bluuebunny/crossref_metadata_2025 huggingface dataset:
Research of Dissimilar Steel Welding for HTR-PM SG Heat Exchange Tube
Authors: Zheng Mingtao , Wang Li
Published: November 2022

The modular High-Temperature Gas-Cooled Reactor nuclear power plant has inherent safety, simple system, high power generation efficiency and wide use. Incoloy800H and 2.25Cr-1Mo heat exchange tubes are used for High-Temperature Gas-Cooled Reactor (HTR-PM) Steam Generator. The steam generator uses the Incoloy800H and 2.25Cr-1Mo heat exchange tubes to transfer the high temperature helium medium to the water medium. The dissimilar steel welds are designed between Incoloy800H and 2.25Cr-1Mo heat exchange tubes. The heat exchange tubes of HTR-PM Steam Generator with small OD, large thickness, and design structure complicated. The dissimilar steel welds between two kinds of heat exchange tubes with limited welding operation space and welding seam quality requirements high. During the HTR-PM Steam Generator operation process, Incoloy800H heat exchange tube, 2.25Cr-1Mo heat exchange tube and the dissimilar steel welds between Incoloy800H and 2.25Cr-1Mo heat exchange tube are service in high temperature environment for a long time, until the steam generator fails. The surface forming quality, conventional properties and high temperature stress-rupture of dissimilar steels weld is required. The quality of dissimilar steel weld of Incoloy800H and 2.25Cr-1Mo heat exchange tubes is directly related to the safe operation of steam generator. Through systematic research including tube-to-tube joint type, the welding material, welding parameters, heat treatment process etc. The results show that using appropriate GTAW process with Nickel base alloy consumable inserts, welded joints can meet all design requirements such as strict inner and outside surface forming quality, conventional performance and the strength of stress-rupture test in HTR-PM Steam Generator service environment. This process has been used in the product manufacturing of demonstration projects, and provides good demonstration experience for similar application scenarios in the industry.
Rapid Assessment Method for Corrosion Flaws of Seawater Cooling Pipes in Nuclear Power Plants
Authors: Han Zhichao , Chang Haijun , Shen Mengling , Rong Zhishen , Li Zhengpeng
Published: November 2022

The corrosion of the fluid to the pipes could damage the pipe structure, and then affect the safe operation of the whole pipeline system in the nuclear power plant. In order to assess the influence of the corrosion flaws on pipe integrity, it is necessary to perform the stress analysis and calculate the remaining strength of the pipes containing flaws. In this paper, the corrosion flaws in the seawater cooling pipes are considered as the volumetric type flaws. The remaining strength of the pipes containing the flaws has been calculated, the minimum required wall thickness of the pipes has been obtained, and the flaws have been assessed according to SY/T 6477 Standard. The finite element method has been used to analyze the pipes containing corrosion flaws. Stress distribution of the pipes has been obtained under the pressure and nozzle loading. Based on the RCC-M Standard, the strength assessment has been conducted. Results showed that the stress calculated from SY/T 6477 Standard is close to that from the finite element method, and it can be considered that the assessment method summarized from SY/T 6477 Standard is suitable for the current pipes containing flaws under the nozzle loadings. Therefore, this method can be used to assess the corrosion flaws of the seawater cooling pipes rapidly, and provide advices for the monitoring and repair of the pipes containing flaws in nuclear power plants.
Study on the Method for the Safety-Related Instrument Calibration Surveillance Interval Extension of Nuclear Power Unit With Analog I&C System Based on Setpoint and Uncertainty Analysis
Authors: Zhang Yong , Zhang Zhao , Wang Zi-Chun , Zhou Yong-Hui , Tang Bo-Wen , Su Min-Hua , Luo Wen-Bo
Published: November 2022

To extend the intervals of Safety-related Instrument Calibration Periodic Test can shorten the refueling outage period and improve unit economy. Based on the general requirements for extending the Safety-related Instrument Calibration Periodic Test Intervals and in consideration of the characteristics of M310 Nuclear Power Unit with analog I&C System, an evaluation method is proposed and investigated, which consist of instrument drift analysis, protection channel analysis, channel uncertainty calculation, setpoint analysis and relevant channel tests evaluation. The research on the extension of steam generator level transmitter calibration test interval is carried out in detail. The results show that the drift resulting from the interval extension will has no effect on the protection channel setpoint, the acceptance criteria for channel consistency test and channel function test should remain unchanged. The research of this paper has a reference value for unit economy improvement and outage optimization.
Study on Methodology and Application of Seismic Level 2 Probabilistic Safety Assessment for Nuclear Power Plants
Authors: Zheng Hongjia
Published: November 2022

Many countries have paid more attention to seismic risk in nuclear power plants after the Fukushima nuclear accident. It indicates that evaluating the risk for seismic event is vitally important. Seismic Level 1 probabilistic safety assessment (PSA) has a mature methodology, but how to perform the study on seismic Level 2 PSA has become a crucial problem needed to be considered deeply by both regulators and operators. In this paper, the methodology of seismic Level 2 probabilistic safety assessment (PSA) is developed for nuclear power plants. Seismic Level 2 PSA is focused on the severe accident phenomenon, progression and source terms release to evaluate the containment response after core damage caused by seismic event. To demonstrate the effectiveness of the proposed approach, this study took a nuclear power plant under construction in China as an example. Seismic Level 2 PSA focuses on crucial elements including Level 1/ Level 2 PSA interface analysis, severe accident design features, severe accident phenomenon, containment event tree analysis, seismic fragility analysis, etc. A risk-informed seismic Level 2 PSA model is developed to evaluate large release frequency (LRF) caused by seismic event. The proposed methodology can be expected to provide an effective framework for performing the seismic Level 2 PSA and decision support to improve the nuclear power plant safety.
Development and Application of Nuclear Power Plant Life Cycle Management Database Platform
Authors: Guochang Cao , Zhao Liu , Fangming Lv , Zhenzhong Yang , He Jilang , Yixin Cui
Published: November 2022

