bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Response Analysis of Floating Nuclear Power Plant Containment Under Marine Environment
Authors: Cui Jialin , Li Lijuan , Zhang Meng , Liu Hongbing , Qu Xianqiang 
Published: April 2023

AbstractFloating nuclear containment is in a harsher environment than conventional onshore nuclear containment. In view of the Marine environment under the condition of floating nuclear power plant containment structure safety, combined water dynamics and structural mechanics, considering the containment response under random movement of hull in the Marine environment, the influence of the containment structure load calculation, thus checking containment when working in pile structure safety, provide theoretical basis for the safe operation of floating nuclear power plants. In this paper, taking a floating nuclear power plant as an example, ANSYS 2021R1, Workbench, Fluent and other software of finite element analysis are used to conduct fatigue simulation of floating nuclear power plant. The time course curve of the 6-dof motion of the ship’s center of gravity is obtained, then, a remote displacement method is adopted to transfer the hull motion to the containment vessel to realize the numerical simulation of the containment vessel movement with the hull, thus to solve maximum normal stress and strain, the maximum load component of containment bearing under the action of Marine environmental load is obtained. The results show that the maximum stress and strain of the vessel increase obviously in the moving state compared with the static state of the vessel, which indicates that the random motion response of the vessel must be considered in the structural safety analysis of the floating nuclear power plant containment.
Research on Process Diagnosis of Severe Accidents Based on Deep Learning and Probabilistic Safety Analysis
Authors: Liu Zheng , Wang Hao 
Published: April 2023

AbstractSevere accident process diagnosis provides data basis for severe accident prognosis, positive and negative effect evaluation of Severe Accident Management Guidelines (SAMGs), especially to quickly diagnose Plant Damage State (PDS) for operators in the main control room or personnel in the Technical Support Center (TSC) based on historic data of the limited number of instruments during the operation transition from Emergency Operation Procedures (EOPs) to SAMGs. This diagnosis methodology is based on tens of thousands of simulations of severe accidents using the integrated analysis program MAAP. The simulation process is organized in reference to Level 1 Probabilistic Safety Analysis (L1 PSA) and EOPs. According to L1 PSA, the initial event of accidents and scenarios from the initial event to core damage are presented in Event Trees (ET), which include operator actions following up EOPs. During simulation, the time uncertainty of operations in scenarios is considered. Besides the big data collection of simulations, a deep learning algorithm, Convolutional Neural Network (CNN), has been used in this severe accident diagnosis methodology, to diagnose the type of severe accident initiation event, the breach size, breach location, and occurrence time of the initial event of LOCA, and action time by operators following up EOPs intending to take Nuclear Power Plant (NPP) back to safety state. These algorithms train classification and regression models with ET-based numerical simulations, such as the classification model of sequence number, break location, and regression model of the break size and occurrence time of initial event MBLOCA. Then these trained models take advantage of historic data from instruments in NPP to generate a diagnosis conclusion, which is automatically written into an input deck file of MAAP. This input deck originated from previous traceback efforts and provides a numerical analysis basis for predicting the follow-up process of a severe accident, which is conducive to severe accident management. Results of this paper show a theoretical possibility that under limited available instruments, this traceback and diagnosis method can automatically and quickly diagnose PDS when operation transit from EOPs to SAMGs and provide numerical analysis basis for severe accident process prognosis.
Preparation and Properties of Graphite Surface Vitrification Y2O3 Coating
Authors: Lei Zhen , Li Hongya , Yu Bingzhai , Geng Binghan 
Published: April 2023

AbstractThe Mo-Y2O3 composite coating was prefabricated on the surface of the graphite crucible by plasma spraying, and then the coating surface was remelted by high-power laser. The coating was subjected to SEM analysis, X-ray diffraction, bond strength testing, and molten terbium metal corrosion test. The results show, After laser cladding treatment, the problems of pores and unmelted particles on the surface of the Mo-Y2O3 coating have been significantly improved, and the porosity has been reduced to less than 1.5%, Vitrified Y2O3 with a thickness of about 80–120 μm and columnar crystal growth was formed on the surface of the coating, and the bonding strength was increased from 2–3 MPa before treatment to 7–11 MPa, In the corrosion assessment test of molten terbium metal, the coating was intact and did not fall off, the surface of the ingot was not adhered, and there was no contamination by impurity elements, which could be easily demolded.
Numerical Study on the Mechanism of Oxygen Diffusion During Oxygen Control Process in Heavy Liquid Metals
Authors: Li Ying , Guo Liang , Zhang Chao , You Hongbo , Zan Yuanfeng 
Published: April 2023

