University of Missouri Research Reactor LEU Fuel Element Flow Test Conceptual Design—Hydraulic Reactor Design Parameters

Abstract

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University of Missouri Research Reactor (MURR) LEU Fuel Fluid-Structure Interaction Analysis

“…The nominal flow rate per element can be calculated by dividing the total flow of 3750 GPM by the number of fuel elements (eight), which is 468.75 GPM. In addition, a 20.0% increase is suggested to envelop the various uncertainties (e.g., primary flow uncertainty, element flow disparity) of the flow rate per element, which results in 562.5 GPM [9]. This elevated flow rate of 562.5 GPM is also considered as a target test value in the planned hydraulic performance test of MURR LEU element [9].…”

“…In addition, a 20.0% increase is suggested to envelop the various uncertainties (e.g., primary flow uncertainty, element flow disparity) of the flow rate per element, which results in 562.5 GPM [9]. This elevated flow rate of 562.5 GPM is also considered as a target test value in the planned hydraulic performance test of MURR LEU element [9]. Therefore, both the nominal and the elevated flow rate per element will be analyzed in this work.…”

“…Since the coolant flows downward through the core of MURR, the inlet is at the top of the fluid domain, and the outlet is at the bottom of the fluid domain, as shown in Figure 4.5 (b). The inlet is a mass flow inlet, and the inlet mass flow rate is 29.237 kg/s, which is calculated from the volumetric flow rate per element of 468.75 GPM [9] and the inlet coolant density of 998.62 kg/m 3 (based on the inlet temperature of 49 °C [1]). The outlet is a pressure outlet, where the pressure is set to be constant at the atmosphere pressure.…”

“…As discussed in Section 4.1.2.2, the inlet mass flow rate of 29.237 kg/s is calculated using the nominal volumetric flow rate per element of 468.75 GPM. It was documented in [9] that the target test value of the planned flow test for hydraulic performance evaluation is 120% of the nominal flow rate, which is 562.5 GPM and corresponds to a mass flow rate of 35.084 kg/s, to envelope various uncertainties. In this work, simulations are performed at both the nominal flow rate (29.237 kg/s) and the higher flow rate (35.084 kg/s).…”

“…The nominal inlet flow rate of 29.237 kg/s is calculated using the nominal volumetric flow rate per element of 468.75 GPM. It was documented in [9] that the upper bounding of the flow rate per element is 120% of the nominal flow rate, which was chosen by engineering judgment to conservatively envelop the core flow uncertainty and element flow disparities due to end channel tolerance and burnup-related channel reduction. In this work, simulation is also performed at the upper bounding flow rate (35.084 kg/s).…”