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天野 由記; Sachdeva, R.*; Gittins, D.*; Anantharaman, K.*; Lei, S.*; Valentin-Alvarado, L. E.*; Diamond, S.*; 別部 光里*; 岩月 輝希; 望月 陽人; et al.
Environmental Microbiome (Internet), 19, p.105_1 - 105_17, 2024/12
被引用回数：0 パーセンタイル：0.00(Genetics & Heredity)Underground research laboratories (URLs) provide a window on the deep biosphere and enable investigation of potential microbial impacts on nuclear waste, CO
and H stored in the subsurface. We carried out the first multi-year study of groundwater microbiomes sampled from defined intervals between 140 and 400 m below the surface of the Horonobe and Mizunami URLs, Japan. The Horonobe and Mizunami microbiomes are dissimilar, likely because the Mizunami URL is hosted in granitic rock and the Horonobe URL in sedimentary rock. Despite this, hydrogen metabolism, rubisco-based CO fixation, reduction of nitrogen compounds and sulfate reduction are well represented functions in microbiomes from both URLs, although methane metabolism is more prevalent at the organic- and CO-rich Horonobe URL. We detected near-identical genotypes for approximately one third of all genomically defined organisms at multiple depths within the Horonobe URL. This cannot be explained by inactivity, as in situ growth was detected for some bacteria, albeit at slow rates. Given the current low hydraulic conductivity and groundwater compositional heterogeneity, ongoing inter-site strain dispersal seems unlikely. Alternatively, the Horonobe URL microbiome homogeneity may be explained by higher groundwater mobility during the last glacial period. Genotypically-defined species closely related to those detected in the URLs were identified in three other subsurface environments in the USA. Thus, dispersal rates between widely separated underground sites may be fast enough relative to mutation rates to have precluded substantial divergence in species composition. Species overlaps between subsurface locations on different continents constrain expectations regarding the scale of global subsurface biodiversity. Overall, microbiome and geochemical stability over the study period has important implications for underground storage applications.
Zarazovski, M.*; Pistra, V.*; Lauerova, D.*; Obermeier, F.*; Mora, D.*; Dubyk, Y.*; Bolinder, T.*; Cueto-Felgueroso, C.*; Szavai, S.*; Dudra, J.*; et al.
Proceedings of ASME 2022 Pressure Vessels and Piping Conference (PVP 2022) (Internet), 11 Pages, 2022/07
The APAL (Advanced Pressurized Thermal Shock (PTS) Analysis for Long-Term Operation (LTO)) project was launched in October 2020 for four years with funding from the European Union's HORIZON 2020 program. Within APAL, an extensive literature review was performed and experience with defining the state-of-the-art of the Warm Pre-Stress (WPS) effect, which has an impact on the reactor pressure vessel (RPV) brittle fracture margin in both deterministic and probabilistic terms, was collected. To gather the worldwide experience of the WPS approaches and models, a comprehensive questionnaire was developed followed by each APAL partner response. It mainly focused on the following aspects: collection of existing WPS approaches and models implemented in standards and rules for RPV brittle fracture assessment; identification of the WPS issues; collection and analysis of the existing experimental data. This work describes worldwide experience and best practice of the WPS and its application for the RPV integrity assessment. The paper's conclusions are also focused on the recommendations for dealing with WPS issues.
Tregoning, R.*; Wallace, J.*; Bouydo, A.*; Costa-Garrido, O.*; Dillstr
m, P.*; Duan, X.*; Heckmann, K.*; Kim, Y.-B.*; Kim, Y.*; Kurth-Twombly, E.*; et al.
Transactions of the 26th International Conference on Structural Mechanics in Reactor Technology (SMiRT-26) (Internet), 11 Pages, 2022/07
破断前漏えいに関する国際ベンチマーク活動は、11か国から14機関が参加して実施された。本ベンチマーク活動では、参加者は最初に所定の寸法の亀裂が自国のLBB許容基準を満足するかを判断し、次に溶接残留応力(WRS)と亀裂の形態が、亀裂開口変位(COD),限界曲げモーメント(CBM)及び漏えい量(LR)の結果に及ぼす影響を特定した。最初のタスクでは、14の参加機関のうち6機関がLBBの要件を満たすことを示した。次のタスクでは、参加機関のCBMの予測の違いは主に用いた材料特性の違いによるものであり、評価手法の違いはそれほど影響しないこと、また、LRの予測の違いはほぼCODの評価手法の違いに起因するが一部は亀裂面圧力(CFP)の処理に起因すること等の結果が得られた。本ベンチマークを通じて、より現実的なLBB評価を行うための要点を特定した。
Tang, J.*; Seo, O.*; Rivera Rocabado, D. S.*; 小板谷 貴典*; 山本 達*; 難波 優輔*; Song, C.*; Kim, J.*; 吉越 章隆; 古山 通久*; et al.
