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Riyana, E. S.; Okumura, Keisuke; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi; Kanno, Ikuo
Journal of Nuclear Science and Technology, 8 Pages, 2024/00
Times Cited Count：0 Percentile：0.18(Nuclear Science & Technology)
-rays of fuel debrisMatsumura, Taichi; Okumura, Keisuke; Fujita, Manabu*; Sakamoto, Masahiro; Terashima, Kenichi; Riyana, E. S.
Radiation Physics and Chemistry, 199, p.110298_1 - 110298_8, 2022/10
Times Cited Count：1 Percentile：31.61(Chemistry, Physical)Riyana, E. S.; Okumura, Keisuke; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi
Journal of Nuclear Science and Technology, 59(4), p.424 - 430, 2022/04
Times Cited Count：1 Percentile：16.35(Nuclear Science & Technology)Riyana, E. S.; Okumura, Keisuke; Terashima, Kenichi; Matsumura, Taichi; Sakamoto, Masahiro
Mechanical Engineering Journal (Internet), 7(3), p.19-00543_1 - 19-00543_8, 2020/06
Riyana, E. S.; Okumura, Keisuke; Terashima, Kenichi
Journal of Nuclear Science and Technology, 56(9-10), p.922 - 931, 2019/09
Times Cited Count：5 Percentile：48.99(Nuclear Science & Technology)Riyana, E. S.*; Suda, Shoya*; Ishibashi, Kenji*; Matsuura, Hideaki*; Katakura, Junichi*; Sun, G. M.*; Katano, Yoshiaki
Journal of Nuclear Science and Technology, 56(5), p.369 - 375, 2019/05
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Nuclear reactors produce a great number of electron antineutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may have information on fuel burn-up and may be detected in future with advanced measurement technology. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectra from various reactors such as typical PWR reactor and others types of reactors for comparison. Our result shows the electron antineutrino flux in the low energy region increases with burn-up of nuclear fuel by accumulated nuclides with low Q values in beta decay.
Riyana, E. S.; Okumura, Keisuke; Terashima, Kenichi
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 4 Pages, 2019/05
Okumura, Keisuke; Riyana, E. S.; Sato, Wakaei*; Maeda, Hirobumi*; Katakura, Junichi*; Kamada, So*; Joyce, M. J.*; Lennox, B.*
Progress in Nuclear Science and Technology (Internet), 6, p.108 - 112, 2019/01
In order to establish the prediction method of the dose rate distribution in the primary containment vessel (PCV) of the Fukushima Daiichi Nuclear Power Station, a series of calculations were carried out in the following way; (1) burnup calculation to obtain fuel composition at the time of accident, (2) activation calculation for the structural materials including impurities, (3) estimation of Cs contamination in PCV based on the result of severe accident analysis by IRID, (4) decay calculation of radioactive nuclides, (5) photon transport calculation to obtain dose rate distribution. After that, Cs concentration around the dry-well of 1F was modified to be consistent with locally measured dose rates in the PCV-investigation by IRID.
Okumura, Keisuke; Riyana, E. S.
JAEA-Conf 2018-001, p.63 - 68, 2018/12
The decommissioning of the Fukushima Daiichi Nuclear Power Station (1F) is an unexplored field. Although the investigations for inside primary containment vessel (PCV) by robots have been underway by IRID, actual situation inside the PCV and the characteristics of fuel debris have not been sufficiently clarified yet. Under such circumstances, the computational simulation with reliable data is an effective means for solving many problems for the 1F decommissioning. Here, as application examples using nuclear data such as JENDL-4.0, we will introduce some researches and developments on (1) prediction of dose rate distribution in PCV, (2) remotely operated vehicle (ROV) system to explore submerged fuel debris in PCV, (3) non-destructive assay of nuclear fuel materials in a fuel debris canister.
Riyana, E. S.; Okumura, Keisuke
no journal, ,
A technology to predict the most probable dose rate distribution in the primary containment vessel (PCV) of the Fukushima Daiichi Nuclear Power Station (1F) have been developed by combined use of sophisticated theoretical calculation and local measurement results. It was applied to the Unit-1 of 1F.
Okumura, Keisuke; Riyana, E. S.; Sato, Wakaei*; Maeda, Hirobumi*; Katakura, Junichi*
no journal, ,
Based on the results of fuel burn-up calculations and activation calculations for structural materials and on those of severe accident progression analyses and internal investigations by IRID, we predicted a three-dimensional dose rate distribution in the containment vessel of Unit 1 at the Fukushima Daiichi Nuclear Power Station.
Okumura, Keisuke; Riyana, E. S.; Sato, Wakaei*; Maeda, Hirobumi*; Fujita, Manabu*
no journal, ,
In order to contribute to the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F) and characterization of 1F fuel debris, we predicted the decay heat of the fuel debris from the time of accident to future and its contributing nuclides, by considering release of volatile fission products.
Okumura, Keisuke; Riyana, E. S.
no journal, ,
We have predicted the dose rate distribution inside PCV of Unit 1 and Unit 2 in 2021 by combination of Monte Carlo calculation with local dose rates measurements obtained so far by the internal investigations of the Fukushima Daiichi Nuclear Power Station.
Okumura, Keisuke; Riyana, E. S.; Sato, Wakaei*; Maeda, Hirobumi*; Katakura, Junichi*
no journal, ,
The three-dimensional dose rate distribution at the end of 2021 in the primary containment vessel of the Fukushima Daiichi Nuclear Power Station was predicted by combining various numerical calculations such as Monte Carlo calculation and measured data obtained in the internal investigations.
Riyana, E. S.; Okumura, Keisuke; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi
no journal, ,
Terashima, Kenichi; Matsumura, Taichi; Kaburagi, Masaaki; Sakamoto, Masahiro; Riyana, E. S.; Okumura, Keisuke
no journal, ,
no abstracts in English
Riyana, E. S.; Okumura, Keisuke; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi
no journal, ,
Terashima, Kenichi; Sakamoto, Masahiro; Matsumura, Taichi; Kaburagi, Masaaki; Riyana, E. S.; Nomi, Takayoshi; Okumura, Keisuke
no journal, ,
no abstracts in English
Riyana, E. S.; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi; Okumura, Keisuke
no journal, ,
Riyana, E. S.
no journal, ,
no abstracts in English
