Design Blueprint: A Fission Surface Power Unit with Free-Piston Stirling Conversion Sized from Its Waste-Heat Budget

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24188988): This study sizes a fission surface power unit delivering 40.0 kilowatts of electricity through free-piston Stirling conversion at an efficiency of 0.25, requiring 160 kilowatts of reactor thermal power and rejecting 120 kilowatts of waste heat through a radiator at 400 kelvin with an area of 91.9 square metres. Uranium-235 consumption is 0.06 kilograms per year, or 0.6 kilograms over a ten-year operating life. Sizing follows from computed energy and thermal budgets derived in the study. This is a computed study with no targeting or weapon application. The work is simulated and computed from stated assumptions, not measured. Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.