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Nakanishi, Ryuzo; Oba, Hironori; Saeki, Morihisa; Wakaida, Ikuo; Tanabe, Rie*; Ito, Yoshiro*
Optics Express (Internet), 29(4), p.5205 - 5212, 2021/02
Times Cited Count：13 Percentile：83.13(Optics)Laser-induced breakdown spectroscopy (LIBS) combined with liquid jets was applied to the detection of trace sodium (Na) in aqueous solutions. The sensitivities of two types of liquid jets were compared: a liquid cylindrical jet with a diameter of 500 
m and a liquid sheet jet with a thickness of 20 m. Compared with the cylindrical jet, the liquid sheet jet effectively reduced the splash from the laser-irradiated surface and produced long-lived luminous plasma. The limit of detection (LOD) of Na was determined to be 0.57 g/L for the sheet jet and 10.5 g/L for the cylindrical jet. The LOD obtained for the sheet jet was comparable to those obtained for commercially available inductively coupled plasma emission spectrometers.
Abe, Yuta; Nakagiri, Toshio; Watatani, Satoshi*; Maruyama, Shinichiro*
JAEA-Technology 2017-023, 46 Pages, 2017/10
JAEA-Technology-2017-023.pdf:8.01MB
This is a report on Abrasive Water Jet (AWJ) cutting work carried out on specimen, which was used for Simulated Fuel Assembly Heating Examination by Collaborative Laboratories for Advanced Decommissioning Science (CLADS) molten core behavior analysis group in February 2016. The simulated fuel assembly is composed of Zirconia for the outer crucible/simulated fuel, stainless steel for the control blade and Zircaloy (Zr) for the cladding tube/channel box. Therefore, it is necessary to cut at once substances having a wide range of fracture toughness and hardness. Moreover, it is a large specimen with an approximate size of 300 mm. In addition, epoxy resin has high stickiness, making it more difficult to cut. Considering these effects, AWJ cutting was selected. The following two points were devised, and this specimen could be cut with AWJ. If it was not possible to cut at one time like a molten portion of boride, it was repeatedly cut. By using Abrasive Suspension Jet (ASJ) system with higher cutting ability than Abrasive Injection Jet (AIJ, conventional method) system, cutting time was shortened. As a result of this work, the cutting method in Simulated Fuel Assembly Heating Examination was established. Incidentally, in the cutting operation, when the cutting ability was lost at the tip of the AWJ, a curved cut surface, which occurs when the jet flowed away from the feeding direction, could be confirmed at the center of the test body. From the next work, to improve the cutting efficiency, we propose adding a mechanism such as turning the cutting member itself for re-cutting from the exit side of the jet and appropriate traverse speed to protect cut surface.
Shoji, Tsugio; Fukui, Yasutaka; Ueda, Takiho
JAEA-Technology 2015-035, 70 Pages, 2016/01
JAEA-Technology-2015-035.pdf:8.07MB
The plasma jet cutting technology (Max output current is 250A) is developed for the dismantling of nuclear facilities in Oarai Research and Development Center. The plasma jet cutting technology is applicable to take out the debris. The plasma jet torch (Max output current is 600A) was produced for this application. This torch is available for the cutting of thick core internal materials in water. The ability of taking out debris and core internal material has been confirmed.
Kotaki, Hideyuki
JAERI-Research 2002-031, 88 Pages, 2002/12
JAERI-Research-2002-031.pdf:3.33MB
We investigate a nonlinear phenomena in laser-plasma interaction, a wakefield excited by intense laser pulses, and a possibility of generating an electron beam by an intense laser pulse. Ionization of gas with a self-focusing causes a broad continuous spectrum with blueshift. The normal blueshift depends on the laser intensity and the plasma density. We have found the spectrum shifts to fixed wavelength independent of the laser power and gas pressure. We call the phenomenon "anomalous blueshift". An intense laser pulse excites a wakefield in plasma. The wakefield excited by 2TW, 50fs laser pulses in a gas-jet plasma is measured with a time-resolved frequency domain interferometer (FDI). This is the first time-resolved measurement of the wakefield of 20GeV/m in a gas-jet plasma. The FDI and the anomalous blueshift will be modified to an optical injection system as an electron beam injector. In a simulation we obtain a high quality intense electron beam. The result illuminates the possibility of a high energy and a high quality electron beam acceleration.
Tachibana, Mitsuo; Shiraishi, Kunio; Yanagihara, Satoshi
JAERI-Tech 2001-014, 42 Pages, 2001/03
In the JPDR dismantling demonstration project, the dismantling activities were conducted for the purpose of verification of remote dismantling machines and collection of various kinds of data on work activities. These lessons were categorized into safety consideration, waste treatment and work efficiency by analyzing the data on work activities. Exemplified are necessities of facility information, efficiency of mock-up tests for evaluation of remote dismantling procedures. There will be useful for implementing other decommissioning projects in safe and efficiency. This report describes the measure taken for remote dismantling activities and the lessons learned from the dismantling activities.
Kunugi, Tomoaki; *; *
Dai-32-Kai Nihon Dennetsu Shimpojiumu Koen Rombunshu, 0, p.565 - 566, 1995/05
no abstracts in English
Kunugi, Tomoaki; *; *; *
Fusion Engineering and Design, 28, p.63 - 71, 1995/00
no abstracts in English
Yoshino, Ryuji; Neyatani, Yuzuru; Isei, Nobuaki; Koide, Yoshihiko; Kawano, Yasunori; A.Tanga*; Campbell, D. J.*; M.F.Johnson*; L.Rossi*
IAEA-CN-60/A5-8, 0, p.685 - 695, 1995/00
no abstracts in English
*; Kunugi, Tomoaki; *
Therm. Sci. Eng., 3(4), p.27 - 33, 1995/00
no abstracts in English
*; *; Matoba, Toru; Yamamoto, Shin
Reza Kenkyu, 20(6), p.375 - 391, 1992/06
no abstracts in English
Fujiki, Kazuo; ; ;
Proc. of the Int. Conf. on Dismantling of Nuclear Facilities; Policies-Techniques, p.219 - 232, 1992/00
no abstracts in English
