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Kirita, Fumio; Tominaga, Masahiro; Yamazaki, Toshihiko; Seshimo, Kazuyoshi; Uryu, Mitsuru
JAEA-Research 2022-006, 61 Pages, 2023/02
JAEA-Research-2022-006.pdf:6.24MB
Nuclear Fuel Cycle Engineering Laboratories (NCL) has been observing ground motion for a long time. On the border from northern Ibaraki prefecture to Fukushima prefecture, inland crustal earthquakes occur less frequently until the 2011 off the Pacific coast of Tohoku Earthquake (hereinafter referred to as Tohoku Earthquake). After Tohoku Earthquake, aftershocks have become more frequent in this area, and in the Hamadori region of Fukushima earthquake that a remarkable long periodic component was observed in the NCL seismic observation record. Until now there were no such things that long periodic components were observed at the observation points near the epicenter of April 2011 Fukushima earthquake, but it was thought basin structure in deep basement around the NCL affected the propagation process to NCL by reflection survey result. As basement structure of NCL affected the seismic wave propagation process, the seismic wave repeatedly reflects and refracts. For that reason, long periodic components of seismic waves may be possibly amplified. In this study, in order to refine the long periodic ground motion evaluation, using a three dimensional ground structure model (3D model) that can reflect the shape of the deep basement structure around the NCL. When modeling 3D ground structure which has a width of about 80km and a length of about 110km and ranges from the epicenter area of April 2011 Fukushima earthquake to the northern coastal area of Ibaraki prefecture modeled, improved the optimum ground structure model using multiple observation records and performed simulation analysis.
Fukuya, Koji*; Fujii, Katsuhiko*; Chimi, Yasuhiro; Hata, Kuniki
Proceedings of 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (Internet), p.523 - 531, 2019/08
For structural integrity assessment on reactor internals of light water reactors, empirical equations of tensile properties as a function of neutron dose, and trend curves of stress-strain relations of neutron-irradiated austenitic stainless steels was proposed by fitting to recently developed database. The data in the database were obtained from reports of national projects in Japan and open literature, which was summarized in the form of data sheets. The empirical equations for tensile properties were formulated by using a saturation-type formulae. The equations were for CW 316 and SA 304/316 stainless steels in the temperature range of 280-350
C and the dose range up to 80 dpa. Stress-strain relation curves were reproduced based on the Swift model. Obtained calculated results by the empirical equations and stress-strain relations were reasonably well fitted to experimental data. The effects of composition and cold-working, etc. on tensile properties were discussed.
Sakurai, Kiyoshi; Yamamoto, Toshihiro
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(2), p.172 - 176, 2005/06
Typical weight estimation methods with Monte Carlo method such as MCNP default, empirical formula, mono-energy neutron attenuation curve, MCNP wwg and adjoint flux are described. The mono-energy neutron attenuation curve method is proposed by authors. Weights estimated by methods except MCNP default and adjoint flux methods are compared with those calculated by MCNP wwg method.
Watanabe, Norio
JAERI-Review 2004-015, 144 Pages, 2004/07
JAERI-Review-2004-015.pdf:25.58MB
In March 6, 2002, significant degradation to the reactor vessel head material adjacent to a control rod drive nozzle was discovered at a U. S. pressurized water reactor (PWR), Davis Besse. Based on the documents issued by the U.S. Nuclear Regulatory Commission (USNRC) and the licensee, this report provides a brief description on circumstances related to discovery of the reactor vessel head degradation, and describes the degraded condition and causes, the USNRC's responses to this event and so on. In attachments, given are the contents of the generic communications (Bulletins, Generic Letters and Information Notices) issued by the USNRC for the events involving boric acid corrosion and degradation of reactor coolant pressure boundary components and the summary of the investigation reports issued by the USNRC's lessons-learned task force.
Mukhovatov, V.*; Shimomura, Yasuo; Polevoi, A. R.*; Shimada, Michiya; Sugihara, Masayoshi; Bateman, G.*; Cordey, J. G.*; Kardaun, O. J. F.*; Pereverzev, G. V.*; Voitsekhovich, I.*; et al.
