Measurement of the angular distribution of -rays after neutron capture by La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

https://doi.org/10.1051/epjconf/201921909001

Parity violating effects enhanced by up to 10 times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,) reaction was measured with La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized La target and a 70% polarized He spin filter whose thickness is 70 atmcm are needed. Therefore high quality He spin filter is developed in JAEA. The measurement result of the (n,) reaction at J-PARC and the development status of the He spin filter will be presented.

Seawater immersion tests of irradiated Zircaloy-2 cladding tube

Sekio, Yoshihiro; Yamagata, Ichiro; Yamashita, Shinichiro; Inoue, Masaki; Maeda, Koji

Proceedings of 2014 Nuclear Plant Chemistry Conference (NPC 2014) (USB Flash Drive), 10 Pages, 2014/10

In the Fukushima Dai-ichi Nuclear Power Plant accident, seawater was temporarily injected into the spent fuel pools since water cooling and feeding functions were lost. For fuel assemblies which experienced seawater immersion, surface corrosion due to seawater constituents and the resultant degradation of mechanical property are of concern. Therefore, in order to assess the integrity of fuel assemblies (especially cladding tubes), the effects of seawater immersion on corrosion behavior and mechanical properties for as-recieved and irradiated Zircaloy-2 cladding tubes were investigated in the present study. As a result, no obvious surface corrosion and no significant degradation in the tensile strength property were observed after both artificial and natural seawater immersion tests for both steels. This suggests that the effects of seawater immersions on corrosion behavior and mechanical property (especially tensile property) for Zircaloy-2 cladding tubes are probably negligible.

Evaluation of irradiation behavior on oxide dispersion strengthened (ODS) steel claddings irradiated in Joyo/CMIR-6

Yano, Yasuhide; Otsuka, Satoshi; Yamashita, Shinichiro; Ogawa, Ryuichiro; Sekine, Manabu; Endo, Toshiaki; Yamagata, Ichiro; Sekio, Yoshihiro; Tanno, Takashi; Uwaba, Tomoyuki; et al.

JAEA-Research 2013-030, 57 Pages, 2013/11

JAEA-Research-2013-030.pdf:48.2MB

It is necessary to develop the fast reactor core materials, which can achieve high-burnup operation improving safety and economical performance. Ferritic steels are expected to be good candidate core materials to achieve this objective because of their excellent void swelling resistance. Therefore, oxide dispersion strengthened (ODS) ferritic steel and 11Cr-ferritic/martensitic steel (PNC-FMS) have been respectively developed for cladding and wrapper tube materials in Japan Atomic Energy Agency. In this study, the effects of fast neutron irradiation on mechanical properties and microstructure of 9Cr-and 12Cr-ODS steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the CMIR-6 at temperatures between 420 and 835C to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures.

Nondestructive evaluation of neutron irradiation damage on type 316 stainless steel by measurement of magnetic properties

Takaya, Shigeru; Yamagata, Ichiro; Ichikawa, Shoichi; Nagae, Yuji; Aoto, Kazumi

International Journal of Applied Electromagnetics and Mechanics, 33(3-4), p.1335 - 1342, 2010/10

https://doi.org/10.3233/JAE-2010-1258

We newly developed a vibrating sample magnetometer (VSM) for neutron irradiated materials to investigate the relationship between neutron irradiation damage and magnetic property. The magnetization curves of type 316 stainless steels irradiated in a fast reactor JOYO, a light water reactor JRR-3M or both of them were measured. The ranges of dose and He content were about 0.1-1.8 dpa and 0.5-35 appm, respectively. As the result, it was revealed that the magnetization at 5 kOe increases monotonously with dose regardless of He content. This result shows the possibility of nondestructive evaluation of dose of structural materials by VSM measurement of surveillance samples.

Development of remote operated vibrating sample magnetometer for evaluation of irradiation damage

Takaya, Shigeru; Yamagata, Ichiro; Ichikawa, Shoichi; Nagae, Yuji; Wakai, Eiichi; Aoto, Kazumi

Hozengaku, 9(1), p.51 - 56, 2010/04

http://ci.nii.ac.jp/naid/40017096232

The remote operated vibrating sample magnetometer (VSM) for neutron irradiated samples has been developed. The maximum range of applied magnetic field is more than 0.5/A/m, and the resolution of magnetization is higher than 510Am. The hysteresis loops of neutron irradiated samples were measured by this VSM, and the relationships between dose, which is one of representative irradiation parameter, and magnetic properties such as magnetic coercive force were examined. As result, it was revealed that there are good correlations between them. This fact shows the possibility of nondestructive evaluation of irradiation damage by using VSM.

