Reactor Operations · Calibrated to the inhour equation
Six-group delayed-neutron point kinetics. Dial in a reactivity step, ramp, or schedule and watch the prompt jump, the delayed-neutron-controlled rise, and — cross $1.00 — the collapse into prompt criticality.
Feedback is a single lumped-temperature node — no spatial distribution, no real thermal-hydraulics, no coolant flow dynamics. α/K_heat/k_cool/T_coolant/T0 are illustrative defaults, not plant-specific values.
Six delayed-neutron precursor groups feed the neutron population alongside the prompt term. Below prompt critical (ρ < β) the precursors set the pace and the reactor settles into a stable period after a fast initial prompt jump. At ρ = β exactly — $1.00 — the prompt term takes over and the period collapses toward Λ; above it, power diverges on the prompt-neutron timescale alone.
| Group | βi | λi (s⁻¹) | half-life |
|---|---|---|---|
| β total | — | ||
Six-group U-235 thermal delayed-neutron data from Keepin (1965), Physics of Nuclear Kinetics, reproduced in DOE-HDBK-1019/1. Λ = 1×10⁻⁴ s is the NRC HRTD §2.1 order-of-magnitude figure, editable above (advanced). Stable-period and SUR readouts are solved from the inhour equation ρ(T) = Λ/T + Σ βi/(1+λiT), independently re-derived and checked against this table by verify-kinetics.js.
Recomputed live from the constants above via the inhour equation — nothing here is hard-coded. This is the pre-verified stable-period/reactivity table; the regression harness cross-checks the same numbers against the tool's own RK4 solver, not just this algebra.
| Stable period T | Reference reactivity | This model | Error |
|---|
Source: NRC HRTD §2.1 reactivity/period relationship, reproduced from the inhour equation with the Keepin data and Λ = 1×10⁻⁴ s.