Analytical method for chemical compositions of volcanic glasses in Tono Geoscience Center; Quantitative measurements of Major Elements by using EPMA and Minor Elements by LA-ICP-MS

Kagami, Saya; Yokoyama, Tatsunori; Umeda, Koji*

JAEA-Testing 2021-001, 49 Pages, 2021/08

JAEA-Testing-2021-001.pdf:3.86MB

To make a contribution to safety assessment for geological disposal of high level radioactive and/or TRU waste, we need to assess long-term stability of geological environment and predict long-term changes of geotectonic events that will occur in the future, especially for Quaternary period ( 2.6 million years ago-present). In the most case, we investigate chronological data of geological events by radiometric dating. When some geological samples have no objects to which radiometric dating method can be applied (e.g., zircon, biotite, wood fragments and plant residues), we can use tephrochronology, which is geological dating method using each layer of tephra (erupted volcanic ash), for dating of geological layers. This chronological method is essential in Japan, where volcanism is very active. Tephra is usually characterized by petrographic characteristics and/or chemical composition (mainly major elements) of volcanic glasses and/or minerals in tephra. In Tono Geoscience Center (Japan Atomic Energy Agency), we develop an analytical technique of chemical composition including trace elements of volcanic glasses for detailed tephra identification. In this paper, we report a sample preparation procedure and analytical methods of chemical compositions of individual volcanic glass shards by using an electron probe microanalyzer and a laser ablation-inductively coupled plasma-mass spectrometer.

Impact of ferrous iron dosing on iron and phosphorus solids speciation and transformation in a pilot scale membrane bioreactor

Wu, H.*; Wang, Y.*; Ikeda, Atsushi; Miller, C. J.*; Waite, T. D.*

Environmental Science; Water Research & Technology, 5(8), p.1400 - 1411, 2019/08

AA2019-0201.pdf:0.72MB

https://doi.org/10.1039/C9EW00225A

In this study, the distributions of iron and phosphorus species in a 1.25 m pilot scale submerged membrane bioreactor dosed with Fe(II) salts to either the membrane chamber or the 1st anoxic chamber were determined using X-ray absorption spectroscopy (XAS) at the iron and phosphorus K-edges. Significant differences in the distribution of Fe species were evident at the commencement of dosing depending on the chamber to which Fe(II) was dosed though these differences were much less distinct by the time steady state conditions were achieved. Both the co-precipitation of P with Fe and adsorption of phosphorus to iron oxides play important roles with regard to the removal of phosphorus from the MBR supernatant with the results of this work suggesting that P removal via formation of Fe(III)-phosphate mineral species is preferred if Fe(II) is dosed to the membrane chamber rather than the 1st anoxic chamber.

Design of the accelerator's operating aid system using self-organizing map

Sakaki, Hironao

Proceedings of 27th Linear Accelerator Meeting in Japan, p.85 - 87, 2002/08

no abstracts in English

Construction of a fast real-time visualization system for JT-60 plasma shape

Hoshi, Y.*; Miura, Yushi; Ouchi, K.*; Kakefuda, Toyokazu*; Akiba, K.*; *; Kawamata, Yoichi; Kurihara, Kenichi

Heisei-12-Nendo Tohoku Daigaku Gijutsu Kenkyukai Hokoku, p.425 - 427, 2001/03

no abstracts in English

Synthesis and identification of organic components of ``Red Oil'' (Contract research)

Miyata, Teijiro; Takada, Junichi; Nakagiri, Naotaka*; Koike, Tadao; Tsukamoto, Michio; *; Nishio, Gunji*

JAERI-Tech 99-040, 194 Pages, 1999/05

JAERI-Tech-99-040.pdf:5.73MB

no abstracts in English

None

PNC TJ1632 98-001, 112 Pages, 1998/03

PNC-TJ1632-98-001.pdf:2.55MB

no abstracts in English

None

*; Ozawa, Kenji; Yoshikawa, Shinji; *

PNC TY1602 97-001, 36 Pages, 1997/04

PNC-TY1602-97-001.pdf:1.09MB

no abstracts in English

Position localization for mobile robots using a colour image of equipment at nuclear plants

Ebihara, Kenichi; Otani, Takayuki; Kume, Etsuo

Robotica, 14(6), p.677 - 685, 1996/11

https://doi.org/10.1017/S0263574700018543

no abstracts in English

Reactor dynamics experiment of nuclear ship Mutsu using pseudo random signal, (III); The third experiment

Hayashi, Koji; Shimazaki, Junya; Nabeshima, Kunihiko; Shinohara, Yoshikuni; Inoue, Kimio*;

JAERI-Research 95-015, 172 Pages, 1995/03

JAERI-Research-95-015.pdf:4.53MB

no abstracts in English

Level-1 PSA on large fast breeder reactor (II); Evaluation of PLOHS frequency with the water steam system with decay heat removal capability

Hioki, Kazumasa

PNC TN9410 94-188, 160 Pages, 1994/05

PNC-TN9410-94-188.pdf:8.75MB

The Systems Analysis Section has been performing a probabilistic Safety Assessment (PSA) on a large fast breeder reactor (FBR) since JFY 1992. The objective of the study is to apply the PSA method to a plant in a conceptual design stage, develop system models, perform quantitative analyses and systematic evaluation, supply valuable insights to enhance reliability and safety, and reflect them to the basic design. The plant analyzed is a 600MWe class large FBR designed by the Plant Engineering Section in the "Large FBR design study" that has been performed since JFY 1990. The failure probability of the Decay Heat Removal System (DHRS) can be reduced approximately two orders if the Water Steam System (WSS) can remove the decay heat for the first 24 hours. The frequency of PLOHS, however, is not reduced to less than one third because the WSS cannot be used for some initiating events and the PLOHS frequency is dominated by the failure probability of DHRS without the WSS. The failure probability of DHRS is dominated by the common cause failures (CCFs) of vanes, dampers and valves around the air-coolers in the Auxiliary Cooling System (ACS). Therefore it is most important to eliminate the CCFs. Assuming that the CCFs have been eliminated by diversifying the components, the frequencies of PLOHS were evaluated. An analysis has shown that if the WSS can remove the decay heat alone, the PLOHS frequency is reduced approximately two orders. In this case the PLOHS frequency is dominated by the failure probability of the DHRS right after the reactor shutdown. The most effective way to reduce the PLOHS frequency is to increasc the redundancy of the DHRS for the first few hours after reactor shutdown. It is known through the experience of preceding plants that the success criteria can be relaxed to one loop natural circulation instead of forced circulation in the best estimate evaluation. It was shown that under such condition, the PLOHS frequency can be as low as 10 ...