| 1. |
- 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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| 2. |
- 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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| 3. |
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| 4. |
- Bechta, Sevostian, et al.
(författare)
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Corium phase equilibria based on MASCA, METCOR and CORPHAD results
- 2008
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 238:10, s. 2761-2771
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Tidskriftsartikel (refereegranskat)abstract
- Experimental data on component partitioning between suboxidized corium melt and steel in the invessel melt retention (IVR) conditions are compared. The data are produced within the OECD MASCAprogram and the ISTC CORPHAD project under close-to-isothermal conditions and in the ISTC METCORproject under thermal gradient conditions. Chemical equilibrium in the U–Zr–Fe(Cr,Ni,. . .)–O system isreached in all experiments. In MASCA tests the molten pool formed under inert atmosphere has twoimmiscible liquids, oxygen-enriched (oxidic) and oxygen-depleted (metallic), resulting of the miscibilitygap of the mentioned system. Sub-system data of the U–Zr–Fe(Cr,Ni,. . .)–O phase diagram investigatedwithin the ISTC CORPHAD project are interpreted in relation with the MASCA results. In METCOR teststhe equilibrium is established between oxidic liquid and mushy metallic part of the system. Results ofcomparison are discussed and the implications for IVR noted.
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| 5. |
- Bechta, Sevostian, et al.
(författare)
-
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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| 6. |
- Bechta, Sevostian, et al.
(författare)
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Corrosion of vessel steel during its interaction with molten corium : Part 2. Model development
- 2006
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 236:13, s. 1362-1370
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Tidskriftsartikel (refereegranskat)abstract
- An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments havebeen conducted on “Rasplav-2” test facility and followed up with physico-chemical and metallographic analyses of melt samples and coriumspecimeningots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere abovethe melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate orcorrosion depth of vessel steel in conditions simulated by the experiments.
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| 7. |
- Bechta, Sevostian, et al.
(författare)
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Corrosion of vessel steel during its interaction with molten corium : Part 1. Experimental
- 2006
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 236:17, s. 1810-1829
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Tidskriftsartikel (refereegranskat)abstract
- This paper is concerned with corrosion of a cooled vessel steel structure interacting with molten corium in air and neutral (nitrogen) atmospheresduring an in-vessel retention scenario. The data on corrosion kinetics at different temperatures on the heated steel surface, heat flux densities andoxygen potential in the system are presented. The post-test physico-chemical and metallographic analyses of melt samples and the corium–specimeningot have clarified certain mechanisms of steel corrosion taking place during the in-vessel melt interaction.
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| 8. |
- Bechta, Sevostian, et al.
(författare)
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Experimental studies of oxidic molten corium-vessel steel interaction
- 2001
-
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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| 9. |
- Bechta, Sevostian, et al.
(författare)
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Experimental study of interactions between suboxidized corium and reactor vessel steel
- 2006
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Ingår i: Proceedings of the 2006 International Congress on Advances in Nuclear Power Plants, ICAPP'06. - 0894486985 - 9780894486982 ; , s. 1355-1362
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Konferensbidrag (refereegranskat)abstract
- One of the critical factors in the analysis of in-vessel melt retention is the vessel strength. It is, in particular, sensitive to the thickness of intact vessel wall, which, in its turn, depends on the thermal conditions and physicochemical interactions with corium. Physicochemical interaction of prototypic UO2-ZrO2-Zr corium melt and VVER vessel steel was examined during the 2nd Phase of the ISTC METCOR Project. Rasplav-3 test facility was used for conducting four tests, in which the Zr oxidation degree and interaction front temperature were varied; in one of the tests, stainless steel was added to the melt. Direct experimental measurements and posttest analyses were used for determining corrosion kinetics and maximum corrosion depth (i.e. the physicochemical impact of corium on the cooled vessel steel specimens), as well as the steel temperature conditions during the interaction, and finally the structure and composition of crystallized ingots, including the interaction zone. The minimum temperature on the interaction front boundary, which determined its final position and maximum corrosion depth was ∼ 1090°C. An empirical correlation for calculation of corrosion kinetics has been derived.
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| 10. |
- 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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| 11. |
- Bechta, Sevostian, et al.
