Scram PJ reach from the bounding-box union of:
- hot-standby box (mode_boundaries.q_shutdown)
- heatup-tight reach envelope (results/reach_heatup_pj_tight.mat)
- operation-LQR reach envelope (results/reach_operation_result.mat)
- LOCA operation envelope (results/reach_loca_operation.mat, 3s)
with precursor + temperature outliers clamped to physical bounds.
Results at probe horizons:
T=10s: 10890 sets in 480s wall — n ∈ [-8e-4, 0.047] T_c [231, 362]
T=30s: 16925 sets in 2892s wall — n ∈ [-4e-4, 0.021] T_c [229, 361]
T=60s: 23919 sets in 705s wall — n ∈ [-2e-4, 0.009] T_c [226, 359]
Monotone n decay, factor-of-5-per-minute even from the wide union.
This is the defensible scram-obligation version: starts from anywhere
the plant could plausibly be (including LOCA-perturbed operation
state), proves n decays. X_exit(scram)=n≤1e-4 still not reached in
60s — same T_max-vs-plant-decay mismatch previously flagged.
Fixed: missing Printf import that had failed the summary block on the
first run (results still computed correctly, just the final print
errored; the matwrite is after the print so the mat file wasn't
saved on that run).
Journal entry for 2026-04-21 extended with the fat-entry result +
the LOCA-reach 3s-horizon numerical-looseness apass. 38 pages.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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