Comparison analysis of temperature fluctuations for double jet of liquid metal cooled fast reactor

Thermal striping is one of great safety concerns for liquid metal cooled fast reactor, and its detailed analysis is thus very important for reactor design and operation. In this paper, large eddy simulation (LES) approach was employed for the accurate simulation of temperature fluctuations for thermal striping in double jet model by using FLUENT. The normalized amplitudes of temperature fluctuations of lead and Lead-Bismuth Eutectic (LBE) were obtained. Then in order to compare temperature fluctuations of lead-based reactor and that of sodium cooled reactor, the same calculation of sodium was also performed. Moreover, the power spectrum density (PSD) of temperature fluctuation of lead, LBE and sodium was analyzed by using MATLAB for investigating the dominant frequencies of temperature fluctuation of the three fluids. It is concluded that both amplitudes and frequencies of lead-based materials fluctuations are larger compared with that of sodium temperature fluctuations, and thermal striping should thus be paid more attention to in lead-based reactor than sodium cooled reactor.