A light-water reactor delivers an electrical power at a thermal efficiency and a…
PHYSICS · Multi-part · Fermi University Physics · Thermal, Statistical & Complex Systems · Nuclear Physics · Temperature, heat and the macroscopic behaviour of matter
Energy from Physics, Ch Running a reactor: kinetics, heat removal, feedback, burn-up and the fuel cycle
Problem
A light-water reactor delivers an electrical power Pe=1.2GWe at a thermal efficiency ηth=Pe/Pth=0.34 and a capacity factor CF=0.92. Its core-average linear heat rate is qˉ′=18kWm−1 in UO2 fuel of thermal conductivity kth=3Wm−1K−1, and each fuel rod has an active length of 3.66m. The fuel is discharged at a burn-up of B=50GWdt−1, enriched from natural uranium of assay xf=0.711% to a product assay xp=4.2% at a tails assay xt=0.20%, in a centrifuge plant using 50kWh per SWU. Assume steady annual operation at the stated power and capacity factor, a uniform core-average linear heat rate equal to qˉ′, and a once-through fuel cycle with no reprocessing.
((a)) Find the reactor's thermal power Pth.
((b)) Find the total length of fuel rod needed to carry Pth at qˉ′, and the number of rods this represents.
((c)) Find the fuel centreline temperature rise above the rod's outer surface at the average linear heat rate.
((d)) Find the feed-to-product mass ratio F/P and the separative work per kilogram of product, in SWU.
((e)) Find the mass of fuel reloaded each year, the mass of natural uranium this requires, the total separative work used per year, the energy this enrichment consumes, and this energy as a percentage of the electricity generated in that year.