scholarly journals VVUQ of a thermal-hydraulic multi-scale tool on unprotected loss of flow accident in SFR reactor

2021 ◽  
Vol 7 ◽  
pp. 3
Author(s):  
Nathalie Marie ◽  
Simon Li ◽  
Amandine Marrel ◽  
Michel Marquès ◽  
Sophie Bajard ◽  
...  
Keyword(s):  
Safety Assessment ◽  
Current Practice ◽  
Local Scale ◽  
Assessment Methodology ◽  
Reactor Safety ◽  
Regulatory Requirement ◽  
Multi Scale ◽  
Safety Studies ◽  
Station Blackout ◽  
Nuclear Safety Authority

Within the framework of the French 4th-generation Sodium-cooled Fast Reactor safety assessment, methodology on VVUQ (Verification, Validation, Uncertainty Quantification) is conducted to demonstrate that the CEA's thermal-hydraulic Scientific Computation Tools (SCTs) are effective and operational for design and safety studies purposes on this type of reactor. This VVUQ-based qualification is a regulatory requirement from the French Nuclear Safety Authority (NSA). In this paper, the current practice of VVUQ approach application for a SFR accidental transient is described with regard to the NSA requirements. It constitutes the first practical, progressively improvable approach. As the SCT is qualified for a given version on a given scenario, the transient related to a total unprotected station blackout has been selected. As it is a very complex multi-scale transient, the SCT MATHYS (which is a coupling of the CATHARE2 tool at system scale, TrioMC tool at component scale and TrioCFD tool at local scale) is used. This paper presents the preliminary VVUQ application to the qualification of this tool on this selected transient. In addition, this work underlines some feedback on design and R&D aspects that should be addressed in the future to improve the SCT.

Safety studies on Korean fusion DEMO plant using Integrated Safety Assessment Methodology: Part 2

2015 ◽  
Vol 98-99 ◽  
pp. 2152-2156 ◽  
Author(s):  
Kyemin Oh ◽  
Myoung-suk Kang ◽  
Gyunyoung Heo ◽  
Hyoung-chan Kim
Keyword(s):  
Safety Assessment ◽  
Assessment Methodology ◽  
Safety Studies

Safety studies on Korean fusion DEMO plant using integrated safety assessment methodology

2014 ◽  
Vol 89 (9-10) ◽  
pp. 2057-2061 ◽  
Author(s):  
Kyemin Oh ◽  
Myoung-suk Kang ◽  
Gyunyoung Heo ◽  
Hyoung-chan Kim
Keyword(s):  
Safety Assessment ◽  
Assessment Methodology ◽  
Safety Studies

Application of Integrated Safety Assessment Methodology to SBO Sequences

2013 ◽  
Author(s):  
C. Queral ◽  
L. Mena-Rosell ◽  
G. Jiménez Varas ◽  
M. Sánchez-Perea ◽  
J. Hortal ◽  
...  
Keyword(s):  
Safety Assessment ◽  
Probability Distributions ◽  
Nuclear Safety ◽  
Uncertain Parameters ◽  
Assessment Methodology ◽  
Hydraulic Analysis ◽  
Station Blackout ◽  
Thermal Hydraulic Analysis ◽  
Safety Limit ◽  
Time Density

The integrated Safety Assessment (ISA) methodology, developed by the Spanish Nuclear Safety Council (CSN), has been applied to a thermal-hydraulic analysis of PWR Station Blackout (SBO) sequences in the context of the IDPSA (Integrated Deterministic-Probabilistic Safety Assessment) network objectives. The ISA methodology allows obtaining the damage domain (the region of the uncertain parameters space where the damage limit is exceeded) for each sequence of interest as a function of the operator actuations times (recovery of AC). Given a particular safety limit or damage limit, several data of every sequence are necessary in order to obtain the exceedance frequency of that limit. In this application these data are obtained from the results of the simulations performed with MAAP code transients inside each damage domain and the time-density probability distributions of the manual actions. Several damage limits have been taken into account within the analysis: local cladding damage (PCT>1477 K); local fuel melting (T>2499 K); fuel relocation in lower plenum and vessel failure. Therefore, to every one of these damage variables corresponds a different damage domain. The results show the capability and necessity of the ISA methodology, or similar, in order to obtain accurate results that take into account time uncertainties.