Nuclear Fusion, 43(9), p.942 - 948, 2003/09
Times Cited Count：43 Percentile：76.6(Physics, Fluids & Plasmas)The values of Q = (fusion power)/(auxiliary heating power) predicted for ITER by three different methods are compared. The first method utilises an empirical confinement time scaling and prescribed radial profiles of transport coefficients, the second approach extrapolates from especially designed ITER similarity experiments, and the third approach is based on partly theory-based transport models. The energy confinement time given by the ITERH-98(y,2) scaling for an inductive scenario with plasma current of 15 MA and plasma density 15% below the Greenwald density is 3.7 s with one estimated technical standard deviation of 14%. This translates in the first approach into an interval for Q of [6-15] at the auxiliary heating power Paux = 40 MW and [6-30] at the minimum heating power satisfying a good confinement ELMy H-mode. Predictions of similarity experiments from JET and of theory-based transport models overlap with the prediction using the empirical confinement-time scaling within its estimated margin of uncertainty.
with surface hydroxyl groups in lithium silicatesNakazawa, Tetsuya; Yokoyama, Keiichi; Grismanovs, V.*; Katano, Yoshio*; Jitsukawa, Shiro
Journal of Nuclear Materials, 307-311(Part2), p.1436 - 1440, 2002/12
Times Cited Count：1 Percentile：10.13(Materials Science, Multidisciplinary)no abstracts in English
D) insertion into the C-C bond in cyclopropane and ethaneKurosaki, Yuzuru; Takayanagi, Toshiyuki
Chemical Physics Letters, 355(5-6), p.424 - 430, 2002/04
Times Cited Count：3 Percentile：8.63(Chemistry, Physical)no abstracts in English
Nakazawa, Tetsuya; Yokoyama, Keiichi; Grismanovs, V.*; Katano, Yoshio*; Jitsukawa, Shiro
Journal of Nuclear Materials, 302(2-3), p.165 - 174, 2002/04
Times Cited Count：3 Percentile：23.39(Materials Science, Multidisciplinary)no abstracts in English
H
+Cl reaction in water; Ab initio molecular orbital study using a cluster modelKurosaki, Yuzuru
Journal of Physical Chemistry A, 105(49), p.11080 - 11087, 2001/12
Times Cited Count：3 Percentile：9.16(Chemistry, Physical)no abstracts in English
; ; ; Omori, Eiichi
JNC TN8410 2001-021, 33 Pages, 2001/09
JNC-TN8410-2001-021.pdf:4.37MB
Carbon-14 released from the nuclear facilities is an important radionuclide for the safety assessment, because it tends to accumulate in environment through food chain and has as a significant impact to personal dose. Carbon-14 has been monitored routinely as one of the main gaseous radionuclides exhausted from the Tokai Reprocessing Plant (TRP) since OCtober of 1991. Furthermore, behavior of carbon-14 in TRP has been investigated through the reprocessing operation and the literature survey. This report describes the result of investigation about the behavior of carbon-14 in TRP as followings. (1)Only a very small amount of carbon-14 in the fuel was liberated into the shear off-gas and most of it was liberated into the dissolver of-gass. Part of the carbon-14 was trapped at the caustic scrubber installed in the of-gas treatment process, and untrapped carbon-14 was released into the environment from the main stack. Amount of carbon-14 released from the main stack was about 4.1
6.5GBq every ton of uranium reprocessed. (2)Carbon-14 trapped at the caustic scrubbers installed in the dissolver off-gas and in the vessel off-gas treatment process is transferred to the low active waste vessel. Amount of carbon-14 transferred to the low active waste vessel was about 5.4 9.6GBq every ton of uranium reprocessed. (3)The total amount of carbon-14 input to TRP was summed up to about 11.915.5 GBq every ton of uranium reprocessed considering the released amount from the main stack and the trapped amount in the off-gas treatment devices. The amount of nitrogen impurity in the initial fuel was calculated about 1522ppm of uranium metal based on the measured carbon-14. (4)The solution in the low active waste vesselis concentrated at the evaporator.Most of the carbon-14 in the solution was transferred into concentrated solution. (5)Tokai vitrification Demonstration Facility (TVF) started to operate in 1994. Since then, carbon-14 has been measured in the ...
