bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Influencing Factors of Soil Sample Self-Absorption With Monte Carlo Method
Authors: Ye Erlei , Shen Chunxia , Nan Hongjie 
Published: November 2022

Abstract
The detection efficiency of soil samples in a cylindrical measuring geometry was calculated using the Monte Carlo method, evaluating the self-absorption corrections in the energy range of 46-2615 keV. By controlling variables, the effects of parameters such as sample density, height and humidity on the self-absorption factor have been studied, and the corresponding correction functions have been obtained. The research results show that: for γ photons of a specific energy, the change of sample density has the greatest impact on self-absorption. For samples whose density is not much different from that of the standard sample, the impact of changes in height and humidity on self-absorption should be considered. In the high-precision measurement of samples containing low-energy γ-photon radionuclides, the errors caused by density, altitude and humidity should be comprehensively considered.
Research on Intelligent Classification Method of Primary Loop Transient in Nuclear Power Plant
Authors: Zhang Run Ze , Chen Zhi Lin , Huang Yong Qiang , Chen Xin 
Published: November 2022

Abstract
The primary circuit transient of nuclear power plant is one of the important references for characterizing the fatigue of primary circuit materials. For the classification of transients, the commonly used method is to determine the category of transients according to the change in value and the operating operation of the unit. This paper forms a complete set of digital transient characteristics through the study of the thermal parameters behind various transients and the exploration of the law of transient occurrence. Combined with new computer technologies such as machine learning, the automatic processing of transient classification is realized. It provides ideas for the key links in the development of the whole-process automation platform for transient management.
Preliminary Sensitivity and Uncertainty Analysis of Accident Tolerant Fuel in SMR
Authors: Liang Yuxuan , Wang Xiang 
Published: November 2022

Abstract
As the technology of small modular reactor (SMR) becomes mature, its safety is getting more attention. In recent research of accident tolerant fuel (ATF) such as the U3Si2 used in a large commercial pressurized water reactor can significantly improve the safety of the core due to its high thermal conductivity and good physicochemical properties. Therefore, applying the ATF in the SMR can also enhance its safety. The mPower with a thermal power output of 530 MW designed by B&W company is selected as one of the SMR. In the design and production process of fuel rods, the design and manufacturing parameters such as fuel pellet diameter, inner diameter of cladding, fuel pellet density and other parameters have uncertain factors. These factors affect the results of effective multiplication factor (keff). In this work, we carried out preliminary sensitivity and uncertainty analysis of the U3Si2 with accident tolerant cladding (FeCrAl, SiC) in mPower using SEPRENT and DAKOTA. Sensitivity analysis performed the relative importance of each input parameters for different ATF combination. Uncertainty analysis gave the tolerance range and uncertainty for different ATF combination.
Construction and Application of Collaborative Editing System for the Nuclear Power Large Comprehensive Report
Authors: Luo Cheng , Jia Lin , Hao Wang , Wu Xiangyong 
Published: November 2022

Abstract
The nuclear power large comprehensive reports need a lot of editing work and participants, the process is opaque, the format is not standardized and there are no effective collaborative tools. Because of overall process improving requirements, report review needs of format verification, optimization process, centralized storage of documents, and specification of document content, our company is in urgent need of new technical means. Collaborative editing is a new technology that is fundamental and critical in multidimensional collaboration of organizations, tasks, resources, processes, and format specifications. This thesis is based on the promotion of collaborative editing of large comprehensive reports, in-depth study of related technologies including the timeliness of collaborative editing, unified document format standards, unified and effective process control, unified document storage and version management from tools, processes and platforms, and proposes a construction plan to solve these existing problems, and finally provides a collaborative editing platform for each major. Construction and application of collaborative editing system for the nuclear power large comprehensive report realizes workflow and standardization, greatly improves editing efficiency and quality of large comprehensive reports, reduces manpower input, human errors, saves management costs of various professions and lately helps HPR1000 successfully pass qualification verification.
A Numerical Study on the Behaviors of Graphite Aerosol in the Containment During a Water Ingress Accident of High Temperature Gas-Cooled Reactors
Authors: Fang Zhu , Zhang Yiyang , Wang Yating , You Zhikai , Sun Libin , Wu Xinxin 
Published: November 2022

