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.
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. .