bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research and First Application of 4D Radiation Dose Calculation in China
Authors: Liu Zhaoxing , Zhao Ri , Liang Runcheng , Zhang Jing , Liu Xin , Liu Liye 
Published: November 2024

Abstract
Current techniques for calculating radiation doses can only provide 3D static dose distributions for upright individuals, falling short of meeting the demands for precise protection in the future. In pursuit of achieving 4D dose calculations, this study implemented polygonal-surface computational human phantoms deformations using three algorithms based on rigid body rotation matrix, volume Laplacian operators, and As-Rigid-As-Possible (ARAP) method. Subsequently, the research on motion-capture-guided phantom deformation was done. Utilizing the tetrahedral transformation technique based on the Delaunay algorithm, high-speed Monte Carlo calculation was achieved. The established methodology underwent first application in nuclear power plants, and the application results, specific to radiation work processes, validated the reliability and practicality of the proposed method. This breakthrough in key technological aspects of the 4D dose calculation method demonstrates its potential application in personnel precision protection during the operation and maintenance of nuclear facilities. The developed technology holds promise for advancing radiation protection in various scenarios within the nuclear industry.
PERFORM: High Temperature and Pressure CHF Experiment Bench Under Six Degrees of Freedom Motion Condition
Authors: Xia Binzhuo , Xia Fanting , Yang Yiming , Zhang Kui , Chen Ronghua , Tian Wenxi , Qiu Suizheng 
Published: November 2024

Abstract
The critical heat flux is the heat flux when the heat transfer on the surface of the nuclear fuel element deteriorates. Once CHF occurs, the fuel element temperature will rise sharply, resulting in a serious nuclear accident. Motion conditions impact the nuclear reactor in a number of ways, including the micro-level CHF mechanism as well as the flow and heat transfer characteristics and bubble distribution in the core. As a result, conducting the CHF test under motion conditions is required. In this study, a high temperature and pressure CHF experiment bench under six degrees of freedom motion condition named PERFORM was designed and built. The test bench was then used for benchmark tests, parameter control during the test was tested and analyzed, and the CHF test results were compared and analyzed with LOOK-UP-TABLE. The findings demonstrate that there is typically less than a 10% difference between the test data of the benchmark test and the LOOK-UP-TABLE approach, indicating the reliability of the PERFORM bench and the accuracy of the CHF test results that are derived from it.
A Study of Vortex Shedding Acts on Steel Vent Stack Based on EU Standards
Authors: Yuanda Liu , Xiting Wu , Minghao Tang 
Published: November 2024

Abstract
This paper calculates and analysis the crosswind resonance and load acts on the steel vent stack of a UK nuclear power plant which caused by the vortex shedding. It is based on BS EN standards. Both downwind loads and cross wind load which perpendicular to the wind velocity are generated when the wind acts on the structure with a circular section. That may cause a huge displacement or damage of the structure. So some measure to reduce the impact is necessary. This paper discuss impaction on self supports stack which cause by structure free length and the supports form and the fatigue. And compares the difference between the Chinese codes and EU codes.
The cross wind load is caused by the vortex shedding effect. When the wind load acts on the structure, it will produce alternating vortices behind both sides of the chimney, and alternately fall off from one side to the other side, forming the vortex shedding effect. When a vortex is created on one side of the structure, the wind speed on the other side increases, causing the air pressure to drop. As a result, the structure is subjected to lateral forces on one side of the vortex. When the vortex alternates on both sides of the structure, a harmonic lateral load with the same frequency as the vortex is formed. Therefore, the fatigue effect caused by fluctuating wind load should be considered in the design of the structure.
As a tall structure, the steel stack must control and reduce wind vibration, especially cross wind vibration, to achieve safety and economic indicators.
If a horizontal support is anchored on middle of the stack, it can not only share the horizontal load at the bottom of the structure, but also reduce the calculation length of the result and increase the natural vibration period of the structure. It can be seen from the calculation in this paper that the structure without horizontal support needs to increase its damping to avoid dam4age by adding frequency modulated mass dampers or wind rings. The cross-wind load caused by vortex shedding is mainly related to the natural vibration frequency of the structure and the logarithmic damping of the structure in BS EN standards. Therefore, the cross-wind effect can be reduced by increasing the logarithmic damping of the structure, optimizing the structure design, and changing the natural vibration frequency of the structure.
Differential Method for Predicting Heat Transfer Deterioration Regimes in Supercritical Channels and Rod Assemblies
Authors: Filonov Vladislav , Filonova Yuliia , Kovalenko Oleksandr , Fedorov Dmitriy 
Published: November 2024

