Stand-Alone Containment Analysis of the PHÉBUS FPT-1 Test With the ASTEC and the MELCOR Codes

2016 ◽  
Author(s):  
Bruno Gonfiotti ◽  
Sandro Paci
Keyword(s):  
State Of The Art ◽  
External Environment ◽  
Fission Products ◽  
Severe Accident ◽  
Sensitivity Analyses ◽  
Complex Task ◽  
Primary Coolant ◽  
Control Volumes ◽  
Coolant System

The estimation of Fission Products (FPs) release from the containment system of a nuclear plant to the external environment during a Severe Accident (SA) is a quite complex task. In the last 30–40 years several efforts were made to understand and to investigate the different phenomena occurring in such a kind of accidents in the primary coolant system and in the containment. These researches moved along two tracks: understanding of involved phenomenologies through the execution of different experiments, and creation of numerical codes capable to simulate such phenomena. These codes are continuously developed to reflect the actual SA state-of-the-art, but it is necessary to continuously check that modifications and improvements are able to increase the quality of the obtained results. For this purpose, a continuous verification and validation work should be carried out. Therefore, the aim of the present work is to re-analyze the Phébus FPT-1 test employing the ASTEC (F) and MELCOR (USA) codes. The analysis focuses on the stand-alone containment aspects of the test, and three different modellisations of the containment vessel have been developed showing that at least 15/20 Control Volumes (CVs) are necessary for the spatial schematization to correctly predict thermal-hydraulics and the aerosol behavior. Furthermore, the paper summarizes the main thermal-hydraulic results, and presents different sensitivity analyses carried out on the aerosols and FPs behavior.

Stand-Alone Containment Analysis of the Phébus Fission Products Test 1 With the ASTEC and the MELCOR Codes

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Bruno Gonfiotti ◽  
Sandro Paci
Keyword(s):  
Source Term ◽  
State Of The Art ◽  
Fission Products ◽  
Severe Accident ◽  
Sensitivity Analyses ◽  
Primary Coolant ◽  
Term Evaluation ◽  
Control Volumes ◽  
Coolant System

The estimation of fission products (FPs) release from the containment system of a nuclear plant to the external environment during a severe accident (SA) is a quite complex task. In the last 30–40 yr, several efforts were made to understand and to investigate the different phenomena occurring in such a kind of accidents in the primary coolant system and in the containment. These researches moved along two tracks: understanding of involved phenomenologies through the execution of different experiments and creation of numerical codes capable to simulate such phenomena. These codes are continuously developed to reflect the actual SA state of the art, but it is necessary to continuously check that modifications and improvements are able to increase the quality of the obtained results. For this purpose, also a continuous verification and validation work should be carried out. Therefore, the aim of the present work is to re-analyze the Phébus fission products test 1 (FPT-1) test employing the accident source term evaluation code (ASTEC) and MELCOR codes (respectively, ASTEC v.2.0 revision 3 patch 3 and MELCOR V2.1.6840 version). The analysis focuses on the stand-alone containment aspects of the test, and three different modelizations of the containment vessel have been developed showing that at least 15/20 control volumes (CVs) are necessary for the spatial schematization to correctly predict the test thermal hydraulics and the aerosol behavior. Furthermore, the paper summarizes the main thermal-hydraulic results and presents different sensitivity analyses carried out on the aerosols and FPs behavior.

scholarly journals Stand-Alone Containment Analysis of the Phébus FPT Tests with the ASTEC and the MELCOR Codes: The FPT-0 Test

2017 ◽  
Vol 2017 ◽  
pp. 1-25 ◽  
Author(s):  
Bruno Gonfiotti ◽  
Sandro Paci
Keyword(s):  
Fission Products ◽  
Severe Accident ◽  
Sensitivity Analyses ◽  
Light Water Reactors ◽  
Control Rod ◽  
Light Water ◽  
Severe Accidents ◽  
Fuel Bundle ◽  
Water Reactors

The integral Phébus tests were probably one of the most important experimental campaigns performed to investigate the progression of severe accidents in light water reactors. In these tests, the degradation of a PWR fuel bundle was investigated employing different control rod materials and burn-up levels in strongly or weakly oxidizing conditions. From the results of such tests, numerical codes such as ASTEC and MELCOR have been developed to describe the evolution of a severe accident. After the termination of the experimental Phébus campaign, these two codes were furthermore expanded. Therefore, the aim of the present work is to reanalyze the first Phébus test (FPT-0) employing the updated ASTEC and MELCOR versions to ensure that the new improvements introduced in such codes allow also a better prediction of these Phébus tests. The analysis focuses on the stand-alone containment aspects of this test, and the paper summarizes the main thermal-hydraulic results and presents different sensitivity analyses carried out on the aerosols and fission products behavior. This paper is part of a series of publications covering the four executed Phébus tests employing a solid PWR fuel bundle: FPT-0, FPT-1, FPT-2, and FPT-3.

