Analysis and Evaluation of the Setting Value Drift of SEBIM Relief Valve Used in Nuclear Power Plant

2013 ◽  
Author(s):  
Xiaochuan Yang ◽  
Chunlei Luo ◽  
Meng Qu ◽  
Rongfa Shen ◽  
Yinhui Che
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Industry ◽  
Relief Valve ◽  
Analysis And Evaluation ◽  
Operation Period ◽  
Pressure Pipeline ◽  
Important System

SEBIM relief valve is mainly used in safety important system of the nuclear power plant to provide the overpressure protection for the pressure vessel and pressure pipeline which related to the nuclear safety. It is probable that the system will lose the overpressure protection function and lead to a major security hidden danger in the nuclear power plant if the relief valve setting value happens drift. So the problem of the SEBIM relief valve setting value drift has becoming the focus of attention of the whole nuclear industry. It is of great significance to study the setting value drift condition of SEBIM relief valve in the practical application. This paper analyzes the structure and operating principle of the SEBIM valve, and studies the main failure mode of the setting value drift of SEBIM relief valve combining with the operating environment of the equipment. And this paper collects the setting value check data of the SEBIM valve used in two domestic nuclear power plants (These two power plants are named NPP A and NPP B in this paper) during its operation period, and carries on the analysis and evaluation.

EDF Decommissioning Programme: A Global Commitment to a Sustainable Development

2003 ◽  
Author(s):  
Jean-Jacques Grenouillet
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Energy ◽  
Cost Effective ◽  
Eu Enlargement ◽  
Nuclear Industry ◽  
Successful Implementation ◽  
Early Closure

Nowadays, decommissioning of nuclear power plants has become a key issue for nuclear industry in Europe. The phasing out of nuclear energy in Germany, Belgium and Sweden, as well as the early closure of nuclear units in applicant countries in the frame of EU enlargement, has largely contributed to consider decommissioning as the next challenge to face. The situation is slightly different in France where nuclear energy is still considered as a safe, cost-effective and environment friendly energy source. Electricite´ de France (EDF) is working on the development of a new generation of reactor to replace the existing one and erection of a new nuclear power plant could start in the next few years. Nevertheless, to achieve this objective, it will be necessary to get the support of political decision-makers and the acceptance of public opinion. Due to the growing concern of these stakeholders for environmental issues, their support can only be obtained if it is possible to demonstrate that nuclear energy industry will not leave behind unsolved issues that will be a burden to the next generations. In this context decommissioning of the first generation of EDF NPPs constitutes a prerequisite for the erection of a new type of nuclear power plant. This paper will present the programme defined by EDF for the decommissioning of its nine already shutdown reactors (Fig. 1). The reasons of the recent evolution of EDF decommissioning strategy will be explained and the key issues that will contribute to the successful implementation of this programme will be addressed. Finally, what has been achieved on sites so far and major planned activities will be described.

Study on the Liquid Seal Discharge Process in an Over-Pressurized Accident

2020 ◽  
Author(s):  
Dan Wu ◽  
Jian Deng ◽  
Sijia Du ◽  
Libo Qian
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Pressure Rise ◽  
Discharge Process ◽  
Relief Valve ◽  
Pressure Rise Rate ◽  
Liquid Seal ◽  
Rise Rate

Abstract In an over pressure accident, one or more pressurizer safety (or relief) valves will open due to the rapid pressure rise process. Once the safety (or relief) valves are open, the liquid seal will be discharged, and this will generate great discharge force to the downstream pipes. Multi-level protection is chosen using pressurizer safety (or relief) valves with different setpoint in most of Nuclear Power Plant, especially in the self-designed Generation-III Nuclear Power Plants. As the over pressure accident progresses, one or more safety (or relief) valves will be open. The downstream pipes will experience one or more times of impacts, which will influence the arrangement of the pipes. The whole discharge process is very complex, and the key influence factors are the pressure rise rate, safety (or relief) valve opening time, liquid seal temperature and volume, and the arrangement of the downstream discharge pipes. In present paper, liquid seal discharge process in an over pressure accident is studied. The pressure rise rate is so fast that three safety (or relief) valves will open one after another, which will generate three impacts on the downstream discharge pipes. It is found that for a specific design of Nuclear Power Plant, well design of the safety (or relief) valve setpoint is very important to the discharge force analysis results.

