Microstructure and texture evolution and ring-tensile properties of recrystallized FeCrAl ODS cladding tubes

Aghamiri, S. M. S.*; Sowa, Takashi*; Ukai, Shigeharu*; Ono, Naoko*; Sakamoto, Kan*; Yamashita, Shinichiro

Materials Science & Engineering A, 771, p.138636_1 - 138636_12, 2020/01

https://doi.org/10.1016/j.msea.2019.138636

Oxide dispersion strengthened (ODS) FeCrAl ferritic steels are being developed as potential accident tolerance fuel cladding materials for the light water reactors (LWRs) due to significant improvement in steam oxidation by alumina forming scale and good mechanical properties up to high temperatures. In this study, the microstructural characteristics and tensile properties of the two FeCrAl ODS cladding tubes with different extrusion temperatures of 1100C and 1150C were investigated during processing conditions. While the hot extruded sample showed micron sized elongated grains with strong -fiber in 110 texture, cold pilger rolling process change the microstructure to submicron/micron size grain structure along with texture evolution to both -fiber (110 texture) and -fiber ({111} texture) via crystalline rotations. Subsequently, final annealing resulted in evolution of microstructure to large grain recrystallized structure starting at recrystallization temperature of 810-850C. Two distinct texture development happened in recrystallized cladding tubes, i.e., only large elongated grains of (110) 211 texture following extrusion temperature of 1100C; and two texture components of (110) 211 and {111} 112 following higher extrusion temperature of 1150C. The different texture development and retarding of recrystallization progress in 1100C-extruded cladding tubes were attributed to higher distribution of oxide particles.

Characteristics of severe accidents of Reduced-Moderation Water Reactor (RMWR)

Yonomoto, Taisuke; Akie, Hiroshi; Kobayashi, Noboru; Okubo, Tsutomu; Uchikawa, Sadao; Iwamura, Takamichi

Proceedings of 6th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operations and Safety (NUTHOS-6) (CD-ROM), 11 Pages, 2004/10

Reduced-Moderation Water Reactor (RMWR) is a light-water cooled high-conversion reactor that is being developed by JAERI with collaboration from the Japanese industries. Since RMWR utilizes the highly enriched plutonium, the safety concern for RMWR includes the possibility of recriticality during severe accidents as is the case with the liquid metal cooled fast breeder reactor. In order to clarify this concern, characteristics of severe accidents of RMWR are analyzed in this study. The results obtained so far indicate that (1) the mechanical impact of recriticality in the core, if occurs, is supposed to be insignificant due to the absence of water, (2) the mixture of the fuel and cladding debris in the lower plenum does not cause recriticality when they are well mixed and distributed flatly, and (3) if requires, the installation of neutron-absorption material with realistic geometry can effectively prevent recriticality in the lower plenum even for the conservatively-assumed spherical accumulation of core debris.

Microstructural evolution during creep of Ni-base solid solution alloys and in-situ observation at high temperature

; ; Kikuchi, Kenji; ; Miura, Takayuki*

Proc. of 4th Int. Conf. on Recrystallization and Related Phenomena (REX'99), p.283 - 288, 1999/00

no abstracts in English

Creep properties of 20% cold-worked Hastelloy XR

Kurata, Yuji; Nakajima, Hajime

Journal of Nuclear Materials, 228, p.176 - 183, 1996/00

https://doi.org/10.1016/S0022-3115(95)00222-7

no abstracts in English

Creep properties of 20% cold worked Hastelloy XR

Kurata, Yuji; Nakajima, Hajime

JAERI-M 94-022, 28 Pages, 1994/02

JAERI-M-94-022.pdf:0.9MB

no abstracts in English

Controlled material relocation concept for recriticality elimination in sodium-cooled fast reactors

Yamano, Hidemasa; Kubo, Shigenobu; Kotake, Shoji

no journal, ,