removal chain of the KERENA boiling water reactor concept developed by Framatome. We discuss modeling concepts for one-dimensional system codes such as ATHLET, RELAP and TRACE and furthermore for computational fluid dynamics codes. Part I dealt with numerical and experimental methods for modeling of condensation inside the emergency condenser and on the containment cooling condenser. This second part deals with boiling and two-phase flow instabilities. [less ▲]

Detailed reference viewed: 73 (7 UL)
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See detailModelling of Passive Heat Removal Systems: A Review with Reference to the Framatome KERENA BWR Reactor: Part I
Moonesi Shabestary, Amirhossein; Viereckl, Frances; Zhang, Yu et al

in Energies (2019)

Passive safety systems are an important feature of currently designed and constructed nuclear power plants. They operate independent of external power supply and manual interventionsand are solely driven ... [more ▼]

Passive safety systems are an important feature of currently designed and constructed nuclear power plants. They operate independent of external power supply and manual interventionsand are solely driven by thermal gradients and gravitational force. This brings up new needs forperformance and reliably assessment. This paper provides a review on fundamental approaches to model and analyze the performance of passive heat removal systems exemplified for the passive heat removal chain of the KERENA boiling water reactor concept developed by Framatome. We discuss modelling concepts for one-dimensional system codes such as ATHLET, RELAP and TRACE and furthermore for computational fluid dynamics codes. Part I deals with numerical and experimental methods for modelling of condensation inside the emergency condensers and on the containment cooling condenser while part II deals with boiling and two-phase flow instabilities. [less ▲]

Detailed reference viewed: 23 (6 UL)
See detailPANAS- Project: Heat Transfer Model Development for Passive Safety Systems,
Leyer, Stephan UL; Hampel; Schuster, C et al

in NURETH-18 (2019, August 18)

Detailed reference viewed: 27 (1 UL)
See detailLuxCube the First CubeSat Student Satellite in Luxembourg
Rabbadan Santana, E; Weiss, T; Djordjevic, A et al

Poster (2019, June 15)

Detailed reference viewed: 16 (0 UL)
See detailEvaluation of Stratified Condensation Models for a slightly inclined tube unsing ATHELT Code
Zhang, Yu; Moonesi Shabestary, Amir Hossein; Bieberle, Andre et al

in NURETH-18 (2019)

Detailed reference viewed: 28 (4 UL)
See detailInvestigation of Thermal Coupling in Condensation Process at COSMEA Facility with ATHLET Code
Zhang, Yu; Leyer, Stephan UL; Hampel, U

in Reactor engineering (2018, October)

Detailed reference viewed: 29 (7 UL)
Peer Reviewed
See detailCFD Simulations of Adiabatic Boiling in Different Riser Geometries
Haag, M; Leyer, Stephan UL

Poster (2018)

Detailed reference viewed: 16 (2 UL)
See detailPraktische Handhabung und Kunst der Modellwahl
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 111 (3 UL)
See detailFull scale BWR containment loca response test at the INKA test facility
Wagner, T.; Leyer, Stephan UL

in International Conference on Nuclear Engineering, Proceedings, ICONE (2015), 2015-January

KERENA is an innovative boiling water reactor concept with passive safety systems (Generation III+) of AREVA. The reactor is an evolutionary design of operating BWRs (Generation II). In order to verify ... [more ▼]

KERENA is an innovative boiling water reactor concept with passive safety systems (Generation III+) of AREVA. The reactor is an evolutionary design of operating BWRs (Generation II). In order to verify the functionality and performance of the KERENA safety concept required for the transient and accident management, the test facility "Integral Teststand Karlstein" (INKA) was built at Karlstein (Germany). It is a mock-up of the KERENA boiling water reactor containment, with integrated pressure suppression system. The complete chain of passive safety components is available. The passive components and the levels are represented in full scale. The volume scaling of the containment compartments is approximately 1:24. The reactor pressure vessel (RPV) is simulated via the steam accumulator of the Karlstein Large Valve Test Facility. This vessel provides an energy storage capacity of approximately 1/6 of the KERENA RPV and is supplied by a Benson boiler with a thermal power of 22 MW. With respect to the available power supply, the containment- and system-sizing of the facility is by far the largest one of its kind worldwide. From 2009 to 2012, several single component tests were conducted (Emergency Condenser, Containment Cooling Condenser, Core Flooding System etc.). On March 21st, 2013, the worldwide first large-scale only passively managed integral accident test of a boiling water reactor was simulated at INKA. The integral test measured the combined response of the KERENA passive safety systems to the postulated initiating event was the "Main Steam Line Break" (MSLB) inside the Containment with decay heat simulation. The results of the performed integral test (MSLB) showed that the passive safety systems alone are capable to bring the plant to stable conditions meeting all required safety targets with sufficient margins. Therefore the test verified the function of those components and the interplay between them as response to an anticipated accident scenario. The test provided evidence that the INKA is worldwide the first large scale test facility to perform integral verification tests of passive safety concepts under plant-like scaling and thermodynamic conditions. Hence, the test facility also shows that it is capable to perform containment response tests for existing Generation II BWRs (with active safety systems) and advanced (passive) reactor designs besides KERENA. These test results can be used to strengthen existing containment codes with regard to heat transfer, natural circulation, gas- and temperature stratification and others. Copyright © 2015 by JSME. [less ▲]

