Kurihara, Momo*; Yasutaka, Tetsuo*; Aono, Tatsuo*; Ashikawa, Nobuo*; Ebina, Hiroyuki*; Iijima, Takeshi*; Ishimaru, Kei*; Kanai, Ramon*; Karube, Jinichi*; Konnai, Yae*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 322(2), p.477 - 485, 2019/11
We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the Cs results were within 2, indicating that the methods were accurate. The relative standard deviations (RSDs) indicating the variability in the results from different laboratories were larger than the RSDs indicating the variability in the results from each separate laboratory.
Hirano, Koichiro; Asano, Hiroyuki; Ishiyama, Tatsuya; Ito, Takashi; Okoshi, Kiyonori; Oguri, Hidetomo; Kondo, Yasuhiro; Kawane, Yusuke; Kikuzawa, Nobuhiro; Sato, Yoshikatsu; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.310 - 313, 2016/11
We have used a beam scraper with the incident angle of 65deg to reduce the beam power deposition density in the MEBT between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC linac. The 65 scraper was irradiated by the H beam up to particle number of 1.47E22. We observed a lot of surface projections with several hundred micrometers high in the beam irradiation damage on the scraper by using the laser microscope. In order to study the limits of scrapers, we constructed a new 3 MeV linac at J-PARC. We will conduct the scraper irradiation test at the end of this year.
Ishizaki, Manabu*; Akiba, Sae*; Otani, Asako*; Hoshi, Yuji*; Ono, Kenta*; Matsuba, Mayu*; Togashi, Takanari*; Kanaizuka, Katsuhiko*; Sakamoto, Masatomi*; Takahashi, Akira*; et al.
Dalton Transactions, 42(45), p.16049 - 16055, 2013/12
We have revealed the fundamental mechanism of specific Cs adsorption into Prussian blue (PB) in order to develop high-performance PB-based Cs adsorbents in the wake of the Fukushima nuclear accident. We compared two types of PB nanoparticles with formulae of Fe[Fe(CN)]3xHO (x = 10-15) (PB-1) and (NH)0.70Fe1.10[Fe(CN)]1.7HO (PB-2) with respect to the Cs adsorption ability. The synthesised PB-1, by a common stoichiometric aqueous reaction between 4Fe and 3[Fe(CN)], showed much more efficient Cs adsorption ability than did the commercially available PB-2.
Utsumi, Yuki*; Sato, Hitoshi*; Kurihara, Hidenao*; Maso, Hiroyuki*; Hiraoka, Koichi*; Kojima, Kenichi*; Tobimatsu, Komei*; Okochi, Takuo*; Fujimori, Shinichi; Takeda, Yukiharu; et al.
Physical Review B, 84(11), p.115143_1 - 115143_7, 2011/09
We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu by means of temperature-dependent hard X-ray photoemission spectroscopy (HX-PES), soft X-ray absorption spectroscopy (XAS), and soft X-ray photoemission spectroscopy (SX-PES) of the valence band. We have described the valence transition in YbInCu in terms of the charge transfer from the CB to Yb 4 states.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Yoshikawa, Ryuji; Ohshima, Hiroyuki; Hamada, Hirotsugu; Kurihara, Akikazu; Uchibori, Akihiro
JAEA-Research 2008-055, 24 Pages, 2008/06
In Japan Atomic Energy Agency, thermal hydraulic studies on sodium-water reaction are being performed with the multi-component and multi-phase code SERAPHIM. The interfacial area concentration of sodium droplets in the steam is important for the accurate analysis of sodium-water reaction. In this report, the theoretical analysis and numerical models for gas jets were reviewed to understand the mixing process of sodium and water. As for theoretical analysis, existing critical flow rate, depressurization and entrainment analysis for jet flows were summarized. The applicability of critical flow rate equations for subcooled water at 17MPa were confirmed after investigating its effect of compressibility. Based on the available knowledge on entrained droplet sizes in gas jets, a transport equation of sodium droplet interfacial area concentration was constructed for multiphase flow simulation.
Takeda, Nobufumi*; Iriya, Keishiro*; Hitomi, Takashi*; Konishi, Kazuhiro*; Kurihara, Yuji*
Obayashigumi Gijutsu Kenkyushoho (CD-ROM), (72), 8 Pages, 2008/00
To evaluate applicability as the steel reinforced concrete of the concrete with the low alkalinity cement which contains pozzolan that has been examined to apply for high level radioactive waste disposals, concrete of 30% water-cement ratio was performed 6-year marine exposure examination, aging of their compressive strength, the intrusion width of the chloride ion and the corrosion of reinforcing bar were investigated. And based on these results, progress of corrosion of reinforcing bar and the outbreak time of reinforcing corrosion crack were predicted. As a result, the following result became clear. (1) There is no fall of the compressive strength of test pieces in 6-year marine exposure examination. (2) There is little penetration of the chloride ion in comparison with the concrete consists of ordinary Portland cement. (3) The corrosion of reinforcing bar starts for the early stage with a little quantity of chloride ion intrusion, the progress until six years is extremely small. (4) the corrosion speed of the reinforcing bar of concrete with low alkali cement in underground water including sea water were estimated as 0.300.55 mg/(cm year). In case of using this concrete to structure with 100 mm cover thickness and 22 mm reinforcing bar diameter, the outbreak time of reinforcing corrosion crack were predicted as 50100 years after construction.