(författare)
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INTERACTION BETWEEN MOLTEN CORIUM UO2+x-ZrO2-FeOy AND VVER VESSEL STEEL
- 2010
-
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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| 12. |
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| 13. |
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| 14. |
- Bechta, Sevostian, et al.
(författare)
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New experimental results on the interaction of molten corium with reactor vessel steel
- 2004
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Ingår i: Proceedings of the 2004 International Congress on Advances in Nuclear Power Plants, ICAPP'04. - : American Nuclear Society. - 0894486802 ; , s. 1072-1081
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Konferensbidrag (refereegranskat)abstract
- In order to justify the concept of in-vessel core melt retention, it is necessary to understand the thermal and physico-chemical phenomena. Especially the interaction of the molten pool with the reactor vessel during outside cooling needs to be understood. These phenomena are very complex, in particular, where interactions with the oxidic melt are concerned. In the early stages of the retention process, the oxidic corium and the vessel steel interact under the conditions of low oxygen potential in the melt. These conditions can be simulated by a molten corium having the composition UO2/ZrO 2Zr, where the degree of Zr-oxidation is in the range between 30 % (C-30) and 100 % (C-100). Corresponding experiments with prototypic melts at low oxygen potentials are being performed in the ISTC METCOR project 2nd phase. These are: MC 5 of corium composition 71w%UO2-29w%ZrO 2 (C-100) in neutral atmosphere (argon), MC 6 of corium composition 76w%UO2-9w%ZrO2-15w%Zr (C∼30), also in argon. In test MC 5, the interaction of molten C-100 corium with a water-cooled steel specimen was studied for the following maximum temperatures at the specimen surface: 1075°C, 1180°C, 1315°C and 1435°C. The total duration of the experiment was ∼ 36 hours. The MC5 test serves as a reference test for determining the characteristics of the interaction between oxidic melt and steel specimen under the conditions of minimum chemical interaction potential. To investigate the effect of substoichiometry, test MC 6 was then performed with suboxidized molten corium C∼30. The maximum surface temperature of the cooled steel specimen was held at ∼ 1400°C. The test duration was ∼ 10 hours. The ablation phenomena were found to differ significantly from those observed both in the reference test, as well as in former tests with oxidized melts, as they involved the formation of a low-melting metallic phase at the interface which contains iron, zirconium and uranium. The paper summarizes the results of the experiments and of the performed posttest analysis for tests MC 5 and MC 6.
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| 15. |
- Bechta, Sevostian, et al.
(författare)
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VVER steel corrosion during in-vessel retention of corium melt
- 2008
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Ingår i: Proceedings of the 3<sup>rd</sup> European Review Meeting on Severe Accident Research (ERMSAR 2008).
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Konferensbidrag (refereegranskat)abstract
- Physicochemical phenomena taking place at the corium-steel interaction during theexternal cooling of reactor vessel can result in high-temperature steel corrosion and thinningof the vessel wall. The ISTC METCOR project's experimental studies have shown that themain factors influencing corrosion depth and kinetics are oxygen potential, melt compositionand steel interfacial temperature but also melt – vessel heat flux.Experimental data are used for building a model for VVER vessel steel corrosion undercorium thermochemical loads and for correlations to quantitatively analyze the influence ofcorrosion on the rector vessel thinning. The finite-element calculations, in which thedeveloped models of corrosion and heat transfer in corium pool were used, were able toreproduce the temperature and stress-and-strain vessel condition.
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| 16. |
- Bechta, Sevostian, et al.
(författare)
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VVER vessel steel corrosion at interaction with molten corium in oxidizing atmosphere
- 2009
-
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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| 17. |
- 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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| 18. |
- Granovsky, V. S., et al.