Abstract
The paper considers a method for determining the heat transfer and hydraulic resistance coefficients at supercritical parameters based on the “narrow channel” approximation. This approach takes into account the presence of transverse exchange of momentum and energy, the intensity of which depends on the radial profile of shear stresses and, to a first approximation, considers density pulsations in the gravity field. In contrast to the classical CFD approach of the same spatial dimension, the described method is simpler, although it remains unclosed with respect to the longitudinal pressure gradient. To overcome this issue, a one-dimensional approach based on the transfer matrix method is used. The technique incorporates an integral form to determine the local HTC (Lyon integral) and friction. The paper provides validation of the approach based on probe experimental studies for CO2, where not only axial temperature profiles during upward and downward flow were experimentally obtained, but also radial profiles were studied in the section with maximum temperature under heat transfer deterioration (HTD). Good agreement in the temperature profiles in the axial and radial directions was obtained in calculations. The considered method predicts the presence of “laminarization” under HTD. An attempt was made to adapt the method for calculations of assemblies in the channel approximation. The results were compared with the studies on the assemblies of fuel rod imitators with supercritical water. The proposed modification of the “narrow channel” method can be used as an alternative to correlations in system codes to perform improved estimations.
Experiment Study on the Liquid Film Behaviors of Annular Flow in the Rectangular Channel
Authors: Ren Quan-yao , Pu Zeng-ping , He Qingche , Liu Haidong , He Hui , Xiao Zhong , Pan Liang-ming 
Published: November 2024

Abstract
Critical heat flux (CHF) is the most important parameter related to the safety performance of heat exchanging equipment, whose triggering mechanisms are very complex and complicated. The prediction of dry-out critical heat flux in a narrow rectangular flow channel was usually based on the accurate prediction on the instantaneous liquid film spatial distribution and its characteristics in annular flow, such as liquid film thickness and disturbance wave destruction rate, and other key parameters. Therefore, it is essential to conduct detailed research on the liquid film behaviors for the annular flow in the narrow rectangular channel. In order to obtain the liquid film thickness, the plate-type liquid film sensor was developed by utilizing the huge differences of electrical conductivity between gas and liquid. The corresponding relationship between the measured voltage and the real void fraction was established with calibration of empirical model, and then the void fraction was converted into liquid film thickness theoretically. Based on the plate-type liquid film sensor, the liquid film was measured in the narrow rectangular channel with a cross-section of 4 mm × 66 mm at different flow conditions. The effects of liquid flow velocity and gas flow velocity on the averaged liquid film thickness and dynamic fluctuation characteristics were analyzed. This study provided data support and theoretical guidance for the accurate prediction of the dry-out type critical heat flux, and was helpful for the design of the fuel assemblies consisting of narrow rectangular channel and the safety assessment of nuclear reactor systems.
Numerical Investigation of Natural Convection Heat Transfer Characteristics in a Swinging Cavity
Authors: Xing Lize , Liu Xiongbin 
Published: November 2024

