The Role of silicon on solute clustering and embrittlement in highly neutron-irradiated pressurized water reactor surveillance test specimens

Takamizawa, Hisashi; Hata, Kuniki; Nishiyama, Yutaka; Toyama, Takeshi*; Nagai, Yasuyoshi*

Journal of Nuclear Materials, 556, p.153203_1 - 153203_10, 2021/12

https://doi.org/10.1016/j.jnucmat.2021.153203

Solute clusters (SCs) formed in pressurized water reactor surveillance test specimens neutron-irradiated to a fluence of 1 10 n/cm were analyzed via atom probe tomography to understand the effect of silicon on solute clustering and irradiation embrittlement of reactor pressure vessel steels. In high-Cu bearing materials, Cu atoms were aggregated at the center of cluster surrounded by the Ni, Mn, and Si atoms like a core-shell structure. In low-Cu bearing materials, Ni, Mn, and Si atoms formed cluster and these solutes were not comprised core-shell structure in SCs. While the number of Cu atoms in clusters was decreased with decreasing nominal Cu content, the number of Si atoms had clearly increased. The cluster radius () and number density () decreased and increased, respectively, with increasing nominal Si content. The shift in the reference temperature for nil-ductility transition (RT) showed a good correlation with the square root of volume fraction () multiplied by r (). This suggested that the dislocation cutting through the particles mechanism dominates the precipitation hardening responsible for irradiation embrittlement. The negative relation between the nominal Si content and RT indicated that increasing of nominal Si content reduces the degree of embrittlement.

Results and analysis of the ASTM round robin on reconstitution

Onizawa, Kunio; Van Walle, E.*; Pavirich, W.*; Nanstad, R.*

NUREG/CR-6777, 81 Pages, 2002/08

no abstracts in English

Effect of irradiation on fracture toughness in the transition range of RPV steels

Onizawa, Kunio; Tobita, Toru; Suzuki, Masahide

Effects of Radiation on Materials (ASTM STP 1366), p.204 - 219, 2000/00

no abstracts in English

Development of reconstitution technique of irradiated speciments, 3; Report for FY 1995 and FY 1996 on JAERI-IHI cooperated research program (Joint research)

Nishiyama, Yutaka; Fukaya, Kiyoshi; Onizawa, Kunio; Suzuki, Masahide; *; *; *; *

JAERI-Tech 98-041, 30 Pages, 1998/10

JAERI-Tech-98-041.pdf:2.0MB

no abstracts in English

Development of reconstitution technique of Charpy impact specimens by surface-activated joining for reactor pressure vessel surveillance

Onizawa, Kunio; Fukaya, Kiyoshi; Nishiyama, Yutaka; Suzuki, Masahide; *; *

Int. J. Press. Vessels Piping, 70(3), p.201 - 207, 1997/00

https://doi.org/10.1016/S0308-0161(96)00033-6

no abstracts in English

Development of reconstitution technique of irradiated specimen, II; Annual report for FY1994 on JAERI-IHI cooperated research program

Nishiyama, Yutaka; Fukaya, Kiyoshi; Onizawa, Kunio; Suzuki, Masahide; Shibata, Katsuyuki; *; *; *; *

JAERI-Tech 96-003, 30 Pages, 1996/02

JAERI-Tech-96-003.pdf:1.55MB

no abstracts in English

Development of reconstitution technique of irradiated specimen; Progress report for FY1993 on cooperated research between JAERI and IHI

Onizawa, Kunio; Fukaya, Kiyoshi; Nishiyama, Yutaka; Suzuki, Masahide; Shibata, Katsuyuki; Kosaka, Atsuo; *; *; *; *; et al.

JAERI-Tech 94-017, 58 Pages, 1994/09

JAERI-Tech-94-017.pdf:2.74MB

no abstracts in English

Integrity evaluations for the 2nd Fugen pressure tube surveillance test

; ; ; ; ; Shibahara, Itaru

PNC TN9410 92-321, 30 Pages, 1992/10

PNC-TN9410-92-321.pdf:0.67MB

Integrity evaluations have been performed for the 2nd Fugen pressure tube test (8 years irradiation, 5.6 10n/cm (E1Mev)). Test items mainly consist of tensile test, bending test, corrosion test and hydrogen analysis. It has become clear using these data that the pressure tube material has maintained its integrity during the irradiation by the integrity assessment on both tensile and fracture toughness properties. Besides, both thickness loss by corrosion and absorbed hydrogen content were lower than those of design values.

Some problems of surveillance test programs in the reactor pressure vessel

Nihon Genshiryoku Gakkai-Shi, 10(6), p.337 - 342, 1968/00

https://doi.org/10.3327/jaesj.10.337

no abstracts in English