Kurihara, Osamu; Hato, Shinji; Kanai, Katsuta; Takada, Chie; Takasaki, Koji; Ito, Kimio; Ikeda, Hiroshi*; Oeda, Mikihiro*; Kurosawa, Naohiro*; Fukutsu, Kumiko*; et al.
Journal of Nuclear Science and Technology, 44(10), p.1337 - 1346, 2007/10
In the case of internal contamination of radionuclides, it is necessary to perform internal dose assessment for radiation protection. For this purpose, the ICRP has given the dose coefficients and the retention and excretion rates for various radionuclides. However, these dosimetric quantities are calculated only in typical conditions, therefore, are not necessarily covered enough in the case of dose assessment in which specific information on the incident or/and individual biokinetic characteristics should be taken into account retrospectively. This paper describes a developed PC-based package of software REIDAC to meet the needs in retrospective dose assessment. REIDAC was verified by comparisons with dosimetric quantities given on the ICRP publications and several examples of practical use were also shown.
Nakayama, Masashi; Iriya, Keishiro*; Fujishima, Atsushi; Mihara, Morihiro; Hatanaka, Koichiro; Kurihara, Yuji*; Yui, Mikazu
Materials Research Society Symposium Proceedings, Vol.932, p.159 - 166, 2006/00
Cementitious material is one of candidates of engineered barriers in TRU and HLW repositories. However, since ordinary Portland cement may rises pH of pore water due to its high alkalinity, bentnite and rock which contact with cementitious barriers as a mulch barrier system may deteriorate for a long term by its high pH. Low alkalinity cement with high pozzolanic material content are developed in order to reduce such hyper alkaline deterioration. This paper shows that pH of pore water of this cement is about 11, and that it can be applied for actual structures as self compacting concrete and shotcrete.
Iriya, Keishiro*; Kurihara, Yuji*; Noda, Masaru*
JNC TJ5400 2004-003, 45 Pages, 2005/02
Kurihara, Yuji; Yui, Mikazu; Tanai, Kenji; Kawakami, Susumu; Sugita, Yutaka; Taniguchi, Naoki; Hirai, Takashi
JNC TN8400 2004-006, 59 Pages, 2004/04
Following studies have been done in this papers in order to apply the technologies based on H12 report to the actual geological conditions of Horonobe underground research laboratory. 1.reconsidering the process of repository design, 2. arrangement of the relations between geological conditions and the performance of engineering barrier systems, 3.present the appropriate form of geological informations, 4.study on the stability of deposition hall.
Kurihara, Yuji; Yui, Mikazu; Tanai, Kenji; Kawakami, Susumu; Sugita, Yutaka; Taniguchi, Naoki; Hirai, Takashi
JNC TN8400 2004-002, 58 Pages, 2004/04
In this paper, the items of in-situ experiments at Horonobe URL with respect to the technical issues about reliability of long-term behavior of engineered barrier system were extracted. And the concepts of the experiments were studied from several points of view such as verification of models and getting the actual behavior. Extracted items of the in-situ experiments are as follows. Coupled Phenomena Test (THMC Test), Buffer & Rock Creep Test, Gas Migration Test, Over-pack Corrosion Test, High-pH Influence Test, Low Alkaline Concrete Execution Test, Engineering-Barrier Emplacement Test, Tunnel Plugging Test.
Kurihara, Yuji; Fujita, Tomo; Kawakami, Susumu; Jintoku, Takashi; Yui, Mikazu; Sugita, Yutaka
JNC TN8400 2003-053, 32 Pages, 2004/03
In previous JNC tequnichal reports, from a view point of long-term safety on geological disposal of high level radioactive waste, the items which should guarantee the performance of each element of the repository were extracted, and it was shown how to guarantee the performance about these items. Furthermore, future R&D requirements were extracted. In this report, the status of each subject in JNC was reported.