In the long life extension operation of nuclear power plant, life cycle management technology can provide reliable support for the economic operation of nuclear power plant, and is an important support technology for the evaluation of nuclear power plant’s continuous operation. In order to promote the development of life cycle management technology in nuclear power plants, information technology is used to transform specific problems into standardized databases, relying on the Operation License Renewal Project, the software platform of life cycle management database for important equipment in nuclear power plant is developed. In addition to the storage function of the equipment life cycle management information, the database has the functions of cost calculation and economic comparison of the long-term operation plan. It includes seven modules: Original Information, Program Management, Aging Mechanism, Out-of-date Evaluation, Failure Rate, Economic Analysis and External Feedback. The database built-in nuclear power plant life cycle management typical equipment such as steam turbines, generators, main transformers, and so on, while users can be independent in life-cycle equipment maintenance to add the need to expand the object. It is considered that the acquisition and reliability of cost data, equipment reliability data, and equipment life and failure rate data are the difficulties of life cycle management of nuclear power plants at present.
Analysis of the Influence of RCCA Swelling on Rod Falling and Study on Mitigation Measures
Authors: Lv Zhipeng , Zhang Guoliang , Li Changzheng , Liu Weichao , Lin Shaofang , Nie Lihong , Li Zhijun , Zhang Anlong
Published: November 2022

Silver-Indium-Cadmium (Ag-In-Cd) is commonly used as the neutron absorption material in PWR, and its swelling under reactor irradiation condition may lead to outward deformation of control rod cladding, and finally affect RCCA dropping. In severe cases, rod dropping time exceeding its limit regulated in operation technical specification and even RCCA sticking caused by Ag-In-Cd excessive swelling may occur, which will threaten reactor safety shutdown. The influence of different swelling forms on the dropping time of RCCA is studied in this paper, and finally the absorber design is optimized based on current PWR absorber design. The results show that the swelling of control rods has little effect on T5, but mainly affects the dropping time T6 in the dashpot section. Different swelling positions have different effects on the dropping time, and the optimized design can improve this swelling effects.
Application of Detail Design Data of Nuclear Power Plant in Project Construction and Operation Under the Background of Digitization
Authors: Huang Huizhen , Tian Licheng , Yan Jiafu
Published: November 2022

Building Information Modeling theory has been more and more welcome all over the world, and has been introduced into nuclear power industry. The so-called ‘smart power station’ being established by many nuclear power enterprises is the embodiment of BIM. With the deepening of digital design and application, the design data has become more and more detailed and accurate, to support all design work such as data exchange between systems and software, automatic drafting, automatic material and working counting, and so on. In addition to design, how should the procurement, construction, installation and power station operation engineers use these data to improve their work efficiency and accuracy is a research topic, which has been highly followed by engineering companies at present. At the same time, the design data is more for design itself. Whether its expression form, depth and breadth can meet the requirements of downstream engineers and how to improve efficiently when they are not satisfied is an important issue that all project participants should pay attention to. This paper gives a sketch of 3D design data, with pipework as an example, to elaborate how to use design data to help other engineers to break down old-style of working mode, and gives some thinking about optimizing design data efficiently to fulfill the requirement of other project participants.
Research on Redundancy Strategy of Nuclear Instrument Control Data Service System
Authors: Zhang Yingying , Hu Yiwu , Li Hualong , Sun Jingle
Published: November 2022

The nuclear instrument control data service system is the data monitoring background of the monitoring layer of the nuclear instrument control system, which has higher requirements for system reliability and data security, and usually adopts the fully redundant configuration structure of dual machine hot standby and double storage. How to arbitrate the server master-salve state according to the real-time diagnosis results, is the key problem faced in the redundant design of the nuclear instrument control system. According to the characteristics of the nuclear instrumentation control system, server failure types are analyzed, and an intelligent hierarchical redundant switching strategy is proposed. The decision-making module is divided into two layers. First of all, different business failure scenarios are divided, and each fault scenario gives a prime and slave arbitration result. Secondly, according to the importance priority, the arbitration result of the first layer is sorted, and the final arbitration result is given. The proposed redundancy strategy supports arbitration under multiple concurrent faults, and can support single-machine deployment and dual-machine deployment, with good switching performance. The technology has been successfully applied in a nuclear power instrumentation control project. The system runs normally in the case of local faults such as single-machine power failure, single-machine network failure, process collapse, etc., ensuring the safe and stable operation of the unit.
Study on Synthesis of the Organophosphorus Functionalized MCM-41 And its Adsorption Property for Dy(III)
Authors: Mao Cong , Sang Hongji , Zheng Jiawei , Wu Yan
Published: November 2022

