Prospects of Technological Improvement of Nuclear and Environmental Safety of World Energy

Today, the most urgent problem of the existing and future nuclear power industry is to ensure the nuclear and environmental safety of the operation of nuclear power reactor units (NPPs) and nuclear power plants (NPPs). It is solved thanks to the application of deeply echeloned protection and an anti-accident complex of methods and means for effective control of the operation of active reactor zones (AZR). However, the danger of existing NPPs in the world from time to time manifests itself in the form of severe post-project accidents and catastrophes with the release into the environment of a significant amount of radioactive materials dangerous for all living things. The results of the analysis show that the unconditional fulfillment of the main requirements of nuclear environmental safety and biocompatibility is possible only in the so-called wave nuclear reactor of the G-V generation, which, unlike reactors of the previous generations III, II+ and IV, does not require supercritical loading of the core with nuclear fuel. In the active zone of this reactor, nuclear-physical processes governed by physical law are implemented, which exclude the operator’s participation in regulating the reactivity of the reactor’s active zone, which makes it the reactor with the highest level of nuclear and environmental safety today, which is based on the principles of so-called internal safety, free from the human factor. The possibility of burning nuclear fuel based on U238 and Th232 in it expands the reserves of energetic nuclear fuel almost to inexhaustibility. The technology of nuclear reactors of the G5 generation through the secondary use of spent irradiated nuclear fuel (SNF) for the production of energy and energy raw materials with simultaneous burning of it to an environmentally safe state is able to quickly reduce the available stocks and further production of dangerous SNF, guarantee the nuclear and environmental safety of NPPs with reactors G5 and to technologically make nuclear post-project accidents and disasters impossible at the level of physical law with the complete elimination of the human factor.

Holistic Approach to Safety and Operational Stability: Analyzing VVER-1200 Reactor Dynamics in SGTR and AC Power Loss

VVER-1200 (Water-Water Energetic Reactor) represents a significant advancement in nuclear power generation, emphasizing the continuous analysis and enhancement of safety systems for reliable operation. The proposed study focuses on simulating combined scenarios involving steam generator tube rupture (SGTR) and AC power loss using core algorithms and models within personal computer transient analyzer (PCTRAN). Reactor kinetic equations, thermal-hydraulic balance, and safety system models are discussed to elucidate their role in simulating SGTR and AC power loss. Safety criteria, boundaries and initial conditions are outlined to provide a comprehensive understanding of the simulation framework. The analysis delves into dynamic behavior of VVER-1200, placing emphasis on thermal-hydraulic implications, essential reactor parameters, and radiation monitoring to facilitate impact evaluation. Continuous monitoring and maintenance of safety systems are underscored to ensure stable core cooling, particularly during proposed transient conditions. Through meticulous analysis and comparison with established benchmarks, this study contributes to bolstering the safety and reliability of VVER-1200 reactors by identifying vulnerabilities, assessing mitigation strategies, and refining emergency response protocols. Practical implications of this study offer a crucial understanding of reactor behavior, safety system performance, and emergency response strategies, thereby improving safety, optimizing operational practices, and reducing risks in nuclear reactor accidents.

Current status and technology development tendency of research reactors in China

The current status and development history of domestic and abroad research reactors (RRs) are mentioned.The representative RRs and their respective technology characteristics are introduced.The utilizations of China's RRs,mainly included as nuclear engineering technology,basic research applications of nuclear technology,teaching and personnel training,are explained.

Nuclear Energy and Its History: Past Consequences, Present Inadequacies and a Perspective for Success

An attempt is made to locate nuclear technology within a logical context considering history, risks, societal catastrophes and perspectives: the need is identified for a new direction in the exploitation in order to restore the role in energy production. We depict the situation coming from a marvelous history of discoveries started at the beginning of the XX century;heroes are recalled who made possible something that is inconceivable today: design, construction and production of electricity in a few years;that history was tainted by intentional nuclear explosions, i.e. the original sin that we are now paying. Then, we attempt to show that the societal risk is an inherent part of the civilization. Restoring the public trust (towards nuclear fission technology) by matching nuclear safety with the current technological status and advancers in risk assessment is the key objective. The “independent assessment”, or a principle for the exploitation of nuclear energy already stated in the 50’s of the previous century, shall then re-appear. This is used to erect the signpost for a “dynamic barricade” to further reduce the risk of operation of nuclear reactors and to match the design with current technological capabilities and with the frontiers of the research.