(författare)
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Modeling of melt retention in EU-APR1400 ex-vessel core catcher
- 2012
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Ingår i: International Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012. - 9781622762101 ; , s. 1412-1421
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Konferensbidrag (refereegranskat)abstract
- A core catcher is adopted in the EU-APR1400 reactor design for management and mitigation of severe accidents with reactor core melting. The core catcher concept incorporates a number of engineering solutions used in the catcher designs of European EPR and Russian WER-1000 reactors, such as thin-layer corium spreading for better cooling, retention of the melt in a water-cooled steel vessel, and use of sacrificial material (SM) to control the melt properties. SM is one of the key elements of the catcher design and its performance is critical for melt retention efficiency. This SM consists of oxide components, but the core catcher also includes sacrificial steel which reacts with the metal melt of the molten corium to reduce its temperature. The paper describes the required properties of SM. The melt retention capability of the core catcher can be confirmed by modeling the heat fluxes to the catcher vessel to show that it will not fail. The fulfillment of this requirement is demonstrated on the example of LBLOCA severe accident. Thermal and physicochemical interactions between the oxide and metal melts, interactions of the melts with SM, sacrificial steel and vessel, core catcher external cooling by water and release of non-condensable gases are modeled.
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| 19. |
- Granovsky, V. S., et al.
(författare)
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Oxidation effect on steel corrosion and thermal loads during corium melt in-vessel retention
- 2014
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 278, s. 310-316
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Tidskriftsartikel (refereegranskat)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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| 20. |
- Gusarov, V.V., et al.
(författare)
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Distribution of components between immiscible melts of a system under nonisothermal conditions
- 2006
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Ingår i: Glass Physics and Chemistry. - 1087-6596 .- 1608-313X. ; 32:6, s. 638-642
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the temperature difference at the interface on the redistribution of components between coexisting liquid phase is analyzed using the U-Zr-O system as an example. It is demonstrated that, in this system, there can arise new dynamic effects in boundary regions of the coexisting phases. These effects are of considerable practical importance, for example, for the prediction of the behavior of the system in severe accidents at nuclear power plants.
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| 21. |
- Gusarov, V.V., et al.
(författare)
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Interaction of a material based on aluminum and iron oxides with a metal melt
- 2007
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Ingår i: Russian journal of applied chemistry. - 1070-4272 .- 1608-3296. ; 80:4, s. 528-535
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Tidskriftsartikel (refereegranskat)abstract
- Interaction of an oxide material with a melt of metals in the combustion mode was studied experimentally. The conditions in which processes of this kind can occur without any increase in the temperatureof the environment are possible were analyzed.
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| 22. |
- Gusarov, V.V., et al.
(författare)
-
Method for producing ceramic materials incorporating ferric oxide, alumina, and silicon dioxide for nuclear-reactor molten core trap
- 2002
-
Patent (populärvet., debatt m.m.)abstract
- NOVELTY - Production of ceramic materials for nuclear reactor molten core trap involves preparation of charge by milling and mixing components, and producing molding powder from charge. This molding powder is molded and formed into briquettes, which are calcined in an air environment at 1300 - 1380 degreesC for 2-14 hr. The briquettes are crushed, the powder is milled and sized to fractions, and mixed with binder. The parts are molded and calcined at 1200-1300 degreesC for 4-14 hr. Silicon dioxide and part of the alumina are introduced into the charge as kaolin, whose content is higher than the desired content of silicon dioxide in material by 2.1-2.3 times. USE - In nuclear power engineering, for confining molten core in water-cooled tank reactors. ADVANTAGE - Enhanced reproducibility of physical and mechanical properties of molten core sacrificial ceramic materials.
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| 23. |
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| 24. |
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| 25. |
- Gusarov, V.V., et al.
(författare)
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Oxidmaterial for fallan av en karnreaktors smalt mantel
- 2001
-
Patent (populärvet., debatt m.m.)abstract
- The inventive oxide material for a molten-core catcher of a nuclear reactor comprises Fe>23< and /or Fe>34< and Al>23<. The content of Al>23< and /or Fe>34 23 <%. Said material can also contain up to 4 mass % of SiO2, preferably from 1 to 4 mass %. The material can be embodied in the form of a ceramic material or concrete which additionally contains up to 20 mass % of cement binder.; The inventive oxide material for a molten-core catcher of a nuclear reactor comprises Fe2O3 and /or Fe3O4 and Al2O3. The content of Al2O3 and /or Fe3O4 ranges from 46 to 80 mass %, and Al2O3 from 16 to 50 mass %. Said material can also contain up to 4 mass % of SiO2, preferably from 1 to 4 mass %. The material can be embodied in the form of a ceramic material or concrete which additionally contains up to 20 mass % of cement binder.