AbstractIn order to investigate the mechanisms and characteristics of oxygen diffusion during oxygen control in Heavy Liquid Metals (HLM). Turbulence model coupling species transport model are used to predict the oxygen transport and distribution in liquid lead-bismuth eutectic (LBE) during gas oxygen control process. The oxygen mass flow coefficients are calculated under diffident LBE temperatures, inlet LBE flow rates, inlet oxygen concentrations and gas/liquid interface oxygen concentrations. A mass transfer correlation for oxygen transport is finally acquired. The simulated results indicate that oxygen transport is mainly influenced by the combined effect of convection and diffusion. Specifically, the mass flow coefficient increases with the increase of mass flow coefficient and LBE temperature. The gas/liquid interface oxygen concentration has little effect on the oxygen mass transfer coefficient in the oxygen transfer device of this study. Comparatively, the smaller inlet oxygen concentration leads to the larger average oxygen mass transfer coefficient and the effects of inlet oxygen concentration become weaker with the increase of flow rate. The numerical data presented in this study represents an essential step to reveal the mechanism of oxygen transport in flowing LBE and provides the theoretical basis for guiding the design of oxygen transfer device in HLM-cooled nuclear reactors.
Research of Steady-State Heat Transfer Performance of Heat Pipe Inside Mobile Heat Pipe Reactor
Authors: Lu Huaichang , Zhou Tao , Liu Wenbin , Mao Shang , Wei Dong , Yao Yao , Gao Tianyu 
Published: April 2023

AbstractHigh-temperature heat pipe is an important element in a mobile heat pipe reactor, and the study of the steady-state heat transfer performance of the heat pipe is of great value to the design and safe application of the heat pipe. Based on COMSOL software, a three-dimensional heat pipe model is established to study the effects of the input power of the evaporative section of the heat pipe and the horizontal acceleration of the heat pipe due to its movement on the heat transfer performance of the potassium heat pipe in steady-state operation. The results show that the overall temperature of the outer wall surface of the heat pipe and the axial temperature variation of the center of the heat pipe are less affected by the horizontal acceleration and more affected by the input thermal power within the study range; the thermal resistance of the heat pipe decreases with the increase of the input power of the evaporation section of the heat pipe, and shows a trend of decreasing and then increasing with the increase of the horizontal acceleration.
Three-Dimensional Pin-by-Pin Transient Analysis for PWR-Core
Authors: Qin Junwei , Li Yunzhao 
Published: April 2023

AbstractTo ensure the safety of PWR-core operation, three-dimensional whole-core transient analysis needs to be carried out for the sake of the pin-power distribution. For this purpose, this paper presents “Bamboo-Transient 2.0”, a three-dimensional pin-by-pin transient analysis program. The program adopts a fully-implicit backward method with finite difference for time variable discretization, a method of exponential function expansion nodal (EFEN) SP3 for the neutron transport calculation, and a multi-channel model for the thermal feedback calculation. In addition, Picard iteration is used to couple the neutronics with thermal-feedback, which is intended to guarantee the convergence of coupling iteration at each time step. Moreover, the program can perform parallel computing based on Message Passing Interface (MPI) for the whole-core pin-by-pin transient analysis. This developed program has been applied to two commercial PWRs, viz. AP1000 and CNP1000. Numerical results of this application demonstrate that Bamboo-Transient 2.0 can yield much more refined results than the traditional legacy coarse-mesh neutron-diffusion programs based on assembly homogenization. Its pin-wise distributions of state parameters are reliable and thus can satisfactorily meet the requirements and purpose of safety analysis.
Numerical Simulation of Convective Heat Transfer of CO2 in a Tube Under Supercritical Pressure at Low Reynolds Numbers
Authors: Li Zhihui 
Published: April 2023