Comparison between computed tomography and magnetic resonance imaging in clinical diagnosis and treatment of tibial platform fractures

BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly affect the patient’s exercise habits and lifestyle.X-ray,computed tomography(CT)and magnetic resonance imaging(MRI)were used in this examination.X-rays are relatively new and easy to operate.However,there are some errors in the observation of fracture collapse and fracture displacement.In recent years,CT and MRI have been actively used to diagnose various types of clinical fractures.They have more diagnostic power than X-ray film.However,some scholars believe that CT is also prone to errors in clinical application.The volume effect leads to missed diagnosis and misdiagnosis in some cases,while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT.To facilitate the selection of clinical examination regimens,this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures.AIM To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures.METHODS A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included.All patients were examined by nuclear MRI and CT scanning.The results were sent to senior physicians in our hospital to complete the diagnosis.RESULTS Nuclear magnetic resonance showed the same effects as CT in four aspects:fracture displacement,bone defect,fracture site and fracture comminution.There was no significant difference in the score data(P>0.05).Nuclear magnetic resonance and CT tended to be consistent in the B3,C2 and C3 fracture diagnosis coincidence rate,combined injury detection rate and fracture detection rate.The diagnostic coincidence rate of type B1,B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT(P>0.05).CONCLUSION MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures,but MRI is more accurate and may be preferred.

Classification of different walnut varieties using low-field nuclear magnetic resonance technology and cluster analysis

To classify different walnut varieties based on water and oil content of walnut,and determine their storage conditions,the low-field nuclear magnetic resonance(LFNMR)technology was used to obtain the NMR transverse relaxation time(T 2)of the samples based on the physical and chemical indicators of the walnut quality.The relationship between the relaxation time and phase state of the internal material of the sample was investigated,and the characteristic parameters of the NMR spectrum signals were statistically analyzed using cluster analysis to determine the different walnut varieties,and three different components,as well as their contents,were detected by a LFNMR spectrometer:firmly bound water,weakly bound water,and weakly bound oil.Test results indicated that the oil peak was dominant in the overall signal intensity compared to the water peaks,in which the firmly bound water phase contributed more to the overall water signal between the water peaks.Using the analytic hierarchy process of cluster analysis,21 walnut samples were classified into three different classes,based on the characteristic parameters of the water-content and oil-content spectrum signals.The first class contains four walnut varieties characterized by least water and highest oil contents;the third class contains two walnut varieties,with the highest water content and least oil content;whereas,the second class contains 15 walnut varieties,with both water and oil contents at medium levels.The results showed that LFNMR led to a rapid detection of moisture and oil contents in walnuts,while cluster analysis classified different walnuts varieties based on these parameters.This study also provided the basis for optimizing the storage methods and storage conditions of walnuts.

Institute of Nuclear Energy Technology Tsinghua University

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Understanding China Through Keywords

Learning keywords is one of the best ways to keep abreast of the latest developments in a country.The China Academy of Translation,a research institute affiliated with the China International Publishing Group,the country’s leading international publisher,regularly analyzes prevailing Chinese terms in various sectors and translates them into a number of foreign languages ranging from English to Arabic. In each issue, Beijing Review presents a selection of these keywords to help readers know more about China.

Understanding China Through Keywords

Learning keywords is one of the best ways to keep abreast of the latest developments in a country.The China Academy of Translation,a research institute affiliated with the China International Publishing Group,the country’s leading international publisher,regularly analyzes prevailing Chinese terms in various