Experimental Investigation on Resistance Characteristics of Wire-Wrapped Fuel Assembly in Lead-Bismuth Eutectic

Aiming to support the design and construction of CLEAR-I, a series hydraulic experiments were performed in KYLIN-II forced circulation thermal-hydraulic loop. In this paper, the flow resistance experiments of full scale fuel assembly were performed. It could be concluded that the pressure drop of the fuel assembly showed a good agreement compared to the experimental results with reactor design value. The maximum relative deviations were only around 6%. The friction factor of the wire-wrapped rod bundle was also measured and compared to the empirical relationship and former experimental results performed in water loop. The results showed that the Novendstern model was more suitable for this rod bundle than Rehme model, and the relative deviation is around 14%. Based on the Reynolds similarity, the friction factor results in water were larger than the values in LBE. That is because at the same Reynolds number, the secondary flow induced by helical wires in water was stronger than that in LBE.