Guidelines on Environmental Fatigue Evaluation for LWR Component

2003 ◽  
Author(s):  
Takao Nakamura ◽  
Itaru Saito ◽  
Yasuhide Asada
Keyword(s):  
Environmental Effects ◽  
Nuclear Power ◽  
Reduction Factor ◽  
Engineering Society ◽  
Fatigue Initiation ◽  
Plant Life ◽  
Actual Operating ◽  
Fatigue Evaluation ◽  
Fatigue Life Reduction ◽  
Operating Plant

Japanese utilities and vendors have taken environmental effects on fatigue (EF) into consideration in the plant life management (PLM) activity of operating plants for several years. In Sep. 2000 MITI notified the utilities to adopt “The Guidelines for Evaluating Fatigue Initiation Life Reduction in LWR Environment (MITI guidelines)” for PLM evaluation of operating plants [1]. In April 2001, the study started to establish detailed procedures for EF evaluation and the committee was organized for developing detailed guidelines at Thermal and Nuclear Power Engineering Society (TENPES). The evaluation guidelines were completed and published as TENPES guidelines [2]. These guidelines proposed several practical options to apply fatigue life reduction factor for environmental effects (Fen) on actual operating plant fatigue evaluation.

Evaluation of Environmental Fatigue in PWR PLM Activities

2005 ◽  
Author(s):  
Masanobu Iwasaki ◽  
Yasukazu Takada ◽  
Takao Nakamura
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Japan Society ◽  
Know How ◽  
Engineering Society ◽  
Fatigue Initiation ◽  
Plant Life ◽  
Fatigue Evaluation ◽  
Term Maintenance

It is important to evaluate environmental fatigue for establishing long-term maintenance plans as part of Plant Life Management (PLM) activities for nuclear power plants. In Japan, the former MITI requested the utilities in 2000 to use “The Guidelines for Evaluating Fatigue Initiation Life Reduction in LWR Environment (MITI guidelines)” for PLM evaluation. In 2002, Thermal and Nuclear Power Engineering Society (TENPES) issued the guidelines for applying the evaluation formulas of MITI guidelines to actual plants. At present, fatigue evaluations taking into account environmental effects as part of PLM activities are conducted in accordance with these guidelines. This paper describes how a typical PWR plant conducts such an evaluation. The Japan Society of Mechanical Engineers (JSME) is now drawing up a code for environmental fatigue evaluation, incorporating the latest data on fatigue experiments and know-how on fatigue evaluation. After being issued, this code will be used to evaluate environmental fatigue in PLM activities.

Development of Fatigue Assessment Method Based on Flaw Tolerance Concept

2013 ◽  
Author(s):  
Seiji Asada ◽  
Takeda Shuhei ◽  
Taiji Hirasawa ◽  
Toshiyuki Saito ◽  
Itaru Saito ◽  
...  
Keyword(s):  
Power Generation ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Assessment Method ◽  
Fatigue Assessment ◽  
Nondestructive Examination ◽  
Flaw Tolerance ◽  
Fatigue Evaluation ◽  
Tolerance Method ◽  
Operating Plant

The Japan Society of Mechanical Engineers (JSME) Committee on Power Generation Facility Codes recognizes the importance of fatigue evaluation methods based on the latest knowledge and is developing a fatigue evaluation method by flaw tolerance. The ASME B&PV Code Section XI has Non-mandatory Appendix L, “Operating Plant Fatigue Assessment” (hereinafter “App. L”), which provides a flaw tolerance method for fatigue evaluation when a cumulative usage factor (CUF) of a component is greater than 1.0. In order to develop a flaw tolerance method for the JSME Codes for nuclear power generation facilities, postulated initial flaws, capability of nondestructive examination, compatibility to rules and flaw tolerance codes are discussed.

An Investigation on the Reduction Schemes of Environmental Fatigue Usage Factor for Pressurizer Surge Line

2011 ◽  
Author(s):  
Sun-yeh Kang ◽  
Won-ho Jo ◽  
Min-sup Song ◽  
Ki-seok Yoon ◽  
Taek-sang Choi ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Light Water Reactor ◽  
Life Extension ◽  
Regulatory Requirement ◽  
Light Water ◽  
Plant Life ◽  
Asme Code ◽  
Surge Line ◽  
Critical Components ◽  
Fatigue Evaluation

For plant life extension, it is the regulatory requirement to assess reactor coolant environmental impacts on critical components of the nuclear power plant including at least those mentioned in NUREG/CR-6260[2]. The pressurizer surge line is the most easy-to-fail component in view of LWR (Light Water Reactor) environments when it comes to meeting the current ASME code limit of the fatigue evaluation. Cumulative Usage Factor (CUF) value could be increased to a maximum of 15.35 times due to the environmental effects, which makes it easy to exceed the allowable fatigue limit (1.0). This paper discusses the process of the environmental correction factor calculation described in NUREG/CR-5704[4], and five proposed schemes for reducing the environmental CUF value to the ASME code limit or below. This paper concludes that the proposed schemes are effective in lowering the environmental CUF value of the pressurizer surge line.

