Beyond the modelThe primary has reached saturation. This model is single-phase: past this point there is no steam, no void, no loss of inventory and no core uncovery, and the water properties are clamped, so the fuel is reported BETTER cooled than it would really be. Everything from here on is extrapolation.Every readout that depends on the liquid primary — coolant and fuel temperatures, primary pressure, DNBR, and the steam side fed through the generators — is now FROZEN at its last valid value and marked. Neutron power, period, the reactivity balance, xenon and decay heat keep running: their own models are still inside their range, though the Doppler and moderator feedbacks inherit the frozen temperatures' error.subcooling —
solving initial conditions…
Reactor—%
Period—s
DNBRfrozen—
T avgfrozen—°C
Steam demandthe power command — the reactor follows, there is no reactor knob
Whole sitestation-wide — reactivity in hours, and the protection system
Protection
Criticality
A nuclear power station you can walk around, run, and break — with the actual reactor physics underneath, not a scripted animation.
Point kinetics with six delayed groups, 1-D neutron diffusion for the axial power shape, xenon and samarium poisoning, radial conduction inside a fuel pellet, and a primary loop that conserves energy — all solved in your browser, 20 times a second. Drag the control rods and watch the flux deform, the fuel centreline climb, and the money move.
What it is not
An educational simulation, not engineering software and not a substitute for licensed operator training. The primary never boils, so there is no LOCA; there is no burnup, so the core never ages; and some constants are fitted to reproduce known answers rather than derived. .