• Title/Summary/Keyword: Nuclear Science

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Development of the vapor film thickness correlation in porous corrosion deposits on the cladding in PWR

  • Yuan Shen;Zhengang Duan;Chuan Lu ;Li Ji ;Caishan Jiao ;Hongguo Hou ;Nan Chao;Meng Zhang;Yu Zhou;Yang Gao
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4798-4808
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    • 2022
  • The porous corrosion deposits (known as CRUD) adhered to the cladding have an important effect on the heat transfer from fuel rods to coolant in PWRs. The vapor film is the main constituent in the two-phase film boiling model. This paper presents a vapor film thickness correlation, associated with CRUD porosity, CRUD chimney density, CRUD particle size, CRUD thickness and heat flux. The dependences of the vapor film thickness on the various influential factors can be intuitively reflected from this vapor film thickness correlation. The temperature, pressure, and boric acid concentration distributions in CRUD can be well predicted using the two-phase film boiling model coupled with the vapor film thickness correlation. It suggests that the vapor thickness correlation can estimate the vapor film thickness more conveniently than the previously reported vapor thickness calculation methods.

Optimization of preventive maintenance of nuclear safety-class DCS based on reliability modeling

  • Peng, Hao;Wang, Yuanbing;Zhang, Xu;Hu, Qingren;Xu, Biao
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3595-3603
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    • 2022
  • Nuclear safety-class DCS is used for nuclear reactor protection function, which is one of the key facilities to ensure nuclear power plant safety, the maintenance for DCS to keep system in a high reliability is significant. In this paper, Nuclear safety-class DCS system developed by the Nuclear Power Institute of China is investigated, the model of reliability estimation considering nuclear power plant emergency trip control process is carried out using Markov transfer process. According to the System-Subgroup-Module hierarchical iteration calculation, the evolution curve of failure probability is established, and the preventive maintenance optimization strategy is constructed combining reliability numerical calculation and periodic overhaul interval of nuclear power plant, which could provide a quantitative basis for the maintenance decision of DCS system.

VIBRATION SIGNAL ANALYSIS OF MAIN COOLANT PUMP FLYWHEEL BASED ON HILBERT-HUANG TRANSFORM

  • LIU, MEIRU;XIA, HONG;SUN, LIN;LI, BIN;YANG, YANG
    • Nuclear Engineering and Technology
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    • v.47 no.2
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    • pp.219-225
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    • 2015
  • In this paper, a three-dimensional model for the dynamic analysis of a flywheel based on the finite element method is presented. The static structure analysis for the model provides stress and strain distribution cloud charts. The modal analysis provides the basis of dynamic analysis due to its ability to obtain the natural frequencies and the vibration-made vectors of the first 10 orders. The results show the main faults are attrition and cracks, while also indicating the locations and patterns of faults. The harmonic response simulation was performed to gain the vibration response of the flywheel under operation. In this paper, we present a Hilbert-Huang transform (HHT) algorithm for flywheel vibration analysis. The simulation indicated that the proposed flywheel vibration signal analysis method performs well, which means that the method can lay the foundation for the detection and diagnosis in a reactor main coolant pump.

A framework of examining the factors affecting public acceptance of nuclear power plant: Case study in Saudi Arabia

  • Salman M. Alzahrani;Anas M. Alwafi;Salman M. Alshehri
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.908-918
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    • 2023
  • The Saudi National Atomic Energy project aims to adopt peaceful nuclear technologies and be part of the country's energy mix. As emerging nuclear energy, it is essential to understand public concerns and acceptability of nuclear energy, as well as the factors influencing acceptance to develop nuclear energy policy and implement nuclear energy programs. The purpose of this study is to analyze the public attitudes and acceptance of nuclear energy among Saudi Arabian citizens by utilizing protection motivation theory and theory of planned behavior. A total of 1,404 participants answered a questionnaire which was distribute by convenience sampling approach. A Structural Equation Modeling framework was constructed and analyzed to understand public behavior toward building the country's first Nuclear Power Plant (NPP). Before analyzing the data, the model was validated. The research concluded that the benefits of nuclear power plants were essential in determining people's acceptance of NPPs. Surprisingly, the effect of the perceived benefits was found higher than the effect of the perceived risks to the acceptance. Furthermore, the public's participation in this study revealed that the NPPs location has a significant impact on their acceptance. Based on the finding, several policy implementations were suggested. Finally, the study's model results would benefit scholars, government agencies, and the business sector in Saudi Arabia and worldwide.