Matsui, Hiroya; Kurihara, Yuji; Makino, Hitoshi
JNC TN5400 2003-004, 50 Pages, 2004/03
This report is described for preliminary plan in Phase II and Phase III taken into consideration of expected geological environment at position of URL based on the results of the investigations until FY 2002/2003. The project progress, duration of construction phse and total cost are considered as important factors for planning as well. The below items of in-situ experiments in Phase II and Phase III are planning. [Phase II] (In-situ experiments for understanding of geological environment) *Geological survey at drift face *Inflow measurement in three shafts *Water pressure monitoring and groundwater sampling around a shaft during excavation of URL *Investigation for EDZ around a shaft *Stress measurement on support *Detail investigations for geological environment around 250m drift and 550m drift *Excavation disturbance experiment in a drift *Investigation for desaturation zone and redox condition around a drift. (Engineered barrier system) *In-situ experiment on low-alkari concrete *In-situ experiment for gas migration in engineering barrier system [Phase III] (In-situ experiments for understanding of geological environment) *EDZ experiment for stress interference *Investigation of long-term behavior of EDZ around a drift *Detail investigation on fault/fault zone *Monitoring for the change of geological environment at earthquake *Backfill test in borehole (Engineered barrier system) *T-H-M-C experiment *In-situ experiment for corrosion of overpack *Investigation of the influence of a concrete to engineering barrier system and geological environment *In-situ experiment for interference between backfill material and geological environment *Backfill test in a drift (Safety assessment) *Tracer tests in engineering barrier system, natural barrier and fault/fault ...
Kawakami, Susumu; Yui, Mikazu; Kurihara, Yuji; Jintoku, Takashi; Sugita, Yutaka
JNC TN8400 2003-037, 26 Pages, 2004/02
In order to contribute to the safety standards and guidelines upon which a administration decides, examination for clarifying how to reflect the result obtained by future R&D was performed in other reports, as the JNC technical reports. In those reports, from a viewpoint of the long-term safety on geological disposal of high-level radioactive waste, the items which should guarantee the performance of each element of the repository were extracted, and it was shown how to guarantee the performance about these items. Furthermore, future R&D requirements were extracted. In this report, the status of each subject in JNC was reported.
Sugita, Yutaka; Kawakami, Susumu; Yui, Mikazu; Makino, Hitoshi; Sawada, Atsushi; Mihara, Morihiro; Kurihara, Yuji
Genshiryoku Bakkuendo Kenkyu, 10(1), p.103 - 112, 2004/00
Sugita, Yutaka; Kurihara, Yuji; Kawakami, Susumu; Jintoku, Takashi; Yui, Mikazu
JNC TN8400 2003-015, 34 Pages, 2003/05
In order to contribute to the safety standards and guidelines upon which a governmental administration decide, examination for clarifying how to reflect the result obtained by future R&D was performed. From a view point of long-term safety on geological disposal, the items which should guarantee the performance of each element which constitutes disposal institutions (by this report, they are the backfill, the plug, the tunnel, and the pit) were extracted, and it was shown what a performance guarantee is concretely offered about these items. Furthermore, based on H12 report as a situation of present R&D for a method of a performance guarantee, the subjects considered that a future R&D is required were extracted.
Sugita, Yutaka; Kawakami, Susumu; Yui, Mikazu; Makino, Hitoshi; ; Kurihara, Yuji; Mihara, Morihiro
JNC TN8400 2003-010, 44 Pages, 2003/04
Regarding closure technology of undergound facilities in geological disposal of the HLW in H12 rport, the fundamental concept that closure technology has no impact against the engineered barrier system(EBS) was described. Performance Assessment(PA) has been performed without considering of the barrier function of closure elements. Following H12 report, the various in-situ data of the closure elements (ex. plug, backfill) have been obtained. Therefore, we considered that the PA of the EBS considering the expecting performance of the closure elements from the view points of both the engineering technology and the PA should be examined. First, the characteristics of rock mass and the function of the closure elements were summarized. Then, the closure scenario was developed preliminarily based on hydrological analysis between a hydraulic fracture and a disposal panel, the fault tree analysis, and so on.
Kawakami, Susumu; Sugita, Yutaka; Kurihara, Yuji; Jintoku, Takashi; Taniguchi, Naoki; Yui, Mikazu
JNC TN8400 2002-026, 42 Pages, 2003/03
In order to contribute to the safety standards and guidelines upon which a administration decides, examination for clarifying how to reflect the result obtained by future R%D was performed. From a viewpoint of the long-term safety on geological disposal, the items which should guarantee the performance of each element which constitutes disposal institutions (by this report, they are the overpack and the buffer material) were extracted, and it was shown what a performance guarantee is concretely offered about these items. Furthermore, based on the H12 report as a situation of present R&D for a method of a performance guarantee, the subjects considered that a future R&D is required were extracted. Moreover, the items of a safety standard and guideline were assumed, and the relation between these items and a performance guarantee items was arranged. One arrangement for clarifying whether to be reflected in the safety regulations and guidelines whose R%D subjects extracted from the performance guarantee items was shown.
Kimura, Toyoaki; Kurihara, Kenichi; Kawamata, Yoichi; Akiba, K.*; ; Terakado, Tsunehisa; Yoshino, Ryuji
Fusion Technology, 32(3), p.404 - 415, 1997/11
no abstracts in English