Identification of altered phases of fuel debris by laser fluorescence spectroscopy (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2022-007, 59 Pages, 2022/06

JAEA-Review-2022-007.pdf:2.09MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Identification of altered phases of fuel debris by laser fluorescence spectroscopy" conducted from FY2018 to FY2021 (this contract was extended to FY2021). Since the final year of this proposal was FY2021, the results for four fiscal years were summarized. The present study aims to identify alteration phases occurring on the surface fuel debris at various conditions, using time-resolved laser fluorescence spectroscopy (TRLFS), which is a selective analytical technique for U(VI), a major constituent of fuel debris and stable in oxidizing conditions.

Identification of altered phases of fuel debris by laser fluorescence spectroscopy (Contract research) FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2019-030, 66 Pages, 2020/03

JAEA-Review-2019-030.pdf:7.11MB

JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. Among the adopted proposals in FY2018, this report summarizes the research results of the "Identification of Altered Phases of Fuel Debris by Laser Fluorescence Spectroscopy". In the present study, we focus on uranium that is the main component element in debris, and identify the altered phase produced on the debris surface under various conditions by time-resolved laser fluorescence spectroscopy (TRLFS) with high sensitivity to hexavalent uranium (U(VI)) that is stable in oxidation environment. In particular, further high-sensitive and high-resolution measurements are implemented by improving the fluorescence yields and suppressing the broadening of the peaks through the measurements at ultra-low temperature. In addition, with the supports by quantum chemical calculations, multivariate analysis, and machine learning, the method will lead to the identification of multicomponent and heterogeneous altered phase of fuel debris.

Time-resolved photoelectron spectroscopy of oxidation on the Ti(0001) surface

Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*

Nuclear Instruments and Methods in Physics Research B, 200, p.376 - 381, 2003/01

https://doi.org/10.1016/S0168-583X(02)01726-3

no abstracts in English

A Laboratory scale apparatus for the time-resolved X-ray absorption spectroscopy using laser plasmas as an X-ray source

Yoda, Osamu; Miyashita, Atsumi; *; *; *; *

Japanese Journal of Applied Physics, 32(SUPPL.32-2), p.255 - 257, 1993/00

no abstracts in English

Time resolved X-ray absorption spectroscopy apparatus using laser plasma as an X-ray source

Yoda, Osamu; Miyashita, Atsumi; *; *; *

Excimer Lasers and Applications III, p.463 - 466, 1991/00

no abstracts in English

Time-resolved reflection spectroscopy for simultaneous monitoring VUV waveform and plasma formation

Itakura, Ryuji

no journal, , 

In this study, we propose and demonstrate a new methodology based on time-resolved vacuum-ultraviolet (VUV) reflection spectroscopy for monitoring plasma formation induced by an intense laser pump pulse. The temporal waveform of a VUV probe pulse is also retrieved simultaneously.