scholarly journals Probabilistic Flood Assessment Methodology for Nuclear Power Plants Considering Extreme Rainfall

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2600
Author(s):  
Beom-Jin Kim ◽  
Minkyu Kim ◽  
Daegi Hahm ◽  
Junhee Park ◽  
Kun Yeun Han
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Probability Distribution ◽  
Nuclear Power ◽  
Power Plants ◽  
Fragility Curves ◽  
Flood Analysis ◽  
Major Equipment ◽  
Distribution Type

Abnormal weather conditions due to climate change are currently increasing on both global and local scales. It is therefore important to ensure the safety of the areas where major national facilities are located by analyzing risk quantitatively and re-evaluating the existing major facilities, such as nuclear power plants, considering the load and capacity of extreme flood conditions. In this study, a risk analysis method is developed that combines flood hazard curves with fragility curves using hydraulic and hydrological models by GIS tools and the @RISK model for the probabilistic flood analysis of nuclear power plant sites. A two-dimensional (2D) analysis is first carried out to estimate flood depths in various watershed scenarios, and a representative hazard curve for both external and internal flooding is made by applying a verified probability distribution type for the flood watersheds. For the analysis of flooding within buildings, an internal grid is constructed using GIS with related design drawings, and based on the flood depth results of the 2D analysis, a hazard curve for the representative internal inundation using a verified probability distribution type is presented. In the present study, walkdowns with nuclear experts are conducted around the nuclear power plant area to evaluate the fragile structures and facilities under possible flooding. After reviewing the 2D inundation analysis results based on the selected major equipment and facilities, the zones requiring risk assessment are re-assigned. A fragility curve applying probability distribution for the site’s major equipment and facilities is also presented. Failure risk analysis of the major facilities is then conducted by combining the proposed hazard and fragility curves. Results in the form of quantitative values are obtained, and the indicators for risks as well as the reliability and optimal measures to support decision-making are also presented. Through this study, it is confirmed that risk assessment based on the proposed probabilistic flood analysis technique is possible for flood events occurring at nuclear power plant sites.

Variance of Atmosphere Dispersion Factor for Accident Release from Nuclear Power Plant

2012 ◽  
Vol 518-523 ◽  
pp. 1242-1246 ◽  
Author(s):  
Rui Ping Guo ◽  
Chun Lin Yang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Probability Distribution ◽  
Wind Direction ◽  
Nuclear Power ◽  
Power Plants ◽  
Atmospheric Dispersion ◽  
Radioactive Material ◽  
The Difference ◽  
Release Height

The growing concern over the effect of atmosphere dispersion resulted from radioactive material was noticeable. This paper demonstrated the variance of atmosphere dispersion factor for accident release from nuclear power plant through running PAVAN (Atmospheric Dispersion of Radioactive Releases from Nuclear Power Plants) model. Also, we investigated the effect of release height (short for H) on atmosphere dispersion factor and compared the correlation between atmosphere dispersion factor and dispersion distance. Our results showed that atmosphere dispersion factor would descend with increased release height. As dispersion distance increasing, the tendency of atmosphere dispersion factor expressed complicated status caused by the difference of wind direction. It was illustrated that the phenomena was caused by the integrated action between the wind direction and release height. The probability distribution of atmosphere dispersion factor also validated that the distribution was depend on the wind direction. Probability analysis indicated that the atmosphere dispersion factor under H=100m was overall less than that under H=75m.

scholarly journals Fire Risk Assessment of Transient Ignition Sources in Domestic Nuclear Power Plants

2021 ◽  
Vol 35 (3) ◽  
pp. 59-67
Author(s):  
Jung-Hyun Ryu
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Evaluation Method ◽  
Fire Risk ◽  
Ignition Source ◽  
Fire Risk Assessment

The fire risk of a nuclear power plant is evaluated using fixed and transient ignition sources. In terms of the overall fire risk, the proportion of transient ignition sources is very small. However, because the uncertainty due to the difference between the assumptions and the modeling method is relatively large, it is necessary to establish a methodology to address this. In this study, the new transient ignition source evaluation method presented in NUREG/CR-6850, the ignition source frequency revised in NUREG-2169, and the input parameters for transient fire modeling presented in NUREG-2233 were used to evaluate the fire risk assessment for transient ignition sources. In this new evaluation methodology, the fire ignition frequency is quantitatively evaluated based on the characteristics of the area, and an area-based scenario evaluation method considering the location of the transient ignition source is proposed for the evaluation within the area. As a result of applying the new methodology to the switchgear room of a reference nuclear power plant, an approximately 70% risk reduction was confirmed compared to the existing EPRI TR-105928 method. In the future, if fire risk assessment for transient ignition sources in nuclear power plants is applied using the results of this study, it is expected that areas whose control is important in the event of a fire can be determined, which should help reduce highly rated fire risks.

scholarly journals Risk Assessment of Extreme Weather Conditions for Nuclear Power Plants at Tidal Rivers

2010 ◽  
Vol 13 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Heinz-Peter Berg ◽  
Matias Krauß
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Water Level ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Tidal Rivers

Risk Assessment of Extreme Weather Conditions for Nuclear Power Plants at Tidal RiversThe effects of flooding on a nuclear power plant site may have a major bearing on the safety of the plant and may result in a common cause failure for safety related systems, such as the emergency power supply systems. For river sites with tidal influences, an extreme flood event - tide combined with storm water level set-up - must be assumed. A storm-tide must be covered with an exceeding frequency of 10-4/a. However, the risk assessment regarding the availability of systems and components of a nuclear power plant also includes the situation of extreme low water level of rivers, i. e. below the minimum water level necessary for the supply of the nuclear power plants with cooling water.

