Periodicity and transversal pressure distribution in a Wire‐wrapped 19‐Pin fuel assembly

Abstract

Summary An experimental setup was designed and constructed to investigate the detailed pressure distribution data of a wire‐wrapped fuel assembly and to evaluate the friction factor correlations. The test section was a wire‐wrapped 19‐pin fuel assembly manufactured with polymethyl methacrylate, and the working liquid was deionized water. A secondary circuit supplying chilled water was built to minimize the changes in the physical properties of the working liquid induced by temperature fluctuation. Eighteen axial differential pressure drops and twelve transversal differential pressure drops with Reynolds number in the range of 3750 to 16 250 were measured. The relation between the friction factor and Reynolds number was analyzed. The results showed that the axial pressure in the edge subchannels varied periodically similar to a helical pitch. The direction of rotation and height of the wire‐wrap spacers in the subchannels have a significant effect on the transversal pressure distribution, especially in the zones where the wire‐wrap spacers cross. Besides, the Rehme correlation and Cheng and Todreas Detailed (CTD) correlation showed the best fit with the experimental data. The critical Reynolds number, where the shift from the transitional to turbulent flow regions occurs, is approximately 11 700, and the difference between the experimental data and the value predicted by the CTD correlation was approximately 8.33%. The experimental data of the pressure distribution in the wire‐wrapped fuel assembly could complement the existing database, which supports the development of fast reactors.

PIV and CFD Study on Crossflow Characteristics in a 7-Pin Wire-Wrapped Bundle Channel

“…The schematic diagram of the VHELP [18] is shown in Figure 1. The primary loop of the experimental platform is driven by a KSB main pump (pump 1).…”

“…The maximum crossflow velocity (0.12 m/s) in the xy plane is about 62.5% of the bulk velocity. According to the existing research, the pressure distribution in the wrapped wire fuel assembly changes periodically along the spiral direction of the wire [18], and it is speculated that the cross-flow velocity distribution is similar to it. The existing CFD calculation [25] confirmed that there is a periodicity of the crossflow velocity distribution in the wire-wrapped fuel assembly.…”

Applicability of RANS models and pressure drop in edge subchannels for 19-pin wire-wrapped fuel bundle channel in CiADS

“…As shown in Fig. 1 , a Visual Hydraulic ExperimentaL Platform (VHELP) was designed and built [ 30 , 31 ]. It consisted of a primary loop and a secondary loop.…”

Review of fuel assembly design in lead‐based fast reactors and research progress in fuel assembly of China initiative accelerator driven system

“…As one of the six reactor concepts of new generation nuclear energy systems selected by the Generation IV International Forum (GIF), 1 lead‐based fast reactors (LFRs), 2,3 cooled by molten lead or lead‐bismuth eutectic (LBE), with excellent neutronic properties, thermal‐hydraulic behaviors, and safety characteristics, have received worldwide extensive attention for a long time. Fuel assembly (FA) that can produce and release energy through chain fission reaction is an essential component of a reactor 4 . However, the design and development of the FA for LFRs is very complicated and challenging mainly due to the inherent special properties of the liquid heavy metal coolant, the harsh service environment, and the relative lack of experimental data and operational experience.…”