Abstract
Floating nuclear reactors offer significant advantages in fields of remote island power supply. However, previous studies have mainly focused on the one-dimensional pipeline systems, and there is limited research on the natural convection characteristics within 2- or 3-dimensional enclosed spaces. This study employs a numerical method to investigate the effect of ocean motion on the natural convection characteristics of a square cavity. The cavity has an isothermal heated wall surface at 333K and an isothermal cooling surface at 313K, and the range of the swing period was chosen as [16s, 96s]. The numerical results indicated that while centripetal and Coriolis forces had little effect on heat transfer performance, they did improve the system’s ability to resist interference, with the most significant contributions to natural convection coming from thermal buoyancy and tangential force. Furthermore, as the swing period increased, the relative intensity of thermal buoyancy and tangential force changed, resulting in two distinct heat transfer performances. When the intensity of tangential force greatly exceeds or falls short of thermal buoyancy, the heat transfer curve remains constant for the majority of the period. Conversely, when the intensities were comparable, the heat transfer curve became sharp and unsteady. The findings of this investigation could provide a useful basis for subsequent research on marine nuclear energy systems and equipment.
Scaling of Horizontal Steam Generator Based on Three-Dimensional Thermal-Hydraulic Simulations
Authors: Lazarevic Milos , Stevanovic Vladimir , Petrovic Milan M. , Milivojevic Sanja , Ilic Milica 
Published: November 2024

Abstract
Thermal-hydraulics of horizontal steam generator (HSG) is numerically simulated and analyzed for the full-scale real HSG at the nominal 100% power built in the 1000 MWe nuclear power plant with the pressurized water reactor and for the scaled-down HSG design with all characteristic dimensions reduced to 50% of the full dimensions and operating at 12.5%, 15.7% and 18.7% of the 100% power of the real HSG. The scaled-down HSG designed is considered with the aim to investigate a design that suits the needs of a nuclear power plant with small modular reactor (SMR), which components should be manufactured in a factory and transported to and assembled at the power plant location. The several power levels of the scaled HSG are applied in the performed simulations in order to obtain steam void and water and steam velocities fields that should provide operating parameter values close to the proven safe and reliable values of the 100% full-scale HSG with mature operating experience. The simulations are performed with an in-house code based on the three-dimensional two-fluid model of two-phase flow and appropriate closure laws for the prediction of interface transport processes, such as vapour-liquid interface friction, vapour and liquid wall friction and liquid evaporation rate under thermal non-equilibrium conditions. The obtained results show a difference between geometry and power scaling. The 50% geometry reduction leads to about 80% of HSG power reduction.
Optimal Design of a Coupling System of Heat Pipe Cooled Reactor With Battery Energy Storage System
Authors: Liu Limin , Liu Ziyin , Guo Ziang , Gu Hanyang 
Published: November 2024

Abstract
Micro nuclear reactors have been seen as one of the potential nuclear energy solutions to carbon emission reduction due to their compact design, flexibility, and economic merits. Heat-pipe-cooled nuclear reactors (HPR) can achieve attention due to their avoidance of single-point failure, passive core heat removal capability, and modularity. If applied in remote grid communities or mining operations, the HPRs will face the challenges of high variability in energy demand and relatively long response time in reactors. This paper presents a conceptual design for a hybrid energy system that combines HPRs with a battery-based energy storage system. The system models are set for the reactor-based hybrid system, which includes the core, heat pipe, Brayton energy conversion system, and battery system. Evaluation is performed on the HPR-based hybrid system to examine its responsiveness to time-varying energy demands. The result shows that the HPR-battery hybrid energy system can significantly increase the load following performance and avoid the abrupt power change appearing in the HPR.
Research on Peaking System of Nuclear Power Plant Based on Energy Storage Scheme of Hydrogen Production and Ammonia Synthesis
Authors: Shi Lingyue , Ye Cheng , He Qinglun , Huang Hong 
Published: November 2024