Analysis of the Degradation Tendency of NPP Cables Using a Wireless Cable Indenting Robot

2013 ◽  
Vol 284-287 ◽  
pp. 1749-1753
Author(s):  
Kyung Nam Jang ◽  
Jong Soeg Kim ◽  
Sun Chul Jeong ◽  
Kyung Heum Park ◽  
Sung Yull Hong
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Condition Monitoring ◽  
Nuclear Power ◽  
Power Plants ◽  
Accelerated Aging ◽  
Test Equipment ◽  
Testing Time ◽  
Operation Period ◽  
Non Destructive

In nuclear power plants, there are many cables that perform safety-related functions. These cables should implement condition monitoring during the operation period in the nuclear power plant, in order to assess the remaining qualified life and extend the qualified life. In this study we focused on the indenting method which can measure the hardness of the cable jacket. This method is selected because it is non-destructive and requires short testing time and small sized equipment. In order to address the problems with the existing indenting test equipment, we developed new indenting test equipment, which could automatically move on the surface of the object cable. The newly developed equipment is designed for a small-sized and light-weight robot using wireless communication in order to implement condition monitoring in a harsh environment or locations that are inaccessible to the tester. The developed wireless cable indenting robot is composed of three parts, which are mechanical and electrical hardware parts and remote-control part. In order to analyze the degradation tendency of the cable, we prepared four thermally aged specimens and one un-aged specimen. Using the developed robot, we measured the modulus of the cable jacket of each specimen. The test data showed that the modulus of the cable jacket increased linearly as the accelerated aging time increased. From these results, we can analyze the degradation trends pertaining to cables installed in nuclear power plant according to the operation period.

Teaching of Nuclear Power Plant Safety at the National Technical University of Ukraine Within the New Course in Safety Culture

2012 ◽  
Author(s):  
Vasilij V. Begun ◽  
Sergij V. Begun ◽  
Olena O. Kilina
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Safety Culture ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Safety Analysis ◽  
Nuclear Industry ◽  
Educational Course ◽  
And Training

The necessity of safety analysis methods and probable scenarios of accidents teaching in the education of experts for nuclear industry in Ukraine has been realised only after the Chernobyl accident. We developed the content of the first educational course in probabilistic safety analysis in 1995 based on the experience of the countries having developed nuclear power, the USA first of all, and on the training course of the Idaho National Laboratory. After this in 1996 the new course in probabilistic safety analysis of nuclear power plant (NPP) was adopted at our university. The new educational course in safety for students was developed and adopted in 2009 educational year - “Safety culture at nuclear installations of Ukraine”. Education and training in safety culture in higher educational institutions and in the nuclear power plants is a part of the general modern process of maintenance of safety, it is recommended by IAEA standards. The principles of safety culture are taken as a basis of the modern concept of safety of nuclear power plants. This work has received a positive appreciation from the management of departments of safety and training of the personnel of operating organization National Nuclear Energy Generating Company Energoatom (NNEGC Energoatom) and from other leaders of nuclear industry. The content of this educational course was discussed at the international scientific conferences on safety culture in 2008 and 2010, and was preliminary printed in the professional journal «Nuclear and radiation safety». The purposes of education have been defined as a survey, generalizing course on safety of the NPP with an allocation of safety issues on the foreground. Practical questions of the equipment and NPP systems work, their interaction in emergencies and the role of the human-operator are studied. The procedure of failure analysis at NPP is studied. Students analyze equipment work, root and direct causes of incidents. Methods of estimation of safety conditions based on observable operational indicators are studied. Parameters, variables and indicators of safety culture are studied. As a result of gained experience we have come to the conclusion about high advisability of educational courses in safety for students. Specially formed knowledge and education in the field of safety from a student’s bench are the basis of safety culture of the future nuclear industry expert.

