DOI: 10.55176/2414-1038-2020-2-150-172

Authors & Affiliations

Sorokin A.P.1, Ivanov Eu.F.1, Kuzina Ju.A.1, Denisova N.A.1, Nizovtsev A.A.1, Privezentsev V.V.1, Sorokin G.A.2
1A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
2Moscow Institute of Physics and Technology, Moscow, Russia

Sorokin A.P.1 – Chief Researcher, Dr. Sci. (Tech.). Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7 (484) 399-84-47; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Ivanov E.F.1 – Leading Researcher, Cand. Sci. (Tech.).
Kuzina Ju.A.1 – Deputy Director General — Director of Nuclear Energetic Department, Cand. Sci. (Tech.).
Denisova N.A.1 – Leading Engineer; Nizovtsev A.A.1 – Head of Laboratory.
Privezentsev V.V.1 – Leading Researcher, Cand. Sci. (Tech.).
Sorokin G.A.2 – Associate Professor of Department of Corporate Information Systems, Cand. Sci. (Tech.).

Abstract

Studies of the boiling of alkali metals show that, compared with boiling water, the process of boiling liquid metals has significant features. Cooling of a fuel assembly in accident conditions when accident protection is triggered and circulation pumps are switched off (ULOF) leads to the study of fuel elements cooling at reduced coolant flow rates or even tipping circulation in fuel assemblies. There is only limited data on the boiling of sodium in fuel assemblies in these regimes. The results of a series of experiments on heat transfer and stability of circulation during boiling of a sodiumpotassium alloy on single fuel assembly models and in a parallel fuel assembly system with natural coolant circulation performed at JSC “SSC RF — IPPE” are presented. The results of comparing the data of the calculated and experimental studies are presented. The influence of the surface roughness of the fuel rods on the heat transfer and flow regimes during boiling of a liquid metal in bundles is demonstrated. The results of experimental studies of heat transfer during boiling of sodium in natural and forced convection regimes in a fuel assembly model with a "sodium cavity" located above the reactor core intended to compensate for the positive sodium void reactivity effect in emergency situations with sodium boiling are also presented. It is shown that it is possible to provide continuous sodium cooling of fuel element simulators in fuel assemblies under these conditions. The results of the generalization of data on heat transfer during boiling of liquid metals in bundles and a cartogram of the regimes of two-phase flow during boiling of liquid metals in bundles are presented. The objectives of further research are discussed.

Keywords
fast neutron reactor, accident, fuel rod assembly, alkali metals, boiling, two-phase flow, heat transfer, stability of circulation, heat transfer crisis, flow regimes, cartogram regimes, roughness, sodium cavity

Article Text (PDF, in Russian)

References

621.039.526.034+621.039.546.8:536.26

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2020, issue 2, 1:14