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Kokubun, Yuji; Nakada, Akira; Seya, Natsumi; Koike, Yuko; Nemoto, Masashi; Tobita, Keiji; Yamada, Ryohei*; Uchiyama, Rei; Yamashita, Daichi; Nagai, Shinji; et al.
JAEA-Review 2023-046, 164 Pages, 2024/03
JAEA-Review-2023-046.pdf:4.2MB
The Nuclear Fuel Cycle Engineering Laboratories conducts environmental radiation monitoring around the reprocessing plant in accordance with the "Safety Regulations for Reprocessing Plant of JAEA, Part IV: Environmental Monitoring". This report summarizes the results of environmental radiation monitoring conducted during the period from April 2022 to March 2023 and the results of dose calculations for the surrounding public due to the release of radioactive materials into the atmosphere and ocean. In the results of the above environmental radiation monitoring, many items were affected by radioactive materials emitted from the accident at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, Incorporated (changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016), which occurred in March 2011. Also included as appendices are an overview of the environmental monitoring plan, an overview of measurement methods, measurement results and their changes over time, meteorological statistics results, radioactive waste release status, and an evaluation of the data which deviated of the normal range.
Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Ma, J.-L.; Sagisaka, Akito; Mori, Michiaki; Pirozhkov, A. S.; Kiriyama, Hiromitsu; et al.
Physics of Plasmas, 15(5), p.053104_1 - 053104_10, 2008/05
Times Cited Count：45 Percentile：83.73(Physics, Fluids & Plasmas)High-flux energetic protons whose maximum energies are up to 4 MeV are generated by an intense femtosecond Titanium Sapphire laser pulse interacting with a 7.5, 12.5, and 25
m thick Polyimide tape targets. The laser pulse energy is 1.7 J, duration is 34 fs, and intensity is 3
10
Wcm
. The amplified spontaneous emission (ASE) has the intensity contrast ratio of 410
. The conversion efficiency from laser energy into proton kinetic energies of 
3% is achieved, which is comparable or even higher than those achieved in the previous works with nanometer-thick targets and the ultrahigh contrast laser pulses (10
).
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
Okuno, Tomoharu*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Tao, Y.*; Nagai, Keiji*; Gu, Q.*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Nishihara, Katsunobu*; Norimatsu, Takayoshi*; et al.
Applied Physics Letters, 88(16), p.161501_1 - 161501_3, 2006/04
Times Cited Count：64 Percentile：87.58(Physics, Applied)no abstracts in English
Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Sasaki, Akira; Sunahara, Atsushi*; Okuno, Tomoharu*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Tao, Y.*; Shimada, Yoshinori*; et al.
Physical Review Letters, 95(23), p.235004_1 - 235004_4, 2005/12
Times Cited Count：147 Percentile：95.58(Physics, Multidisciplinary)no abstracts in English
Shimada, Yoshinori*; Nishimura, Hiroaki*; Nakai, Mitsuo*; Hashimoto, Kazuhisa*; Yamaura, Michiteru*; Tao, Y.*; Shigemori, Keisuke*; Okuno, Tomoharu*; Nishihara, Katsunobu*; Kawamura, Toru*; et al.
Applied Physics Letters, 86(5), p.051501_1 - 051501_3, 2005/01
Times Cited Count：113 Percentile：94.26(Physics, Applied)no abstracts in English
Tang, H.; Daido, Hiroyuki; Kishimoto, Maki; Sukegawa, Kota*; Tai, R.; Mesesson, S.*; Tanaka, Momoko; Lu, P.; Kawachi, Tetsuya; Nagashima, Keisuke; et al.
Japanese Journal of Applied Physics, 42(2A), p.443 - 448, 2003/02
Times Cited Count：14 Percentile：50.38(Physics, Applied)no abstracts in English
Suzuki, Masayuki; Daido, Hiroyuki; Choi, I. W.*; Yu, W.*; Nagai, Keiji*; Norimatsu, Takayoshi*; Mima, Kunioki*; Fiedorowicz, H.*
Physics of Plasmas, 10(1), p.227 - 233, 2003/01
Times Cited Count：18 Percentile：50.18(Physics, Fluids & Plasmas)no abstracts in English
Suzuki, Masayuki; Yamagami, Susumu; Nagai, Keiji*; Norimatsu, Takayoshi*; Mima, Kunioki*; Murakami, Yoichi*; Nakayama, Takeyoshi*; Yu, W.*; Fiedorowicz, H.*; Choi, I. W.*; et al.