The composite of organophosphorus groups loaded on MCM-41(MCM-Zr-TBP) was prepared by multi-steps impregnation method to develop a novel adsorbent for radioactive lanthanides extraction from the secondary contaminated water. The synthesized hybrid material was characterized by SEM and TG. Dy(III) was taken as the representative of trivalent lanthanides. The adsorption performance of Dy(III) on MCM-Zr-TBP composite was systematically studied as the functions of solution pH, initial concentration, interaction time and aqueous temperature. The results showed that Dy(III) adsorption on MCM-Zr-TBP composite was highly dependent on aqueous pH and initial metal ion concentration. Compared with the Freundlich and pseudo-first order models, the Langmuir and pseudo-second order models presented better fitting for the adsorption data. These results indicated that MCM-Zr-TBP was found to be an effective and competent adsorbent, which could be used for the effective removal of lanthanides from the wastewater.
PWR Spent Fuel Dry Storage Loading Pattern and Safety Evaluation
Authors: Wen Li , Jinghui Gao , Gang Li , Shengdong Zhong , Jin Xu , Bingquan Zhao
Published: November 2022

This paper describes the loading pattern, safety evaluation and operating experiences of PWR plant off-site Spent Fuel Dry Storage System (SFDSS). According to the limits from the SFDSS criticality and heat-transfer safety analysis, ALARA principle and AFA series fuel characteristics, technical staff complete the loading pattern and safety evaluation by analyzing influence of assemblies’ initial enrichment, burn up and cooling time. This paper also shows the temperature and dose data during AFA series fuel SFDSS loading, transportation and storage, which can indicate the actual condition of SFDSS criticality, heat-transfer and radiation. In general, AFA series fuel SFDSS is in good condition and meet the expected design and safety requirements.
Research on Structural Optimization Technology of Fuel Assembly Parts Based on Topology and Optimal Design
Authors: Fan Huabin , Xu Shiyin , Jia Huili
Published: November 2022

The top nozzle is an important part of the fuel assembly and is located at the core coolant outlet, which has an important impact on the uniformity of the coolant flow distribution at the core outlet and the overall pressure drop of the fuel assembly[1]. The peak stress of the top nozzle under each working condition appears at the position of the adapter plate, top nozzle and the pressure drop of the top nozzle is closely related to the flow area, height and local characteristics of the adapter plate. In this paper, the overall structure of the adapter plate is optimized to reduce the pressure drop as much as possible on the premise of ensuring that the stress meets the requirements of the standard limit. The 3D modeling software NX is used to establish the geometric model of the top nozzle, and it is transferred to ANSYS to establish a finite element model for simulation optimization design. On this basis, the key dimension parameters of the adapter plate (such as the thickness of the rib, etc.) are selected as design variables, and the law of its influence on the blocking area and stress is studied, and the structure size is further optimized.
Study of Breeding Performance in a Heat Pipe Cooled Traveling Wave Reactor With Th and U Fuels
Authors: Ma Kunfeng , Hu Po
Published: November 2022

Heat pipe cooled traveling wave reactor (HPTWR) is a newly proposed heat pipe reactor. The HPTWR can achieve the low enrichment of loaded fuel, high power density, and long-term continuous operation for the power supply of decentralized electricity markets. Due to the excellent breeding capability of the HPTWR, the Th fuel is also added into the breeding fuel region of the reactor to achieve the Th-U fuel cycle in this work. The Monte Carlo code RMC is used to obtain the reactivity swing, propagation of axial power peak, burnup and the productions of bred fissile nuclides for the HPTWR with Th and U fuels. The study shows that the HPTWR with 14.3% 235U enrichment of ignition fuel and 20% 235U enrichment of breeding fuel can continuously operate for 41 years without refueling when the mass fraction of 232Th in heavy metals of breeding fuel region is 50% at the initial time. The propagation velocity of axial power peak and total burnup for the HPTWR with the Th and U fuels is about 0.3659 cm/years and 89.32 GWd/THM during the 41 years operation respectively. The productions of the bred 239Pu, 241Pu and 233U in the HPTWR with Th and U fuels are about 356.40 kg of 239Pu, 1.57 kg of 241Pu and 199.94 kg of 233U at the end of life respectively. The obtained results in this study demonstrate that the HPTWR can achieve the Th fuel breeding in the case of the low 235U enrichment loading (≤ 20%) and long-term continuous operation (> 40 years).
Criticality Study of Spent Fuel Storage Rack of Ship-Based Small Modular Reactor
Authors: Ye Yaoxin , Zhao Jun , Xu Yunfei
Published: November 2022

The boron-free fuel storage pool of the ship-based SMR is part of the ship’s fuel operation and storage system. The spent fuel storage rack in the fuel temporary pool is used to store spent fuel assemblies unloaded from the core after the ship’s reactor is shut down. Compared with onshore reactors, ship-based reactors face more complex marine conditions and accident conditions during the operation on the sea, such as tilting, swaying, and collision, etc. As a consequence, the fuel storage rack of the ship will be deformed and there is a risk of supercritical accident. In this work, the criticality study of spent fuel storage rack of a ship-based reactor was performed. First, the deformation of storage rack under marine conditions and accident conditions were obtained by mechanical analysis. Then, various criticality analysis models were established and the critical calculation was carried out by the JMCT Monte Carlo code, accounting for the deformation of such conditions of the spent fuel storage rack. The effects of different marine conditions and accident conditions on the effective multiplication factor of the ship-based storage rack were investigated. The results show that the studied ship-based boron-free storage rack is in a subcritical state under the conditions considered above.
Research and Application Innovation of Digital Twin Technologies for Key Equipment of Nuclear Power Plants
Authors: Zhao Dong , Guan Fenghua
Published: November 2022

