Is this good for educators?

Yes — this version of "Reactor Kinetics for a fallout plume" is framed for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs.

Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Educators · Reactor Kinetics

Reactor Kinetics for a fallout plume

Built for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs. Simulate a fallout plume live below — adjust the inputs and watch it respond, right in your browser.

Reactor Point KineticsLive

power, reactivity & period

Controls

Presets

Reactivity ρ

Speed1×

A small step in reactivity does not blow the power up instantly, because a fraction of neutrons are released with a delay. Those delayed neutrons slow the response to a controllable timescale — the reactor period. But push reactivity past the delayed fraction β and it goes prompt-critical, growing on the neutron lifetime — millisecond-fast and uncontrollable.

▶ Run in Python

Data Inspector

Reactivity0.15 $

Regimedelayed (controllable)

Power1.00e+0

Governing equation

\frac{d n}{d t} = \frac{ρ - β}{Λ} n + i \sum λ_{i} C_{i} (ρ = 0.0010, β = 0.0065)

Reading this result: Positive but below β — delayed neutrons stretch the response onto a stable, controllable reactor period.

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Frequently asked questions

Is this good for educators?: Yes — this version of "Reactor Kinetics for a fallout plume" is framed for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.