Applied Surface Science, 587, p.152797_1 - 152797_8, 2022/06
被引用回数：11 パーセンタイル：69.49(Chemistry, Physical)水素貯蔵材料として重要な立方体形状Pdナノ粒子の水素吸収と拡散メカニズムをX線光電子分光とDFT計算を用いて調べた。表面領域では粒子の大きさによらず、ほぼ同様の水素吸収挙動を示した。四面体サイトよりも八面体サイトの水素占有率が大きいことがわかった。表面の乱れによってPd-H結合が弱くなるため、小さいサイズのPdナノ粒子に吸収された水素原子は、より活発に粒子内部に拡散することが分かった。これが低水素圧での水素吸着に重要な役割を果たしている。
Do, Thi-Mai-Dung*; Sujatanond, S.*; 小川 徹
Nuclear Science and Engineering, 196(5), p.584 - 599, 2022/05
被引用回数：1 パーセンタイル：9.64(Nuclear Science & Technology)軽水炉過酷事故時のモリブデン酸セシウム(CsMoO
)の化学的挙動は未解明なままである。本研究では、1530-530Kの乾燥(Ar)及び湿潤(Ar+HO)条件下で、ステンレス鋼(SUS304)へのモリブデン酸セシウム(CsMoO)の沈着挙動を実証した。乾燥条件ではCsMoOはSUS表面で部分的に分解し、鉄(Fe)とクロム(Cr)の酸化を誘起した。また、1500Kではモリブデン金属(Mo)と二酸化モリブデン(MoO)が表面に検出され、セシウムは酸化物層中にクロムと共存していた。1230KではCsMoOとMo金属の両方がSUS表面で確認された。湿潤条件下では、SUSの酸化はCsMoO蒸気の影響を受けた。1500K以上ではモリブデンは酸化鉄層にスポット状に検出されたが、セシウムは検出されなかった。1230KでMoはSUS酸化物表面に検出された。730-530Kでは乾燥、湿潤のどちらでもSUS上にCsMoOが沈積した。これらの結果は、Cs-Fe-Cr-Mo-O系の熱力学モデルとの関連で議論された。こうして、原子炉冷却設備内部におけるCsMoOの化学的挙動を明らかにした。
Bentaib, A.*; Chaumeix, N.*; Nyrenstedt, G.*; Bleyer, A.*; Maas, L.*; Gastaldo, L.*; Kljenak, I.*; Dovizio, D.*; Kudriakov, S.*; Schramm, B.*; et al.
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 11 Pages, 2022/03
In case of a core melt-down accident in a light water nuclear reactor, hydrogen is produced during reactor core degradation and released into the reactor building. In case of failure of in-vessel corium retention, a large amount of carbon monoxide (CO) in addition to H and other gases may be produced during molten core concrete interaction (MCCI). This subsequently creates a combustion hazard. A local ignition of the combustible mixture may generate standing flames or initially slow propagating flames. Depending on geometry, mixture composition and turbulence level, the flame can accelerate or be quenched after a certain distance. The pressure and temperature loads generated by the combustion process may threaten the integrity of the containment building and safety equipment. The evaluation of such loads requires validated codes which can be used with a high level of confidence. Currently, turbulence and steam effect on flame propagation mechanisms are not well reproduced by combustion models usually implemented in safety tools and further model enhancement and validation are still needed. For this purpose and at the initiative of the SAMHYCO-NET project consortium and of the European Technical Safety Organization Network (ETSON), a benchmark on hydrogen combustion was organized with the goal to identify the current level of the computational tools in the area of hydrogen combustion simulation under conditions typical for safety considerations in a Nuclear Power Plant (NPP). This benchmark is composed of four main steps with increasing difficulty starting from flame propagation in homogenous dry atmosphere and finishing with more representative conditions with (H/HO/O/N) stratified mixtures. In this paper, only experiments related to flame propagation in homogenous atmosphere are considered.
