A free online nuclear reactor simulator and operator academy

THE CONTROL ROOM puts you at the panel of a full-scale pressurized water reactor — real point-kinetics physics with six delayed-neutron groups, xenon and samarium poisoning, decay heat, thermal-hydraulics, and a protection system with authentic trips and permissives. It runs entirely in your browser: no download, no signup, no cost. Your progress saves locally as you work from first shift to a Master Operator license.

The course — 14 units, 100+ lessons, challenges, and exams

0. Welcome to the Control Room — your first shift at a 3,411-megawatt pressurized water reactor.
1. The Atom and the Chain Reaction — what fission is, why it releases so much energy, and how neutrons make it a chain.
2. Criticality — reactivity, the delayed-neutron miracle, and your first criticality, by hand.
3. The Reactor That Steers Itself — feedback: why a PWR fights fire with physics before any human or computer reacts.
4. The Poisoned Core — xenon-135: the isotope that schedules your shifts and once trapped Chernobyl.
5. Heat, Water, and the Edge of Boiling — thermal-hydraulics: moving 3,411 MW without ever quite boiling.
6. The Plant Beyond the Core — steam, spinning iron, and why the reactor answers to the turbine.
7. Instruments and Interlocks — the plant's senses, the trip table, and the art of not being fooled.
8. The Grand Startup — cold iron to the grid: the full startup, your hands on everything.
9. Defense in Depth — barriers, backups, and the engineering of never-just-one-mistake.
10. Breaking the Plant — reactivity accidents, tube ruptures, blackouts, and the trips that catch them.
11. The Casebook — ten real accidents, replayed with you at the panel.
12. A World of Reactors — BWR, CANDU, gas, sodium, salt, naval, SMR: same physics, different bargains.
13. The License — a startup exam, two blind diagnosis drills, and the master exam.

Case studies of real nuclear accidents

Replay history from the operator's chair: SL-1, NRX, Windscale, Fermi-1, Browns Ferry, Three Mile Island, Chernobyl, Davis-Besse, Tokaimura, and Fukushima — each rebuilt in the simulator with the causal chain intact.

Eight reactor designs

Operate the reference PWR, then a BWR, CANDU, RBMK, a gas-cooled reactor, a sodium fast reactor, a molten salt reactor, a naval propulsion plant, and a small modular reactor — the same physics engine, retuned to each design's real parameters.

More tools and games at titanmiller.net, including CLOSED LOOP, the sister academy on PID control.