Public Acceptance of Spent Fuel Reprocessing Project

2017 ◽  
Author(s):  
Zijian Wang ◽  
Shanfang Huang ◽  
Xiaoyu Guo ◽  
Kan Wang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Industry ◽  
Spent Fuel ◽  
The Public ◽  
Spent Fuel Reprocessing ◽  
Fuel Reprocessing

At present, there are hundreds of nuclear power plants in operation around the world. Anti-nuclear movements continue in many places, although the nuclear power plants have good operating records. It has some factors, and the first factor that the public knows little about nuclear industry, results in regarding the nuclear power plant mysterious. This condition relates to destructive scene by nuclear weapon with nuclear industry, deeming it unacceptable to take this risk. Secondly, construction of nuclear power plant and off site emergency may occupy large land. The public hopes to be rewarded more to offset the risk by their imagination. Last, it relates to the political environment of one country. Every country has its own situation, so the strategies of developing nuclear power plant are widely different. The public is not familiar with other nuclear engineering projects except nuclear power plants, and hence the boycott happens more frequently. Sino-French cooperation on nuclear fuel cycle project is the first large-scale commercial spent fuel reprocessing plant, which is the biggest cooperative project between China and France until now. AREVA is responsible for technology, and CNNC is responsible for building. Spent fuel reprocessing is the most important part of nuclear fuel cycle back end, which separates uranium and plutonium from spent fuel, and manufactures MOX fuel with recycled resources for using in nuclear reactor again. This will make the best use of the uranium resources. After that process, the fission products needed to be disposed reduce significantly. And it is good for environmental protection. The public protest happened in one of the candidate sites, when CNNC carried out the preliminary work of site selection. For meeting the enormous energy demands, the fossil energy may be exhausted in the future due to the greenhouse gases emission. Chinese government speeds up the development of new energy. Nuclear energy is the only technology with no emission of greenhouse gases and will be rapidly developed. Along with the nuclear power units continuing to increase, they become the critical factors in restricting the sustainable development of nuclear energy. That is efficient utilization of uranium resources, spent fuel intermediate storage, reprocessing, and geologic disposal of high level radioactive waste. To this project, it not only has a great current demand, but also closely relates to transition of energy structure. The public has different views in the project progressing, which results in wide concern and discussion. The article took this event for example, and analyzed the reason from all directions. Besides, the author put forward own views for the public acceptance events about nuclear engineering projects except nuclear power plant.

Monitoring Liquid Radioactive Waste Discharges Released from Nuclear Power Plant

2014 ◽  
Vol 1059 ◽  
pp. 83-90 ◽  
Author(s):  
Marián Bujna ◽  
Miroslav Prístavka ◽  
Maroš Korenko ◽  
Petr Dostál
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Negative Impact ◽  
Liquid Radioactive Waste ◽  
Nuclear Industry ◽  
Protective Measures ◽  
The Impact

The purpose of this paper is to monitor the amount of discharged radioactive liquid discharges from nuclear power plant and propose ways to reduce the amount given. The report consists of a literature review, objective and methodology proposed. The methodology and results consist of distribution of waste, originally liquid radioactive waste (LRW), a source of LRW, a year-round monitoring of liquid effluents of nuclear power plant and eventual adoption of protective measures. Tritium, as one of the LRW, is a radioactive substance having a negative impact on the environment. In the course of our research, we have found an increased dose of tritium over permitted annual limit. We investigated the impact of tritium on the environment and took protective measures to reduce the amount of tritium released in the environment. The report may serve as a basis for other nuclear power plants and the entire nuclear industry.