Abstract
The graphite dust is a special problem for pebble-bed high temperature gas-cooled reactors (HTGR), due to the close coupling with the fission products. A large fraction of graphite particles deposit on the tube bundles of steam generator (SG) due to the particle-vortex interaction and thermophoresis effect. Once a water-ingress accident occurs, the graphite dust may resuspend due to the rapid change of flow field. A certain fraction of resuspended dust, together with some fission products, could be discharged to the containment if the overpressure protection of the primary circuit is triggered. The distributions of deposited and airborne particles in the containment are crucial for the safety analysis and source term evaluation. In this work, we use a Eulerian-Lagrangian method to numerically study the transport and deposition behaviors of graphite aerosol in the full-scale containment during a water-ingress accident. Particularly, the effects of highly irregular shape of graphite particles on the particle-wall and particle-fluid interactions are incorporated. The statistical results that as the tracking time increases, the deposition rate first drops rapidly and then exponentially decreases. The deposition fraction is 80.38% for the floors, 9.83% for the shell of the containment, and 3.55% for other surfaces. Only 6.24% of particles are suspended in the air. As the particle size increases, the deposition fraction increases first and then decreases, reaching a maximum value at 3 μm. We also discuss the effect of the down direction of overpressure relief outlet on particle deposition. The result shows a fraction of 11.68% of airborne particles, which is about 2 times than that of the up direction. Our simulation not only demonstrates that the containment has a good capability to retain the graphite dust in a water-ingress accident scenario, but also provides a support for the engineering design of the overpressure relief system of HTGRs.
Radiographic Examination of Electric Heater Tube Weld for HPR1000 Pressurizer
Authors: Yu Jintao , Lu Dandan , Zhang Jianlei 
Published: November 2022

Abstract
HPR1000 (Hua-long Pressurized Reactor) nuclear power technology is a third generation nuclear power technology independently developed by China and has completely independent intellectual property rights. The pressurizer is one of the most important equipments in nuclear power plants. Compared to the regulator of the CPR1000 pressurizer, the HL-1000 pressurizer designed by CNPDC has as many as 108 electric heaters. Each electric heater contains a weld of electric heating sleeve to connection. RT should be completed at least 216 exposures, if each weld is exposure with a minimum of two 90 degree shots, in this paper, the authors have improved RT examination technique of these welds and verified it on the actual products. The results show that the new technique can reduce the number of exposures by more than one third and speed up the manufacture of the whole pressurizer regulator.
Numerical Simulation on the Flow-Induced Vibration of Two Square Cylinders in Staggered Arrangement
Authors: Wu Yidong , Shi Li , Wu Xinxin , Wang Xiaoxin 
Published: November 2022

Abstract
Based on the design of the heat transfer tube bundles with square cross section of the steam generators in the high temperature reactor-pebble bed modules (HTR-PM), the flow-induced vibration (FIV) of two single-degree-of-freedom (SDOF) square cylinders in staggered arrangement were investigated to guide the design, processing and manufacture of heat transfer components. Numerical simulation on the FIV of two square cylinders in staggered arrangement was carried out at Reynolds number Re = 100 with the mass ratio of 20. The wake structures of two square cylinders in different arrangements were analyzed. Three distinct flow regimes, i.e. one single-street modes S-I and two double-street modes T-I and T-II, are identified based on Strouhal numbers and flow structures. The amplitude and frequency of FIV response and the lift coefficient of two square cylinders at Ur = 1–30 were obtained to analyze the FIV behavior. The results show that upstream cylinder in the arrangements of mode S-Ia① and S-Ia② is prone to galloping while downstream cylinder in the arrangements of mode S-Ia③ and T-I is prone to galloping. The VIV amplitude of downstream cylinder in most staggered arrangements is much larger than that of single square cylinder while the VIV of upstream cylinder is suppressed.
Study on the Influence of Roughness on Fuel Rod Gap Heat Transfer
Authors: Liu Weichao , Zhang Guoliang , Li Changzheng , Cao Jin , Lin Shaofang , Fu Xiangang , Nie Lihong , Deng Yongjun 
Published: November 2022

Abstract
The behavior of pellet-cladding gap is very complex, which includes many physical phenomena, such as the change of gap size caused by pellet swelling and cladding creep, the change of gap gas composition caused by fission gas release, and the change of thermal conductivity of single component and multi-component gas.
Pellet-cladding gap heat transfer coefficient is a key parameter for safety analysis, which directly affects the thermal-mechanical performance of fuel rods under different conditions. Among them, pellet-cladding gap is the key parameter affecting pellet-cladding gap heat transfer. Because the roughness of the outer surface of the pellet and the inner surface of the cladding directly affects the size of the gap, it is necessary to conduct in-depth research on it.
The research on the influence of pellet and cladding roughness on pellet-cladding gap heat transfer focuses on the experimental study and model building, but seldom on the influence of the irradiation process in the fuel reactor.
On the basis of studying the steady-state and transient operation of fuel rods and the influence of roughness on various gap heat transfer modes, the influence law and mechanism of roughness on pellet-cladding gap heat transfer are discussed, which has guiding significance for the design of new fuel rods.
A Digital Proof of Concept (POC) for Simulating the Coupled Phenomena Between Neutronics, Structural and Fluid Dynamics in a Reactor Core
Authors: Liu Jie , Zhang Chunyu , Zheng Zhihao , Min Jiesheng 
Published: November 2022