Bendo, A.*; 松田 健二*; 西村 克彦*; 布村 紀男*; 土屋 大樹*; Lee, S.*; Marioara, C. D.*; 都留 智仁; 山口 正剛; 清水 一行*; et al.
Materials Science and Technology, 36(15), p.1621 - 1627, 2020/09
被引用回数：13 パーセンタイル：53.27(Materials Science, Multidisciplinary)アルミニウム合金の準安定相は機械的性質に最も寄与する一次のナノサイズの析出物である。7xxx系アルミニウム合金における硬度の連続的上昇はクラスターやGPゾーンから準安定の
相への相変態に関係する。構造的および組成的変態は最も低い活性化エネルギーの経路に従って生じる。本研究は、構造的相変態がどのようにして生じるかを拡散の最短経路に基づいて評価するものであり、高分解能透過型電子顕微鏡を用いて、相変態の動的挙動を捉えることに成功した。
P
rez S
nchez, R.*; Jurado, B.*; Mot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.
Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09
被引用回数：21 パーセンタイル：76.54(Physics, Multidisciplinary)Reliable neutron-induced-reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising alternatives to access these cross sections. In this work, we successfully applied the surrogate-reaction method to infer for the first time both the neutron-induced fission and radiative capture cross sections of 
Pu in a consistent manner from a single measurement. This was achieved by combining simultaneously measured fission and 
-emission probabilities for the 
Pu(
He, He') surrogate reaction with a calculation of the angular-momentum and parity distributions populated in this reaction. While other experiments measure the probabilities for some selected -ray transitions, we measure the -emission probability. This enlarges the applicability of the surrogate-reaction method.
松田 健二*; 安元 透*; Bendo, A.*; 土屋 大樹*; Lee, S.*; 西村 克彦*; 布村 紀男*; Marioara, C. D.*; Lervik, A.*; Holmestad, R.*; et al.
Materials Transactions, 60(8), p.1688 - 1696, 2019/08
被引用回数：20 パーセンタイル：66.81(Materials Science, Multidisciplinary)アルミニウム合金の時効硬化と析出に及ぼすCu添加の効果を、硬度測定,引張試験,高分解能透過型電子顕微鏡(HRTEM)および高角度環状暗視野走査透過型電子顕微鏡(HAADF-STEM)によって調べた。高硬度,高強度,低伸びは析出物の数密度の増加によるZn+Mg量の増加に起因することが分かった。
西村 克彦*; 松田 健二*; Lee, S.*; 布村 紀男*; 島野 寛基*; Bendo, A.*; 渡邊 克己*; 土屋 大樹*; 並木 孝洋*; 戸田 裕之*; et al.
Journal of Alloys and Compounds, 774, p.405 - 409, 2019/02
被引用回数：3 パーセンタイル：14.31(Chemistry, Physical)Temperature and time dependences of magnetization of Al-1.0%Zn-4.2%Mg, Al-2.6%Zn-3.2%Mg, Al-4.1%Zn-1.1%Mg, and Al-5%Zn (at.%) alloys were measured in the range between 10 and 310 K after various periods of natural aging and peak-aged heat treatments. Enhanced diamagnetic contributions on the magnetization were observed for the as-quenched Al-Zn-Mg alloys for the first time. The enhanced diamagnetism observed in Al-2.6%Zn-3.2%Mg and Al-4.1%Zn-1.1%Mg were found to largely alter in natural aging, while that of Al-1.0%Zn-4.2%Mg little changed. After peak-aged heat treatments, the diamagnetism of Al-Zn-Mg was largely reduced. The binary Al-5%Zn showed neither enhanced diamagnetism nor natural aging effect on the magnetization. Isothermal time variations of magnetization of Al-Zn-Mg alloys at 300 K were found to be related with solute-vacancy clustering.
Bendo, A.*; 松田 健二*; Lee, S.*; 西村 克彦*; 戸田 裕之*; 清水 一行*; 都留 智仁; 山口 正剛
Materialia, 3, p.50 - 56, 2018/11
Microstructure evolution of alloy with composition Al-3.4Zn-1.9 Mg (at. %) was tracked using high resolution imaging and electron diffraction during ageing at 120 C after being initially natural aged for 4 days. Hydrogen was charged in microstructure by cutting samples in Electrical Discharge Machine immediately after being quenched from solid solution temperature. Transmission Electron Microscope observations revealed a higher presence of high aspect ratio GPII-zones in microstructure of hydrogen charged and aged samples. Correlation was made with previously reported hydrogen effect into vacancy formation.