Data science in economics: comprehensive review of advanced machine learning and deep learning methods

2020 ◽  
Author(s):  
Saeed Nosratabadi ◽  
Amir Mosavi ◽  
Puhong Duan ◽  
Pedram Ghamisi ◽  
Ferdinand Filip ◽  
...  
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Data Science ◽  
State Of The Art ◽  
Science Methods ◽  
Learning Models ◽  
Diverse Range ◽  
Hybrid Machine ◽  
Economics Research

This paper provides a state-of-the-art investigation of advances in data science in emerging economic applications. The analysis was performed on novel data science methods in four individual classes of deep learning models, hybrid deep learning models, hybrid machine learning, and ensemble models. Application domains include a wide and diverse range of economics research from the stock market, marketing, and e-commerce to corporate banking and cryptocurrency. Prisma method, a systematic literature review methodology, was used to ensure the quality of the survey. The findings reveal that the trends follow the advancement of hybrid models, which, based on the accuracy metric, outperform other learning algorithms. It is further expected that the trends will converge toward the advancements of sophisticated hybrid deep learning models.

State-of-the-Art: A Systematic Literature Review on Image Segmentation in Latent Fingerprint Forensics

2019 ◽  
Vol 12 ◽  
Author(s):  
Megha Chhabra ◽  
Manoj Kumar Shukla ◽  
Kiran Kumar Ravulakollu
Keyword(s):  
Image Segmentation ◽  
Background Noise ◽  
State Of The Art ◽  
Recognition Rate ◽  
Poor Quality ◽  
Latent Fingerprint ◽  
In The Beginning ◽  
The Comparative Study ◽  
Finger Skin

: Latent fingerprints are unintentional finger skin impressions left as ridge patterns at crime scenes. A major challenge in latent fingerprint forensics is the poor quality of the lifted image from the crime scene. Forensics investigators are in permanent search of novel outbreaks of the effective technologies to capture and process low quality image. The accuracy of the results depends upon the quality of the image captured in the beginning, metrics used to assess the quality and thereafter level of enhancement required. The low quality of the image collected by low quality scanners, unstructured background noise, poor ridge quality, overlapping structured noise result in detection of false minutiae and hence reduce the recognition rate. Traditionally, Image segmentation and enhancement is partially done manually using help of highly skilled experts. Using automated systems for this work, differently challenging quality of images can be investigated faster. This survey amplifies the comparative study of various segmentation techniques available for latent fingerprint forensics.

Thermodynamic Data of Iodine Reactions Calculated by Quantum Chemistry. Training Set of Molecules

2008 ◽  
Vol 73 (10) ◽  
pp. 1340-1356 ◽  
Author(s):  
Katarína Mečiarová ◽  
Laurent Cantrel ◽  
Ivan Černušák
Keyword(s):  
Quantum Chemistry ◽  
Ab Initio ◽  
Thermodynamic Data ◽  
Theoretical Calculations ◽  
Reactor Core ◽  
Fission Products ◽  
Vapour Phase ◽  
Reactor Accident ◽  
Training Set ◽  
Coolant System

This paper focuses on the reactivity of iodine which is the most critical radioactive contaminant with potential short-term radiological consequences to the environment. The radiological risk assessments of 131I volatile fission products rely on studies of the vapour-phase chemical reactions proceeding in the reactor coolant system (RCS), whose function is transferring the energy from the reactor core to a secondary pressurised water line via the steam generator. Iodine is a fission product of major importance in any reactor accident because numerous volatile iodine species exist under reactor containment conditions. In this work, the comparison of the thermodynamic data obtained from the experimental measurements and theoretical calculations (approaching "chemical accuracy") is presented. Ab initio quantum chemistry methods, combined with a standard statistical-thermodynamical treatment and followed by inclusion of small energetic corrections (approximating full configuration interaction and spin-orbit effects) are used to calculate the spectroscopic and thermodynamic properties of molecules containing atoms H, O and I. The set of molecules and reactions serves as a benchmark for future studies. The results for this training set are compared with reference values coming from an established thermodynamic database. The computed results are promising enough to go on performing ab initio calculations in order to predict thermo-kinetic parameters of other reactions involving iodine-containing species.