Abstract
Numerical simulation is a key technology for improvement of nuclear reactor design and maintenance with its low cost and safety comparing to traditional experiments, especially when irradiation is involved. Various software exist today in the fields of structural mechanics fluid dynamics and even neutronics to model and understand these phenomena. Nevertheless, coupled simulation of the reactor core represents a span of different mechanisms with intricate links between neutronics, materials and the surrounding coolant. With increasing computing power, advanced coupling of the phenomena occurring in the reactor core is being developed nowadays.
In the present study, a multi-physics coupling framework is developed by coupling three codes, i.e., a neutronics transport code, a computational fluid dynamics code and the finite element structural analysis code. The three solvers are hosted within the open-source platform SALOME. Besides this framework, the platform also contains additional modules to realize the full process of a multi-physics simulation. The multi-physics coupling framework provides a strong scalability, users are able to add user-defined modules though open API interface.
This paper provides a route forward for the development of the framework, along with the description of its various anticipated modules and functionalities. Ultimately, it is expected that the multi-physics coupling framework will achieve the full process of a multi-physics simulation, including preprocessing, neutronics calculation, structural analysis, CFD (Computational Fluid Dynamics) simulation, multi-physics coupling simulation, post-processing, and data analysis.
The Study of Removal of Secondary Neutron Source of HPR-1000
Authors: Xiao Huiwen , Li Xiang , Liu Guoming , Zhang Yicheng , Shao Zeng , Xu Min , Yi Xuan , Yang Haifeng 
Published: November 2022

Abstract
When the reactor was in the subcritical state, the criticality safety of the core was monitored by the source range detector which was placed out of the core. According to the “Initial Loading Test for Pressurized Water Reactor of Nuclear Power Plant” (NB/T 20434-2017RK), the recommended value of count rate of the detector was larger than 0.5 cps. But during loading and other subcritical reactor conditions, the number of neutrons in the core is relatively low, causing that the count rate of the ex-core source range detectors could not reach 0.5 cps. Thus, secondary neutron source was placed in the following cycle of reactor to increase the neutron count rate of the ex-core source range detectors to 0.5 cps to meet the standard. In fact, the use of secondary neutron sources raises a number of problems, such as: 1) the production of radioactive and other tritium from secondary neutron sources, the total production of which is a limiting criterion for the construction of nuclear power plants; 2) the increased procurement costs of secondary neutron sources; and 3) the vulnerability to damage due to the long presence of secondary neutron sources in the core, increase the radioactivity level of the primary circuit. Because of the use of low leakage loading fuel management in HPR-1000, the spent fuel assemblies were placed closer to the source range detector and generated more neutrons, it is possible for the ex-core source range detectors to meet the counting requirement of 0.5 cps regardless of whether the core is in the subcritical state. This paper studied the removal of secondary neutron source in HPR-1000. The neutron source intensity of spent fuel assemblies and neutron count rate in fuel loading process were calculated in a conservative method with three dimension monte carlo code. The calculated results had shown that the removal of secondary neutron source in HPR-1000 satisfies safety requirements.
Application Research on Human Reliability Analysis Method of Class C Human Action of China Fast Reactor
Authors: Niu Jingjuan 
Published: November 2022

Abstract
According to the current situation of human reliability analysis of China fast reactor, combined with the operation experience of China Experimental Fast Reactor (CEFR), this study not only identifies the method of important personnel actions, but also standardizes the technical process of human reliability analysis. Compared methods of four kinds human reliability analysis, finally, the SPAR-H method is choose for CLASS C. According to the mathematical model of this methods, the calculation code for system analysis is developed using Visual Basic language. Based the standardization of the technical process, the code using examples CLASS C are provided, finally the standard technical documentation of HRA is edited. Based on the results of the calculation analysis, some recommendations are provided for systems design, human-machine interface design, regulation design and training program. The above is only an example. In the future, it is necessary to analyze more human actions of CLASS C, so as to give suggestions on the impact of human factors in various fields. To achieve the goal of minimize the impact of CLSS C human actions on the design and application of the whole project.
Commissioning and Cold Test of HLLW Vitrification Plant of China
Authors: Ruan Minzhi , Liu Yingzi , Zhang Jinyao , Sun Minhang , Liu Xuelian 
Published: November 2022

