| 1. |
- Almjashev, V.I., et al.
(author)
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Phase equilibria in the FeO(1+x)-UO(2)-ZrO(2) system in the FeO(1+x)-enriched domain
- 2010
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 400:2, s. 119-126
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Journal article (peer-reviewed)abstract
- Experimental results of the investigation of the FeO(1+x)UO(2)-ZrO(2) system in neutral atmosphere are presented. The ternary eutectic position and the composition of the phases crystallized at this point have been determined. The phase diagram is constructed for the FeO(1+x)-enriched region and the onset melting temperature of 1310 degrees C probably represents a local minimum and so will be a determining factor in this system and its application to safety studies in nuclear reactors.
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| 2. |
- Almjashev, V.I., et al.
(author)
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Ternary eutectics in the systems FeO-UO2-ZrO2 and Fe2O3-U3O8-ZrO21
- 2011
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In: Radiochemistry. - 1066-3622. ; 53:1, s. 13-18
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Journal article (peer-reviewed)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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| 3. |
- Bechta, Sevostian, et al.
(author)
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Influence of corium oxidation on fission product release from molten pool
- 2010
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In: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 240:5, s. 1229-1241
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Journal article (peer-reviewed)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. |
- Bechta, Sevostian, et al.
(author)
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INTERACTION BETWEEN MOLTEN CORIUM UO2+x-ZrO2-FeOy AND VVER VESSEL STEEL
- 2010
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In: Nuclear Technology. - : American Nuclear Society. - 0029-5450 .- 1943-7471. ; 170:1, s. 210-218
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Journal article (peer-reviewed)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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| 5. |
- Granovsky, V. S., et al.
(author)
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Oxidation effect on steel corrosion and thermal loads during corium melt in-vessel retention
- 2014
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In: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 278, s. 310-316
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Journal article (peer-reviewed)abstract
- During a severe accident with core meltdown, the in-vessel molten core retention is challenged by the vessel steel ablation due to thermal and physicochemical interaction of melt with steel. In accidents with oxidizing atmosphere above the melt surface, a low melting point UO2+x-ZrO2-FeOy corium pool can form. In this case ablation of the RPV steel interacting with the molten corium is a corrosion process. Experiments carried out within the International Scientific and Technology Center's (ISTC) METCOR Project have shown that the corrosion rate can vary and depends on both surface temperature of the RPV steel and oxygen potential of the melt. If the oxygen potential is low, the corrosion rate is controlled by the solid phase diffusion of Fe ions in the corrosion layer. At high oxygen potential and steel surface layer temperature of 1050 degrees C and higher, the corrosion rate intensifies because of corrosion layer liquefaction and liquid phase diffusion of Fe ions. The paper analyzes conditions under which corrosion intensification occurs and can impact on in-vessel melt retention (IVR).
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