▶ DRAWING BOARD — inputs
Solve the point-reactor-kinetics ODEs live. Adjust reactivity, the delayed fraction β, and the prompt generation time Λ; the power transient redraws.
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▶ POWER TRANSIENT — P(t) / P₀
Logarithmic power axis. Time window auto-fits the response. Readouts: prompt jump, asymptotic reactor period, final power ratio.
- reactivity ρ
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- prompt jump
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- stable period T
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- P/P₀ at tend
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- regime
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▶ WHAT THIS ILLUSTRATES
The point-reactor-kinetics equations track a spatially-lumped neutron population n (∝ power) coupled to delayed-neutron precursor concentrations ci:
dn/dt = ((ρ − β)/Λ)·n + Σ λ_i·c_i dc_i/dt = (β_i/Λ)·n − λ_i·c_i
Reactivity ρ is entered in dollars ($ = ρ/β). At ρ = 1$ the reactor is prompt critical — power runs away on the prompt-neutron timescale Λ. Below that, delayed neutrons (the β term) set a controllable reactor period. This is the dynamic core that big finite-element / Monte-Carlo codes solve at full spatial fidelity:
- MOOSE (Idaho National Lab) — the multiphysics finite-element framework whose reactor-physics apps (Griffin / Rattlesnake) solve the time-dependent neutron transport this toy lumps into one point. mooseframework.inl.gov ↗
- IAEA ONCORE — the IAEA initiative promoting open-source reactor-analysis codes (OpenMC) for member-state R&D and training. iaea.org/…/oncore ↗
- OpenMC — open-source Monte Carlo particle transport; the kind of code ONCORE teaches for criticality & transient analysis. openmc.org ↗