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Optimization of Water-to-Fuel Ratios (W/F) in Clad Cylinder Arrays. Jason E. Huffer, M.S. Washington Safety Management Solutions (WSMS) Jason.Huffer@wsms.com. Simplified Derivation: N=3, t=0. From geometry: Solve for h: Cell Area: Fuel Area:. Water-to-Fuel Ratio. Water-to-Fuel Ratio:.
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Optimization of Water-to-Fuel Ratios (W/F) in Clad Cylinder Arrays Jason E. Huffer, M.S. Washington Safety Management Solutions (WSMS) Jason.Huffer@wsms.com
Simplified Derivation: N=3, t=0 • From geometry: • Solve for h: • Cell Area: • Fuel Area:
Water-to-Fuel Ratio • Water-to-Fuel Ratio: With algebra manipulate into a function of P/R: This function can be graphed over the range of 2< P/R < 4:
Derive the Mathematical Solution Derivative from W/F Equation: Setting the above derivative to zero, multiply by the radical, and simplify:
Quadratic Attack • Isolating the radical to one side, squaring both sides and simplifying yields: Solving with the quadratic equation: Tests reveal that a Pitch-to-Radius Ratio of 3.2205 results in the maximum possible water to fuel ratio of 0.4941, justifying the bounding assumption of P/R=0.5. Now Do N= 4, 5, 6, 7, 8, 9, 10 ... N and add a clad thickness (t):
General Solutions • Handley/Huffer Pitch Optimization Equation: W/F Ratio Note: This h is not in the Paper
One complaint about the above approach was that it is just looking at the “EDGE EFFECT”. • Yes, and now we can Quantify the Edge Effect!
Varying the pitch for the above configuration of pellets with LEU (5.0 wt.% U-235) yields:
Varying the pitch for the above configuration of rods with LEU (5.0 wt.% U-235) yields Notice that the effect is damped with the addition of cladding.
Alternate Fuels • Weapons Grade (WG-MOX) Plutonium (35 wt.%) • and Natural Uranium (65 wt.%) • Reactor Grade (RG-MOX) Plutonium (35 wt.%) • and LEU Uranium w/3 wt.% U-235 (65 wt.%) Modeling the Molybdenum Boat Stacking Incident:
Conclusion • Applies to any stacked cylinder array. • Accident scenarios where spilled cylinders could pass through optimum pitch. • The analysis will have to optimize the pitch to determine maximum array reactivity.
Stephanie Corinne Huffer Memorial Scholarship Endowment Fund • North Carolina State University-Animal Sciences • No Alcohol or Illegal Drug use • Involvement in abstinence programs on campus • Tax deductible donations • Yearly “Meet and Greet” for Donors and Recipients • http://www.cals.ncsu.edu/givenow Keyword: Huffer • http://www.cals.ncsu.edu/advancement/Stephanie%20Huffer.htm