Abstract
Prior to radioactive operations, the Vitrification Plant of China (VPC) will implement a cold-commissioning plan or strategy that will include functional test, water test, simulant test and glass pouring test to not only test the process systems, auxiliary systems and melter performance, but also allow operators to increase facility operating experience and be familiar with remote handling in hot cells before introducing radioactive material into the plant. The process technique used is based on the German liquid fed ceramic-lined electric waste glass melter (LFCM) designed to process high level liquid waste (HLLW) containing highly noble metals (Ru, Rh, Pd).
Several batches of simulants tests are performed and the operation data including melter temperature and initiating procedure are analyzed. A maximum process rate is determined according to the applied process parameters including the high operating temperature. And in different operating modes, including idling mode and operating mode, the effect of different feed rates on the formation of the cold cap and the temperature in different areas of the melter are investigated.
The paper gives an overview about the current status of the VPC plant. The strategy of commissioning and cold test operations are described in detail.
Development of Drift Flux-Type Correlations Considering Bubble Induced Turbulence in Vertical Gas-Liquid Metal Two-Phase Flow
Authors: Wang Di , Liang Ren , Lin Zhikang , Ouyang Yong , Shen Yonggang , Lu Xianghui , Qiu Suizhen 
Published: November 2022

Abstract
In hypothetical steam generator tube rupture (SGTR) accident scenario of pool-type liquid metal cooled fast breeder reactor, water is injected from SG into primary circuit through the break and flash. The injected steam bubbles may transport into the core region and insert positive reactivity, which threaten the reactor safety. To accurately predict the void fraction for evaluation of accident consequence, drift flux model applied to gas-liquid metal two-phase flow is useful and need to be developed. In this contribution, an algebraic model aimed at bubble induced turbulence (BIT) is introduced to improve the underestimation of turbulent viscosity calculated by Clark’s force balance model to accurately predict the one-dimensional liquid velocity distribution along radial direction in flow channel. On this basis, the distribution parameter is calculated. Analysis result shows that distribution parameter is assuming very high values at low Re number. With Froude number increase, distribution parameter tends to decrease. At lower void factions, distribution parameter is also assumed to be high values. It indicates that the pipe size, flow rate and void fraction can all influence distribution parameter. Considering the quantitative laws of above influence factors obtained by theoretical analysis and fitting test data, a new correlation for gas-liquid metal two-phase flow is developed and evaluated.
Research on the Supercharging Performance of the Annular Multi-Nozzles Ejector at the Suction Port of a Centrifugal Pump
Authors: Ma Fubing , Fan Guangming , Xu Junxiu , Yan Changqi , Hao Shuai , Zhou Yuning 
Published: November 2022

Abstract
The coolant may vaporize in the centrifugal pump to cause cavitation in pool-type nuclear heating reactor. Installing a jetting device at the pump suction port is an effective means of applying jetting technology to solve the problem of preventing cavitation in centrifugal pumps. In this paper, an annular multi-nozzles ejector was designed and an experimental system was constructed to test the actual supercharging performance of the device. When the high-energy fluid at the pump outlet flowed through the device, it was first mixed uniformly in the annular chamber, and then injected through the nozzles to mix with the main flow to increase the pressure of the main flow. The static pressure at the suction port of the pump increased. Accordingly, the available Net Positive Suction Head (NPSHa) of the pump increased. The test was constructed around the total flow flux through the pump invariable and the main loop flow flux invariable two schemes. The results show that when the proportion of the return flow flux was same, the greater the total flow flux through the pump, the higher the pressure increment at the pump suction port; when the proportion of the return flow flux was larger, the difference in the pressure increment corresponding to different total flow fluxes was larger. When the flow flux through the main circuit of the system was same, the pressure increment increased nonlinearly with the increase of the return flow flux. Increasing the return flow flux was beneficial to the supercharging performance of the jetting device.
Joint Extraction of Entities and Relations Based on Hybrid Feature Representations
Authors: Kun-peng Xing , Yang Xue , De-yan Kong , Wei Dong , Zhen-yan Ji 
Published: November 2022

Abstract
Although the fine-tuning pre-training model technique has obtained tremendous success in the domains of named entity recognition and relation extraction, realistic scenarios exist with many triples of nested entities and overlapping relations. Existing works focus on solving the overlapping triple problem where multiple relational triples in the same sentence share the same entity. In this work, we introduce a joint entity-relation extraction framework based on hybrid feature representation. Our framework consists of five primary parts: constructing hybrid feature representations, bidirectional LSTM encoder, head entity recognition module, entity type classification, and relation tail entity recognition. First, we fuse character-level vector and word-level vector representations via a max-pooling operation to enrich text feature information. Second, the hybrid feature representation is fed into a bidirectional LSTM to capture the correlation between characters and entities. Third, the head entity recognition module employs two identical binary classifiers to detect the start and end positions of entities separately. Then the entity type classification module filters out entities classified as non-entity types by softmax. Finally, we regard relation tail entity recognition as a machine reading comprehension task to eliminate the problem of entity overlap. Specifically, we regard the combination of head entities and relations as queries to query possible tail entities from the text. This framework efficiently handles the polysemy problem, considerably enhances knowledge extraction efficiency, and accurately extracts overlapping triples in domain texts with complicated relationships.