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1
Study on crystalline rock aiming at evaluation method of long-term behavior of rock mass (Joint research)
Fukui, Katsunori*; Hashiba, Kimihiro*; Matsui, Hiroya
JAEA-Research 2017-010, 61 Pages, 2017/11
JAEA has started this study as a collaboration study with Tokyo University from 2016. In the fiscal year of 2016, creep testing on Tage tuff was continuously conducted. Existing theory of rate process and stochastic process was modified to be applied to evaluate effects of water, and then the modified theory was validated based on the results of strength and creep tests performed under dry and wet conditions. Furthermore, effects of water contents on stress-strain curves were examined by uniaxial compression testing under various water content conditions.
2
Study on effects of coupled phenomenon on long-term behavior for crystalline rock (Joint research)
Kimoto, Kazushi*; Ichikawa, Yasuaki*; Matsui, Hiroya
JAEA-Research 2017-009, 18 Pages, 2017/11
JAEA has started this study as joint research with Okayama University from 2016. In fiscal year 2016, several kinds of elastic wave velocity were measured using ultra sonic sensors and laser Doppler vibrometer to evaluate the anisotropy of different elastic wave in granite. The velocity measurements were carried out focused on transmitted wave and surface wave. The results showed that strong anisotropy was observed in transmitted P- wave velocity while weak anisotropy was observed in transmitted S-wave and group velocity estimated by surface velocity measurement. In addition, data obtained from surface velocity measurement was partitioned into transmitted and reflected waves and analyzed them in detail. It resulted that elastic wave due to mineral particles consist of granite was dispersed; however, significant dispersion was only observed at specific location.
3
Thermodynamic equilibrium constants for important isosaccharinate reactions; A Review
Rai, D.*; Kitamura, Akira
Journal of Chemical Thermodynamics, 114, p.135 - 143, 2017/11
Isosaccharinic acid is a cellulose degradation product that can form in low-level nuclear waste repositories and is known to form strong complexes with many elements, including actinides, disposed of in these repositories. We (1) reviewed the available data for deprotonation and lactonisation constants of isosaccharinic acid, and the isosaccharinate binding constants for Ca, Fe(III), Th, U(IV), U(VI), Np(IV), Pu(IV), and Am(III), (2) summarized complexation constant values for predicting actinide behavior in geologic repositories in the presence of isosaccharinate, and (3) outlined additional studies to acquire reliable thermodynamic data where the available data are inadequate.
4
Development of determination method of $$^{93}$$Mo content in metal waste generated at the Japan Power Demonstration Reactor
Shimada, Asako; Omori, Hiroyuki*; Kameo, Yutaka
Journal of Radioanalytical and Nuclear Chemistry, 314(2), p.1361 - 1365, 2017/11
A separation method of Mo from Nb, Zr, and the matrix elements of rubble waste was modified to determine the content of $$^{93}$$Mo in metal waste. A separation scheme to treat 1 g of metal waste was established by optimizing the amount of ascorbic acid, the rinsing solution, and repeating of the procedure. A thin-layer source was prepared using direct drop deposition and evaporation to measure $$^{93}$$Mo content. Finally, $$^{93}$$Mo content in the metal waste generated at the Japan Power Demonstration Reactor was analyzed using the developed method.
5
Mizunami Underground Research Laboratory Project, Plan for fiscal year 2017
Ishibashi, Masayuki; Hama, Katsuhiro; Iwatsuki, Teruki; Matsui, Hiroya; Takeuchi, Ryuji; Ikeda, Koki; Mikake, Shinichiro; Iyatomi, Yosuke; Sasao, Eiji; Koide, Kaoru
JAEA-Review 2017-019, 29 Pages, 2017/10
The Mizunami Underground Research Laboratory (MIU) project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline host rock (granite) at Mizunami City in Gifu Prefecture, central Japan. On the occasion of the reform of the entire JAEA organization in 2014, JAEA identified three important issues on the geoscientific research program: "Development of countermeasure technologies for reducing groundwater inflow", "Development of modelling technologies for mass transport" and "Development of drift backfilling technology", based on the latest results of the synthesizing research and development (R&D). These R&D on three remaining important issues have been carrying out on the MIU project. This report summarizes the R&D activities planned for fiscal year 2017 based on the MIU Master Plan updated in 2015 and so on.