HREM of Nano-Oxide Particle in ferritic Oxide Dispersion Strengthened Steels

Yamashita, Shinichiro; Yamagata, Ichiro; Akasaka, Naoaki; Ukai, Shigeharu

Materia, 42(12), 878 Pages, 2003/00

Focusing on the cover layer materials (as the Radon Barrier Materials), which could have the effect to restrain the radon from scattering into the air and the effect of the radiation shielding, we produced the radon barrier materials with crude bentonite on an experimental basis, using the rotary type comprehensive unit for grinding and mixing, through which we carried out the evaluation of the characteristics thereof.

Effects of Irradiation Environment of Fast Reactor's Fuel Elements on Void Swelling in P,Ti-Modified 316 Stainless Steel

Akasaka, Naoaki; Yamagata, Ichiro;

20th Symposium on Effects of Radiation on Materials, p.443 - 456, 2001/00

None

Evaluation of lrradiation performance in Monju-type fuel subassembly (MFA-1)

Donomae, Takako; ; ; Akasaka, Naoaki; Yamagata, Ichiro; ;

JNC TN9400 2000-075, 374 Pages, 1999/08

JNC-TN9400-2000-075.pdf:18.85MB

The irradiation test of the Monju-type fuel subassembly, MEA-1, was conducted at FFTF as a Joint Research Program of Fuels and Materials between DOE and PNC. MFA-1 subassembly is consisted of cladding tube, wrapper tube, wrapping wire which are all made of PNC316, as well as 85% low density pellet. The pellet peak burnup and maximum fast neutron fluence reached 147.1GWd/t and 21.410n/m, respectively. Based on the results of Post-irradiation examination, Subassembly and fuel elements behaviors have been evaluated, and the following results were obtained. (1)The wrapper tube elongation and dilation are relatively small, and the fuel pin diameter changes were measured to be about 4% in maximum. The Bundle-Duct lnteraction (BDI) was confirmed not to be severe condition in Monju-type fuel assembly up to the fast neutron fluence of 21.410n/m. (2)In the claddings with the sand-brusted treatment to shave the flaw on the inner surface, the enhanced sweIling was measured, compared with PNC316 claddings manufactured by the usual process. lt is considered that this swelling enhancement in sand-brusted claddings attributed to relatively higher level of residual stress and lower cold-worked. (3)The deferent temperature dependency in swelling was evaluated for cladding and wrapping wire: the peak swelling temperature to be 495C for cladding and 475C for wrapping wire. 0n the contrary, the swelling-temperature dependency for wrapper tube was not able to be determined.

R&D project on irradiation damage management technology for structural materials of long-life nuclear plant, 2; Reports of coupling irradiation (JRR-3 and JOYO) and hot facilities work (WASTEF, JMTR-HL, MMF and FMF)

Matsui, Yoshinori; Takahashi, Hiroyuki; Ichise, Kenichi; Usami, Koji; Endo, Shinya; Iwamatsu, Shigemi; Yonekawa, Minoru; Ito, Kazuhiro; Yamamoto, Masaya; Soga, Tomonori; et al.

no journal, , 

"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from 2006 fiscal year in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupling irradiations or single irradiations by JOYO fast reactor and JRR-3 fission reactor were performed for about two years. The irradiation specimens are the very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we will present about the overall plan, work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.

Nondestructive evaluation of neutron irradiation damage on austenitic stainless steels by measurement of magnetic flux density

Takaya, Shigeru; Nagae, Yuji; Aoto, Kazumi; Yamagata, Ichiro; Ichikawa, Shoichi; Konno, Shotaro; Ogawa, Ryuichiro; Wakai, Eiichi

no journal, , 

Magnetic flux densities for neutron irradiated specimens of austenitic stainless steels were measured by using a flux gate (FG) sensor to investigate the nondestructive evaluation method of irradiation damage parameters, dose and He content. The range of dose, He content and irradiation temperature of the neutron irradiated samples studied in this paper were 0.01-30 displacement per atom (dpa), 1.0-17 appm and 470-560 C, respectively. Magnetic flux density increased with dose although there may be a threshold dose for magnetic property to change between 2 and 5 dpa for 316FR. This result shows the possibility of nondestructive evaluation of dose by measuring magnetic flux density by an FG sensor. On the other hand, magnetic flux density did not depend on He content.