Nuclear power equipment is an important part of nuclear power plant. It has the characteristics of complex system structure, long manufacturing cycle, long-term operation under irradiation conditions and poor working environment. It has high requirements for product quality grade. High reliability nuclear power equipment is an important premise and guarantee for the smooth construction and safe operation of nuclear power plant. Through digital twin technology, optimizing the design, manufacturing, operation and maintenance process of nuclear power equipment and improving the operation and maintenance efficiency of systems and equipment will be an important direction for the digital transformation and intelligent upgrading of nuclear power plants. This paper studies the digital twin core technologies such as multi-scale modeling, multidisciplinary joint simulation, virtual reality presentation and data mining, draws lessons from the concept of data life cycle management, develops the digital design platform of nuclear power equipment, realizes the integration of three-dimensional design, analysis, verification and Simulation of nuclear power equipment, and integrates the key data and models of nuclear power equipment operation, Provide support for the monitoring and maintenance of in-service equipment, and promote the digital transformation and upgrading of R & D and operation of key equipment in nuclear power plants.
Experimental Study on Pressure Pulsation of RCP With Steam Generator
Authors: Huang Song , Song Yu , Yin Junlian , Xu Rui , Wang Dezhong
Published: November 2022

The reactor coolant pump (RCP) is an important equipment for transporting coolant. Its safe and dependable functioning is linked to the nuclear power plant’s stable operation. Two input conditions of the nuclear main pump were investigated in the experiment: The nuclear main pump’s inlet was connected to the straight pipe section, and the steam generator’s inlet was connected to the steam generator. The second connection mode look more like real nuclear power facilities. Due to the varied upper inlet connection, pressure pulsation with various characteristics occurs in the core main pump. When the steam generator is linked to the nuclear main pump’s input, the nuclear main pump’s pressure pulsation increases dramatically. And the entire pump has an obvious low frequency of about 3.9Hz, which has become the first primary frequency of pressure pulsation in the entire pump.
The Core Design Modifications for Stirling Thermal-Electric Integrated Micro Reactor
Authors: Yan Xia , Ou Xuedong , Lin Mingqiang , Mou Jian , Sun Shaolei , Chi Chunyun , Zhao Chunqing , Zhou Qin
Published: November 2022

Currently a two-step designing method of sequential neutronic physics and Stirling physical analysis was used for a Miniature Integrated nuclear Reactor design with gravity independent Autonomous Circulation (ACMIR). It was proposed in this article to optimize the intermediate/transitive variables of dead volume and heat exchange area/dead volume ratio as much as possible in the first step so that the system objectives in the second step can be better achieved. The ACMIR core was modified from using rod typed fuels to using plate typed fuels, making use of the plated core’s advantages of easy compression of coolant flow channel while maintaining large heat transfer area. As applied to a 40kWt cooperative dual Stirling power system design of ACMIR, the output power and efficiency index of the system had been significantly improved from 981W to 6395W (each Stirling), with efficiency from 7.4% to 26.6%.
Design and Development of Intelligent Replacement Robot for Radioactive Spent Filter Element in NPP and Its Performance Validation
Authors: Ge Yongjun , Lin Yishan , Xie Honghu , Yang Jinchun
Published: November 2022

During the operation of a nuclear power plant, many main systems will generate variety of radioactive spent filter elements. These filter elements are main solid waste which need to be replaced regularly to keep safety of these systems. Because these filter elements have a certain level of radioactivity, the replacement operation has a higher risk. Therefore, according to the national and nuclear power plant radioactive waste regulations, it is necessary to ensure the safe and reliable operation of the radiation protection, make sure that operator and facilities are protected from radiation exposure or minimized. Based on the analysis of the filter element replacement process and equipment of domestic nuclear power units in service, combined with the requirements of newel construction of intelligent nuclear power plants, it is necessary to propose a radioactive spent filter element intelligent replacement ROBOT program. This paper discusses the design scheme of a new intelligent replacement robot for radioactive spent filter elements, and key issues involving fully automatic replacement technology for radioactive filter elements, such as filter layout and filter element replacement process optimization, robot grabbing actuator design, robot positioning mechanism design and accuracy guarantee, etc. have been systematically studied. A set of robot systems with intelligent replacement of radioactive irrationality have been developed. The test has been verified and the technical conditions for implementation in NPP have been met.
A Drive-Through Passenger Vehicle Inspecting System Using X-Ray Digital Radiography
Authors: Tong Jianmin , Huang Yibin , Guo Xiaojing , Chen Liu , Cong Peng , Wang Zhentao , Xing Guilai , Wang Liqiang
Published: November 2022