6
Data of groundwater chemistry obtained in the Horonobe Underground Research Laboratory Project; 2014-2016
Miyakawa, Kazuya; Mezawa, Tetsuya; Mochizuki, Akihito; Sasamoto, Hiroshi
JAEA-Data/Code 2017-012, 60 Pages, 2017/10
Development of technologies to investigate properties of deep geological environment and model development of geological environment have been pursued in "Geoscientific Research" in the Horonobe Underground Research Laboratory (Horonobe URL) project. A geochemical model which is a part of geological environment model requires the data of groundwater chemistry around the Horonobe URL for the development. This report summarizes the data obtained for 3 years from the fiscal year 2014 to 2016, especially for the results for measurement of physico-chemical parameters and analysis of groundwater chemistry, in the Horonobe URL project.
7
Detection and correlation of tephra-derived smectite-rich shear zones by analyzing glass melt inclusions in mineral grains
Ishii, Eiichi; Furusawa, Akira*
Engineering Geology, 228, p.158 - 166, 2017/10
We present detailed mineralogical and geochemical analyses of clay-rich shear zones that are associated with bedding-parallel or bedding-oblique faults in drill cores of a siliceous mudstone from the Horonobe area, northern Hokkaido, Japan. The bedding-parallel shear zones are rich in smectite and some shear zones are characterized by melt inclusions hosted by plagioclase and quartz. The chemical compositions of melt inclusions in six shear zones are very similar, but distinct from those of melt inclusions in other shear zones. These six shear zones consistently occur in horizons $$sim$$350 m shallower than a known tephra layer. These mineralogical characteristics and stratigraphic positions suggest that the six shear zones occur within the same tephra layer and that the smectite formed as a result of burial diagenesis of volcanic glass. Tephra-derived smectite-rich shear zones can be detected and correlated by analyzing melt inclusions preserved in mineral grains.
8
Simulation of saturation process in a transuranium disposal facility
Takayama, Yusuke; Iizuka, Atsushi*; Kawai, Katsuyuki*
Environmental Geotechnics (Internet), 4(5), p.339 - 352, 2017/10
Due to its low permeability and excellent expansion characteristics, bentonite materials are considered to be the material of choice for engineered barriers in Trans-Uranium (TRU) disposal facilities. It is necessity to predict the mechanical behaviour of bentonite using numerical simulation to evaluate the long-term performance of a TRU disposal facility. In this paper, a comprehensive summary of the saturation process of bentonite and its mathematical modelling was explained. Subsequently, a series of numerical simulations were carried out. First, a one-dimensional swelling pressure test simulation was carried out in order to examine the swelling characteristics of buffer and backfill. Next, we simulated the saturation process in a TRU disposal facility from an initially unsaturated state. The mechanical behaviour of bentonite buffer and backfill in a TRU disposal facility during the saturation process was examined.
9
The Development of extra high head pump for cutoff grout drainage in a deep vertical shaft
Shirase, Mitsuyasu*; Abe, Akimasa*; Nago, Makito*; Ishii, Eiichi; Aoyagi, Kazuhei; Wakasugi, Shinichi*
Doboku Gakkai Heisei-29-Nendo Zenkoku Taikai Dai-72-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.1795 - 1796, 2017/09
JAEA has executed the underground facility construction operation from February 2011 to June 2014, while carrying out the maintenance and research project until 2018. This report is about the extra high head pump which was able to drain the high specific gravity grout drainage, which develops during grouting operation at this facility, directly from 250m underground to the surface.
