The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Emmanuel Porcheron - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical approaches of aerosol removal in spray conditions for containment application
Nuclear Engineering and Design, 2010Co-Authors: Emmanuel Porcheron, Pascal Lemaitre, Denis Marchand, William Plumecocq, Amandine Nuboer, Jacques VendelAbstract:TOSQAN is an experimental program undertaken by the Institut de Radioprotection et de Surete Nucleaire (IRSN) in order to perform thermal hydraulic containment studies. The TOSQAN facility is a large enclosure devoted to simulate typical accidental thermal hydraulic flow conditions in Nuclear pressurized water reactor (PWR) containment. The TOSQAN facility, which is highly instrumented with non-intrusive optical diagnostics, is particularly adapted to Nuclear Safety code validation. The present work is devoted to study a water spray injection used as a mitigation means in order to washout aerosol fission products.
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the tonus cfd code for hydrogen risk analysis physical models numerical schemes and validation matrix
Nuclear Engineering and Design, 2008Co-Authors: S Kudriakov, F Dabbene, E Studer, A Beccantini, J P Magnaud, H Paillere, A Bentaib, A Bleyer, J Malet, Emmanuel PorcheronAbstract:The French Atomic Energy Commission (CEA) and the Radiation protection and Nuclear Safety Institute (IRSN) are developing a hydrogen risk analysis code (Safety code) which incorporates both lumped parameter (LP) and computational fluid dynamics (CFD) formulations. In this paper we present the governing equations, numerical strategy and schemes used for the CFD approach. Typical numerical studies will be presented for hydrogen distribution and combustion applications in realistic large geometries.
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development of a global rainbow refractometry technique to measure the temperature of spray droplets in a large containment vessel
Measurement Science and Technology, 2006Co-Authors: Pascal Lemaitre, Emmanuel Porcheron, Gerard Grehan, Laurent BouillouxAbstract:In order to study the heat and mass transfers between a spray of droplets and the atmosphere in thermal-hydraulics conditions representative of a severe accident in a Pressurized Water Nuclear Reactor, the French Institute for Radioprotection and Nuclear Safety (IRSN) developed the TOSQAN facility. The present paper presents the development and the quantification of an optical diagnostic, global rainbow refractometry, in order to measure falling droplet temperature.
Sunil S Chirayath - One of the best experts on this subject based on the ideXlab platform.
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combined Nuclear Safety security risk analysis methodology development and demonstration through a case study
Progress in Nuclear Energy, 2018Co-Authors: Mohammad A Hawila, Sunil S ChirayathAbstract:Abstract Destruction of critical Nuclear infrastructure would have a debilitating effect on national public health, Safety, national economy and security. For this reason, analysts perform Safety risk analyses on the performance of the Nuclear system to quantify and understand the nature of unwanted events. Since the world has gone through many changes after the terrorist attacks of 9/11, Nuclear security risk analysis also became a necessity. To date, the Safety and security risk analyses have been done separately without a combined evaluation. Study results are presented for three types of risk analyses for a pure security initiating event, pure Safety initiating event, and a combined analysis of Safety-security risk for either a security or Safety initiating event. The pure security risk analysis uses adversary sequence diagram and pathway analysis to calculate the initiating security event frequency of a successful adversary attack. The pure Safety analysis represented a series of natural (random) Safety system component failure events for which a Safety system failure frequency was calculated using SAPHIRE probabilistic risk analysis code. On the other hand, the combined Safety-security analysis considered a security initiating event followed by Safety system failure or vice versa. The main outcome of the comparative study of three different types of risk analyses is that pure Safety risk evaluation without considering the possibility of a simultaneous security attack would underestimate the risk value. Failure frequency due to a security event should be combined with the Safety system failure analysis for a meaningful risk analysis and the Estimate of Adversary Sequence Interruption (EASI) model can be employed for this purpose. The usefulness of a combined Safety-security risk analysis is demonstrated through a case study for the spent fuel storage pool facility.
Fuesang Lien - One of the best experts on this subject based on the ideXlab platform.