Using X-ray or γ-ray to inspect vehicles is an effective way to find threats such as stowaways and contrabands hidden inside. Popularly used vehicle inspection devices at present require passengers to get off the vehicle, and then the vehicle is dragged by a conveyor to move through the inspection device. One disadvantage of such devices is that inspecting efficiency is very low. In this paper, a drive-through mode passenger vehicle inspecting system is introduced, with which passengers in a vehicle need not get off and efficiency is greatly improved. Patented high-pressure gas ionization chamber is used as radiation detector to collect the low radiation signal. A deep-learning study algorithm is adopted to realize image recognition to find specified object. The system can greatly increase security check efficiency with good image quality.
Study of Pre-Oxidization Law and Fretting Wear Resistance of CZ2 Alloy Cladding
Authors: Sun Guocheng , Lin Shi , Wang Xu , Chen Liutao
Published: November 2022

In the core of pressurized water nuclear reactor, coolant flow-induced vibration of Grid to rod fretting (GTRF) is the dominant factor leading to fuel rod damage. pre-oxidization treatment of zirconium cladding forming a ceramic layer on its surface is the main way to reduce the GTRF wear. In this paper, the growth law of CZ2 alloy cladding pre-oxidization zirconia ceramic layer formed in air was studied. The micro-hardness and elastic modulus of CZ2 alloy cladding and zirconia ceramic layer were measured by in-situ nano-mechanical testing system., while the morphology of these pre-oxidization zirconia ceramic layer were observed by scanning electron microscope. The fretting wear properties of the pre-oxidization zirconia ceramic layer were studied by high temperature and high pressure fretting wear tests. The results show that the pre-oxidization zirconia ceramic layer growth law of CZ2 alloy cladding at 560°C and 600°C is consistent, and the pre-oxidization zirconia ceramic layer are compact and crack-free. The pre-oxidization zirconia ceramic layer can improve the fretting wear resistance of CZ2 alloy cladding at high temperature and high pressure, and the maximum wear depth were reduced by 80%.
Study on Out-Pile Performance of CZ Zirconium Alloy Guide Tube
Authors: Gao Changyuan , Shi Lin , Zhang Guoliang , Xu Yang , Chen Minli , Chen Liutao , Tan Jun
Published: November 2022

Based on the composition of CZ1 alloy and CZ2 alloy, guide tubes were fabricated. The performance of CZ1 and CZ2 alloy guide tube was studied. Through microscopic observation, it can be seen that the CZ alloy guide tube has a completely recrystallized structure with fine grains and dispersed second phase particles. Autoclave Corrosion test shows that the corrosion resistance of CZ1 and CZ2 alloy in pure water at 360°C is better than recrystallized Zr-4 alloy and Zr-1Sn-1Nb alloy tubes, and the corrosion resistance of CZ1 alloy in steam at 400°C is similar to recrystallized Zr-4 alloy and better than CZ2 and recrystallized Zr-1Sn-1Nb alloy. The mechanical test shows that the yield strength and tensile strength of CZ alloy are equal to or slightly higher than recrystallized Zr-4 alloy and Zr-1Sn-1Nb alloy at room temperature and elevated temperature. The out-pile axial creep tests show that the creep deformation of various alloys are very small for low stress (60MPa) conditions, and the axial creep resistance of CZ alloy is better than that of recrystallized Zr-4 alloy and inferior to recrystallized Zr-1Sn-1Nb alloy for high stress (> 100MPa) conditions. According to the comprehensive evaluation of the out-pile test results, CZ alloy guide tube has excellent out-pile performance, and CZ alloys have the prospect of being used as guide tube material.
Study on Water Chemistry and Temperature Adaptability of CZ Zirconium Alloy
Authors: Chen Hansen , Gao Changyuan , Chen Liutao , Wang Xu , Tan Jun
Published: November 2022

The corrosion behavior of zirconium alloys is closely related to the water chemistry and operating temperature of the primary circuit. The increase of operating temperature, Li concentration and pH value will have a significant negative impact on the corrosion behavior of zirconium alloy. Autoclave corrosion tests of CZ and Zr-4 alloys were carried out under different water chemistry conditions (Li concentration and pH300 were 3.5ppm/7.2, 4.5ppm/7.2, 4.5ppm/7.5, 7ppm/7.5 respectively) and temperature conditions (360 °C, 400 °C, 430 °C, 450 °C, 500 °C). The effects of different temperature and water chemistry conditions on the corrosion rate of different zirconium alloys were obtained and the information of oxide film thickness and hydrogen content of different samples in different corrosion stages were obtained to study the temperature and water chemistry adaptability of zirconium alloys. The experimental results show that breakaway corrosion and nodule corrosion occur in Zr-4 alloy above 430 °C, and the thickness of oxide film and hydrogen absorption increase significantly. However, the corrosion law of CZ alloys keep the same from 360 °C to 500 °C, and there is no breakaway corrosion or nodule corrosion. The relationships between corrosion rate and temperature accord with Arrhenius formula, showing good temperature adaptability. Under relatively severe water chemistry conditions (Li concentration and pH300 are 4.5 ppm and 7.5 respectively), the corrosion rate of various zirconium alloys does not increase obviously, and there is no nodule corrosion phenomenon. The increase of oxide film thickness and hydrogen absorption capacity is not obvious, showing good water chemistry adaptability.
Analytical Study for Low Ground Contact Ratio of Buildings Due to the Basemat Uplift Using a Three-Dimensional Finite Element Model
Authors: Choi Byunghyun , Nishida Akemi , Shiomi Tadahiko , Kawata Manabu , Li Yinsheng
Published: November 2022