Proceedings of 2nd International Conference on Inertial Fusion Sciences and Applications (IFSA 2001), p.1252 - 1255, 2001/00
no abstracts in English
Chatani, Keiji; ; ; Masui, Tomohiko*; Nagai, Akinori; ;
PNC TN9410 92-186, 63 Pages, 1992/06
Dose rates around UGT (Upper Guide Tube) of CRDM (Control Rod Drive Mechanism) have been measured in Experimental Fast Reactor "JOYO" during the 9th periodical inspection in order to reflect the study on the shield thickness of UIS (Upper Internal Structure) cask, which has been planned to be used for a Large Fast Reactor. Absolute amount of radioactive corrosion products (CP) is evaluated by gamma spectra analysis for waste water from cleaned UGT. The results on this study are summarized as follows: (1)Measured dose rates distribution around UGT before and after clean-up show the same reduction. The affection of CP is not clearly observed for the dose rate distribution. (2)The relative values of dose rate, which are evaluated by considering the inside structure of UGT, show the attenuation of 10
from bottom to sodium level of UGT. The above relative distribution agrees well with that of measurement data using U-235 fission chamber, which was conducted at MK-I core start-up tests, except the stellite region. (3)As to the relative values of dose rate, calculation by "DOT3.5" and estimation by measured dose rate agree within factor 3 for the attenuation of 10. It is confirmed that the calculation can predict well the measurement. (4)Absolute amount of CP estimated by gamma spectra analysis and waste water analysis is 180 MBq. 
Co dominates 92 % of CP. This value agrees with the prediction by corrosion product behavior analysis code "PSYCHE" within factor 2.
Yamanouchi, Sadamu; Kuwajima, Y.; Namekawa, Takashi; Inui, T.; Kondo, M.; Tani, Y.; Usui, Keiji; Nagai, Shuichiro
PNC TN9410 85-138, 109 Pages, 1985/03
The JOYO MK-I core fuel subassembly PPJX13 was irradiated in JOYO MK-I core (location; 000) from 50 MW test through 75 MW 6th cycle. The average burnup was about 40,100 MWD/MTM. Five fuel pins was selected in the subassembly. Destructive examination items were metallographic examination (fuel and cladding), micro-hardness measurement, cladding density measurement and burnup measurement. The following results were obtained; (1) Central void of about 250Mm
, columner grain region, equiaxed region (gas bubble region) and densified equiaxed region was formed by fuel restrusting. (2) Fuel and Cladding residual gap width were 20 m 89 m. Fuel-cladding chemical interaction was 13 m at the maximum cladding temperature. (3) Carbide precipitation along the grain boundary and twinning zone were observed at high temperature position in cladding. Cladding micro-hardness indicated high value at low temperature position. (4) The cladding density change of 1.10% were observed in R material. (5) Burnup measurement by 
Nd isotope analysis using mass spectrometer showed 5.22 atom % at the center position of the center fuel pin.
Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Ma, J.-L.; Sagisaka, Akito; Mori, Michiaki; Pirozhkov, A. S.; Kiriyama, Hiromitsu; et al.
no journal, ,
The efficient proton beam whose maximum energy of up to 4 MeV was produced by the 50TW short pulse intensity Ti:Sap laser irradiated on the polyimide target [(C
H
O
N
)n] with the thicknesses of 7.5m, 12.5m, 25m, which is transparent to the 800 nm laser. The laser parameters are energy of 1.7J, pulse width of 35fs and the intensity of 310 Wcm. The contrast of the ASE component is 410. The conversion efficiency from laser energy into the proton kinetic energy is up to 3%. This conversion efficiency is comparable or even higher than the results obtained with the same level laser ( J energy) interacts with the nano-meter level ultra thin target. In this paper we discuss on the comparison between our results and other experimental results obtained in other facilities.
Ito, Fuyumi; Nishimura, Akihiko; Norimatsu, Takayoshi*; Nagai, Keiji*
no journal, ,
The purpose of the research is to apply the micro capsule technology to the facility maintenance. The micro capsule technology for laser fusion target was developed at the institute of laser engineering Osaka University. We have a plan to apply the fabrication technology of polystyrene micro capsules to the facility maintenance where the magnetic particle testing for complex piping system is investigated.
Ito, Chikara; Naito, Hiroyuki; Ito, Hideaki; Imaizumi, Kazuyuki; Nagai, Akinori; Ito, Keisuke; Nishimura, Akihiko; Oba, Hironori; Wakaida, Ikuo; Sugiyama, Akira; et al.
no journal, ,
no abstracts in English