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extension of staggered grid based ausm family schemes for use in Nuclear Safety analysis codes
International Journal of Multiphase Flow, 2017Co-Authors: Qiulan Zeng, Nusret Ugurhan Aydemir, Fuesang LienAbstract:Abstract To overcome the numerical difficulties of the density-based method for low-Mach-number two-phase flow, this paper adopts the AUSM + and AUSMDV schemes based on a staggered-grid arrangement. The water faucet, air-water shock tube, oscillating manometer and air-water phase separation problems are used as benchmark tests to validate the implementation of the generic four-equation two-fluid model. The present results reveal the advantages of using staggered-grid-based AUSM + and AUSMDV schemes over the collocated-grid-based counterpart. With a staggered-grid arrangement, odd-even decoupling issues can be avoided. Thus, no sound speed scaling or additional diffusion terms are needed when using AUSM + and AUSMDV schemes for low-Mach-number two-phase flow. Furthermore, since the pressure and void fraction are already stored at the interface of the velocity control volume, no interpolation of interfacial pressure is needed for momentum equations. Finally, this study will help integrate AUSM + and AUSMDV schemes into staggered-grid-based thermal hydraulic codes, e.g. CATHENA, used in the Nuclear industry. Moreover, to tackle the stiffness issues in relation to phase appearance and disappearance, we propose a new staggered-grid-based scheme referred to as AUSMFVS, which combines the accuracy of AUSM + and the stability of FVS.
Stephen M Bowman - One of the best experts on this subject based on the ideXlab platform.
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scale 6 comprehensive Nuclear Safety analysis code system
Nuclear Technology, 2011Co-Authors: Stephen M BowmanAbstract:Version 6 of the Standardized Computer Analyses for Licensing Evaluation (SCALE) computer software system developed at Oak Ridge National Laboratory, released in February 2009, contains significant new capabilities and data for Nuclear Safety analysis and marks an important update for this software package, which is used worldwide. This paper highlights the capabilities of the SCALE system, including continuous-energy flux calculations for processing multigroup problem-dependent cross sections, ENDF/B-VII continuous-energy and multigroup Nuclear cross-section data, continuous-energy Monte Carlo criticality Safety calculations, Monte Carlo radiation shielding analyses with automated three-dimensional variance reduction techniques, one- and three-dimensional sensitivity and uncertainty analyses for criticality Safety evaluations, two- and three-dimensional lattice physics depletion analyses, fast and accurate source terms and decay heat calculations, automated burnup credit analyses with loading curve search, and integrated three-dimensional criticality accident alarm system analyses using coupled Monte Carlo criticality and shielding calculations.
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scale 6 comprehensive Nuclear Safety analysis code system
Nuclear Technology, 2011Co-Authors: Stephen M BowmanAbstract:Version 6 of the Standardized Computer Analyses for Licensing Evaluation (SCALE) computer software system developed at Oak Ridge National Laboratory, released in February 2009, contains significant...
Mohammad A Hawila - One of the best experts on this subject based on the ideXlab platform.
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combined Nuclear Safety security risk analysis methodology development and demonstration through a case study
Progress in Nuclear Energy, 2018Co-Authors: Mohammad A Hawila, Sunil S ChirayathAbstract:Abstract Destruction of critical Nuclear infrastructure would have a debilitating effect on national public health, Safety, national economy and security. For this reason, analysts perform Safety risk analyses on the performance of the Nuclear system to quantify and understand the nature of unwanted events. Since the world has gone through many changes after the terrorist attacks of 9/11, Nuclear security risk analysis also became a necessity. To date, the Safety and security risk analyses have been done separately without a combined evaluation. Study results are presented for three types of risk analyses for a pure security initiating event, pure Safety initiating event, and a combined analysis of Safety-security risk for either a security or Safety initiating event. The pure security risk analysis uses adversary sequence diagram and pathway analysis to calculate the initiating security event frequency of a successful adversary attack. The pure Safety analysis represented a series of natural (random) Safety system component failure events for which a Safety system failure frequency was calculated using SAPHIRE probabilistic risk analysis code. On the other hand, the combined Safety-security analysis considered a security initiating event followed by Safety system failure or vice versa. The main outcome of the comparative study of three different types of risk analyses is that pure Safety risk evaluation without considering the possibility of a simultaneous security attack would underestimate the risk value. Failure frequency due to a security event should be combined with the Safety system failure analysis for a meaningful risk analysis and the Estimate of Adversary Sequence Interruption (EASI) model can be employed for this purpose. The usefulness of a combined Safety-security risk analysis is demonstrated through a case study for the spent fuel storage pool facility.