The basemat uplift is a phenomenon that the bottom of the basemat of a building partially rises from the ground due to overturning moments and vertical motions during earthquake. The degree of the basemat uplift can be indicated using a ground contact ratio which is defined as a ratio of the contact area of the bottom of the basemat to its entire area. The problem is that, at a large earthquake, the basemat uplift becomes large, so-called low ground contact ratio state, and the basemat falls resultant to recontact between the basemat and the ground, and large acceleration response occur on the floor of the building. It is a crucial aspect in the seismic evaluation of a nuclear facility building. It affects not only structural integrity of the building but also the response of the equipment installed in the building. However, the building behavior under the low ground contact ratio state lacks sufficient study. In this study, we conducted seismic response analyses for the building using a three-dimensional finite element model and simulated shaking table experiments focused on the basemat uplift and confirmed the validity of this analysis method. Since the basemat uplift is a strong non-linear phenomenon, we conducted computer simulations under the same analysis conditions with three different analysis codes, namely E-FrontISTR, FINAS/STAR, and TDAPIII, and compared the results. We investigated the influence on the structural response caused by the difference of the adhesive force of the basemat and the bearing ground at the low ground contact ratio state. In addition, we studied the influence of numerical parameters to the structural response through sensitivity analyses. This paper reports the analysis results and the insights obtained from our investigations.
Tackle Your Feelings: Experience of Help-Seeking for Mental Well-Being Concerns in Professional Rugby Union Players
Authors: Lyons Deirdre , Clarke Philip , Dempsey Robert C.
Published: November 2022

Limited research into professional rugby union players’ experiences of seeking formal support for their mental health exists, despite comparable rates of mental health issues among elite rugby players with the general population. This qualitative study explored professional players’ actual experiences of accessing Rugby Players Ireland’s mental well-being service, via separate focus group discussions with professional players (n = 5) and player development managers (n = 4) who refer players into the service. An inductive reflexive thematic analysis identified three themes detailing players’ (a) journey to disclosure of their mental health difficulties, (b) their expectations and engagement with the well-being service, and (c) participants’ reflections on mental health experiences in a high-performance environment. Embedding mental health as a key component of player development in high-performance environments, improving mental health literacy, normalizing mental health experiences, and encouraging help-seeking would help promote player well-being and support holistic development alongside sporting performance.
Oyster reef restoration fails to recoup global historic ecosystem losses despite substantial biodiversity gain
Authors: Hemraj Deevesh A. , Bishop Melanie J. , Hancock Boze , Minuti Jay J. , Thurstan Ruth H. , Zu Ermgassen Philine S. E. , Russell Bayden D.
Published: November 2022

Human activities have led to degradation of ecosystems globally. The lost ecosystem functions and services accumulate from the time of disturbance to the full recovery of the ecosystem and can be quantified as a “recovery debt,” providing a valuable tool to develop better restoration practices that accelerate recovery and limit losses. Here, we quantified the recovery of faunal biodiversity and abundance toward a predisturbed state following structural restoration of oyster habitats globally. We found that while restoration initiates a rapid increase in biodiversity and abundance of reef-associated species within 2 years, recovery rate then decreases substantially, leaving a global shortfall in recovery of 35% below a predisturbed state. While efficient restoration methods boost recovery and minimize recovery shortfalls, the time to full recovery is yet to be quantified. Therefore, potential future coastal development should weigh up not only the instantaneous damage to ecosystem functions but also the potential for generational loss of services.
Macrophage acetyl-CoA carboxylase regulates acute inflammation through control of glucose and lipid metabolism
Authors: Yeudall Scott , Upchurch Clint M. , Seegren Philip V. , Pavelec Caitlin M. , Greulich Jan , Lemke Michael C. , Harris Thurl E. , Desai Bimal N. , Hoehn Kyle L. , Leitinger Norbert
Published: November 2022

Acetyl-CoA carboxylase (ACC) regulates lipid synthesis; however, its role in inflammatory regulation in macrophages remains unclear. We generated mice that are deficient in both ACC isoforms in myeloid cells. ACC deficiency altered the lipidomic, transcriptomic, and bioenergetic profile of bone marrow–derived macrophages, resulting in a blunted response to proinflammatory stimulation. In response to lipopolysaccharide (LPS), ACC is required for the early metabolic switch to glycolysis and remodeling of the macrophage lipidome. ACC deficiency also resulted in impaired macrophage innate immune functions, including bacterial clearance. Myeloid-specific deletion or pharmacological inhibition of ACC in mice attenuated LPS-induced expression of proinflammatory cytokines interleukin-6 (IL-6) and IL-1β, while pharmacological inhibition of ACC increased susceptibility to bacterial peritonitis in wild-type mice. Together, we identify a critical role for ACC in metabolic regulation of the innate immune response in macrophages, and thus a clinically relevant, unexpected consequence of pharmacological ACC inhibition.
The rapid evolution of flagellar ion selectivity in experimental populations of
E. coli
Authors: Ridone Pietro , Ishida Tsubasa , Lin Angela , Humphreys David T. , Giannoulatou Eleni , Sowa Yoshiyuki , Baker Matthew A. B.
Published: November 2022