Detailed reference viewed: 203 (13 UL)
See detailNaturkonstanten
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 60 (3 UL)
See detailEffizienz der Pi Theorem Methodik
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 55 (2 UL)
See detailAllometrie
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 38 (3 UL)
See detailDimensionshomogenität: Erkenntnis ohne Wissen?
Unger, Jochem; Leyer, Stephan UL

Book published by Springer-Verlag (2015)

Detailed reference viewed: 114 (4 UL)
See detailMonetär-technologisches Wechselspiel
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 71 (0 UL)
See detailPi-Theorem
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 68 (2 UL)
See detailModell und Original
Unger, Jochem; Leyer, Stephan UL

in Dimensionshomogenität (2015)

Detailed reference viewed: 57 (0 UL)
See detailPassive integral LOCA accident testing at Karlstein test facility
Drescher, R.; Wagner, T.; Prasser, H.-M. et al

in International Congress on Advances in Nuclear Power Plants, ICAPP 2014 (2014), 3

KERENA is an innovative boiling water reactor concept with passive safety systems (Generation III+) of AREVA . In order to verify the functionality and performance of the concept required for the ... [more ▼]

KERENA is an innovative boiling water reactor concept with passive safety systems (Generation III+) of AREVA . In order to verify the functionality and performance of the concept required for the transient and accident management, the test facility "Integral Teststand Karlstein" (INKA) was built in Karlstein (Germany). It is a mockup of the KERENA boiling water reactor containment, with integrated pressure suppression system. The complete chain of passive safety components is available. While the scaling of the passive components and the levels match the original values, the volume scaling of the containment compartments is approximately 1:24. The reactor pressure vessel (RPV) is simulated via the steam accumulator of the Karlstein Large Valve Test Facility (GAP). This vessel provides an energy storage capacity of approximately 1/6 of the KERENA RPV and is supplied by a Benson boiler with a thermal power of 22 MW. With respect to the available power supply, the containment- and system-sizing of the facility is by far the largest one of its kind worldwide. On March 21, 2013 the worldwide first large-scale, only passively managed, integral accident test of a boiling water reactor was simulated at INKA. The integral test measured the combined response of the KERENA passive safety systems to the postulated initiating event "Main Steam Line Break" (MSLB) inside the Containment with decay heat simulation. The main goals were to show the performance and the interaction of the KERENA passive safety systems, the ability to keep the core covered, to discharge the decay heat via the appropriate pathway under all circumstances and to maintain the containment within defined limits, i.e. to bring the plant to a controlled state. The performed integral test (MSLB) was being initiated via the opening of the leak at original RPV boundary conditions (75 bar reactor pressure). The leak causes a mass and energy flow from the reactor pressure vessel into the containment. The resulting drop in the RPV water level activates the Emergency Condenser, so that an additional path for energy transfer out of the RPV in parallel to the leak is opened. The pressure increase in the containment is limited via the containment pressure suppression system (short term) and the containment cooling condensers (long term). The results of the test showed that the passive safety systems alone are capable to bring the plant to stable conditions meeting all required safety targets with sufficient margins. Therefore the test verified the function of those components and the interplay between them as response to an anticipated accident scenario. The test provided evidence that the INKA is worldwide the first large scale test facility to perform integral verification tests of passive safety concepts under plant-like scaling and thermodynamic conditions. [less ▲]

Detailed reference viewed: 137 (9 UL)
See detailPassive BWR integral LOCA testing at the Karlstein test facility INKA
Drescher, Robert; Wagner, Thomas; Leyer, Stephan UL

in ATW - Internationale Zeitschrift fuer Kernenergie (2014)

Detailed reference viewed: 64 (6 UL)