Study on Incorporation of a New Design Fatigue Curve Into the JSME Environmental Fatigue Evaluation Method

2019 ◽  
Author(s):  
Seiji Asada ◽  
Shengde Zhang ◽  
Masahiro Takanashi ◽  
Yuichirou Nomura
Keyword(s):  
Nuclear Power ◽  
Evaluation Method ◽  
Fatigue Curve ◽  
Fatigue Analysis ◽  
Analysis Method ◽  
Energy Research ◽  
Research Committee ◽  
Engineering Society ◽  
Fatigue Evaluation ◽  
Generation Facility

Abstract A new fatigue analysis method was developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society JWES). If the new design fatigue curves are incorporated into the Environmental Fatigue Evaluation Method of the Japan Society of Mechanical Engineers (JSME), the environmental fatigue analysis can be optimized. The Subgroup on Fatigue Evaluation of the Subcommittee on Nuclear Power in the Main Committee on Power Generation Facility Codes in the JSME is reviewing the new design fatigue curves to incorporate into the JSME Environmental Fatigue Evaluation Method. This paper discuss the new design fatigue curves which is under review.

JSME Codes on Environmental Fatigue Evaluation

2006 ◽  
Author(s):  
Takao Nakamura ◽  
Makoto Higuchi ◽  
Takehiro Kusunoki ◽  
Yasuaki Sugie
Keyword(s):  
Fatigue Life ◽  
Environmental Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Evaluation Method ◽  
Water Environment ◽  
Cooling Water ◽  
Practical Method ◽  
Plant Equipment ◽  
Fatigue Evaluation

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]

scholarly journals Demonstration of Fatigue for LTO License of NPP Borssele

2015 ◽  
Author(s):  
M. H. C. Hannink ◽  
F. J. Blom ◽  
P. W. B. Quist ◽  
A. E. de Jong ◽  
W. Besuijen
Keyword(s):  
Environmental Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Integrated Approach ◽  
Temperature Measurements ◽  
Fatigue Assessment ◽  
Term Operation ◽  
Load Monitoring ◽  
Number Of Cycles ◽  
Ageing Management

Long Term Operation (LTO) of nuclear power plants (NPPs) requires an ageing management review and a revalidation of Time Limited Ageing Analyses (TLAAs) of structures and components important for nuclear safety. An important ageing effect to manage is fatigue. Generally, the basis for this is formed by the fatigue analyses of the safety relevant components. In this paper, the methodology for the revalidation of fatigue TLAAs is demonstrated for LTO of NPP Borssele in the Netherlands. The LTO demonstration starts with a scoping survey to determine the components and locations having relevant fatigue loadings. The scope was defined by assessment against international practice and guidelines and engineering judgment. Next, a methodical review was performed of all existing fatigue TLAAs. This also includes the latest international developments regarding environmental effects. In order to reduce conservatism, a comparison was made between the number of cycles in the analyses and the number of cycles projected to the end of the intended LTO period. The projected number of cycles is based on transient counting. The loading conditions used in the analyses were assessed by means of temperature measurements by the fatigue monitoring system (FAMOS). As a result of the review, further fatigue assessment or assessment of environmental effects was necessary for certain locations. New analyses were performed using state-of-the-art calculation and assessment methods. The methodology is demonstrated by means of an example of the surge line. The model includes the piping, as well as the nozzles on the pressurizer and the main coolant line. The thermal loadings for the fatigue analysis are based on temperature measurements. Fatigue management of the NPP is ensured by means of the fatigue concept where load monitoring, transient counting and fatigue assessment are coupled through an integrated approach during the entire period of LTO.

Environmental effects of nuclear power

1980 ◽  
Vol 26 (6) ◽  
pp. 450
Author(s):  
P.J. Jones
Keyword(s):  
Environmental Effects ◽  
Nuclear Power

Fatigue Evaluation for Thermally Stratified DVI Piping

2012 ◽  
Author(s):  
Hwan Ho Lee ◽  
Joon Ho Lee ◽  
Dong Jae Lee ◽  
Seok Hwan Hur ◽  
Il Kwun Nam ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Heat Removal ◽  
Local Stress ◽  
Piping System ◽  
Hydraulic Analysis ◽  
Fatigue Evaluation ◽  
Core Cooling ◽  
Thermal Hydraulic Analysis

A numerical analysis has been performed to estimate the effect of thermal stratification in the safety injection piping system. The Direct Vessel Injection (DVI) system is used to perform the functions of Emergency Core Cooling and Residual Heat Removal for an APR1400 nuclear power plant (Korea’s Advanced Power Reactor 1400 MW-Class). The thermal stratification is anticipated in the horizontally routed piping between the DVI nozzle of the reactor vessel and the first isolation valve. Non-axisymmetric temperature distribution across the pipe diameter induced by the thermal stratification leads to differential thermal growth of the piping causing the global bending stress and local stress. Thermal hydraulic analysis has been performed to determine the temperature distribution in the DVI piping due to the thermal stratification. Piping stress analysis has also been carried out to evaluate the integrity of the DVI piping using the thermal hydraulic analysis results. This paper provides a methodology for calculating the global bending stresses and local stresses induced by the thermal stratification in the DVI piping and for performing fatigue evaluation based on Subsection NB-3600 of ASME Section III.

Sign in / Sign up

Export Citation Format

Share Document