Determining which cellular processes facilitate adaptation requires a tractable experimental model where an environmental cue can generate variants that rescue function. The bacterial flagellar motor (BFM) is an excellent candidate—an ancient and highly conserved molecular complex for bacterial propulsion toward favorable environments. Motor rotation is often powered by H
+
or Na
+
ion transit through the torque-generating stator subunit of the motor complex, and ion selectivity has adapted over evolutionary time scales. Here, we used CRISPR engineering to replace the native
Escherichia coli
H
+
-powered stator with Na
+
-powered stator genes and report the spontaneous reversion of our edit in a low-sodium environment. We followed the evolution of the stators during their reversion to H
+
-powered motility and used both whole-genome and RNA sequencing to identify genes involved in the cell’s adaptation. Our transplant of an unfit protein and the cells’ rapid response to this edit demonstrate the adaptability of the stator subunit and highlight the hierarchical modularity of the flagellar motor.
Psychological distress and eustress in cancer and cancer treatment: Advances and perspectives
Authors: Wu Yuanjun , Zhou Laiyan , Zhang Xuanwei , Yang Xue , Niedermann Gabriele , Xue Jianxin
Published: November 2022

Facing cancer diagnosis, patients with cancer are prone to psychological stress and consequent psychological disorders. The association between psychological stress and cancer has long been a subject of high interest. To date, preclinical studies have gradually uncovered the promotive effects of psychological distress on tumor hallmarks. In contrast, eustress may exert suppressive effects on tumorigenesis and beneficial effects on tumor treatment, which brings a practicable means and psychosocial perspective to cancer treatment. However, the underlying mechanisms remain incompletely understood. Here, by focusing on the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, as well as stress-related crucial neurotransmitters and hormones, we highlight the effects of distress and eustress on tumorigenesis, the tumor microenvironment, and tumor treatment. We also discuss the findings of clinical studies on stress management in patients with cancer. Last, we summarize questions that remain to be addressed and provide suggestions for future research directions.
High-temperature adaptation of an
OsNRT2.3
allele is thermoregulated by small RNAs
Authors: Zhang Yong , Tateishi-Karimata Hisae , Endoh Tamaki , Jin Qiongli , Li Kexin , Fan Xiaoru , Ma Yingjun , Gao Limin , Lu Haiyan , Wang Zhiye , Cho Art E. , Yao Xuefeng , Liu Chunming , Sugimoto Naoki , Guo Shiwei , Fu Xiangdong , Shen Qirong , Xu Guohua , Herrera-Estrella Luis Rafael , Fan Xiaorong
Published: November 2022

Climate change negatively affects crop yield, which hinders efforts to reach agricultural sustainability and food security. Here, we show that a previously unidentified allele of the nitrate transporter gene
OsNRT2.3
is required to maintain high yield and high nitrogen use efficiency under high temperatures. We demonstrate that this tolerance to high temperatures in rice accessions harboring the HTNE-2 (high temperature resistant and nitrogen efficient-2) alleles from enhanced translation of the
OsNRT2.3b
mRNA isoform and the decreased abundance of a unique small RNA (sNRT2.3-1) derived from the 5′ untranslated region of
OsNRT2.3
. sNRT2.3-1 binds to the
OsNRT2.3a
mRNA in a temperature-dependent manner. Our findings reveal that allelic variation in the 5′ untranslated region of
OsNRT2.3
leads to an increase in OsNRT2.3b protein levels and higher yield during high-temperature stress. Our results also provide a breeding strategy to produce rice varieties with higher grain yield and lower N fertilizer input suitable for a sustainable agriculture that is resilient against climate change.
Local thermoelectric response from a single Néel domain wall
Authors: Puttock Robert , Barton Craig , Saugar Elias , Klapetek Petr , Fernández-Scarioni Alexander , Freitas Paulo , Schumacher Hans W. , Ostler Thomas , Chubykalo-Fesenko Oksana , Kazakova Olga
Published: November 2022

Spatially resolved thermoelectric detection of magnetic systems provides a unique platform for the investigation of spintronic and spin caloritronic effects. Hitherto, these investigations have been resolution-limited, confining analysis of the thermoelectric response to regions where the magnetization is uniform or collinear at length scales comparable to the domain size. Here, we investigate the thermoelectric response from a single trapped domain wall using a heated scanning probe. Following this approach, we unambiguously resolve the domain wall due to its local thermoelectric response. Combining analytical and thermal micromagnetic modeling, we conclude that the measured thermoelectric signature is unique to that of a domain wall with a Néel-like character. Our approach is highly sensitive to the plane of domain wall rotation, which permits the distinct identification of Bloch or Néel walls at the nanoscale and could pave the way for the identification and characterization of a range of noncollinear spin textures through their thermoelectric signatures.
Successful targeting of PD-1/PD-L1 with chimeric antigen receptor-natural killer cells and nivolumab in a humanized mouse cancer model
Authors: Liu Wai Nam , So Wing Yan , Harden Sarah L. , Fong Shin Yie , Wong Melissa Xin Yu , Tan Wilson Wei Sheng , Tan Sue Yee , Ong Jessica Kai Lin , Rajarethinam Ravisankar , Liu Min , Cheng Jia Ying , Suteja Lisda , Yeong Joe Poh Sheng , Iyer N. Gopalakrishna , Lim Darren Wan-Teck , Chen Qingfeng
Published: November 2022