PROGRESS REPORT ON FAST BREEDER REACTOR SAFETY STUDIES

1959 ◽  
Author(s):  
L.A. Beach ◽  
A.G. Pieper ◽  
M.P. Young
Keyword(s):  
Progress Report ◽  
Fast Breeder Reactor ◽  
Reactor Safety ◽  
Safety Studies

scholarly journals Multi-Scale Evaluation of the TSEB Model over a Complex Agricultural Landscape in Morocco

2020 ◽  
Vol 12 (7) ◽  
pp. 1181
Author(s):  
Jamal Elfarkh ◽  
Jamal Ezzahar ◽  
Salah Er-Raki ◽  
Vincent Simonneaux ◽  
Bouchra Ait Hssaine ◽  
...  
Keyword(s):  
Latent Heat ◽  
Complex Terrain ◽  
Large Scale ◽  
Agricultural Landscape ◽  
Local Scale ◽  
Heat Fluxes ◽  
Balance Model ◽  
Modis Data ◽  
Multi Scale ◽  
Basin Scale

An accurate assessment of evapotranspiration (ET) is crucially needed at the basin scale for studying the hydrological processes and water balance especially from upstream to downstream. In the mountains, this term is poorly understood because of various challenges, including the vegetation complexity, plant diversity, lack of available data and because the in situ direct measurement of ET is difficult in complex terrain. The main objective of this work was to investigate the potential of a Two-Source-Energy-Balance model (TSEB) driven by the Landsat and MODIS data for estimating ET over a complex mountain region. The complexity is associated with the type of the vegetation canopy as well as the changes in topography. For validating purposes, a large-aperture scintillometer (LAS) was set up over a heterogeneous transect of about 1.4 km to measure sensible (H) and latent heat (LE) fluxes. Additionally, two towers of eddy covariance (EC) systems were installed along the LAS transect. First, the model was tested at the local scale against the EC measurements using multi-scale remote sensing (MODIS and Landsat) inputs at the satellite overpasses. The obtained averaged values of the root mean square error (RMSE) and correlation coefficient (R) were about 72.4 Wm−2 and 0.79 and 82.0 Wm−2 and 0.52 for Landsat and MODIS data, respectively. Secondly, the potential of the TSEB model for evaluating the latent heat fluxes at large scale was investigated by aggregating the derived parameters from both satellites based on the LAS footprint. As for the local scale, the comparison of the latent heat fluxes simulated by TSEB driven by Landsat data performed well against those measured by the LAS (R = 0.69, RMSE = 68.0 Wm−2), while slightly more scattering was observed when MODIS products were used (R = 0.38, RMSE = 99.8 Wm−2). Based on the obtained results, it can be concluded that (1) the TSEB model can be fairly used to estimate the evapotranspiration over the mountain regions; and (2) medium- to high-resolution inputs are a better option than coarse-resolution products for describing this kind of complex terrain.

An Integrated Safety Assessment System for Near-Surface Disposal of Low- and Intermediate-Level Radioactive Waste in Korea

2003 ◽  
Author(s):  
JooWan Park ◽  
Chang-Lak Kim ◽  
Jin Beak Park ◽  
Eun Yong Lee ◽  
Youn Myoung Lee ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Safety Assessment ◽  
Assessment System ◽  
Intermediate Level ◽  
Radioactive Waste Disposal ◽  
System Level ◽  
Assessment Methodology ◽  
Regulatory Requirements ◽  
Near Surface ◽  
Intermediate Level Radioactive Waste

An integrated safety assessment system to be used for evaluation of near-surface disposal concept has been developed within the framework of safety assessment methodology taken for low- and intermediate-level radioactive waste disposal in Korea. It is to provide an evaluation of the safety of the disposal system in a clear, comprehensive and well-documented manner, and to integrate the results into a defensible package showing reasonable assurance of compliance with regulatory requirements for licensing application. This system is made up of two key components, a system-level safety assessment code and an input database/quality assurance module for safety assessment, which both are interfaced with each other.

Hybrid Probabilistic and Possibilistic Safety Assessment: Methodology and Application

2001 ◽  
Author(s):  
Kazuyuki Kato ◽  
Osamu Amano ◽  
Takao Ikeda ◽  
Hideji Yoshida ◽  
Hiroyasu Takase
Keyword(s):  
Safety Assessment ◽  
System Development ◽  
Probability Density Functions ◽  
Density Functions ◽  
Data Sets ◽  
Assessment Methodology ◽  
Membership Functions ◽  
Fuzzy Membership Functions ◽  
High Level ◽  
Support Decision Making

Abstract This paper presents a unified methodology to handle variability and ignorance by using probabilistic and possibilistic techniques respectively. The methodology has been applied to the safety assessment of geological disposal of high level radioactive waste. Ignorances associated with scenarios, models and parameters were defined in terms of fuzzy membership functions derived through a series of interviews to the experts, while variability was formulated by means of probability density functions (pdfs) based on available data sets. The exercise demonstrated the applicability of the new methodology and, in particular, its advantage in quantifying ignorances based on expert opinion and in providing information on the dependence of assessment results on the level of conservatism. In addition, it was shown that sensitivity analysis can identify key parameters contributing to uncertainties associated with results of the overall assessment. The information mentioned above can be utilized to support decision making and to guide the process of disposal system development and optimization of protection against potential exposure.

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