Study on crystalline rock aiming at evaluation method of long-term behavior of rock mass, 2 (Joint research)

Fukui, Katsunori*; Hashiba, Kimihiro*; Matsui, Hiroya

JAEA-Research 2018-006, 57 Pages, 2018/10

JAEA-Research-2018-006.pdf:2.99MB

It is important to evaluate the stability of a repository for high-level radioactive waste not only during the design, construction and operation phases, but also during the post-closure period, for time frames likely exceeding several millennia or longer. The rock mass around the tunnels could be deformed through time in response to time dependent behavior. In view of above points, this study has been started as a collaboration study with the University of Tokyo from FY2016. In the FY2017, the creep test of Tage tuff was continuously conducted and reached its twentieth year. The overview of the test was described, and the phenomenological aspects and the mechanisms of the creep of tuff were discussed with comparing the long- and short-term creep tests. The effects of loading rate and water content on rock strength were examined under various water conditions. The variable-compliance-type constitutive model was modified to reproduce those under uniaxial tension.

Fracture toughness tests of 9 Cr type steels at elevated temperature; 2 nd. Report

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PNC TN9410 91-132, 85 Pages, 1991/06

PNC-TN9410-91-132.pdf:1.47MB

A series of high temperature fracture toughness tests of 9Cr type steels was put in practice on a three-years scheme in 1988. In this experimental study, Mod.9Cr-1Mo steel, 9Cr-2Mo steel and 9Cr-1Mo-Nb-V steel are tested, and these fructure toughness are investigated on the basis of J integral. In a first year, high temperature fracture toughness test method was established using R-curve method and unloading compliance method, and J values of Mod. 9Cr-1Mo steel were measured at RT, 400C, 500C, 550C and 600C. In a second year, fracture toughness tests of 9Cr-2Mo steel, 9Cr-1Mo-V-Nb steel and these aged materials were performed, and several factors which affected fracture toughness values of 9Cr type steels were clarified. In this report, the test results in a second year are summarized. In a last year, fracture toughness tests of weldment and thick plate of 9Cr type steel are going to be carried out. Furthermore, an effect of crack direction on J value will be studied.

Ductile fracture behavior and LBB evaluation of circumferentially cracked type 304 stainless stell piping under bending load

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Atsuryoku Gijutsu, 24(5), p.236 - 244, 1986/00

http://joi.jlc.jst.go.jp/JST.Journalarchive/hpi1972/12.236

no abstracts in English