A portable power unit is usually imagined as limited by how much heat it can make. It is at least as often limited by how much it can get rid of, and by how much of its own output it spends running itself.
This simulator couples a reactor core, a closed recuperated helium Brayton cycle and an air-cooled radiator, so those limits can be found rather than asserted — including the ones that are not where intuition puts them.
Where the heat goes, and what is left by the time it reaches the connector.
Reactor power, coolant flow, pressure ratio and ambient temperature are not independent knobs with independent effects. Fouling the heat exchanger costs temperature and almost no power; degrading the radiator costs power and almost no temperature. The simulator exists so that the difference can be found rather than argued about.
There is no neutronics: power follows the setpoint through a rate limiter and a lag, and reactivity is not modelled. There is no dose: the shielding view computes shell mass and narrow-beam attenuation and stops there. Past the selected material's service limit the model says it is out of range instead of reporting a number.
Fixed simulated timestep, closed-form solution each step, no random numbers and no dependence on frame rate. Scenario events fire on simulated time, so a run on a slow machine and a run on a fast one produce the same numbers at the same second.
Educational and conceptual system model. Not a safety analysis, not a licensing tool, and not a representation of any particular product.