Exploring Science Communication of Global Issue and Suggesting its Implication in Science Education: The Cases about Nuclear Energy of Korea and Japan

  • Park, Young-Shin;Chung, Woon-Gwan;Otsuji, Hisashi
    • Journal of the Korean earth science society
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    • v.39 no.5
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    • pp.483-500
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    • 2018
  • The purpose of this study was to explore what kinds of science communication are ongoing in formal and informal settings for learning about nuclear energy, which is very important issue domestically and internationally. The researchers collected and analyzed data from science textbooks at elementary and middle school levels, from exhibitions in Y informal hall that belongs to one nuclear power plant, and from 40 bestselling books about nuclear energy in order to explore the kind of science communication. The same process was used to explore Japanese case so that we could compare the results with Korean cases and draw implications for enhancing science communication about nuclear energy. The science communication of nuclear energy in Korea included implicit and indirect content espoused in science textbooks; two opposite views displayed in bestselling books, and positive aspects mainly displayed in exhibition of information hall in nuclear power plant. It is suggested that both direct and explicit science communication along with the neutral viewpoints including positive and negative ones be provided for the public to form a good understanding of nuclear energy.

Online training and education from the VR-1 reactor-Lessons learned

  • Ondrej Novak;Tomas Bily;Ondrej Huml;Lubomir Sklenka;Filip Fejt;Jan Rataj
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4465-4471
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    • 2023
  • Hands-on education and training is a key part of fixing and developing technology knowledge and is an inherent part of many engineering and scientific curricula. However, access to large complex training facilities, such as nuclear reactor, could be limited by various factors, such as unavailability of those facilities in the region, high traveling costs or harmonization of the schedules of hands-on E&T with theoretical lectures and with the operational schedule of the facility. To handle the issue, several success stories have been reached with the introduction of the Internet Reactor Labs (IRL). The Internet Reactor Labs can strongly contribute to accessibility of training at research reactors and can contribute to improvements in their utilization. The paper describes the development of the Internet Reactor Lab at the VR-1 reactor of the Czech Technical University in Prague. Contrary to single-purpose IRLs, it presents various modalities of online teaching and training in experimental reactor physics and reactor operation in general as well as outreach activities that have been developed in recent years.

Development and validation of reactor nuclear design code CORCA-3D

  • An, Ping;Ma, Yongqiang;Xiao, Peng;Guo, Fengchen;Lu, Wei;Chai, Xiaoming
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1721-1728
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    • 2019
  • The advanced node core code CORCA-3D is one of the independent developed codes of NPIC for the nuclear reactor core design. CORCA-3D code can calculate the few-group cross section, solve the 3D diffusion equations, consider the thermal-hydraulic feedback, reconstruct the pin-by-pin power. It has lots of functions such as changing core status calculation, critical searching, control rod value calculation, coefficient calculation and so on. The main theory and functions of CORCA-3D code are introduced and validated with a lot of reactor measured data and the SCIENCE system. Now, CORCA-3D code has been applied in ACP type reactor nuclear cores design.

Digitalization as an aggregate performance in the energy transition for nuclear industry

  • Florencia de los Angeles Renteria del Toro;Chen Hao;Akira Tokuhiro;Mario Gomez-Fernandez;Armando Gomez-Torres
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1267-1276
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    • 2024
  • The emerging technologies at the industrial level have deployed rapidly within the energy transition process innovations. The nuclear industry incorporates several technologies like Artificial Intelligence (AI), Machine Learning (ML), Digital Twins, High-Performance-Computing (HPC) and Quantum Computing (QC), among others. Factors identifications are explained to set up a regulatory framework in the digitalization era, providing new capabilities paths for nuclear technologies in the forthcoming years. The Analytical Network Process (ANP) integrates the quantitative-qualitative decision-making analysis to assess the implementation of different aspects in the digital transformation for the New-Energy Transition Era (NETE) with a Nuclear Power Infrastructure Development (NPID).

Radioactive gas diffusion simulation and inhaled effective dose evaluation during nuclear decommissioning

  • Yang, Li-qun;Liu, Yong-kuo;Peng, Min-jun;Ayodeji, Abiodun;Chen, Zhi-tao;Long, Ze-yu
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.293-300
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    • 2022
  • During the decommissioning of the nuclear facilities, the radioactive gases in pressure vessels may leak due to the demolition operations. The decommissioning site has large space, slow air circulation, and many large nuclear facilities, which increase the difficulty of workers' inhalation exposure assessment. In order to dynamically evaluate the activity distribution of radionuclides and the committed effective dose from inhalation in nuclear decommissioning environment, an inhalation exposure assessment method based on the modified eddy-diffusion model and the inhaled dose conversion factor is proposed in this paper. The method takes into account the influence of building, facilities, exhaust ducts, etc. on the distribution of radioactive gases, and can evaluate the influence of radioactive gases diffusion on workers during the decommissioning of nuclear facilities.