AbstractThe supercritical carbon dioxide (S-CO2) Brayton cycle has the advantages of compact layout, simple structure, high thermal efficiency, clean working quality, its application in lead-cooled fast reactor power conversion system helps the miniaturization and modularization of the whole system. The development of an efficient and compact supercritical CO2 heat exchanger has important reference significance for improving the thermal efficiency of the system of lead-cooled fast reactor. Supercritical CO2 can operate in high Reynolds number turbulence and low Reynolds number turbulence in heat exchanger. The convective heat transfer of supercritical pressure CO2 flowing upward and downward in a vertical circular tube (d = 2 mm) at low inlet Reynolds number (Rein = 1970) was numerically simulated by different turbulence models to study the effects of variable properties, buoyancy and thermal acceleration on wall temperature and turbulent kinetic energy. The results showed that the heat transfer deterioration and enhancement occurred at the entrance of the heating section during the upward flow, which was mainly attributed to the influence of buoyancy and heat acceleration on the turbulent kinetic energy distribution. The LB turbulence model was used to simulate the heat transfer phenomenon, which was occurred in the downward flow.
Research of Helium Thermal Power System Based on Lead-Cooled Fast Reactor
Authors: Li Zhihui 
Published: April 2023

AbstractThe Helium Brayton cycle with re-compression has the advantages of compact layout, simple structure, thermal high efficiency, good heat transfer characteristics and small friction characteristics, its application in the power conversion system of the lead-cooled fast reactor and the high temperature gas-cooled reactor helps the miniaturization of the whole system. In this paper, the mathematical model was established for Helium Brayton cycle with re-compression and the 100 MWt lead-cooled fast reactor power system was calculated. The effects of several key factors such as the turbine inlet temperature, the turbine outlet pressure, the high pressure compressor outlet pressure, the low pressure compressor outlet pressure and the recuperator outlet temperature were analyzed. The results show that the turbine outlet pressure, the turbine inlet temperature and the high/low pressure compressor outlet pressure have remarkable effects on thermal efficiency of the system. Thermal efficiency of the system increases first and then decreases with the turbine outlet pressure increasing as well as increases with turbine inlet temperature. The research results of this paper could provide important theoretical reference both for thermal cycle parameters for 100 MWt lead-cooled fast reactor and system design of power cycle based on the lead-cooled fast reactor.
Study on Capiliary Characteristics of Stainless Steel Wire Mesh Wick of Alkali Metal Heat Pipe
Authors: Zhu Yiru , Zhang Luteng , Xi Zhiguo , Ma Zaiyong , Sun Wan , Zhu Longxiang , Pan Liangming 
Published: April 2023

AbstractThe capillary characteristics of the wicks are of great significance to the normal operation of the heat pipe,and this study carried out the wick experiment of vertical reel stainless steel wire mesh in liquid sodium working medium and the visual observation experiment of sodium film in the wire mesh wick. The experimental results show that when the temperature of liquid sodium is about 400 ℃, the capillary phenomenon of stainless steel wire mesh occurs more obviously, and after 450 ℃, the evaporation of sodium is gradually obvious and accompanied by the mass fluctuation of the wire mesh wick. The visual observation experiment of sodium liquid film in the wire mesh found that the wetting and transition point of sodium on the surface of the stainless steel wire mesh was about 410 ℃, which was a good verification of the occurrence of the more obvious capillary phenomenon of the wick at about 400 ℃.
Thermodynamic Equilibrium Analysis of Steam Reforming Reaction of Radioactive Waste Oil
Authors: Wu Xuan , Li Wenyu , Lin Li , Liang Yi , Zhang Jiaheng , Gu Wenlu , Fan Jiheng , Shen EnWei , Xiong KouHong 
Published: April 2023

AbstractAt present, there are much radioactive waste oil temporarily stored in nuclear fuel processing plants, nuclear industry research institutes and operating nuclear power plants in China, which brings great storage pressure and safety risks to the operating nuclear facilities. In this paper, the components analysis of 40# waste oil used in nuclear facilities was carried out, and the elemental composition and chemical composition of the waste oil were obtained. The analysis showed that the main elements in the waste oil were C and H, and the main chemical components were alkanes, alkenes, aromatic hydrocarbons and alcohols with carbon chain length of 10–40. Using Aspen Plus software, the process flow model of waste oil’s steam reforming treatment was established. Based on the components analysis results of the waste oil, organic mixtures such as ethanol, ethane and propane were selected as the model components, and the element composition close to waste oil was obtained by adjusting the proportion of each component. The mixture was used as the source input of Aspen Plus to achieve good simulation results. The experimental results obtained under Pt catalyst at 400 ℃ were in good agreement with the simulation results, which confirmed the validity of the model. The thermodynamic equilibrium analysis of waste oil steam reforming reaction was carried out by using the verified model. The influence of reaction temperature (350–1150 ℃), pressure (0.01–100bar) and water to carbon ratio (0.01–100) on reforming reaction and off gas components in balanced state was studied. The conclusions are as follows: (1) The steam reforming reaction of waste oil has no obvious inhibition when the reaction pressure is less than 1bar, so the reforming reaction should be carried out under the condition of negative pressure less than 1bar; (2) The temperature should be maintained above 750 ℃ to ensure the complete steam reforming reaction; (3) Carbon deposition can be completely eliminated when the water/carbon ratio is higher than 1, and when the water/carbon ratio is higher than 10, the product components do not change with the water/carbon ratio.
Simulation Study of the Neutron Scattering Camera Based on Plastic Scintillator and MPPC
Authors: Li Ji , Shan Qing 
Published: April 2023