Probabilistic Safety Assessment Technology for Commercial Nuclear Power Plant Security Evaluation

2004 ◽  
Author(s):  
James K. Liming ◽  
David H. Johnson ◽  
Andrew A. Dykes
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Security Management ◽  
Probabilistic Safety Assessment ◽  
Tools And Techniques

Commercial nuclear power plant physical security has received much more intensive treatment and regulatory attention since September 11, 2001. In light of advancements made by the nuclear power industry in the field of probabilistic safety assessment (PSA) for its power plants over that last 30 years, and given the many examples of successful applications of risk-informed regulation at U. S. nuclear power plants during recent years, it may well be advisable to apply a “risk-informed” approach to security management at nuclear power plants from now into the future. In fact, plant PSAs developed in response to NRC Generic Letter 88-20 and related requirements are used to help define target sets of critical plant safety equipment in our current security exercises for the industry. With reasonable refinements, plant PSAs can be used to identify, analyze, and evaluate reasonable and prudent approaches to address security issues and associated defensive strategies at nuclear power plants. PSA is the ultimate scenario-based approach to risk assessment, and thus provides a most powerful tool in identifying and evaluating potential risk management decisions. This paper provides a summary of observations of factors that are influencing or could influence cost-effective or “cost-reasonable” security management decision-making in the current political environment, and provides recommendations for the application of PSA tools and techniques to the nuclear power plant operational safety response exercise (OSRE) process. The paper presents a proposed framework for nuclear power plant probabilistic terrorist risk assessment (PTRA) that applies these tools and techniques.

Real-Time Online Risk Monitoring and Management Method for Maintenance Optimization in Nuclear Power Plant

2018 ◽  
Author(s):  
Anqi Xu ◽  
Zhijian Zhang ◽  
HuaZhi Zhang ◽  
Min Zhang ◽  
He Wang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Real Time ◽  
Nuclear Power ◽  
Power Plants ◽  
Time Dependent ◽  
Risk Level ◽  
Online Risk ◽  
Risk Monitoring

As a nuclear power plant system configuration risk assessment tool, Risk Monitor (RM) can periodically update Living-PSA risk monitoring model to calculate risk information. It not only provides operating personnel with the real-time risk information, but also reduces human error in test and maintenance work, in order to ensure that the high-risk configurations are identified and controlled. Traditionally, the high-risk identification of planning activities is mainly based on technical specification (TS) and operating experience, etc. It is lack of quantitative risk assessment to support decision-making, especially when multiple systems or components are out of service or being restored. Planning risk assessment in existing risk monitors is time-consuming and error-prone, because they typically depend on manually screening and confirming risk-related planned events. Besides, online time-dependent characteristics of NPP systems are ignored. The reliability parameters are taken as constant values providing that components and systems always work under the predefined conditions. Thus, the risk level during planning period is not affected by the current configuration, or the operation history of equipment. With the widespread application of digital instrument control systems (I&C) in nuclear power plants, the technology of Real-time Online Risk Monitoring (RORM) was put forward. It improves the acquisition technique of current equipment status, modeling and updating technique of Living-PSA Model and provides more accurate, realistic prediction of risk level for planning configurations. This paper briefly introduces the design of the system structure, database, interfaces and functions of Real-time Online risk monitoring (RORM). It is characterized by the following features: online acquisition of the initial configuration before planning period, time-dependent risk monitoring modeling and updating in time. And it focuses how the real-time online risk monitoring technology of nuclear power plants help the nuclear power plant minimize the risk level of maintenance plan and optimize the maintenance schedule. Also, the calculation method of risk monitoring measures is improved based on the concept of “online, time-dependent”. Finally, the risk management method for optimization of planning activities is proposed.

Study on Shutdown Fire PRA for Nuclear Power Plant

2018 ◽  
Author(s):  
Meiru Liu ◽  
Qingnan Zhao ◽  
Wei Deng ◽  
Jinyan Du ◽  
Lin Sun
Keyword(s):  
Risk Assessment ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
East Coast ◽  
Fire Risk ◽  
The Core ◽  
Core Damage ◽  
Risk Result

Fire Probabilistic Risk Assessment (PRA) is one of the main methods of fire safety analysis for nuclear power plants (NPPs). At present, the fire PRA under the at-power condition has been widely studied, while the research on the low power and shutdown condition (LPSD) is quite limited. Therefore, in this paper, a second generation NPP on the east coast of China is taken as the research target, and the analysis methods are based on the latest LPSD fire PRA theory in report NUREG/CR-7114. This paper studies the initiating events and ignition frequencies of fire PRA considering the real conditions in LPSD, and established LPSD Fire PRA model, finally obtained the quantitative risk result of the core damage caused by the fire According to the results of this LPSD fire PRA, the fire risk-significant sources and fire risk weakness are found out and the improvement suggestions have been promoted.

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.

Sign in / Sign up

Export Citation Format

Share Document