bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary Research on Digital Twin of Main Thermodynamic Systems in Nuclear Power Plant for Thermal Performance Monitoring
Authors: Zhang Xun , Hou Jianfei , Zimmermann Heino , Xiang Zhaohui 
Published: November 2022

Abstract
The performance degradation and latent fault of equipment may cause unplanned outage or power reduction in nuclear power plant, as a result, the operation and maintenance costs increase. By developing a nuclear power plant digital twin, some potential abnormalities can be detected and predictive maintenance can be performed to avoid equipment failure. So, a digital twin for main thermodynamic systems in an operating nuclear power plant is built by using EPOS code to monitor its thermal performance. Firstly, a thermodynamic system simulation model containing primary loop, secondary loop and cooling system is developed according to design documents, and the design parameters under full load are used to calculate all the equipment’s nominal values. Then the thermal performance of specific equipment is identified under partial loads. Some fitting process are needed to find the correlations between different variables and the fitting curves will be embedded into the equipment model if necessary. Moreover, a data reconciliation technique is used to assimilate the system model depending on measurements of operating nuclear power plant and the digital twin is gained at last. The result shows that the digital twin can represent the thermal performance of real plant very well although a few of measure inconsistencies are detected during the data reconciliation process.
Research on Standardization System of Smart Site for Nuclear Power Plant Construction
Authors: Ren Changchun , Wu Gang 
Published: November 2022

Abstract
Beginning with the study of the engineering characteristics of nuclear power plant construction and the development situation of smart site of construction at home and abroad, this paper clearly puts forward the necessity and urgency of developing smart site standardization system in the field of nuclear power plant engineering. This paper researches the application scenarios of information technologies such as Internet of Things, 5G, Big Data and AI in the field of engineering construction, and systematically expounds the business architecture, functional architecture, technical architecture and data architecture of smart site of construction. By analyzing the specific requirements of each participant of the nuclear power plant construction on the vision, business objectives, functional requirements and information security constraints of the smart site, this paper researches and puts forward the standardized architecture of the smart site network infrastructure and information system consistent with the field of nuclear power plant construction, and focuses on the systematical framework and core contents of the General Technical Requirements, and the On-Site Implementation Guidelines, and the Construction & Operation Management Specifications, of the smart site information platform for nuclear power plant construction. The purpose of this paper is to provide a standardized system construction idea for all participants in the nuclear power plant construction to carry out digital transformation in the new round of nuclear power construction opportunity period.
Study of Effective Isolation Technology of Main Feedwater
Authors: Zhao Jiaming , Fang Liqiang , Ding Liang 
Published: November 2022

Abstract
This paper presents an effective isolation technology of main feed water including three sets of main feed water isolation devices for some nuclear power plant, and then model and calculate the whole feed water system using the commercial software “PIPENET”, including feed water hammer simulation, calculating the possible conditions of different isolation valves closing including one valve closing, two valves closing and three valves closing. Besides the special design for hydropneumatic type isolation valve having two sets of actuators is to ensure the availability of hydropneumatic type isolation valve during losing of power. However, the closing time of the valve is within a range, including the normal closing time and the unusual closing time during losing of power, which should be considered and designed by water hammer simulating and accident analysis. The final closing time of hydropneumatic type isolation valve is 6–12s. The effective isolation technology resolves the effective isolation of main feed water, reduces the risk of temperature and pressure exceeding of containment, ensures the tightness of containment, prevents the releasing of the radioactive substance during the occurring of main steam pipe break (MSLB) plus safety shutdown earthquake (SSE). Besides, when the steam generator rupture occurring, it can prevent the overflow of steam generator, the isolated accidental steam generator will not release a large amount of radioactive substance to environment. In addition, when the feed water rupture occurring, the accidental steam generator can be isolated; when there is accident in the feed water control, the relevant feed water can be isolated and the steam generator will not be overflowed. The effective isolation technology has great significance for reliability operation and safe operation of nuclear power plant.
Development and Application of a Real-Time Visualization and Simulation Platform Based on the Generic Platform Interface ICoCo and the Qt Framework
Authors: Shen Yanyi , Chen Hongli , Ding Tao , Liu Tianyi , Tang Junjie 
Published: November 2022