Bentaib, A.*; Chaumeix, N.*; Grosseuvres, R.*; Bleyer, A.*; Gastaldo, L.*; Maas, L.*; Jallais, S.*; Vyazmina, E.*; Kudriakov, S.*; Studer, E.*; et al.
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 11 Pages, 2018/10
In the framework of the French MITHYGENE project, the new highly instrumented ENACCEF2 facility was built at the Institut de Combustion Aerothermique Reactivite et Environnement (ICARE) of the Centre National de la Recherche Scientifique (CNRS) in Orleans (France) to address the flame propagation in hydrogen combustion during a severe accident. The ENACCEF2 facility is a vertical tube of 7.65 m height and 0.23 m inner diameter. In the lower part of the tube, annular obstacles are installed to promote turbulent flame propagation. At the initiative of the MITHYGENE project consortium and the European Technical Safety Organisation Network (ETSON), a benchmark on hydrogen combustion was organised with the goal to identify the current level of the computational tools in the area of hydrogen combustion simulation under conditions typical for safety considerations for NPP. In the proposed paper, the simulation results obtained by participating organizations, using both Computational Fluid Dynamics (CFD) and lumped-parameter computer codes, are compared to experimental results and analysed.
MoO, in severe accident conditions, 1; Partitioning of Cs and Mo among gaseous speciesDo, Thi Mai Dung*; Sujatanond, S.*; 小川 徹
Journal of Nuclear Science and Technology, 55(3), p.348 - 355, 2018/03
被引用回数：7 パーセンタイル：51.69(Nuclear Science & Technology)シビアアクシデント時のセシウム挙動理解のために、水素-水蒸気環境におけるCsMoOの高温化学を調べた。CsMoO-MoO
疑似二元系をRedlich-Kister型の熱化学モデルで記述した。モデルの検証のために、CsMoOの蒸発損失速度を熱天秤で乾燥及び湿潤アルゴン雰囲気下で測定し、解析により正確に予測評価できることを示した。同モデルを用いて、全電源喪失によるBWR炉心損傷時のCs及びMoの気相化学種間での分配を評価した。
-spectroscopy at an intense cold neutron beam facilityJentschel, M.*; Blanc, A.*; de France, G.*; Kster, U.*; Leoni, S.*; Mutti, P.*; Simpson, G.*; Soldner, T.*; Ur, C.*; Urban, W.*; et al.
Journal of Instrumentation (Internet), 12(11), p.P11003_1 - P11003_33, 2017/11
被引用回数：43 パーセンタイル：84.98(Instruments & Instrumentation)A highly efficient array of high-purity germanium (HPGe) detectors was developed and operated at the cold neutron beam facility PF1B of the Institut Laue-Langevin (ILL) to carry out nuclear structure studies, via measurements of -rays following neutron-induced capture and fission reactions. The setup consisted of a collimation system producing a pencil beam with a thermal capture equivalent flux of about 10
ns
cm
at the target position and negligible neutron halo. The target was surrounded by an array of eight to ten anti-Compton shielded EXOGAM Clover detectors, four to six anti-Compton shielded large coaxial GASP detectors and two standard Clover detectors. For a part of the campaign the array was combined with 16 LaBr:(Ce) detectors from the FATIMA collaboration.
Chen, S.*; Doornenbal, P.*; Obertelli, A.*; Rodriguez, T. R.*; Authelet, G.*; 馬場 秀忠*; Calvet, D.*; Ch
teau, F.*; Corsi, A.*; Delbart, A.*; et al.
Physical Review C, 95(4), p.041302_1 - 041302_6, 2017/04
被引用回数：31 パーセンタイル：89.26(Physics, Nuclear)Neutron-rich isotopes of selenium, 
Se, where studied via in beam -ray spectroscopy after nucleon removal reactions at RIBF in RIKEN. The low-energy excitations of these nuclei were investigated using - coincidences, and the first and second excited 2
states were found at remarkably low energies. The analysis and comparison with self-consistent beyond-mean field calculations suggest that both shape coexistence and triaxiality are needed to describe these isotopes.
