| 1. |
- Asmolov, V.G., et al.
(författare)
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Crucible-type core catcher for VVER-1000 reactor
- 2005
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Ingår i: Proceedings of the American Nuclear Society - International Congress on Advances in Nuclear Power Plants 2005, ICAPP'05. - : Curran Associates, Inc.. - 9781604236934 ; , s. 1221-1227
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Konferensbidrag (refereegranskat)abstract
- For new designs of NPPs with VVER-1000 reactors a crucible-type core catcher has been developed to stabilize and cool down molten corium in the reactor pit. The paper addresses distinguishing features of the concept including the "sacrificial" material and the core catcher design. Main phenomena in the catcher have been analyzed.
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| 2. |
- Bechta, Sevostian, et al.
(författare)
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Experimental studies of oxidic molten corium-vessel steel interaction
- 2001
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Ingår i: Nuclear Engineering and Design. - 0029-5493 .- 1872-759X. ; 210:1-3, s. 193-224
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Tidskriftsartikel (refereegranskat)abstract
- The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere.
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| 3. |
- Asmolov, V.G., et al.
(författare)
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Partitioning of Zr, U and FP between Molten Oxidic and Metallic Corium
- 2004
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Ingår i: Proceeding of MASCA Seminar.
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Konferensbidrag (refereegranskat)abstract
- Interaction of molten corium and liquid iron/stainless steel has been studied in different tests of theMASCA-1 program. These tests utilized the technology of induction melting in a cold crucible. Themasses of tested corium were approximately 0.5, 2 and 100 kg. Representative quantities of Mo, Ru,SrO, BaO, CeO2 and La2O3 served as fission product simulants.After the suboxidized melt - steel interaction U and Zr have been found in the metallic phase.To quantify the partitioning of Zr, U and fission products an extensive experimental program has beenperformed. The following key parameters have been identified: oxygen potential in the melt (degree ofZr-oxidation), the corium/steel mass ratio and U/Zr ratio. The paper discusses the influence of theseparameters on the partitioning of the main species.
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| 4. |
- Almjashev, V.I., et al.
(författare)
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Ternary eutectics in the systems FeO-UO2-ZrO2 and Fe2O3-U3O8-ZrO21
- 2011
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Ingår i: Radiochemistry. - 1066-3622. ; 53:1, s. 13-18
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Tidskriftsartikel (refereegranskat)abstract
- The systems FeO–UO2–ZrO2 (in inert atmosphere) and Fe2O3–U3O8–ZrO2 (in air) were studied. Forthe FeO–UO2–ZrO2 system, the eutectic temperature was found to be 1310°С, with the following componentconcentrations (mol %): 91.8 FeO, 3.8 UO2, and 4.4 ZrO2. For the Fe2O3–U3O8–ZrO2 system, the eutectictemperature was found to be 1323°С, with the following component concentrations (mol %): 67.4 FeO1.5,30.5 UO2.67, and 2.1 ZrO2. The solubility limits of iron oxides in the phases based on UO2(ZrO2,FeO) andUO2.67(ZrO2,FeO1.5) were determined
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| 5. |
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| 6. |
- Bechta, Sevostian, et al.
(författare)
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CORPHAD and METCOR ISTC projects
- 2005
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Ingår i: Proceedings of The first European Review Meeting on Severe Accident Research (ERMSAR-2005).