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| 26. |
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| 27. |
- Gusarov, V.V., et al.
(författare)
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Physicochemical Modeling and Analysis of the Interaction between a Core Melt of the Nuclear Reactor and a Sacrificial Material
- 2005
-
Ingår i: Glass Physics and Chemistry. - : Springer Science and Business Media LLC. - 1087-6596 .- 1608-313X. ; 31:1, s. 53-66
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Tidskriftsartikel (refereegranskat)abstract
- -The problems regarding the design of a new class of materials, namely, sacrificial materials for usein devices intended for localization of a core melt of the nuclear reactor, are considered. Criteria are proposedfor the proper choice of the chemical composition of a sacrificial material, as well as of the composition andmicrostructure of its constituents. The possible alternatives are outlined and analyzed. The results of designinga variant of the composition of sacrificial materials are presented. The experimental data on the interaction ofan oxide sacrificial material with simulators of the metal and oxide phases of the core melt are discussed. A newtype of combustion of materials, namely, the liquid-phase combustion, is revealed. It is demonstrated that thematerial designed can be used in systems intended for localization of a core melt of the nuclear reactor.
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| 28. |
- Gusarov, V.V., et al.
(författare)
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Physicochemical simulation of the combustion of materials with the total endothermal effect
- 2007
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Ingår i: Glass Physics and Chemistry. - 1087-6596 .- 1608-313X. ; 33:5, s. 492-497
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Tidskriftsartikel (refereegranskat)abstract
- A new type of combustion, namely, the combustion of materials without heating of the environment, is described, and the conditions under which this process can occur are analyzed. It is demonstrated that the possibility of occurring the process under consideration depends substantially on the microstructure of the material. The characteristics of the material for which the liquid-phase combustion takes place without an increase in the temperature of the melt are determined using the interaction of a material based on iron and aluminum oxides with the Fe-Zr-O melt as an example.
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| 29. |
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| 30. |
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| 31. |
- 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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| 32. |
- Khabensky, V.B., et al.
(författare)
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Severe accident management concept of the VVER-1000 and the justification of corium retention in a crucible-type core catcher
- 2009
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Ingår i: Nuclear Engineering and Technology. - 1738-5733. ; 41:5, s. 561-574
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Tidskriftsartikel (refereegranskat)abstract
- First ex-vessel core catcher has been applied to the practical design of NPPs with VVER-1000 reactors built in China(Tyanvan) and India (Kudankulam) for severe accident management (SAM) and mitigation of SA consequences. The paperpresents the concept and basic design of this crucible-type core catcher as well as an evaluation of its efficiency. Theimportant role of oxidic sacrificial material is discussed. Insight into the behaviour of the molten pool, which forms in thecatcher after core relocation from the reactor vessel, is provided. It is shown that heat loads on the water-cooled vessel wallsare kept within acceptable limits and that the necessary margins for departure from nucleate boiling (DNB) and of vesselfailure caused by thermo-mechanical stress are satisfactorily provided for.
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| 33. |
- Khabensky, V.B., et al.
(författare)
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System for localization and cooling of corium of accidental light water nuclear reactor
- 2003
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Patent (populärvet., debatt m.m.)abstract
- FIELD: systems for localization and cooling of melted body at emergency its exit for the limits of the reactor's body. ^ SUBSTANCE: cooling trap is located in the mine under the reactor and fulfilled in the form of a vessel with installed in it a basket with sacrificial materials-diluters of uranium containing and steel components of corium. The bottom of the cooling drum is no less than on 30% thicker of its walls and has an incline to the center in the limits of 10-20 degrees; sacrificial materials-diluters are formed in the shape of briquettes enclosed in the steel drum. The mass of the material-diluters of oxide uranium containing and steel components of corium are determined with the help of calculated ratio computations which take into considerations: the mass of components of the corium, incoming from the reactor; physical parameters of components of melt; density of critical thermal flow drawing off the melts to cooling water through the drum. It is proposed to fulfill the directing arrangement for the body in the form of a funnel located between the bottom of the reactor and the higher edge of the trap. At that the walls of the directing arrangement are covered with heat-resistant concrete, over which a covering of easily melted concrete is put on. ^ EFFECT: the invention allows to increase efficiency and reliability of the system by way of improving conditions for coming in and cooling of melted corium in the trap. ^ 4 cl, 1 dwg
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| 34. |
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| 35. |
- Sulatsky, A.A., et al.
