Authors & Affiliations
Zagorulko Yu.I., Ganichev N.S.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
Zagorulko Yu.I. – Leading Researcher, Cand. Sci. (Techn.), A.I. Leypunsky Institute for Physics and Power Engineering. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7(484) 399-80-84; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Ganichev N.S. – Head of laboratory, A.I. Leypunsky Institute for Physics and Power Engineering.
Abstract
Investigation results on energy effects at corium simulators/sodium thermal interaction suggest high enough energy release as in the form of sodium phase expansion mechanical work, so due to sodium corium relocation. Experimentally estimated duration of thermal interaction active stage equals 5—10 ms, which corresponds to time history characteristic of large-scale interaction. One of the most plausible mechanisms for observed phenomena explanation could be related to sodium thermal inter-action with iron metallic phase, formed due to separation of initial melt onto metallic and ceramic phases. Iron melt temperature is essentially higher than melt point temperature. Temperature condi-tions at metallic phase-sodium boundary satisfy requirements of sodium spontaneous evaporation while contact temperature exceeds spontaneous nucleation temperature in the system “Fe—Na”. As applied to severe accidents scenarios, e.g. ULOF type, iron melt simulated steal melt. It could be suggested that phase separation phenomenon will take place as well in the system “UO2-steel melt”. One could expect the identical thermal interaction mechanism at least for the part of metallic dispersed phase, for which satisfactory wetting is possible during initial contact. Thermal interaction energy release should be accounted for as for severe accidents initial stages, so in the course of the accidents development, e.g. at analysis of the processes occurring in corium traps, where thermal interaction between steel melt and sodium are quite plausible. In the report, hypothetical mechanism of large-scale thermal interaction is considered going out of phase separation phenomenon, observed in the system "Al2O3—Fe".
Keywords
sodium, corium, simulators, melt, severe accidents, thermal interaction, energy effects, homogenous nucleation, contact temperature, phase separation
Article Text (PDF, in Russian)
References
1. Fauske H.K. Some aspects of liquid-liquid heat transfer and explosive boiling. Proc. Fast Reactor Safety Meet. Beverly Hills, 1974, pp. 992—1005.
2. Bird M.J. Experimental Studies of Thermal Interactions between Thermite Generated Molten Fuel and Sodium. Proc. LMFBR Safety Top. Meet. Lyon, 1982, vol. 3, pp. 430.
3. Shins H.A. Critical Review of Fuel Coolant Interactions with Particular Reference to UO2-Na. Res Mechanica, 1988, vol. 23.
4. Berthoud G. Description of Fuel-Coolant Thermal Interaction Model with Application in the Interpretation of Experimental results. Nuclear Engineering and Design, 1984, vol. 2.
5. Zagorul'ko Yu.I., Kashcheev M.V., Ganichev N.S., Zhmurin V.G. Vozmozhnye mekhanizmy povrezhdaemosti obolochki tvehlov v usloviyah poteri raskhoda teplonositelya (natrij, voda) cherez toplivnuyu sborku [Possible mechanisms of damage to the fuel element cladding in conditions of loss of coolant flow (sodium, water) through the fuel assembly]. Trudy konferencii “Teplofizicheskie ehksperimental'nye i raschyotno-teoreticheskie issledovaniya v obosnovanie harakteristik i bezopasnosti yadernyh reaktorov na bystryh nejtronah (Teplofizika-2012)” [Proc. conf. “Thermophysical experimental and theoretical calculations to substantiate the characteristics and safety of fast neutron nuclear reactors (Thermalphysics-2012)”]. Obninsk, 2013, vol. 1, pp. 148—157.
6. Huber F., Kaiser A., Peppler W. Experiments on the Behavior of Thermite Melt Injected into Sodium Final report on the THINA test results. Proc. IAEA/IWGFR Technical Committee Meeting on Material-Coolant Interactions and Material Movement and Relocation in Liquid Metal Fast Reactors. Ibaraki, Japan, 1994, pp. 167.
7. Livolant M. SCARABEE: A Test Reactor and Programme to Study Fuel Melting and Propagation in connection with Local Faults Objectivеs and Results. Proc. Inf. Fast reactor Safety Meet. Snowbird, 1990, vol. 2, pp. 177—184.
8. Deitrich L.W. Evaluation of Energy Conversion in TREAT MARK-II Loop Experiments. Transaction of the American Mathematical Society, 1971, vol. 14, no. 1, pp. 278—279.
9. Shins H.A., Gunnerson F.S. Boiling and Fragmentation Behavior during Fuel Sodium Interactions. Nuclear Engineering and Design, 1986, vol. 91.
10. Kaiser A. Peppler W. Will H. SIMBATH 1976—1992. Seventeen Years of Experimental Investigation of Key Issues Concerned with Severe reactor Accidents. Proc. IAEA/IWGER Technical Committee Meeting on Material-Coolant Interactions and Material Movement and Relocation in Liquid Metal Fast Reactors. Ibaraki, Japan, 1994, pp. 349.
11. Kovalyov Yu.P., Zagorul'ko Yu.I., ZHmurin V.G. Teplovye ehffekty pri gorenii termitnoj smesi U+MoO3 [Thermal effects when burning a thermite mixture U+MoO3]. Preprint FEI-2745 - Preprint IPPE-2745. Obninsk, 1998.
UDC 621.039.5
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2018, issue 5, 5:12
