Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

Anomalous small-angle X-ray scattering (ASAXS) study of irradiation-induced nanostructure change in Fe-ion beam irradiated oxide dispersion-strengthened (ODS) steel

Kumada, Takayuki; Oba, Yojiro; Motokawa, Ryuhei; Morooka, Satoshi; Tominaga, Aki; Tanida, Hajime; Shobu, Takahisa; Konno, Azusa; Owada, Kenji*; Ono, Naoko*; et al.

Journal of Nuclear Materials, 528, p.151890_1 - 151890_7, 2020/01

https://doi.org/10.1016/j.jnucmat.2019.151890

We have developed an anomalous small-angle X-ray scattering (ASAXS) diffractometer in SPring-8 to investigate irradiation-induced nanostructural change in ion-beam irradiated stainless steel. A thermally-aged MA956 stainless steel sample displays power-law scattering that follows the Porod law at the magnitude of scattering vector, Q, below 0.5 nm and an overlapped shoulder around 0.7 nm. After the ion-beam irradiation, the intensity of the shoulder remained unchanged, whereas that of the power-law scattering nearly doubled. This result indicates that none of the structural parameters of the Cr-rich nanoprecipitates, such as the number density, size, and interface roughness, were changed by the irradiation.

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Nuclear Fusion, 47(10), p.S668 - S676, 2007/10

https://doi.org/10.1088/0029-5515/47/10/S15

The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 510 m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.

The Summary report on engineering design activities in the International Thermonuclear Experimental Reactor (ITER) project

Mori, Masahiro; Shoji, Teruaki; Araki, Masanori; Saito, Keiji*; Senda, Ikuo; Omori, Junji*; Sato, Shinichi*; Inoue, Takashi; Ono, Isamu*; Kataoka, Takahiro*; et al.

Nihon Genshiryoku Gakkai-Shi, 44(1), p.16 - 89, 2002/01

http://ci.nii.ac.jp/naid/10007669933

no abstracts in English

Acoustic emission analysis of fatigue failure of LMFBR primary coolant piping

*; *; Machida, Tadao*; Tomoda, Yoshio*; *; *; ; *; ; *; et al.

PNC TN251 75-01, 93 Pages, 1975/01

PNC-TN251-75-01.pdf:3.0MB

Recently, "acoustic emission(ae) analysis" calls attention as a dynamic and non-destructive material testing method. We can get information of material defects and cracks by catching acousticsignals from themselves, so it may be possible to know the propagation of latent cracks dynamically, to find the location of defects or to predict the failure. Therefore it may be said that this "acousticemission method" is one of the best methods of the inservice inspection of the primary coolant piping of liquid metal cooled fast breeder reactor(LMFBR). But for the application of this method, in addition to the fundamental tests, it is necessary to recognize AE characteristics of the piping by the experimental measurement of the AE signals in the cyclic loading test of the piping components. For this purpose, acontract of cooperative work was made between criepi who had much experience in AE measurement in the material tests and PNC who was doing cyclic fatigue test of the piping components. There it was agree

Novel qualitative evaluation method of microstructure in ODS alloy by anomalous small-angle X-ray scattering technique

Konno, Azusa; Oba, Yojiro; Tominaga, Aki; Morooka, Satoshi; Ono, Naoko*; Hashimoto, Naoyuki*; Ukai, Shigeharu; Owada, Kenji*; Motokawa, Ryuhei; Kumada, Takayuki; et al.

no journal, , 

An ODS alloy is one of the promising candidate materials applicable to the fusion reactor because of its high-temperature creep strength and irradiation resistance. However, the ODS ferritic stainless steel with high Cr content sometimes suffers from the embrittlement related to phase separation below 748 K for a long term using in the reactor. It is, therefore, an important issue to understand embrittlement phenomena from not only macrostructural viewpoint but also microstructural one. Anomalous Small Angle X-ray Scattering (A-SAXS) is a unique and potential evaluation method that can analyze complex microstructure. This method can extract the signal only from an element of interest to implant the X-ray of the wavelength near orbit electron of the element. In this study, we performed both the A-SAXS analysis and TEM observation for high Cr-ODS alloy in order to assess the applicability of the A-SAXS technique as a microstructure determination and compared the A-SAXS signal with the TEM micrograph. The specimen of the commercial MA956 (Fe-20Cr-4.8Al-0.4Ti-0.02C-0.4YO (mass%)) were thermally-aged at 748 K for 1, 10, 100 and 1000 hrs, and measured using the A-SAXS diffractometer at BL22XU in SPring-8 and a TEM. The A-SAXS data reveal that the average size of Cr precipitations increases with increasing the aging time. Also, using the A-SAXS profiles, it was estimated that there were two cases; one is the case that the microstructure does have a distinct interface between the matrix and Cr precipitate. The other case is the microstructure does not have the distinct interface. On the other hand, in TEM observation, the periodic modulated structure was observed for 10 hrs thermally-aged sample, and the sphere precipitation was confirmed for 100 hrs thermally-aged sample. It was suggested that there would be a crucial phase separation mode from spinodal decomposition to nucleation-growth between 10 and 100 hrs.