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Konferensbidrag (refereegranskat)abstract
- The ongoing CORPHAD Project (Phase Diagrams for Multicomponent SystemsContaining Corium and Products of its Interaction with NPP Materials) started in August2001. The main aim of the project is to experimentally determine the relevantphysicochemical data on phase diagrams of binary, ternary, quaternary and prototypic multicomponent systems, which are important for analysis and modelling of a severe accident (SA)and efficient planning of severe accident management (SAM) measures. The data should bedirectly used for the European NUCLEA database development and validation. The followingsystems are in the focus of the project: (1) UO2 – FeO, (2) ZrO2 – FeO, (3) SiO2– Fe2O3, (4)UO2 – SiO2, (5) UO2 – ZrO2-FeO, (6) UO2 – ZrO2-FeOy, (7) U-O-Fe, (8) Zr-O-Fe, (9) U-OZr, (10) U-Zr-Fe-O, (11) complex corium mixtures.The experimentally determined data of the listed diagrams include: coordinates ofcharacteristic points (eutectics, peritectics and others); liquidus and solidus concentrationcurves; component solubility limits in the solid phase; tie line coordinates and temperatureconcentration regions of the miscibility gap. Different methodologies are used for the phasediagram study. Classical methods of thermal analysis, like DTA and DSC are combined withmethods specifically developed for corium studies.The METCOR project (Investigation of Corium Melt Interaction with NPP ReactorVessel Steel) started in April 1999. The objectives of the project are to qualify and to quantifyphysico-chemical phenomena of corium melt interaction with reactor vessel steel cooled fromthe outside. The variable parameters of the interaction tests are: oxygen potential in thesystem, corium composition, interaction interface temperature and heat flux from corium tosteel. The medium scale tests with corium mass of about 2 kg are carried out by using highfrequency induction heating of the corium melt in a cold crucible.The METCOR & CORPHAD work-packages are performed by Russian partners inclose collaboration with leading European scientific institutes in the area of corium researchas well as with the European nuclear industry.This paper briefly describes the results obtained in both projects and their possibleapplication for SA analysis and SAM. The paper concludes with recommendations for futureresearch activities in the framework of METCOR and CORPHAD projects.
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| 7. |
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| 8. |
- Bechta, Sevostian, et al.
(författare)
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Influence of corium oxidation on fission product release from molten pool
- 2010
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 240:5, s. 1229-1241
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Tidskriftsartikel (refereegranskat)abstract
- Qualitative and quantitative determination of the release of low-volatile fission products and core materialsfrom molten oxidic corium was investigated in the EVAN project under the auspices of ISTC. Theexperiments carried out in a cold crucible with induction heating and RASPLAV test facility are described.The results are discussed in terms of reactor application; in particular, pool configuration, melt oxidationkinetics, critical influence of melt surface temperature and oxidation index on the fission productrelease rate, aerosol particle composition and size distribution. The relevance of measured high releaseof Sr from the molten pool for the reactor application is highlighted. Comparisons of the experimentaldata with those from the COLIMA CA-U3 test and the VERCORS tests, as well as with predictions fromIVTANTHERMO and GEMINI/NUCLEA codes are made. Recommendations for further investigations areproposed following the major observations and discussions.
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| 9. |
- Bottomley, D., et al.
(författare)
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Severe accident research in the core degradation area : An example of effective international cooperation between the European Union (EU) and the Commonwealth of Independent States (CIS) by the International Science and Technology Center
- 2012
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 252, s. 226-241
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Tidskriftsartikel (refereegranskat)abstract
- The International Science and Technology Center (ISTC) was set up in Moscow to support non-proliferation of sensitive knowledge and technologies in biological, chemical and nuclear domains by engaging scientists in peaceful research programmes with a broad international cooperation. The paper has two following objectives: to describe the organization of complex, international, experimental and analytical research of material processes under extreme conditions similar to those of severe accidents in nuclear reactors and, to inform briefly about some results of these studies. The main forms of ISTC activity are Research Projects and Supporting Programs. In the Research Projects informal contact expert groups (CEGs) were set up by ISTC to improve coordination between adjacent projects and to encourage international collaboration. The European Commission was the first to use this. The CEG members - experts from the national institutes and industry - evaluated and managed the projects' scientific results from initial stage of proposal formulation until the final reporting. They were often involved directly in the project's details by joining the Steering Committees of the project. The Contact Expert Group for Severe Accidents and Management (CEG-SAM) is one of these groups, five project groups from this area from the total of 30 funded projects during 10 years of activity are detailed to demonstrate this: (1) QUENCH-VVER from RIAR, Dimitrovgrad and IBRAE, Moscow, and PARAMETER projects (SF1-SF4) from LUCH, Podolsk and IBRAE, Moscow; these concerned a detailed study of bundle quenching from high temperature; (2) Reactor Core Degradation; a modelling project simulating the fuel rod degradation and loss of geometry from IBRAE, Moscow; (3) METCOR projects from NITI, St. Petersburg on the interaction of core melt with reactor vessel steel; (4) INVECOR project, NNE Kurchatov City, Kazakhstan; this is a large-scale facility to examine the vessel steel retention of 60 kg corium during the decay heat; and finally, (5) CORPHAD and PRECOS projects, NITI, St. Petersburg undertook a systematic examination of refractory ceramics relevant to in-vessel and ex-vessel coria, particularly examining poorly characterised, limited data or experimentally difficult systems.
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| 10. |
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