Abstract
It is of necessity and importance for the development of a real-time visualization and simulation platform for the lead-cooled fast reactor in order to provide a better learning and research platform for technicians. In this research, a visualization platform for the primary loop system of medium-sized modular lead-cooled fast reactor M2LFR-1000 has been developed based on Generic Platform Interface ICoCo and Qt framework, relying on the system code Relap5. The simulation code used in the visualization platform is first wrapped by the generic platform interface ICoCo (Interface for Code Coupling) and then compiled to a shared library. A multithreading C++ script is developed as the supervisor, which supervises the system code Relap5 and realizes the control of real-time simulation. The graphical man-machine interface of the platform is developed by a set of UI elements provided by Qt Widgets Module. The communication between simulation code and GUI is performed with the signals and slots mechanism, which requires a Qt’s C++ extension developed as the meta-object compiler (moc). Via the actual operation by the visualization and simulation platform, the results verify that the platform can realize the real-time simulation and control of the primary loop system of M2LFR-1000 and provide a practical means of real-time monitoring and regulation of reactor operations for technicians.
Preliminary Core Calculation on Reactivity Compensation for SiC Matrix Fuel Compact HTTR With Erbium Burnable Poison and Plutonium Fissile Material
Authors: Nishimura Yosuke , Allaf Mohammad Amer , Okita Shoichiro , Goto Minoru , Okamoto Koji 
Published: November 2022

Abstract
Proposed higher power density HTGR by removing the graphite sleeve and implementing the SiC matrix fuel compact has neutronics problem on criticality. Present study selected Er burnable poison and Pu fissile material as possible candidate to compensate the reactivity. To ensure core performance of HTTR modeled reactors, the various tests were carried out using Serpent 2 code, and nuclear characteristic data were obtained successfully. The obtained results verified the expected characteristics. It was demonstrated that both Er and Pu solved criticality issue. Furthermore, especially Pu-loaded core showed better burn-up performance compared to current HTGR. One possible option that proposed reactor can also burn Pu safely based on the concept of small-Clean Burn-HTGR was concluded.
Study on the Manufacturing Process of Large Super Alloy X-750 Forgings for Nuclear Equipment
Authors: Chen Mei-fang , Cao Sheng-qiang , Dong Kai 
Published: November 2022

Abstract
X-750 is a nickel-chromium based super alloy with high strength, high toughness, excellent creep resistance and good stress relaxation resistance at high temperature. It can be used in the manufacture of holddown springs for reactor vessel internals (RVI). Because of high content of alloying elements and the large size of ingot for the RVI holddown spring, observations by optical microscopy (OM) and scanning electron microscopy (SEM) showed that there was obvious dendrite segregation and serious carbonitride net in the as-cast electroslag remelting (ESR) ingot. Before forging, homogenization treatment was carried out for the ESR ingot to reduce element segregation, and promote the secondary carbonitrides dissolve into the alloy, which could significantly improve the malleability of the billet and reduce forging cracks. The homogenization process adopted in this study was annealing at 1220°C for 70 hours. In addition, the final forging temperature also played a key role in the control of formability of the billet and grain size of the forging. The carbonitrides or grain size of both the as-cast and forged samples annealed at 900°C∼1200°C for 10h were observed, and also charpy impact tests were carried out on the forged and annealed samples. The results showed that the final forging temperature for upsetting and drawing process should be no less than 1100°C, and the final forging temperature for forming process could be reduced to 1000°C. After solution and aging treatment, the comprehensive mechanical properties of the forging were excellent, with KV impact value at room temperature as high as 92J, yield strength of tensile test at 350°C up to 696MPa, and tensile strength up to 1019MPa.
Energy Analysis and Parametric Study of Hydrogen and Electricity Co-Production System Coupled With a Very-High-Temperature Gas-Cooled Reactor
Authors: Ni Hang , Qu Xinhe , Zhao Gang , Zhang Ping , Peng Wei 
Published: November 2022

Abstract
Hydrogen is an important clean alternative energy resource for the future, and nuclear hydrogen production can efficiently produce carbon-free hydrogen on a large scale. In this study, a hydrogen and electricity co-production system coupling iodine-sulfur cycle with a very-high-temperature gas-cooled reactor is proposed. The helium on the secondary side of the intermediate heat exchanger provides high-grade heat for the sulfuric acid decomposition reactor and hydroiodic acid decomposition reactor, and the steam extracted from the power generation circuit provides low-grade heat for other hydrogen production components. A supercritical steam generator is used and a reheating section is designed to improve power generation efficiency. The energy analysis reveals that as the hydrogen production rate increases, the power generation efficiency decreases, whereas the overall hydrogen and electricity efficiency increases. The power generation efficiency and overall hydrogen and electricity efficiency of the system are 38.2 % and 45.5 % at a hydrogen production rate of 161.73 mol/s. The parametric study shows that the power generation efficiency and overall hydrogen and electricity efficiency of the system increase with an increase in the main steam temperature or main steam pressure, and decrease with an increase in the reheated steam pressure. Among the three parameters, the main steam temperature markedly affects the performance of the system, followed by the reheated steam pressure and main steam pressure.
Analysis of Reliability and Life of Fission Ionization Chamber of Nuclear Instrumentation System (NIS)
Authors: Zhou Yulin , Qiu Shunli , Ge Mengtuan , Sun Guangzhi , Xiao Wei , Liu Haifeng 
Published: November 2022