10
Analytical study on the Excavation Damaged Zone in the 350 m gallery at the Horonobe Underground Research Laboratory
Aoyagi, Kazuhei; Ishii, Eiichi
Shigen, Sozai Koenshu (Internet), 4(2), 7 Pages, 2017/09
高レベル放射性廃棄物の地層処分において、処分坑道等の地下施設の掘削による応力再配分の影響により、坑道壁面周辺岩盤の水理・力学特性が顕著に変化する領域が生じる。このような領域を掘削損傷領域(Excavation Damaged Zone: EDZ)と呼ぶ。幌延深地層研究センターの350m調査坑道では、堆積軟岩である珪質泥岩を対象として、ボアホール・テレビューア観察、コア観察および透水試験を行い、坑道周辺のEDZの水理・力学特性を調査している。試験結果から、坑道掘削に起因して生じた引張割れ目の発達と透水係数の増大が認められたことから、坑道から0.2$$sim$$1.0mの範囲にEDZが発生したと推定した。これを理論的に検証するために、二次元の水理・力学連成解析を実施した。解析では、坑道掘削直後は掘削解放面を非排水条件、支保工設置後は排水条件とした。この結果、壁面から0.6$$sim$$1.4mの範囲まで引張破壊が生じる結果となり、原位置で観測されたEDZの範囲と概ね整合する結果が得られた。また、坑道掘削時の非排水挙動に伴う有効応力の低下が、原位置で確認された引張割れ目の形成や発達に寄与していることが示された。以上のことから、連成解析により、原位置のEDZの発生メカニズムを把握することができた。
11
Clearance of concrete generated from modification activities of JRR-3; Results for measuring and evaluating radioactivity concentration
Ogoshi, Yurie; Satoyama, Tomonori; Kishimoto, Katsumi; Nanri, Tomohiro; Suzuki, Takeshi; Tomioka, Osamu; Takaizumi, Hirohide*; Kanno, Tomoyuki*; Maruyama, Tatsuya*
JAEA-Technology 2017-017, 152 Pages, 2017/08
At Nuclear Science Research Institute, clearance works for about 4,000 tons of extremely low-level radioactive concrete debris, which were generated from the modification activities of JRR-3 from FY 1985 to FY 1989 and stored in the waste storage facility NL, carried out. First of this clearance works, method for measuring and evaluating radioactivity concentration was approved by Minister of MEXT on July 25, 2008. And then, clearance works were started from FY 2009. Measuring and evaluating radioactivity concentration was achieved by using the approved method, and was confirmed by government. And then, clearance works were completed in FY 2014. The clearance concrete was recycled as a material for restoration works of the 2011 off the Pacific coast of Tohoku Earthquake. This report summarizes the results of measuring and evaluating radioactivity concentration, achievement of confirmation by government, recycling of cleared concrete and cost for clearance works.
12
Development of the observational construction technology in the Horonobe Underground Research Laboratory
Aoyagi, Kazuhei; Nago, Makito*
Jiban Kogakkai-Shi, 65(8), p.12 - 15, 2017/08
In this paper, we described the development of the supporting tool of observational construction of the underground research laboratory, and the monitoring result of hydro-mechanical properties around the gallery wall. As an observational construction tool, we developed a "3D geological structure/construction data visualization system". The geological data, measurement data, construction data, and prediction analysis results are visualized and integrated comprehensively as the construction proceeds. The planned support pattern was examined according to the visualized data. In addition, the Excavation Damaged Zone (EDZ) was extended within 1.0 m from the gallery wall. In this area, hydraulic conductivity was enhanced. However, the extent of the EDZ was not enlarged along with time; the stability of the support was also confirmed on the basis of the measurement of stress in the shotcrete. Integrating these results the observational construction considering the development of an EDZ can be established. This technology will have an important role in geological disposal of high-level radioactive waste.
