Updated Knowledge Implemented to the Revision of Environmental Fatigue Evaluation Method for Nuclear Power Plant in JSME Code

Author(s):  
Makoto Higuchi ◽  
Takao Nakamura ◽  
Yasuaki Sugie

Many examinations concerning the fatigue life reduction for structural materials of nuclear power plants in water simulated LWR coolants had been carried out after the first paper had been recognized in Japan [1, 2]. Based on these results, the method to evaluate the fatigue damage for the materials exposed to the LWR coolant had been developed. After 1990s in Japan, the Environmental Fatigue Data Committee (EFD) of the Thermal and Nuclear Power Engineering Society (TENPES), the Project on Environmental Fatigue Testing (EFT) supported by the Japan Power Engineering and Inspection Corporation (JAPEIC) and the Japan Nuclear Energy Safety Organization (JNES) and some utility joint studies have investigated the environmental fatigue. In September 2000, the Nuclear Power Generation Safety Management Division of the Agency for Natural Resources and Energy, Ministry of International Trade and Industry issued “Guidelines for Evaluating Fatigue Initiation Life Reduction in the LWR Environment” (hereafter, called “the MITI Guidelines”) [3]. These guidelines include an equation to evaluate environmental fatigue and require electric utilities to consider the environmental effects in their Plant Life Management (PLM) activities. However, the MITI Guidelines do not provide specific and practical techniques for evaluating environmental fatigue under actual plant conditions. Accordingly, TENPES took on the task to produce one. In 2002 TENPES issued the “Guidelines on Environmental Fatigue Evaluation for LWR Component” [4, 5] (hereafter, called “the TENPES Guidelines”) based on the techniques developed by the EFD Committee. A set of Rules, called the Environmental Fatigue Evaluation Method (EFEM), was established in the Codes for Nuclear Power Generation Facilities - Environmental Fatigue Evaluation Method for Nuclear Power Plants (JSME S NF1-2006, EFEM-2006)[6], which was issued in March 2006 by reviewing the equations for the environmental fatigue life correction factor, Fen, specified in the MITI Guidelines, and the techniques for evaluating environmental fatigue specified in the TENPES Guidelines, and considering the new environmental fatigue data including JNES-SS report (August 2005) [7]. The EFEM revised version has been drafted by incorporating the updated knowledge described in JNES-SS report (April 2007) [8] and is scheduled to be issued by the end of 2009. This paper introduces the revision in it and their technical basis. Additionally, future issues are addressed to be considered in the improvement of the EFEM.

Author(s):  
Takao Nakamura ◽  
Makoto Higuchi ◽  
Takehiro Kusunoki ◽  
Yasuaki Sugie

The “Guidelines for Evaluating Fatigue Initiation Life Reduction in the LWR Environment” (the MITI Guidelines) including equations to evaluate environmental fatigue were issued and notified the electric utilities in September 2000 by the former Agency for Natural Resources and Energy in Japan. The MITI Guidelines require the Japanese utilities to take into account environmental effects when conducting fatigue evaluation associated with Plant Life Management (PLM) activities for operating nuclear power plants. However, the MITI guidelines do not specify how to conduct the environmental fatigue evaluation under actual plant conditions. To provide a concrete and practical method to deal with environmental effects on fatigue evaluation of plant equipment, Thermal and Nuclear Power Engineering Society established the “Guidelines on Environmental Fatigue Evaluation for LWR Component” (the TENPES Guidelines) in 2002. Since then, the Japan Society of Mechanical Engineers (JSME) has reviewed the equations to calculate the environmental fatigue life correction factor, Fen in the MITI guidelines and the methods to evaluate the environmental fatigue in the TENPES guidelines considering the latest environmental fatigue data. Based on the result of the review, JSME intends to establish new environmental fatigue evaluation method. This paper explains the scheme and the technical basis of the evaluation methods in JSME codes, and the positioning of the codes to apply them to actual plant conditions. Another paper is released separately that shows the background of the equation to evaluate the fatigue life under the reactor cooling water environment.[19]


