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Title: Study on life extension of aged RPV material based on probabilistic fracture mechanics: Japanese round robin

Abstract

This paper is concerned with round-robin analyses of probabilistic fracture mechanics (PFM) problems of aged RPV material. Analyzed here is a plate with a semi-elliptical surface crack subjected to various cyclic tensile and bending stresses. A depth and an aspect ratio of the surface crack are assumed to be probabilistic variables. Failure probabilities are calculated using the Monte Carlo methods with the importance sampling or the stratified sampling techniques. Material properties are chosen from the Marshall report, the ASME Code Section XI, and the experiments on a Japanese RPV material carried out by the Life Evaluation (LE) subcommittee of the Japan Welding Engineering Society (JWES), while loads are determined referring to design loading conditions of pressurized water reactors (PWR). Seven organizations participate in this study. At first, the procedures for obtaining reliable PFM solutions with low failure probabilities are examined by solving a unique problem with seven computer programs. The seven solutions agree very well with one another, i.e., by a factor of 2 to 5 in failure probabilities. Next, sensitivity analyses are performed by varying fracture toughness values, loading conditions, and pre and in-service inspections. Finally, life extension simulations based on the PFM analyses are performed. It is clearlymore » demonstrated from these analyses that failure probabilities are so sensitive to the change of fracture toughness values that the degree of neutron irradiation significantly influences the judgment of plant life extension.« less

Authors:
;  [1];  [2]
  1. Univ. of Tokyo (Japan)
  2. Toshiba Corp., Tokyo (Japan); and others
Publication Date:
OSTI Identifier:
6466568
Resource Type:
Journal Article
Journal Name:
Journal of Pressure Vessel Technology; (United States)
Additional Journal Information:
Journal Volume: 117:1; Journal ID: ISSN 0094-9930
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; PRESSURE VESSELS; FRACTURE MECHANICS; SENSITIVITY ANALYSIS; SERVICE LIFE; PWR TYPE REACTORS; REACTOR MATERIALS; COMPUTERIZED SIMULATION; FRACTURE PROPERTIES; NUCLEAR POWER PLANTS; PHYSICAL RADIATION EFFECTS; PROBABILISTIC ESTIMATION; STRESS INTENSITY FACTORS; THEORETICAL DATA; CONTAINERS; DATA; ENRICHED URANIUM REACTORS; INFORMATION; LIFETIME; MATERIALS; MECHANICAL PROPERTIES; MECHANICS; NUCLEAR FACILITIES; NUMERICAL DATA; POWER PLANTS; POWER REACTORS; RADIATION EFFECTS; REACTORS; SIMULATION; THERMAL POWER PLANTS; THERMAL REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS; 210200* - Power Reactors, Nonbreeding, Light-Water Moderated, Nonboiling Water Cooled

Citation Formats

Yagawa, G, Yoshimura, S, and Handa, N. Study on life extension of aged RPV material based on probabilistic fracture mechanics: Japanese round robin. United States: N. p., 1995. Web. doi:10.1115/1.2842095.
Yagawa, G, Yoshimura, S, & Handa, N. Study on life extension of aged RPV material based on probabilistic fracture mechanics: Japanese round robin. United States. doi:10.1115/1.2842095.
Yagawa, G, Yoshimura, S, and Handa, N. Wed . "Study on life extension of aged RPV material based on probabilistic fracture mechanics: Japanese round robin". United States. doi:10.1115/1.2842095.
@article{osti_6466568,
title = {Study on life extension of aged RPV material based on probabilistic fracture mechanics: Japanese round robin},
author = {Yagawa, G and Yoshimura, S and Handa, N},
abstractNote = {This paper is concerned with round-robin analyses of probabilistic fracture mechanics (PFM) problems of aged RPV material. Analyzed here is a plate with a semi-elliptical surface crack subjected to various cyclic tensile and bending stresses. A depth and an aspect ratio of the surface crack are assumed to be probabilistic variables. Failure probabilities are calculated using the Monte Carlo methods with the importance sampling or the stratified sampling techniques. Material properties are chosen from the Marshall report, the ASME Code Section XI, and the experiments on a Japanese RPV material carried out by the Life Evaluation (LE) subcommittee of the Japan Welding Engineering Society (JWES), while loads are determined referring to design loading conditions of pressurized water reactors (PWR). Seven organizations participate in this study. At first, the procedures for obtaining reliable PFM solutions with low failure probabilities are examined by solving a unique problem with seven computer programs. The seven solutions agree very well with one another, i.e., by a factor of 2 to 5 in failure probabilities. Next, sensitivity analyses are performed by varying fracture toughness values, loading conditions, and pre and in-service inspections. Finally, life extension simulations based on the PFM analyses are performed. It is clearly demonstrated from these analyses that failure probabilities are so sensitive to the change of fracture toughness values that the degree of neutron irradiation significantly influences the judgment of plant life extension.},
doi = {10.1115/1.2842095},
journal = {Journal of Pressure Vessel Technology; (United States)},
issn = {0094-9930},
number = ,
volume = 117:1,
place = {United States},
year = {1995},
month = {2}
}