13
Replacement of the glove port equipped with glove box in Nuclear Fuel Reprocessing Facility
Horigome, Kazushi; Taguchi, Shigeo; Nishida, Naoki; Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko
Nippon Hozen Gakkai Dai-14-Kai Gakujutsu Koenkai Yoshishu, p.381 - 384, 2017/08
東海再処理施設では、プルトニウム等の核燃料物質を安全に取り扱うため、閉じ込め機能(負圧)を有するグローブボックス(GB)が設置されており、各GBには、グローブを取り付けるためのグローブポート(ベークライト製)が取り付けられている。グローブポートには、グローブをグローブポートに直接取り付けるタイプと、インナーリングと呼ばれる塩ビ製の環に取り付けたグローブをグローブポートに挿入して取り付けるタイプ(以下、押し込み式グローブポート)の2種類が使われている。平成28年4月に、押し込み式グローブポートの1基に2ヵ所の割れが東海再処理施設において初めて確認された。なお、割れによるGB内の負圧の異常や、GB外への放射性物質の漏えいは確認されなかった。グローブポートは、ポートとポート押さえでパネルを挟み込む形で、ポートとポート押さえをネジで固定することによりGBパネルに取り付けられている。このため、固定ネジを取外すことでグローブポートは取り外しが可能な構造ではあるが、グローブポートをそのまま取外した場合、閉じ込め機能が破れ、GB内の放射性物質を拡散させる恐れがあるため、拡散防止措置を講じた上で、グローブポートの交換を実施する必要があった。そこで今回、GB内部の汚染をコントロールしながらグローブポートを更新する手法を確立した。本発表では、その交換手法について報告する。
14
Design and application of greenhouse on the maintenance of analytical machineries in Tokai Reprocessing Plant
Suzuki, Yoshimasa; Tanaka, Naoki; Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko
Nippon Hozen Gakkai Dai-14-Kai Gakujutsu Koenkai Yoshishu, p.385 - 389, 2017/08
Greenhouse is used in order to prevent diffusion of radioactive materials on the maintenance of machineries and decomposition of the analytical equipment such as glove box in Tokai Reprocessing Plant (TRP). The specifications of the greenhouse change depending on a risk of the radiation exposure, operation and environment. Design and application of original greenhouses in the analytical laboratory of TRP is summarized.
15
Consideration of methodology for estimating hydrochemistry based on results of resistivity logging in deep boreholes
Mizuno, Takashi; Iwatsuki, Teruki; Matsuzaki, Tatsuji*
Oyo Chishitsu, 58(3), p.178 - 187, 2017/08
本研究では、北海道幌延地域に分布する新第三系堆積岩を対象に、ボーリング孔において実施される比抵抗検層結果から間隙水の水質を定量的に把握するための手法について検討を行った。比抵抗検層結果からの水質の推定については、Archieの式等を用いて等価NaCl濃度を算出した。この等価NaCl濃度と、ボーリングコアから抽出した間隙水中のNaCl濃度の分析値をt検定により比較した結果、対象としたボーリング孔11孔のうち7孔において有意差(有意水準5%)がないと判断できた。分析値と計算値が一致しなかったボーリング孔については、塩分濃度が低いためにArchieの式が適用できないことや、ボーリング孔掘削時の掘削水が孔壁から混入したことによる水質の変化が原因と考えられた。これらを踏まえ、一定の条件を満たせば比抵抗検層結果から間隙水のNaCl濃度が定量的に推定可能であることを示すとともに、実際の調査現場において必要となる手順を整理した。
16
Preparation of uranium and plutonium mixed spike optimized for MOX analysis by isotope dilution mass spectrometry
Horigome, Kazushi; Taguchi, Shigeo; Yamamoto, Masahiko; Kuno, Takehiko; Surugaya, Naoki
JAEA-Technology 2017-016, 20 Pages, 2017/07
Mixed spikes of uranium and plutonium have been prepared for the determination of uranium and plutonium in dissolved MOX solution by isotope dilution mass spectrometry. Enriched uranium metal NBL CRM116 and plutonium metal NBL CRM126 were accurately weighed and then dissolved in nitric acid, respectively. Their dissolved solutions were mixed in a mass ratio of 1 to 2. The preparation values of uranium and plutonium were 1.0530 $$pm$$ 0.0008 mg/g (k=2) of uranium with a $$^{235}$$U relative mass fraction of 93.114 wt% and 2.0046 $$pm$$ 0.0019 mg/g (k=2) of plutonium with a $$^{239}$$Pu relative mass fraction of 97.934 wt%, respectively. The concentrations of uranium and plutonium in spike were confirmed by reverse isotope dilution mass spectrometry using tracer of $$^{233}$$U and $$^{242}$$Pu. Finally, the prepared spike was validated by parallel analysis of simulated sample of dissolved MOX solution. This spike was applied to measure the uranium and plutonium amount content of dissolved MOX solutions using isotope dilution mass spectrometry.