Abstract
Fission ionization chamber of Nuclear Instrumentation System (NIS) is an essential equipment for the nuclear power plant. By measuring the neutron fluence rate in the immediate range (IR), the power level of the reactor can be determined. In order to ensure its performance to get accurate measurement results, the reliability and aging degree should be analyzed so that we can replace the fission ionization chamber before it expires. In this paper, the aging mechanism of NIS fission ionization chamber is analyzed and calculated from four aspects: moderator degradation, irradiation damage, sensitive uranium plating loss and detector working gas loss. The calculation model is the fission ionization chamber developed by our institute. As the results indicated, moderator degradation and irradiation damage of neutrons cause tiny effect of detector performance. The uranium plating loss caused by neutron reaction leads to 2% detector sensitivity decrease when irradiation time reaches 45.8 years. The working gas loss leads to less than 2% detector sensitivity decrease in 146.4 years if the gas leakage is highly controlled. Furthermore, the mean time between failure (MTBF) is analyzed and calculated. This research provides detailed analysis and methods to determine the reliability and life of NIS fission ionization chamber. And the results indicated that the detector developed by our institute has high reliability to apply in the cruel environment outside the reactor.
Anomalies Detection in Structures, System and Components for Supporting Nuclear Long Term Operation Program
Authors: Cancemi Salvatore Angelo , Lo Frano Rosa 
Published: November 2022

Abstract
Long Term Operation (LTO) of nuclear power plants (NPPs) will play a key role to reach net zero target. Monitoring and predictive approach detecting in advance faulty SCCs conditions may provide a further key tool in LTO framework. Detecting anomalies may allow the transition from time-based to condition-based predictive maintenance of the NNPs. Predictive algorithms could reduce the number of unplanned outages caused by reactor system failures (one-day outage of a 1000-MW NPPs causes losses of about 500 k$), improving the capacity factor, and keeping high safety margin level of NPPs. To this end, innovative approach by unsupervised machine learning technique (ML) is proposed to detect anomalies of SSCs. Based on principal component analysis and mahalanobis distance is possible to detect in advance the failure of the components. To the purpose a 2D digital twin of primary nuclear pipe under nominal conditions (inner temperature of 300° and an internal pressure of 15.5 MPa) is implemented in finite element code to provide a dataset for unsupervised ML code. The algorithm is then tested under anomaly pattern that deviate from nominal conditions. The results show good code prediction capabilities anticipating the pipe failure. Traditional monitoring combined with ML technique may support LTO program increasing the safety and competitiveness of NPPs.
Research on the Correlations of Fission Source Distribution in the Monte Carlo Algorithm Using Mathematical Tools
Authors: Shen Pengfei , Jiang Shihang , Hu Yingzhe , Wang Kan 
Published: November 2022

Abstract
In the Monte Carlo algorithm, the power iteration method is commonly used to obtain the Fission Neutron Bank of each cycle. This method uses the offspring produced by the neutrons of the previous cycle as the next cycle’s fission neutron bank. Thus, there is physical continuity between the adjacent cycle’s fission source distributions (FSD). This physical continuity of this process will lead to the mathematical correlation of fission source distributions. We extensively investigate the correlation of fission source distributions using mathematical approaches. We analyzed the correlations of the FSD with different geometric scales and the adjacent number of cycles. The results show that the correlations between two fission source distributions decline with the adjacent cycle number increases. The miniature models would take dozes of cycles for the correlations to decline to be negligible, while the standard reactor core model would use around 500 cycles to decline. These correlations should be carefully removed if a non-bias Monte Carlo calculation is carried out. In the BEAVRS core model, the correlations would result in around 80 percent underestimating the variance for the flux tally of assemblies. These methods can be easily implemented in the standard Monte Carlo codes.
Fully rubbery Schottky diode and integrated devices
Authors: Jang Seonmin , Shim Hyunseok , Yu Cunjiang 
Published: November 2022