Abstract
With the continuous advancement of the “dual carbon” strategic goal, the power industry, as the main force of energy consumption, actively carries out technological innovation and improves the utilization ratio of clean energy, so the demand for nuclear power peak shaving gradually increases. Based on the current situation of electric power energy utilization and hot research on the green development path of hydrogen production and ammonia synthesis, this paper puts forward a peaking solution of a new energy storage system for nuclear power plants based on green electricity conversion. Taking the daily load tracking mode of AP1000 nuclear power unit as an example, considering the operation efficiency under different loads, the power regulation process of the system is quantitatively calculated by using APROS simulation software. We add a waste heat recovery and utilization structure to improve the energy utilization efficiency, and the economy of this system is evaluated to be more persuasive. It provides an idea of transforming surplus electricity into zero-carbon energy storage for peak shaving problem of nuclear power plants, and has certain reference significance for the development of nuclear comprehensive utilization.
Kriging Surrogate Modelling of Multiplication Factor With Random Effect
Authors: Wang Yizhen , Hao Chen 
Published: November 2024

Abstract
Large computational expenses hinder the use of Monte Carlo simulations in reactor design optimization. Surrogate modelling could therefore be used to reduce such computational expense by constructing computationally inexhaustive models for certain reactor responses of interests. However, the random effect inherited in Monte Carlo neutronics simulation results are generally not considered during constructing such surrogates, which is expected to result in large surrogate prediction biases. In this work, a stochastic Kriging surrogate modelling technique is used to reproduce Monte Carlo estimated multiplication factor while explicitly taking their random effects into account. It is shown that involving random effect in Kriging surrogate modelling process could significantly improve the accuracy of surrogate predicted multiplication factors. Specifically, it could mitigate the fluctuation appeared in Kriging surrogate predicting biases, and narrow the surrogate predictions centered around the mean values of referenced Monte Carlo simulated multiplication factor. It is analyzed that stochastic random effect resulted non-smoothing variation of multiplication factor with varying design inputs is responsible for such observation. As Kriging method follows Gaussian process assumption, where the commonly adopted Radial Basis Kernel (RBK) is not able to model the non-smoothing distance related correlation appeared in responses with random effect. Including an additional extrinsic covariance in the Kriging modelling process could therefore mitigate such non-smoothing behavior and stabilize surrogate model’s prediction performance.
Dynamic Simulation of a Small Modular Sodium-Cooled Fast Reactor Coupled With Molten Salt Energy Storage System
Authors: Jin Jinrong , Wan Jiashuang , Wu Shifa , Nuerlan Areai 
Published: November 2024

Abstract
The small modular sodium-cooled fast reactor plays a vital role in Generation-IV reactors, requiring the capability of load-follow operation to address the challenges posed by rapidly fluctuating electric loads on the power grid. Nevertheless, the thermal and mechanical stresses associated with load-follow operation can be undesirable for fuel and other reactor components. To address this, an alternative approach is proposed, focusing on operating the reactor at or near steady state and storing excess energy in a thermal heat storage system. The stored thermal energy can be efficiently utilized during periods of peak electric demand, effectively mitigating grid variability resulting from daily load demand changes and intermittent renewable energy sources. The sodium-cooled fast reactor is the most promising candidate for coupling with the molten salt thermal heat storage systems because the reactor coolant inlet and outlet temperatures of sodium-cooled fast reactors are in the margin of the molten salt working temperature. This study focuses on the integration of a molten salt energy storage system between the intermediate sodium loop and secondary loop of the modular sodium-cooled fast reactor. By employing this configuration, the coupled system enables the reactor to operate at nominal full power effectively, even during periods of variable electric demand. The research emphasizes the dynamic responses and control strategy of the coupled system. Initially, mathematical models for the small modular sodium-cooled fast reactor and molten salt energy storage system are proposed and implemented using MATLAB/SIMULINK. Subsequently, according to the operation strategies and control logics, the conventional PID control systems are designed for both the small modular sodium-cooled fast reactor and molten salt energy storage system. The dynamic simulations of load-follow scenarios are conducted to assess the performance of the small modular sodium-cooled fast reactor coupled with molten salt energy storage system. The simulation results demonstrate the feasibility of utilizing a molten salt energy storage system coupled with a small modular sodium-cooled fast reactor to efficiently minimize power swings during periods of variable electric load. Consequently, the coupled system significantly enhances the operational flexibility, safety, and cost-effectiveness of the sodium-cooled fast reactor, making it a promising and sustainable solution for ensuring grid stability and meeting the increasing energy demands of the future. Overall, this research contributes to advancing the state-of-the-art in small modular reactor technology, providing valuable insights into the integration of energy storage systems with sodium-cooled fast reactors, and showcasing the potential benefits in terms of enhanced operational performance, grid stability, and sustainability.
Evaluating the Impact of Neutron Absorber Materials on Spent Fuel Pool Rack Criticality Using OpenMC Monte Carlo Code
Authors: Buyrukcu Busra , Buyrukcu Eray , Litskevich Dzianis , Whittle Karl 
Published: November 2024