O molecules from surface hydroxyl groups in silicatesNakazawa, Tetsuya; Yokoyama, Keiichi; Grismanovs, V.*; Katano, Yoshio*
Journal of Nuclear Materials, 297(1), p.69 - 76, 2001/07
Times Cited Count：9 Percentile：56.04(Materials Science, Multidisciplinary)no abstracts in English
Manokhin, V. N.*; Odano, Naoteru; Hasegawa, Akira
JAERI-Research 2001-013, 22 Pages, 2001/03
JAERI-Research-2001-013.pdf:1.46MB
no abstracts in English
Noda, Kimio; Shinohara, Kunihiko; Kanamori, Masashi
JNC TN8410 2001-010, 35 Pages, 2000/10
JNC-TN8410-2001-010.pdf:3.85MB
We, the radiation control section of JNC have had two important experiences on the JCO critical accident and the JNC fire-explosion accident. Especially, at the critical accident in JCO, it was essential to take an action on the radiation protection activities for the evacuated neighboring inhabitants to the safety area. During the accident, we carried out the radiation protection activities, at the beginning of the accident, environmental monitoring of the surrounding area. Especially for the JCO accident, we took an action to terminate criticality, radiation shielding and monitoring, environmental monitoring, radiation survey of the residents, radiation monitoring of exhaust air.
+CH
H+CH reaction and its isotopic variantsKurosaki, Yuzuru; Takayanagi, Toshiyuki
Journal of Chemical Physics, 113(10), p.4060 - 4072, 2000/09
Times Cited Count：22 Percentile：55.8(Chemistry, Physical)no abstracts in English
NO(
B
)NO(
)+H reactionKurosaki, Yuzuru*; Takayanagi, Toshiyuki
Journal of Molecular Structure; THEOCHEM, 507(1-3), p.119 - 126, 2000/07
no abstracts in English
H+ClCHCl reactionKurosaki, Yuzuru*
Journal of Molecular Structure; THEOCHEM, 503(3), p.231 - 240, 2000/05
no abstracts in English
*; *
JNC TN9200 2000-001, 133 Pages, 2000/02
The 11th Meeting for Reporting Safety Research on FBR and ATR was held at the exhibition hall (TECHNO O-ARAI) in OEC on the 15th of December in 1999. The reports of each subject in FY1996-1998 were presented before discussion at this meeting. The 11 subjects had been selected from the subjects (34 in total) on power reactor in fast breeder reactor, earthquake-proof and probabilistic safety assessment according to the decisions of sub-meetings in Sectional Meeting of Safety Research. This meeting was open to the public, and large attendance outside of JNC was invited for the purpose of getting some advice from related specialists. This report contains presentation papers, questions and answers, list of attendance, etc. Refer to the JNC open report for detailed results of safety research in FY1996-1998.
Sumiyama, Morio*
JNC TJ8400 2000-009, 138 Pages, 2000/02
To evaluate corrosion behavior of carbon steel, a candidate materials of overpack, buried in soil for a long time, the water pipes buried in freshwater clay for a long time we digged out and the soil environment and the corrosion weight loss of pipes have been researched. From the results, a corrosion model (an empirical equation), an oxygen reduction reaction rate-determing step type, of carbon steel buried in soil was introduced. The corrosion data of under ground pipe collected by the Japan Community Gas Associations was used to increase reliability of the corrosion model equation. These data are one of researches of corrosion behavior of carbon steel buried in soil for a long time studied by at home and abroad. 38 samples buried freshwater clay were selected in 171 samples. With estimating the corrosion velocities and the soil environment factors of the above data, the maximum depth of pit corrosion was calculated by the statistical method of the extreme values using the area of overpack as the recurrent time. The correlation between the soil environment factors and the corrosion weight loss was obtained by the correlation analysis. The corrosion model of the maximum depth of pit corrosion at 0.99 of cumulative probability was compared between the under ground pipe data and the above data. On the reference data and the above data, the corrosion model equation; H = aY
was compared with the maximum depth of pit corrosion at 0.99 cumulative probability. The data of water pipes and community gas pipes at 0.99 cumulative probability showed the reasonable values when these data were compared with the reference data. So that the model was proved as a good corrosion model m the neutral low dissolved oxygen environment.
+HCH+H and CD+HCDH+H reactions using variational transition state theory and the multidimensional semiclassical tunneling methodKurosaki, Yuzuru*; Takayanagi, Toshiyuki
Journal of Chemical Physics, 110(22), p.10830 - 10842, 1999/06
Times Cited Count：20 Percentile：53.59(Chemistry, Physical)no abstracts in English
+HCH+H reactionKurosaki, Yuzuru*; Takayanagi, Toshiyuki
Chemical Physics Letters, 299(1), p.57 - 63, 1999/00
Times Cited Count：15 Percentile：43.5(Chemistry, Physical)no abstracts in English