Pb ground states from 
-decay studies using the total-absorption techniqueEstvez Aguado, M. E.*; Algora, A.*; Agramunt, J.*; Rubio, B.*; Tain, J. L.*; Jordn, D.*; Fraile, L. M.*; Gelletly, W.*; Frank, A.*; Csatl
s, M.*; et al.
Physical Review C, 92(4), p.044321_1 - 044321_8, 2015/10
被引用回数：16 パーセンタイル：68.90(Physics, Nuclear)The decay of Pb has been studied using the total absorption technique at the ISOLDE (CERN) facility. The -decay strength deduced from the measurements, combined with QRPA theoretical calculations, allow us to infer that the ground states of the Pb isotopes are spherical. These results represent the first application of the shape determination method using the total absorption technique for heavy nuclei and in a region where there is considerable interest in nuclear shapes and shape effects.
on the reduction of lithium titanate induced by H in the sweep gas土谷 邦彦; Alvani, C.*; 河村 弘; 山田 弘一*; Casado, S.*; Contini, V.*
Fusion Engineering and Design, 69(1-4), p.443 - 447, 2003/09
被引用回数：4 パーセンタイル：31.06(Nuclear Science & Technology)核融合炉ブランケットのトリチウム増殖材であるチタン酸リチウム(LiTiO
)微小球の湿式法による製造に際しては、微細な結晶粒径を得るために酸化物(TiO等)の添加が不可欠である。しかしながら、TiOを添加したLiTiOの化学的特性については明らかにされていない。そのため、スイープガス中の水素によるLiTiOのTiO添加量に対する還元効果を調べた。この結果、500-800
の温度範囲では、TiOを添加したLiTiOの還元反応率は、TiOを添加しない場合より減少することが分かった。また、LiTiOにTiOを添加したものは、水分及び不純物ガスの吸着量がTiOを添加しない場合より小さく、ブランケット初期装荷時におけるスイープガス中への不純物ガスの放出が低減できた。
TiO pebbles fabricated by direct-wet process土谷 邦彦; 河村 弘; 内田 宗範*; Casado, S.*; Alvani, C.*; 伊藤 義夫*
Fusion Engineering and Design, 69(1-4), p.449 - 453, 2003/09
被引用回数：19 パーセンタイル：74.93(Nuclear Science & Technology)核融合炉ブランケットで用いられるトリチウム増殖材として、低温でのトリチウム放出性、化学的安定性等の観点から、チタン酸リチウム(LiTiO)微小球が注目されている。これまで、LiTiO溶液からLiTiO微小球を製造できる直接湿式法を提案し、LiTiO微小球の予備製造試験を行ったが、目標焼結密度(80~85%T.D.)の微小球を得ることが出来なかった。そのため、LiTiOの溶解、ゲル球の生成及び焼結の各プロセスについて技術開発を行った。各種の溶媒を用いた溶解試験の結果、LiTiOは30%過酸化水素水で室温でも完全に溶解できた。この溶解液の粘性を調整し、アセトン中に滴下することにより、割れの少ないゲル球を製造できるとともに、こうして得られたゲル球を焼結することにより結晶粒径5
m以下で目標焼結密度を満足した微小球を製造できることを明らかにした。
下司 和男; Ikda, T.*; Kobayashi, J.*; Makita, Y.*; Nakamura, E.*; Niizeki, N.*; Nomura, S.*; Sakudo, T.*; Shiozaki, Y.*; Tatsuzaki, I.*; et al.
Landolt-Brnstein, New Series III/3 Suppl., 496 Pages, 1974/00
抄録なし
Delgado, S.*; Giganon, A.*; 入澤 恵理子; 五十嵐 誉廣; 加藤 千明
no journal, ,
核燃料再処理プラントの長期健全性確保には、特に硝酸や酸化性イオンと接触するステンレス鋼(SS)の腐食を効果的に予測・管理することが重要である、腐食プロセスは、硝酸種との酸化還元反応によって決定される硝酸中の酸化性イオンの安定性と、これらのイオンとSSとの直接的な腐食反応という2つの主要因の影響を受ける。Np(VI)/Np(V)、Pu(VI)/Pu(IV)など、さまざまな酸化性イオンのペアを用いた実験とシミュレーションのデータを用いて、これらの要因を組み込んだ腐食モデルを開発した。これらのシミュレーションにより、酸化還元反応と腐食速度が原子力プラントに与える影響が明らかになった。