In recent decades, chimeric antigen receptor (CAR)–engineered immune effector cells have demonstrated promising antileukemic activity. Nevertheless, their efficacy remains unsatisfactory on solid cancers, plausibly due to the influence of tumor microenvironments (TME). In a novel mouse cancer model with a humanized immune system, tumor-infiltrating immunosuppressive leukocytes and exhausted programmed death protein-1 (PD-1)
high
T cells were found, which better mimic patient TME, allowing the screening and assessment of immune therapeutics. Particularly, membrane-bound programmed death ligand 1 (PD-L1) level was elevated on a tumor cell surface, which serves as an attractive target for natural killer (NK) cell–mediated therapy. Hematopoietic stem cell–derived CAR-NK (CAR pNK) cells targeting the PD-L1 showed enhanced in vitro and in vivo anti-solid tumor function. The CAR pNK cells and nivolumab resulted in a synergistic anti-solid tumor response. Together, our study highlights a robust platform to develop and evaluate the antitumor efficacy and safety of previously unexplored therapeutic regimens.
Aqueous alteration processes in Jezero crater, Mars—implications for organic geochemistry
Authors: Scheller Eva L. , Razzell Hollis Joseph , Cardarelli Emily L. , Steele Andrew , Beegle Luther W. , Bhartia Rohit , Conrad Pamela , Uckert Kyle , Sharma Sunanda , Ehlmann Bethany L. , Abbey William J. , Asher Sanford A. , Benison Kathleen C. , Berger Eve L. , Beyssac Olivier , Bleefeld Benjamin L. , Bosak Tanja , Brown Adrian J. , Burton Aaron S. , Bykov Sergei V. , Cloutis Ed , Fairén Alberto G. , DeFlores Lauren , Farley Kenneth A. , Fey Deidra M. , Fornaro Teresa , Fox Allison C. , Fries Marc , Hickman-Lewis Keyron , Hug William F. , Huggett Joshua E. , Imbeah Samara , Jakubek Ryan S. , Kah Linda C. , Kelemen Peter , Kennedy Megan R. , Kizovski Tanya , Lee Carina , Liu Yang , Mandon Lucia , McCubbin Francis M. , Moore Kelsey R. , Nixon Brian E. , Núñez Jorge I. , Rodriguez Sanchez-Vahamonde Carolina , Roppel Ryan D. , Schulte Mitchell , Sephton Mark A. , Sharma Shiv K. , Siljeström Sandra , Shkolyar Svetlana , Shuster David L. , Simon Justin I. , Smith Rebecca J. , Stack Kathryn M. , Steadman Kim , Weiss Benjamin P. , Werynski Alyssa , Williams Amy J. , Wiens Roger C. , Williford Kenneth H. , Winchell Kathrine , Wogsland Brittan , Yanchilina Anastasia , Yingling Rachel , Zorzano Maria-Paz
Published: November 2022

The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments.
Precise genomic editing of pathogenic mutations in
RBM20
rescues dilated cardiomyopathy
Authors: Nishiyama Takahiko , Zhang Yu , Cui Miao , Li Hui , Sanchez-Ortiz Efrain , McAnally John R. , Tan Wei , Kim Jiwoong , Chen Kenian , Xu Lin , Bassel-Duby Rhonda , Olson Eric N.
Published: November 2022

Mutations in RNA binding motif protein 20 (
RBM20
) are a common cause of familial dilated cardiomyopathy (DCM). Many
RBM20
mutations cluster within an arginine/serine-rich (RS-rich) domain, which mediates nuclear localization. These mutations induce RBM20 mis-localization to form aberrant ribonucleoprotein (RNP) granules in the cytoplasm of cardiomyocytes and abnormal alternative splicing of cardiac genes, contributing to DCM. We used adenine base editing (ABE) and prime editing (PE) to correct pathogenic p.R634Q and p.R636S mutations in the RS-rich domain in human isogenic induced pluripotent stem cell (iPSC)–derived cardiomyocytes. Using ABE to correct
RBM20
R634Q
human iPSCs, we achieved 92% efficiency of A-to-G editing, which normalized alternative splicing of cardiac genes, restored nuclear localization of RBM20, and eliminated RNP granule formation. In addition, we developed a PE strategy to correct the
RBM20
R636S
mutation in iPSCs and observed A-to-C editing at 40% efficiency. To evaluate the potential of ABE for DCM treatment, we also created
Rbm20
R636Q
mutant mice. Homozygous (R636Q/R636Q) mice developed severe cardiac dysfunction, heart failure, and premature death. Systemic delivery of ABE components containing ABEmax-VRQR-SpCas9 and single-guide RNA by adeno-associated virus serotype 9 in these mice restored cardiac function as assessed by echocardiography and extended life span. As seen by RNA sequencing analysis, ABE correction rescued the cardiac transcriptional profile of treated R636Q/R636Q mice, compared to the abnormal gene expression seen in untreated mice. These findings demonstrate the potential of precise correction of genetic mutations as a promising therapeutic approach for DCM.
Porous Pellicle Formation of a Filamentous Bacterium,
Leptothrix
Authors: Kunoh Tatsuki , Yamamoto Tatsuya , Prasad Manoj , Ono Erika , Li Xiaojie , Sugimoto Shinya , Iida Eiji , Obana Nozomu , Takeda Minoru , Nomura Nobuhiko , Utada Andrew S.
Published: November 2022

Efficient and sustainable management of water resources is becoming a fundamental issue for supporting growing populations and for developing economic activity. Fundamental to this management is the treatment of wastewater.