| 1. |
- Khabensky, V. B., et al.
(författare)
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Effect of temperature gradient on chemical element partitioning in corium pool during in-vessel retention
- 2018
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Ingår i: Nuclear Engineering and Design. - : Elsevier Ltd. - 0029-5493 .- 1872-759X. ; 327, s. 82-91
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents some results of the ISTC (International Science and Technology Center)-financed project ‘Investigation of Corium Melt Interaction with NPP Reactor Vessel Steel’ (METCOR). In the METCOR experiments the metallic phase of a two-liquid system was produced by the interaction between hot suboxidized corium and cooled VVER vessel steel, with the steel being corroded. Models of corrosion mechanisms in the considered conditions are used to systematize data on the limiting temperature of corrosion/(dissolution) of the vessel steel. A considerable influence of thermal gradient conditions is shown, which has to be taken into account in the analysis of molten pool behaviour.
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| 2. |
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| 3. |
- 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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| 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. |
- 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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| 6. |
- Bechta, Sevostian, et al.
(författare)
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Interaction between molten corium UO2+X-ZrO2-FeO y and VVER vessel steel
- 2009
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Ingår i: Proceeding of International Conference on Advances in Nuclear Power Plants, ICAPP 2008. - : Curran Associates, Inc.. - 9781605607870 ; , s. 210-218
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Konferensbidrag (refereegranskat)abstract
- In case of an in-vessel corium retention (1VR) the deterioration of vessel steel properties can be caused both by the steel melting and by its physicochemical interaction with corium. The interaction behavior has been studied in the medium-scale experiments with a prototypic corium within the METCOR project. The resulting experimental data give an insight into the steel corrosion during its interaction with U02+x- Zr02- FeOy melt in air and steam. It has been observed that the corrosion rate is almost the same in air and steam atmosphere; if the temperature on the interaction interface increases beyond a certain level, corrosion intensifies, which is explained by the formation of liquid phases in the interaction zone. The available experimental data have been used for developing a correlation of corrosion rate versus temperature and heat flux.
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| 7. |
- Bechta, Sevostian, et al.
(författare)
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INTERACTION BETWEEN MOLTEN CORIUM UO2+x-ZrO2-FeOy AND VVER VESSEL STEEL
- 2010
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Ingår i: Nuclear Technology. - : American Nuclear Society. - 0029-5450 .- 1943-7471. ; 170:1, s. 210-218
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Tidskriftsartikel (refereegranskat)abstract
- In case of in-vessel corium retention during a severe accident in a light water reactor, weakening of the vessel wall and deterioration of the vessel steel properties can be caused both by the melting of the steel and by its physicochemical interaction with corium. The interaction behavior has been studied in medium-scale experiments with prototypic corium. The experiments yielded data for the steel corrosion rate during interaction with UO2+x-ZrO2-FeOy melt in air and steam at different steel surface temperatures and heat fluxes from the corium to the steel. It has been observed that the corrosion rates in air and steam atmosphere are almost the same. Further, if the temperature at the interface increases beyond a certain level, corrosion intensifies. This is explained by the formation of liquid phases in the interaction zone. The available experimental data have been used to develop a correlation for the corrosion rate as afunction of temperature and heat flux.
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| 8. |
- Bechta, Sevostian, et al.
(författare)
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VVER vessel steel corrosion at interaction with molten corium in oxidizing atmosphere
- 2009
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 239:6, s. 1103-1112
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Tidskriftsartikel (refereegranskat)abstract
- The long-term in-vessel corium retention (IVR) in the lower head bears a risk of the vessel wall deterioration caused by steel corrosion. The ISTC METCOR Project has studied physicochemical impact of prototypic coria having different compositions in air and steam and has generated valuable experimental data on vessel steel corrosion. It is found that the corrosion rate is sensitive to corium composition, but the composition of oxidizing above-melt atmosphere (air, steam) has practically no influence on it. A model of the corrosion process that integrates the experimental data, is proposed and used for development of correlations.
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| 9. |
- Bechta, Sevostian, et al.
(författare)
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Water boiling on the corium melt surface under VVER severe accident conditions
- 2000
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Ingår i: Nuclear Engineering and Design. - 0029-5493 .- 1872-759X. ; 195:1, s. 45-56
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Tidskriftsartikel (refereegranskat)abstract
- Experimental results are presented on the interaction of corium melt with water supplied on its surface. The tests were conducted in the `Rasplav-2' experimental facility. Corium melt was generated by induction melting in the cold crucible. The following data were obtained: heat transfer at boiling water-melt surface interaction, gas and aerosol release, post-interaction solidified corium structure. The corium melt charge had the following composition, mass%: 60% UO2+x-16% ZRO2-15% Fe2O3-6% Cr2O3-3% Ni2O3. The melt surface temperature ranged within 1920-1970 K.
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| 10. |
- Almyashev, V. I., et al.
(författare)
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Oxidation effects during corium melt in-vessel retention
- 2016
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Ingår i: Nuclear Engineering and Design. - : Elsevier. - 0029-5493 .- 1872-759X. ; 305, s. 389-399
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Tidskriftsartikel (refereegranskat)abstract
- In the in-vessel corium retention studies conducted on the Rasplav-3 test facility within the ISTC METCOR-P project and OECD MASCA program, experiments were made to investigate transient processes taking place during the oxidation of prototypic molten corium. Qualitative and quantitative data have been produced on the sensitivity of melt oxidation rate to the type of oxidant, melt composition, molten pool surface characteristics. The oxidation rate is a governing factor for additional heat generation and hydrogen release; also for the time of secondary inversion of oxidic and metallic layers of corium molten pool.
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