AbstractNuclear safety has always been the lifeline of the development of the nuclear industry, and the supervision and management of special nuclear materials is a very important part of nuclear safety. By measuring fission neutron generated by the special nuclear materials, the type and position of special nuclear materials can be determined. In this paper, a neutron scattering camera (NSC) based on plastic scintillator and MPPC was designed to detect the fission neutron in the n-γ mixed field, and then to realize the localization and discrimination of fission materials. The designed NSC contains two layers of detector arrays. The first and second layers are consisted of five and nine detection units, respectively. In order to discriminate neutrons and gamma-rays, EJ-276 plastic scintillator is chosen as the detection medium because of its PSD performance. At the same time, MPPC was used to collect the fluorescence generated in the scintillator. For optimizing the NSC, the Geant4 Monte Carlo simulation toolkit is used to study the whole detection process of the NSC. In the simulation, the factors affecting image reconstruction in neutron source image reconstruction have studied by simulation. The influences of the thickness and radius of the detection units in two layers, the distance between two layers on the image reconstruction were studied in detail. According to the simulation results, the thickness of front detector unit, radius of detector unit, thickness of back detector unit and distance between two layers were determined to be 3 cm, 5 cm, 8 cm and 50 cm, respectively.
Modeling and ballistic tests of selected soft point projectiles in a water medium
Authors: Żochowski Paweł , Pacek Dawid , Bednarczyk Ewa , Bajkowski Marcin , Grygoruk Roman , Magier Mariusz , Szczurowski Krzysztof , Jasiński Marcin 
Published: April 2023

AbstractMethods used nowadays in forensic laboratories allow to stop some kinds of projectiles with degree of deformation which lets to use them for comparing traces to projectiles found on the crime scene. However they are not useful for every type of projectiles. Comparative physical tests are enough to indicate the best method for soft catching projectiles. For this aim point of view no modeling needed. The paper presents the results of ballistic tests of impact of chosen types of soft point projectiles into water. The behavior of projectiles of various shapes, with different kinetic energy, was analyzed. On the basis of the obtained results, the projectiles with the highest susceptibility to deformation were identified. Research works described in the paper were performed within the framework of the project Laboratory stand for stopping high-energy projectiles financed from the National Centre for Research and Development (Agreement no. DOB-BIO10/04/02/ 2019). The project is implemented in cooperation with Warsaw University of Technology, Military Institute of Armament Technology and Tebbex 2 since 2019 to 2022.
Norms of structured random matrices
Authors: Adamczak Radosław , Prochno Joscha , Strzelecka Marta , Strzelecki Michał 
Published: April 2023

AbstractFor $$m,n\in \mathbb {N}$$

m
,
n
∈
N

, let $$X=(X_{ij})_{i\le m,j\le n}$$

X
=

(

X

ij

)

i
≤
m
,
j
≤
n

be a random matrix, $$A=(a_{ij})_{i\le m,j\le n}$$

A
=

(

a

ij

)

i
≤
m
,
j
≤
n

a real deterministic matrix, and $$X_A=(a_{ij}X_{ij})_{i\le m,j\le n}$$

X
A

=

(

a

ij

X

ij

)

i
≤
m
,
j
≤
n

the corresponding structured random matrix. We study the expected operator norm of $$X_A$$

X
A

considered as a random operator between $$\ell _p^n$$

ℓ
p
n

and $$\ell _q^m$$

ℓ
q
m

for $$1\le p,q \le \infty $$

1
≤
p
,
q
≤
∞

. We prove optimal bounds up to logarithmic terms when the underlying random matrix X has i.i.d. Gaussian entries, independent mean-zero bounded entries, or independent mean-zero $$\psi _r$$

