Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Chimi, Yasuhiro; Sato, Kenji*; Kasahara, Shigeki; Umehara, Ryuji*; Hanawa, Satoshi
Proceedings of Contribution of Materials Investigations and Operating Experience to Light Water NPPs' Safety, Performance and Reliability (FONTEVRAUD-9) (Internet), 10 Pages, 2018/09
To investigate the influence of Zinc (Zn) injection on primary water stress corrosion cracking (PWSCC) growth behavior, crack growth tests of 10% cold-worked Alloy 600 were performed in simulated primary water environment of pressurized water reactor (PWR) at 320
C with a low-concentration (5-10 ppb) Zn injection under dissolved hydrogen (DH) conditions of 5, 30, and 50 cc/kgH
O. As a result of the crack growth tests, DH-dependence of crack growth rate (CGR) showed a similar tendency to the predicted CGR based on the CGR data without Zn injection, indicating almost no effect of a low-concentration Zn injection on the crack growth behavior. Moreover, the microstructural analyses of oxide films formed inside the crack and on the specimen surface were conducted, and the intake of Zn in the oxides was detected on the specimen surface, but not detected inside the crack. This result was considered to be the cause of no Zn injection effect on the crack growth behavior.
; *; Yoshida, Eiichi; Aoto, Kazumi
JNC TN9400 2000-011, 33 Pages, 1999/03
JNC-TN9400-2000-011.pdf:13.45MB
The damage was observed in rupture disk for the A-loop superheater of sodium-water reaction products releasing system for MONJU on March 3, 1998. Low temperature creep and stress corrosion cracking tests were carried out as the causes investigation of the damage. As the result, the followings are clarified. (1)The possibility that low temperature creep is the principal damage is small. (2)The stress corrosion cracking under NaOH environment due to the reaction of Na vapor and moisture condensed on the surface of glass beads as remains is the most probable cause on the damage. (3)Comparatively many glass beads remained in damaged surface. The gap between rupture disk and vacuum support was narrower than other parts, and they were not directly exposed to the Na vapor for a long time. The above factors caused the perfect intergranular cracking by stress corrosion. Since NaOH was chemically changed into the harmless NaO on the location except for damaged zone by full Na vapor, the stress corrosion cracking was not generated.
Chimi, Yasuhiro; Sato, Kenji*; Kasahara, Shigeki; Umehara, Ryuji*; Hata, Kuniki; Hanawa, Satoshi; Nishiyama, Yutaka
no journal, ,
To investigate the influence of Zinc (Zn) injection on primary water stress corrosion cracking (PWSCC) growth behavior, crack growth tests of 10% cold-worked Alloy 600 in simulated primary water environment of pressurized water reactor (PWR) at 320C and 360C, with and without Zn injection, under dissolved hydrogen (DH) conditions of 5, 30, and 50 cc/kgHO. As a result of the crack growth tests at 360C, it is implied that Zn injection suppresses the oxidation inside the crack and the crack growth rate (CGR). From the crack growth tests at 320C with Zn injection, DH-dependence of CGR showed a similar tendency to the predicted CGR based on the CGR data without Zn injection. Obvious influence of Zn injection on DH-dependence of CGR at 320C was not observed in the present study.