Measurement methods for the radioactive source distribution inside reactor buildings using a one-dimensional optical fiber radiation sensor (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Nagoya University*

JAEA-Review 2021-033, 55 Pages, 2021/12

JAEA-Review-2021-033.pdf:2.9MB

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 FY2019, this report summarizes the research results of the "Measurement methods for the radioactive source distribution inside reactor buildings using a one-dimensional optical fiber radiation sensor" conducted in FY2020. We are developing a one-dimensional optical fiber radiation sensor that can estimate the radioactive source distribution "along lines" instead of "at points". To improve the conventional time-of-flight optical fiber radiation sensor for the application under high dose rate environment, basic evaluation tests were conducted using various optical fibers with different diameters and materials. We found the usefulness of quartz optical fiber as a one-dimensional radiation sensor with high position resolution. We also conducted the study of a newly-developed

Measurement of high-energy neutron fluxes and spectra around the J-PARC mercury spallation neutron target using multi-foil activation method

Kasugai, Yoshimi; Harada, Masahide; Kai, Tetsuya; Oi, Motoki; Meigo, Shinichiro; Maekawa, Fujio

JAEA-Data/Code 2015-033, 28 Pages, 2016/03

JAEA-Data-Code-2015-033.pdf:1.78MB

The high-energy neutron fluxes and spectra around the mercury spallation neutron source at MLF of J-PARC were measured by the multi-foil activation method. The threshold energies of neutron reactions utilized in this experiment covered from 0.1 to 50 MeV. The foil irradiation was carried out on the first beam-run of MLF from May 30th to 31th, 2008. After the irradiation, the induced radioactivity of each foil was measured using an HPGe detector, and the neutron-induced reaction-rate distribution around the mercury target was determined. Using these data, the high-energy neutron fluxes and spectra were deduced with unfolding method in which the neutron spectra calculated with PHITS code were used as the initial-guess spectra. By comparison between the initial and the unfolded spectra, it was shown that most of the calculation results, which had been the basis of the neutronics design of the MLF target assembly, were consistent with the experimental data within 30%.

A Factorization of LET effects of ion induced photostimulated luminescence

Abe, Ken*; Saito, Kiwamu*; To, Kentaro; Kojima, Takuji; Sakai, Takuro

JAERI-Review 99-025, TIARA Annual Report 1998, p.103 - 105, 1999/10

https://jopss.jaea.go.jp/pdfdata/JAERI-Review-99-025.pdf

no abstracts in English

Preparation of dosimetry code for static experiment critical facility STACY (Contract research)

Sakurai, Kiyoshi; Miyoshi, Yoshinori; Nakamura, Takemi*; Sato, Osamu*

JAERI-Data/Code 99-021, 99 Pages, 1999/03

JAERI-Data-Code-99-021.pdf:3.03MB

no abstracts in English

Effect of external stress on the microstructural change during electron-irradiation in nickel

; Katano, Y.; Shiraishi, K.

Journal of Nuclear Science and Technology, 21(9), p.671 - 677, 1984/00

https://doi.org/10.3327/jnst.21.671

no abstracts in English

Neutron Dosimetry by the Spectrum Weighting Function Method with a NE213 Liquid Scintillator

;

JAERI-M 9982, 21 Pages, 1982/03

JAERI-M-9982.pdf:0.82MB

no abstracts in English

Experimental evaluation of reactor neutron spectrum in irradiation field; Practical applicability of multi-foil activation and of obtaining unique evaluated spectrum in thermal to intermediate energy region studied using critical facility

Kondo, I.;

Journal of Nuclear Science and Technology, 18(6), p.461 - 472, 1981/00

https://doi.org/10.3327/jnst.18.461

no abstracts in English

Annual report of Division of Thermonuclear Fusion Research and Division of Large Tokamak Development; 1977.4-1978.3

;

JAERI-M 8059, 280 Pages, 1979/02

JAERI-M-8059.pdf:8.57MB

no abstracts in English

Effect of the light output efficiency of charged particles on an unfolded neutron spectrum by an NE213 organic scintillator

;

Nuclear Instruments and Methods, 148(2), p.395 - 397, 1978/02

no abstracts in English

The Unfolding code system for the NE213 liquid scintillator

;

JAERI-M 6952, 25 Pages, 1977/02

JAERI-M-6952.pdf:0.61MB

no abstracts in English

Lessons learned from good practices during the accident at Fukushima Daiichi Nuclear Power Station in light of resilience engineering

Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*

no journal, , 

The accident at the Fukushima Daiichi Nuclear Power Station, which was triggered by the Great East Japan Earthquake, has presented significant issues about in which the safety of massive socio-technical systems is structured. We must derive the greatest number of lessons possible from this accident to ensure the safety of systems in the future, but the lessons learned so far have mainly focused on risks and been deduced from an analysis of failures that led to the accident. This paper references the approach of Resilience Engineering which aims to extend successes in a changing environment, and focuses on the actions that prevented "further catastrophe" through an analysis of the Fukushima accident and derives new lessons to improve the capability to handle "unforeseen contingencies."