Repeatability and reproducibility of measurements of low dissolved radiocesium concentrations in freshwater using different pre-concentration methods

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

https://doi.org/10.1007/s10967-019-06696-2

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.

Proton-exchange mechanism of specific Cs adsorption lattice defect sites of Prussian blue filled with coordination and crystallization water molecules

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

https://doi.org/10.1039/c3dt51637g

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.

Identified charged hadron production in collisions at = 200 and 62.4 GeV

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

https://doi.org/10.1103/PhysRevC.83.064903

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.

Prediction of crack due to corrosion of reinforcing bar in low alkali concrete

Takeda, Nobufumi*; Iriya, Keishiro*; Hitomi, Takashi*; Konishi, Kazuhiro*; Kurihara, Yuji*

Obayashigumi Gijutsu Kenkyushoho (CD-ROM), (72), 8 Pages, 2008/00

http://www.obayashi.co.jp/technology/shoho/072/2008_072_14.pdf

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.

Development of low alkaline cement considering pozzolanic reaction for support system in HLW repository construction

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.

Design Studies on the Engineered Barrier System and on the in-situ Experiments under the Conditions of Geological Environment in Horonobe

Kurihara, Yuji; Yui, Mikazu; Tanai, Kenji; Kawakami, Susumu; Sugita, Yutaka; Taniguchi, Naoki; Hirai, Takashi

JNC TN8400 2004-006, 59 Pages, 2004/04

JNC-TN8400-2004-006.pdf:5.97MB

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.

Activity of Studies on the Performance Guarantee of the Engineered Barrier System for the Geological Disposal of High-Level Radioactive Waste (Vol. 2)

Kurihara, Yuji; Fujita, Tomoo; Kawakami, Susumu; Jintoku, Takashi; Yui, Mikazu; Sugita, Yutaka

JNC TN8400 2003-053, 32 Pages, 2004/03

JNC-TN8400-2003-053.pdf:0.41MB

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.

Activity of Studies on the Performance Guarantee of the Engineering Barrier System for the Geological Disposal of High-Level Radioactive Waste

Kawakami, Susumu; Yui, Mikazu; Kurihara, Yuji; Jintoku, Takashi; Sugita, Yutaka

JNC TN8400 2003-037, 26 Pages, 2004/02

JNC-TN8400-2003-037.pdf:1.33MB

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.

Studies on the Performance Guarantee for the Engineered Barrier System on Geological Disposal of High-Level Radiactive Waste(Vol.2)

Sugita, Yutaka; Kurihara, Yuji; Kawakami, Susumu; Jintoku, Takashi; Yui, Mikazu

JNC TN8400 2003-015, 34 Pages, 2003/05

JNC-TN8400-2003-015.pdf:2.65MB

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.

Studies on the performance guarantee for the engiineering barrier system on geological disposal of high-level radioactive waste

Kawakami, Susumu; Sugita, Yutaka; Kurihara, Yuji; Jintoku, Takashi; Taniguchi, Naoki; Yui, Mikazu

JNC TN8400 2002-026, 42 Pages, 2003/03

JNC-TN8400-2002-026.pdf:12.1MB

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.