scholarly journals Revisiting the Analysis of the Isochronous Mass Measurements of Uranium Fission Fragments at the ESR

2020 ◽  
Vol 227 ◽  
pp. 02012
Author(s):  
R. S. Sidhu ◽  
R. J. Chen ◽  
Yu. A Litvinov ◽  
Y. H. Zhang ◽  
Keyword(s):  
Experimental Data ◽  
Data Analysis ◽  
State Of The Art ◽  
Fission Products ◽  
Mass Measurements ◽  
Fission Fragments ◽  
Uranium Fission

The re-analysis of experimental data on mass measurements of ura- nium fission products obtained at the ESR in 2002 is discussed. State-of-the-art data analysis procedures developed for such measurements are employed.

scholarly journals Effective coverage and budget implications of skill-mix change to improve neonatal nursing care: an explorative simulation study in Kenya

2019 ◽  
Vol 4 (6) ◽  
pp. e001817 ◽  
Author(s):  
Apostolos Tsiachristas ◽  
David Gathara ◽  
Jalemba Aluvaala ◽  
Timothy Chege ◽  
Edwine Barasa ◽  
...  
Keyword(s):  
Quality Of Care ◽  
Neonatal Mortality ◽  
Nursing Care ◽  
Public Hospitals ◽  
Sensitivity Analyses ◽  
Full Time ◽  
Skill Mix ◽  
Neonatal Nursing ◽  
Low Middle Income Countries

IntroductionNeonatal mortality is an urgent policy priority to improve global population health and reduce health inequality. As health systems in Kenya and elsewhere seek to tackle increased neonatal mortality by improving the quality of care, one option is to train and employ neonatal healthcare assistants (NHCAs) to support professional nurses by taking up low-skill tasks.MethodsMonte-Carlo simulation was performed to estimate the potential impact of introducing NHCAs in neonatal nursing care in four public hospitals in Nairobi on effectively treated newborns and staff costs over a period of 10 years. The simulation was informed by data from 3 workshops with >10 stakeholders each, hospital records and scientific literature. Two univariate sensitivity analyses were performed to further address uncertainty.ResultsStakeholders perceived that 49% of a nurse full-time equivalent could be safely delegated to NHCAs in standard care, 31% in intermediate care and 20% in intensive care. A skill-mix with nurses and NHCAs would require ~2.6 billionKenyan Shillings (KES) (US$26 million) to provide quality care to 58% of all newborns in need (ie, current level of coverage in Nairobi) over a period of 10 years. This skill-mix configuration would require ~6 billion KES (US$61 million) to provide quality of care to almost all newborns in need over 10 years.ConclusionChanging skill-mix in hospital care by introducing NHCAs may be an affordable way to reduce neonatal mortality in low/middle-income countries. This option should be considered in ongoing policy discussions and supported by further evidence.

UBAR

2021 ◽  
Vol 20 (3) ◽  
pp. 1-25
Author(s):  
Elham Shamsa ◽  
Alma Pröbstl ◽  
Nima TaheriNejad ◽  
Anil Kanduri ◽  
Samarjit Chakraborty ◽  
...  
Keyword(s):  
Resource Management ◽  
Quality Of Experience ◽  
State Of The Art ◽  
State Of Charge ◽  
User Preference ◽  
Management Approach ◽  
High Quality ◽  
Trade Off ◽  
Run Time

Smartphone users require high Battery Cycle Life (BCL) and high Quality of Experience (QoE) during their usage. These two objectives can be conflicting based on the user preference at run-time. Finding the best trade-off between QoE and BCL requires an intelligent resource management approach that considers and learns user preference at run-time. Current approaches focus on one of these two objectives and neglect the other, limiting their efficiency in meeting users’ needs. In this article, we present UBAR, User- and Battery-aware Resource management, which considers dynamic workload, user preference, and user plug-in/out pattern at run-time to provide a suitable trade-off between BCL and QoE. UBAR personalizes this trade-off by learning the user’s habits and using that to satisfy QoE, while considering battery temperature and State of Charge (SOC) pattern to maximize BCL. The evaluation results show that UBAR achieves 10% to 40% improvement compared to the existing state-of-the-art approaches.

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