17
Diffusion experiment using block sample of the Toki granite
Hama, Katsuhiro; Iwasaki, Riyo*; Morikawa, Keita*
JAEA-Technology 2017-015, 45 Pages, 2017/07
Tono Geoscience Center of Japan Atomic Energy Agency has been carrying out the Mizunami Underground Research Laboratory Project. The goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This experiment was planned to understand the influence of the microscopic structure in the rock mass on the mass transport property. The diffusion experiment using rock sample was carried out. The macroscopic and microscopic observations were carried out to understand the distribution of tracer (uranine) after the diffusion experiment. The uranine was observed in the plagioclase, in the grain boundary and in the microfracture in the mineral grains. These results suggested that distribution of mineral and of microfracture could affect the diffusion property of uranine.
18
Rapid measurement of the chloride diffusion coefficient in concrete from combination of non-steady-state migration experiment and EPMA
Ogino, Masataka*; Owaki, Eiji*; Shirase, Mitsuyasu*; Nakayama, Masashi
Konkurito Kogaku Nenji Rombunshu (DVD-ROM), 39(1), p.703 - 708, 2017/07
塩化物イオンの拡散係数はコンクリートの耐久性を評価する重要な指標であるが、耐久性の高いコンクリートは物質透過抵抗性に優れるため、測定に時間を要する。著者らは非定常の電気泳動操作にEPMAを組み合わせた迅速法について検討した。浸入した塩化物イオンについて、浸入範囲と濃度分布を求め、塩化物イオンの分布から電気泳動が主たる輸送機構ではないと判断される浸入範囲を除外し、Nernst-Planckの式により拡散係数を求めた。この拡散係数は、塩水浸せき試験により得られる値とほぼ同等である。従来の試験と比較し、試験期間を1$$sim$$2割程度に短縮できる可能性があることが確認できた。
19
Application of controlled-potential coulometry as a primary method for the characterization of plutonium nitrate solutions being used for reference materials (Joint Research)
Yamamoto, Masahiko; Holland, M. K.*; Cordaro, J. V.*; Kuno, Takehiko; Surugaya, Naoki
JAEA-Technology 2017-014, 63 Pages, 2017/06
In this study, the controlled-potential coulometry has been applied as a primary method for characterizing the Pu master solutions being used as alternative source material for IDMS spikes. The coulometry system compliance with ISO12183 has been used for measurement. It has been calibrated using equipment traceable to the SI units. Plutonium standard samples have been measured to confirm the accuracy. The relative standard deviation is below 0.05%. The results agree with the reference value within $$pm$$0.05%. It is found that the Pu can be precisely analyzed by the coulometry system. Then, the Pu nitrate solution, which has been purified from mixed oxide powder containing relatively high $$^{239}$$Pu, has been measured. The relative standard deviation is below 0.05%. The relative expanded uncertainty is less than 0.074% at the 95% confidence interval (k=2). It is indicated that coulometric assay of Pu is fit for the purpose of characterizing reference materials.
20
Backfilling test in drilling pits as part of Groundwater REcovery Experiment in Tunnel (GREET) Project
Takayasu, Kentaro; Onuki, Kenji*; Kawamoto, Koji*; Takayama, Yusuke; Mikake, Shinichiro; Sato, Toshinori; Onoe, Hironori; Takeuchi, Ryuji
JAEA-Technology 2017-011, 61 Pages, 2017/06
The Groundwater REcovery Experiment in Tunnel (GREET) was put into effect as development of drift backfilling technologies. This test was conducted by making the Closure Test Drift (CTD) recovered with water after carrying out a plug around 40m distance from northern edge face of horizontal tunnel of depth 500m, for the purpose of investigation of recovering process of rock mass and groundwater under the influence of excavation of tunnel. This report presents the efforts of backfilling investigation using bentonite composite soil and execution of backfilling into borehole pits excavated in the CTD which were carried out in fiscal 2014 as a part of GREET, and succeeding observation results inside pits from September 2014 to March 2016.