ψ
r

($$r\in (0,2]$$

r
∈
(
0
,
2
]

) entries. In certain cases, we determine the precise order of the expected norm up to constants. Our results are expressed through a sum of operator norms of Hadamard products $$A\circ A$$

A
∘
A

and $$(A\circ A)^T$$

(
A
∘
A
)

T

.
Towards a fast PET/MRI protocol for breast cancer imaging: maintaining diagnostic confidence while reducing PET and MRI acquisition times
Authors: Jannusch Kai , Lindemann Maike E. , Bruckmann Nils Martin , Morawitz Janna , Dietzel Frederic , Pomykala Kelsey L. , Herrmann Ken , Bittner Ann-Kathrin , Hoffmann Oliver , Mohrmann Svjetlana , Umutlu Lale , Antoch Gerald , Quick Harald H. , Kirchner Julian 
Published: April 2023

Abstract
Objectives
To investigate the diagnostic feasibility of a shortened breast PET/MRI protocol in breast cancer patients.

Methods
Altogether 90 women with newly diagnosed T1tumor-staged (T1ts) and T2tumor-staged (T2ts) breast cancer were included in this retrospective study. All underwent a dedicated comprehensive breast [18F]FDG-PET/MRI. List-mode PET data were retrospectively reconstructed with 20, 15, 10, and 5 min for each patient to simulate the effect of reduced PET acquisition times. The SUVmax/mean of all malign breast lesions was measured. Furthermore, breast PET data reconstructions were analyzed regarding image quality, lesion detectability, signal-to-noise ratio (SNR), and image noise (IN). The simultaneously acquired comprehensive MRI protocol was then shortened by retrospectively removing sequences from the protocol. Differences in malignant breast lesion detectability between the original and the fast breast MRI protocol were evaluated lesion-based. The 20-min PET reconstructions and the original MRI protocol served as reference.

Results
In all PET reconstructions, 127 congruent breast lesions could be detected. Group comparison and T1ts vs. T2ts subgroup comparison revealed no significant difference of subjective image quality between 20, 15, 10, and 5 min acquisition times. SNR of qualitative image evaluation revealed no significant difference between different PET acquisition times. A slight but significant increase of IN with decreasing PET acquisition times could be detected. Lesion SUVmax group comparison between all PET acquisition times revealed no significant differences. Lesion-based evaluation revealed no significant difference in breast lesion detectability between original and fast breast MRI protocols.

Conclusions
Breast [18F]FDG-PET/MRI protocols can be shortened from 20 to below 10 min without losing essential diagnostic information.

Key Points
• A highly accurate breast cancer evaluation is possible by the shortened breast [18F]FDG-PET/MRI examination protocol.
• Significant time saving at breast [18F]FDG-PET/MRI protocol could increase patient satisfaction and patient throughput for breast cancer patients at PET/MRI.
Investigation of turbulent superstructures in Rayleigh–Bénard convection by Lagrangian particle tracking of fluorescent microspheres
Authors: Weiss Stephan , Schanz Daniel , Erdogdu Ahmed Oguzhan , Schröder Andreas , Bosbach Johannes 
Published: April 2023

AbstractWe present spatially and temporally resolved velocity and acceleration measurements of turbulent Rayleigh–Bénard convection (RBC) in the entire fluid sample of square horizontal cross section with length $$L=320$$

L
=
320

mm and height $$H=20$$

H
=
20

mm, resulting in an aspect ratio of $$\Gamma =H/L=16$$

Γ
=
H
/
L
=
16

. The working fluid was water with a Prandtl number of Pr=7 and the Rayleigh number was set to $${\text{Ra}}= 1.1\times 10^6$$

Ra
=
1.1
×

10
6

. In order to minimize surface reflections, we used fluorescent polyethylene microspheres as tracer particles that were imaged at a rate of 19 Hz by six cameras. From the images, the particle positions, velocities, and accelerations were determined via the ‘Shake-The-Box’ (STB) Lagrangian particle tracking algorithm. With this approach, we could simultaneously track more than 300,000 particles and hence study the resulting turbulent structures in the Eulerian and Lagrangian frames while resolving the smallest spatial and temporal scales of the flow.