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
Vanderley Vasconcelos ◽  
Wellington Antonio Soares ◽  
Raissa Oliveira Marques ◽  
Silvério Ferreira Silva Jr ◽  
Amanda Laureano Raso
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Human Factors ◽  
Nuclear Power ◽  
Power Plants ◽  
Failure Modes ◽  
Cooling System ◽  
Human Reliability ◽  
Non Destructive ◽  
Plant Components

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. This inspection is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI is reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components, such as FMEA (Failure Modes and Effects Analysis) and THERP (Technique for Human Error Rate Prediction). An example by using qualitative and quantitative assessesments with these two techniques to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues, is presented.

scholarly journals Python TensorFlow Big Data Analysis for the Security of Korean Nuclear Power Plants

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1467
Author(s):  
Sangdo Lee ◽  
Jun-Ho Huh ◽  
Yonghoon Kim
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Network Traffic ◽  
Nuclear Power ◽  
Power Plants ◽  
Security Requirements ◽  
Republic Of Korea ◽  
Continuous Data ◽  
Cyber Attack ◽  
The Republic

The Republic of Korea also suffered direct and indirect damages from the Fukushima nuclear accident in Japan and realized the significance of security due to the cyber-threat to the Republic of Korea Hydro and Nuclear Power Co., Ltd. With such matters in mind, this study sought to suggest a measure for improving security in the nuclear power plant. Based on overseas cyber-attack cases and attacking scenario on the control facility of the nuclear power plant, the study designed and proposed a nuclear power plant control network traffic analysis system that satisfies the security requirements and in-depth defense strategy. To enhance the security of the nuclear power plant, the study collected data such as internet provided to the control facilities, network traffic of intranet, and security equipment events and compared and verified them with machine learning analysis. After measuring the accuracy and time, the study proposed the most suitable analysis algorithm for the power plant in order to realize power plant security that facilitates real-time detection and response in the event of a cyber-attack. In this paper, we learned how to apply data for multiple servers and apply various security information as data in the security application using logs, and match with regard to application of character data such as file names. We improved by applying gender, and we converted to continuous data by resetting based on the risk of non-continuous data, and two optimization algorithms were applied to solve the problem of overfitting. Therefore, we think that there will be a contribution in the connection experiment of the data decision part and the optimization algorithm to learn the security data.

Transition to Online Cable Insulation Condition Monitoring

2021 ◽  
Author(s):  
S. W. Glass ◽  
Leonard S. Fifield ◽  
Mychal P. Spencer
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Management Program ◽  
Capacitance Measurement ◽  
Test Bed ◽  
Test Environment ◽  
Specific Test ◽  
Motor Test

Abstract Nuclear power plant cables were originally qualified for 40 year life and generally have not required specific test verification to assure service availability through the initial plant qualification period. However, license renewals to 60 and 80 years of operation require a cable aging management program that depends on some form of test and verification to assure fitness for service. Environmental stress (temperature, radiation, chemicals, water, and mechanical) varies dramatically within a nuclear power plant and, in some cases, cables have degraded and required repair or replacement before their qualified end-of-life period. In other cases, cable conditions have been mild and dependable cable performance confirmed to extend well beyond the initial qualified life. Most offline performance-based testing requires cables to be decoupled and de-energized for specially trained technicians to perform testing. These offline tests constitute an expensive operational burden that limits the economic viability of nuclear power plants. Although initial investment may be higher, new online test practices are emerging as options or complements to offline testing that avoid or minimize the regularly scheduled offline test burden. These online methods include electrical and fiber-optic partial discharge measurement, spread spectrum time or frequency domain reflectometry, distributed temperature profile measurements, and local interdigital capacitance measurement of insulation characteristics. Introduction of these methods must be supported by research to confirm efficacy plus either publicly financed or market driven investment to support the start-up expense of cost-effective instrumentation to monitor cable condition and assure reliable operation. This work summarizes various online cable assessment technologies plus introduces a new cable motor test bed to assess some of these technologies in a controlled test environment.

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