(författare)
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Molten corium interaction with oxidic sacrificial material of WER core catcher
- 2005
-
Ingår i: Proceedings of the American Nuclear Society. - 9781604236934 ; , s. 1238-1246
-
Konferensbidrag (refereegranskat)abstract
- The results of experimental studies on the interaction between the oxidic corium melt containing unoxidized zirconium and sacrificial materials of the VVER core catcher are presented. The phenomena of suboxidized corium interaction with sacrificial material have been determined and appropriate model has been developed.
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| 36. |
- Vasilenko, V.A., et al.
(författare)
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NITI severe accident research under ISTC coordination
- 2009
-
Ingår i: Proceedings of FISA 2009, Seventh European Commission conference on Euratom research and training in reactor systems. - 9789279133022
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Konferensbidrag (refereegranskat)abstract
- From the very start of ISTC activities NITI has been involved in its projects on the conversion of industrial and engineering potential from military to civil needs and priorities. These projects include studies aimed at efficient severe accident management (SAM) and safety enhancement of commercial nuclear reactors. Detailed information on the projects is published in /1 - 11/.Most of the experimental studies have been carried out in the RASPLAV experimental platform, which:- Comprises 4 experimental facilities integrated into the shared infrastructure of auxiliary and protective systems. The experimental facilities are based on the principle of induction melting in a cold crucible (IMCC) at different heating frequencies;- Enables melting and various manipulations with chemically prototypic corium having mass up to8 kgand temperature up to 3200 С in different atmospheres (inert (Ar, He), oxidizing (steam, air), or their mixtures);- Is certified for work with unirradiated uranium and radiolabeled fission product simulants.In the EU countries results of these ISTC projects are used for reactor application particularly for optimization of NUCLEA - European thermodynamic database, development and implementation of different SAM concepts. Results delivered by the ISTC projects together with data of other projects carried out within national programs have an important reactor application inRussia, i.e.:- Jointly with SPbAEP ex-vessel SAM concept [12] has been developed, which foresees corium retention in the reactor cavity of Tyanvan NPP (China) and Kudankulam NPP (India) equipped by VVER-1000 reactors.- New oxidic sacrificial material [13] has been developed jointly with ISCh RAS and RSC KI. This material is a key component in the above-mentioned melt retention concept.- New crucible-type core catcher for VVER-1000 [14] has been developed and justified in collaboration with SPbAEP, RRC KI, IBRAE RAS, PKF of ROSENERGOATOM, ISCh RAS, SPbGETU, IPPE and SPb GTI (TU).- Concept of in-vessel corium retention has been justified for VVER-640 project based on the application of passive safety systems.The developed concept, ex-vessel catcher and innovative solutions are currently in use in the NPP-2006 projects with VVER-1200, which are under construction inRussia.Long-term and diverse experience in international projects coordinated by the ISTC generated fruitful cooperation on severe accident issues between NITI and European organizations. The following formats of cooperation can be mentioned:- Multi-lateral exchanges with European scientific research centers collaborating within the ISTC projects.- Multi-lateral cooperation coordinated by the OECD and RSC KI with the participants of MASCA program. NITI took part in preparing CORTRAN program proposal.- Bilateral cooperation within the ISTC partnership projects.- Bilateral cooperation with CEA coordinated by Rosatom.- Communication with SARNET, so far unilateral (SARNET members have an access to the ISTC project results through the CEG-SAM website).Short-term perspectives of a broader cooperation are related to the NITI’s initiative to participate in:- ROSATOM-EUROATOM program. In particular, a joint call on containment phenomena is under preparation for transnational use of large scale experimental facilities: MISTRA, CEA – PANDA, PSI – KMS, NITI- SARNET network of excellence, i.e. in the packages related to severe accident research.
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