Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Development of thermohydraulic codes for modeling liquid metal boiling in LMR fuel subassemblies

Sorokin, G.A.; Avdeev, E.F. (Institute of Nuclear and Power Engineering, Obninsk, Kaluga Region (Russian Federation)); Zhukov, A.V.; Bogoslovskaya, G.P.; Sorokin, A.P. (State Scientific Center of Russian Federation, Institute of Physics and Power Engineering, Obninsk, Kaluga Region (Russian Federation))

Abstract

An investigation into the reactor core accident cooling, which are associated with the power grow up or switch off circulation pumps in the event of the protective equipment comes into action, results in the problem of liquid metal boiling heat transfer. Considerable study has been given over the last 30 years to alkaline metal boiling including researches of heat transfer, boiling patterns, hydraulic resistance, crisis of heat transfer, initial heating up, boiling onset and instability of boiling. The results of these investigations have shown that the process of liquid metal boiling has substantial features in comparison with water boiling. Mathematical modeling of two phase flows in fast reactor fuel subassemblies have been developed intensively. Significant success has been achieved in formulation of two phase flow through the pin bundle and in their numerical realization. Currently a set of codes for thermohydraulic analysis of two phase flows in fast reactor subassembly have been developed with 3D macrotransfer governing equations. These codes are used for analysis of boiling onset and liquid metals boiling in fuel subassemblies during loss-of-coolant accidents, of warming up of reactor core, of blockage of some part of flow cross section in fuel subassembly.

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key words: boiling; calculation methods; fast reactors; fuel element clusters; heat transfer; liquid metals; mathematical models; reactor cooling systems; three-dimensional calculations; two-phase flow
Reference:
Technical committee meeting on methods and codes for calculations of thermohydraulic parameters for fuel, absorber pins and assemblies of LMFR's with traditional and burner cores. Obninsk (Russian Federation) 27-31 Jul 1998
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--1157, pp:110-128