A fully rubbery stretchable diode, particularly entirely based on stretchy materials, is a crucial device for stretchable integrated electronics in a wide range of applications, ranging from energy to biomedical, to integrated circuits, and to robotics. However, its development has been very nascent. Here, we report a fully rubbery Schottky diode constructed all based on stretchable electronic materials, including a liquid metal cathode, a rubbery semiconductor, and a stretchable anode. The rubbery Schottky diode exhibited a forward current density of 6.99 × 10
−3
A/cm
2
at 5 V and a rectification ratio of 8.37 × 10
4
at ±5 V. Stretchy rectifiers and logic gates based on the rubbery Schottky diodes were developed and could retain their electrical performance even under 30% tensile stretching. With the rubbery diodes, fully rubbery integrated electronics, including an active matrix multiplexed tactile sensor and a triboelectric nanogenerator–based power management system, are further demonstrated.
Early choroidal changes detected by swept-source OCT in type 2 diabetes and their association with diabetic kidney disease
Authors: Da Silva Monica Oliveira , Chaves Anne Elise Cruz do Carmo , Gobbato Glauber Correa , Lavinsky Fabio , Schaan Beatriz D'Agord , Lavinsky Daniel 
Published: November 2022

IntroductionMicrovascular changes in eye and kidney shares some common factors in diabetes mellitus (DM). The purpose was to evaluate choroidal thickness (CT) and choriocapillaris (CC) density in patients with type 2 diabetes (T2D) and their association with diabetic kidney disease (DKD) using swept-source optical coherence tomography (SS-OCT).Research design and methodsA cross-sectional study was conducted with patients with T2D with mild or no diabetic retinopathy (DR) and non-diabetic controls. CT was measured with SS-OCT, and CC vascular density was measured with OCT angiography. These parameters were compared with inner retinal layers thickness in patients with and without DKD and non-diabetic controls.ResultsNinety-three eyes from patients with T2D and 34 eyes from controls volunteers were included. Within the T2D group, 56 eyes with DKD and 37 eyes from patients with no diabetic kidney disease were examined. A statistically significant reduction of CT was observed in patients with DKD compared with controls, with no difference in CC density. There was an association between ganglion cell layer and central choroidal thickness reduction in the DKD group.ConclusionsPatients with T2D with DKD showed a decrease in CT with no difference in CC density compared with non-diabetic controls. This thinning might be related to vascular changes of choroidal layers such as Haller’s and Sattler’s with preservation of CC density, which is crucial for outer retina and retinal pigment epithelium health. Longitudinal studies are warranted to determine the association of choroidal changes with the pathogenesis of diabetes, and its association with early DKD and progression to more severe DR.
Investigating transmission of SARS-CoV-2 using novel face mask sampling: a protocol for an observational prospective study of index cases and their contacts in a congregate setting
Authors: Jaenisch Thomas , Lamb Molly M , Gallichotte Emily N , Adams Brian , Henry Charles , Riess Jeannine , van Sickle Joni Triantis , Hawkins Kellie L , Montague Brian T , Coburn Cody , Conners Bauer Leisha , Kovarik Jennifer , Hernandez Mark T , Bronson Amy , Graham Lucy , James Stephanie , Hanenberg Stephanie , Kovacs James , Spencer John S , Zabel Mark , Fox Philip D , Pluss Olivia , Windsor William , Winstanley Geoffrey , Olson Daniel , Barer Michael , Berman Stephen , Ebel Gregory , Chu May 
Published: November 2022

IntroductionThis study aims to measure how transmission of SARS-CoV-2 occurs in communities and to identify conditions that lend to increased transmission focusing on congregate situations. We will measure SARS-CoV-2 in exhaled breath of asymptomatic and symptomatic persons using face mask sampling—a non-invasive method for SARS-CoV-2 detection in exhaled air. We aim to detect transmission clusters and identify risk factors for SARS-CoV-2 transmission in presymptomatic, asymptomatic and symptomatic individuals.Methods and analysisIn this observational prospective study with daily follow-up, index cases and their respective contacts are identified at each participating institution. Contact definitions are based on Centers for Disease Control and Prevention and local health department guidelines. Participants will wear masks with polyvinyl alcohol test strips adhered to the inside for 2 hours daily. The strips are applied to all masks used over at least 7 days. In addition, self-administered nasal swabs and (optional) finger prick blood samples are performed by participants. Samples are tested by standard PCR protocols and by novel antigen tests.Ethics and disseminationThis study was approved by the Colorado Multiple Institutional Review Board and the WHO Ethics Review Committee. From the data generated, we will analyse transmission clusters and risk factors for transmission of SARS-CoV-2 in congregate settings. The kinetics of asymptomatic transmission and the evaluation of non-invasive tools for detection of transmissibility are of crucial importance for the development of more targeted control interventions—and ultimately to assist with keeping congregate settings open that are essential for our social fabric.Trial registration numberClinicalTrials.gov (#NCT05145803).