Author(s):  
William D. Rezak

One of America’s best kept secrets is the success of its nuclear electric power industry. This paper presents data which support the construction and operating successes enjoyed by energy companies that operate nuclear power plants in the US. The result—the US nuclear industry is alive and well. Perhaps it’s time to start anew the building of nuclear power plants. Let’s take the wraps off the major successes achieved in the nuclear power industry. Over 20% of the electricity generated in the United States comes from nuclear power plants. An adequate, reliable supply of reasonably priced electric energy is not a consequence of an expanding economy and gross national product; it is an absolute necessity before such expansion can occur. It is hard to imagine any aspect of our business or personal lives not, in some way, dependent upon electricity. All over the world (in 34 countries) nuclear power is a low-cost, secure, safe, dependable, and environmentally friendly form of electric power generation. Nuclear plants in these countries are built in six to eight years using technology developed in the US, with good performance and safety records. This treatise addresses the success experienced by the US nuclear industry over the last 40 years, and makes the case that this reliable, cost-competitive source of electric power can help support the economic engine of the country and help prevent experiences like the recent crisis in California. Traditionally, the evaluation of electric power generation facility performance has focused on the ability of plants to produce at design capacity for high percentages of the time. Successful operation of nuclear facilities is determined by examining capacity or load factors. Load factor is the percentage of design generating capacity that a power plant actually produces over the course of a year’s operation. This paper makes the case that these operating performance indicators warrant renewed consideration of the nuclear option. Usage of electricity in the US now approaches total generating capacity. The Nuclear Regulatory Commission has pre-approved construction and operating licenses for several nuclear plant designs. State public service commissions are beginning to understand that dramatic reform is required. The economy is recovering and inflation is minimal. It’s time, once more, to turn to the safe, reliable, environmentally friendly nuclear power alternative.


2019 ◽  
Vol 186 (4) ◽  
pp. 524-529
Author(s):  
Si Young Kim

Abstract The intercomparison test is a quality assurance activity performed for internal dose assessment. In Korea, the intercomparison test on internal dose assessment was carried out for nuclear facilities in May 2018. The test involved four nuclear facilities in Korea, and seven exposure scenarios were applied. These scenarios cover the intake of 131I, a uranium mixture, 60Co and tritium under various conditions. This paper only reviews the participant results of three scenarios pertinent to the operation of nuclear power plants and adopts the statistical evaluation method, used in international intercomparison tests, to determine the significance values of the results. Although no outliers were established in the test, improvements in the internal dose assessment procedure were derived. These included the selection of intake time, selection of lung absorption type according to the chemical form and consideration of the contribution of previous intake.


2011 ◽  
Vol 130-134 ◽  
pp. 3708-3711
Author(s):  
Chuan Sheng Xie ◽  
Sheng Ping Hua ◽  
Da Peng Dong ◽  
Xiao Xi Jia

A fuzzy comprehensive evaluation method for nuclear power plants is introduced in this article. First, a risk index system is established of which these indicators will be explained accordingly latter. Then, an evaluation set is constructed, and the weight of each index and corresponding membership is determined according to suggestions of experts and membership function to make evaluation level by level ,until a final comprehensive evaluation is obtained. This method is not very objective but simple and available.


2015 ◽  
Vol 59 (3) ◽  
pp. 91-98
Author(s):  
V. Šefl

Abstract In this literature review we identify and quantify the parameters influencing the low-cycle fatigue life of materials commonly used in nuclear power plants. The parameters are divided into several groups and individually described. The main groups are material properties, mode of cycling and environment parameters. The groups are further divided by the material type - some parameters influence only certain kind of material, e.g. sulfur content may decreases fatigue life of carbon steel, but is not relevant for austenitic stainless steel; austenitic stainless steel is more sensitive to concentration of dissolved oxygen in the environment compared to the carbon steel. The combination of parameters i.e. conjoint action of several detrimental parameters is discussed. It is also noted that for certain parameters to decrease fatigue life, it is necessary for other parameter to reach certain threshold value. Two different approaches have been suggested in literature to describe this complex problem - the Fen factor and development of new design fatigue curves. The threshold values and examples of commonly used relationships for calculation of fatigue lives are included. This work is valuable because it provides the reader with long-term literature review with focus on real effect of environmental parameters on fatigue life of nuclear power plant materials.


2021 ◽  
Vol 35 (3) ◽  
pp. 59-67
Author(s):  
Jung-Hyun Ryu

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.


10.12737/4944 ◽  
2014 ◽  
Vol 3 (3) ◽  
pp. 60-73 ◽  
Author(s):  
Хвостова ◽  
Marina Khvostova ◽  
Острецов ◽  
Igor Ostretsov ◽  
Кузнецов ◽  
...  

The article considers current state of safety of nuclear power engineering. It presents a brief summary of stress-tests at nuclear power plants in the European Union and Russia. It reveals that the power on breeders shall not develop due to its low efficiency, high expenses and the risk of propagation of nuclear materials. Moreover, construction of plutonium processing production operations on nuclear power plant platforms with breeders, production of mixed uranium-plutonium nuclear fuel and synthesis ofamericium-241 in the spent nuclear fuel calls ecological safety into question. The article also addresses conceptual issues of creation of environmentally friendly nuclear power on the basis of nuclear relativistic technology. It is shown that such power shall not produce "bomb" materials and, therefore, will find extensive application around the world. Thereby the most challenging international problems of the present will be solved. The new nuclear power can become a basis for hydrogen production, which might solve practically all problems of mankind, including even food, by means of nuclear energy.


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