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Brissonneau, L.*; 池内 宏知; Piluso, P.*; Gousseau, J.*; David, C.*; Testud, V.*; Roger, J.*; Bouyer, V.*; 北垣 徹; 仲吉 彬; et al.
Journal of Nuclear Materials, 528, p.151860_1 - 151860_18, 2020/01
被引用回数：15 パーセンタイル：86.19(Materials Science, Multidisciplinary)In the framework of JAEA-CEA collaboration, experimental studies have been conducted for estimating the material characteristics of corium debris representative of the Fukushima Daiichi nuclear damaged plants. A test has been performed in the VULCANO facility in CEA Cadarache to simulate the concrete corium interaction (CCI) with prototypic corium (using depleted uranium) and concrete of Fukushima Daiichi 1F1 Nuclear Plant. This paper presents the Post Test Analyses on 9 samples representative of the CCI during this test: in the corium pool, in the crusts and at the vertical and horizontal interfaces with the concrete. Analyses have been performed by SEM/EDS, X-Ray Diffraction, complete dissolution and ICP, micro-hardness measurements of the main phases. The major phases encountered are uranium rich and zirconium rich oxides forming nodules from micrometers to millimeters size, chromium-iron rich precipitates of several micrometers, metallic Fe-Ni droplets and chromium-silicon rich filaments in a matrix, likely vitreous, rich in concrete elements: Si, Al, Ca, but containing up to 12 cations. The matrix is the softer oxide phase, when the Cr rich precipitates are the harder. The analyses are consistent with the estimated macroscopic ablation ratio, but do not still explain the important axial ablation observed for this specific basaltic concrete. The different phases formation, distribution and solidification path are discussed. First comparisons are proposed with the former CCI tests with European concretes. These results give helpful insights for the future dismantling of the plant and for a deeper understanding of the CCI process for basaltic concrete.
北垣 徹; 池内 宏知; 矢野 公彦; Brissonneau, L.*; Tormos, B.*; Domenger, R.*; Roger, J.*; 鷲谷 忠博
Journal of Nuclear Science and Technology, 56(9-10), p.902 - 914, 2019/09
被引用回数：7 パーセンタイル：61.94(Nuclear Science & Technology)Characterization of fuel debris is required to develop fuel debris removal tools. Especially, knowledge pertaining to the characteristics of molten core-concrete interaction (MCCI) product is needed because of the limited information available at present. The samples of a large-scale MCCI test performed under quenching conditions, VULCANO VW-U1, by CEA were analyzed to evaluate the characteristics of the surface of MCCI product generated just below the cooling water. As a result, the microstructure of the samples were found to be similar despite the different locations of the test sections. The Vickers hardness of each of the phases in these samples was higher than that of previously analyzed samples in another VULCANO test campaign, VBS-U4. From the comparison between analytical results of VULCANO MCCI test product, MCCI product generated under quenching condition is homogeneous and its hardness could be higher than that of the bulk MCCI product.
北垣 徹; 池内 宏知; 矢野 公彦; 荻野 英樹; Haquet, J.-F.*; Brissonneau, L.*; Tormos, B.*; Piluso, P.*; 鷲谷 忠博
Progress in Nuclear Science and Technology (Internet), 5, p.217 - 220, 2018/11
Characterization of the fuel debris is required to develop fuel debris removal tools for the decommissioning of Fukushima Daiichi Nuclear Power Plant (1F). In this study, the VULCANO MCCI test, VBS-U4, was selected as 1F similar conditions and the characteristics of the samples were examined. In the molten pool sample, the round-edged corium-rich oxides region, with diameters of 1-10 mm, is surrounded by a concrete-rich oxide region. It shows convection of the molten pool. Other samples also show the features of the MCCI progression. The main chemical forms of the samples are SiO
, (U,Zr)O, Fe and so on. The microstructure of the samples is heterogeneous structure composed of these phases. The difference in Vickers hardness between the metallic phases and the oxide phases is a distinctive characteristic. It can be noted that the heterogeneous distribution of metallic phases in 1F MCCI products interrupt with the removal operation such as by damaging the core-boring bit.
矢野 公彦; 北垣 徹; 荻野 英樹; 鷲谷 忠博; Pascal, P.*; Jean-Fran
ois, H.*; Patricia, C.*; Anne, B.*; Brissonneau, L.*; Brigitte, T.*; et al.
no journal, ,
フランス原子力・代替エネルギー庁(CEA)との共同研究契約において、CEAが実施した過去の大型MCCI試験による生成物を用いてMCCI生成物の特性把握を実施した。コリウム酸化物相とコリウム相/コンクリート相の境界部を含むサンプルを選定し、SEM/EDSによる観察とビッカース硬さ試験機による測定を行った。
北垣 徹; 池内 宏知; 矢野 公彦; 荻野 英樹; Brissonneau, L.*; Tormos, B.*; Piluso, P.*
no journal, ,
Under a collaborative agreement with CEA, the phases and microstructures of large-scale MCCI test products from PLINIUS/VULCANO experiments have been analyzed. The phases and microstructures vary at different sampling locations, each of which is representative of a product to be generated under severe accident conditions and which is considered to be close to that of Fukushima Daiichi Nuclear Power Station Unit 1.
池内 宏知; 平野 弘康; 鷲谷 忠博; Piluso, P.*; Brissonneau, L.*
no journal, ,
大規模MCCI試験によりMCCI生成物の特性の不均一性を調べ、試験サンプルの分析により得られた相や硬さ等の情報から燃料デブリ取出し作業への提言を取りまとめた。
Brissonneau, L.*; Gousseau, J.*; Piluso, P.*; Bouyer, V.*; 北垣 徹; 池内 宏知; 矢野 公彦; 鷲谷 忠博
no journal, ,
In case of severe accident in a nuclear reactor, the mixture obtained from fuel core and pins (mainly UO and zirconium), called corium, can penetrate the steel vessel and interact with the concrete, as in the Fukushima Daiichi NPP (1F) severe accidents. A specific test has been realized with a concrete similar to the one of the Fukushima Daiichi NPP (1F) and an "oxide metal" corium. Ten samples were collected from representative places (corium core, crust, vertical and horizontal interfaces) and examined by SEM and XRD. The talk will present some of the main features of the solids formed after CCI.