Abstract
The impact of different neutron absorber materials on the criticality of the spent fuel pool rack geometry has been investigated in this study. OpenMC Monte Carlo code has been used for modelling the geometry of the spent fuel pool rack and the k-eigenvalue/criticality calculations. The criticality calculations consist of three stages. In the first stage, the k-eigenvalue criticality calculations were made using two different neutron absorber plates, which are an aluminium-boron carbide composite and a Gd-containing aluminium-boron carbide composite. In the following stage, k-eigenvalue calculations were performed by removing neutron absorber plates from the rack geometry and adding Gd (1 wt.%) directly to the rack wall composition. In the final stage, criticality calculations were made by using different neutron absorber elements like Gd, B, and Sm and their different concentrations within the rack wall composite. It can be understood from the analyses that Gd is a significant neutron absorber material, particularly when it is incorporated directly within the spent fuel pool rack wall composition. With this approach, the need for neutron absorber plates has been eliminated by adding neutron absorber elements directly within the rack wall composition. In this way, systems will become simpler, and potentially, the cost will be reduced.
Basic self-disturbance in adolescents at risk of psychosis: temporal stability investigated by the experience sampling method in a mixed method study
Authors: Baklund Lise , Røssberg Jan Ivar , Melbye Sigurd Arne , Møller Paul 
Published: November 2024

BackgroundBasic self-disturbance (BSD), also called anomalous self-experiences (ASEs), are core phenotypic markers for schizophrenia spectrum disorders and a prepsychotic vulnerability marker considered to be temporally stable (trait-phenomenon). Studies of BSD in children and adolescents are lacking.ObjectiveTo be clinically useful, we need to know more about the characteristics and temporal development of BSD in prepsychotic phases.MethodThis study used a smartphone application measuring the occurrence and subjective intensity of ASEs in the daily life of 27 help-seeking adolescents (12–18 years) repeatedly over a period of 6 months. A total of 5223 unique application-reports based on individually selected and verbatim descriptions of personal core ASEs were analysed by mixed methods.FindingsThe intensity of ASEs, within subjects and between subjects and irrespective of time intervals or baseline scores obtained by the Examination of Anomalous Self-Experience (EASE) were relatively stable with a mean variability of 1.25 (0.4) SD. Participants with low EASE total scores at baseline had a significantly lower score on ASE intensity than those with high baseline EASE total scores at baseline (mean 2.42 vs 3.42, p=0.046).Conclusion and clinical implicationsIn this study, ASEs were not reported as essentially fluctuating experiences but as almost constantly present, demonstrating BSD as a mainly trait phenomenon in prepsychotic phases in persons under the age of 18. Considering the continuous experience of BSD and its predictive value for psychosis development, ASEs should be targeted and monitored to the same extent as other prepsychotic features.