EAL classification rules¶

Emergency Action Level (EAL) thresholds per NEI 99-01, encoded as deterministic predicates the eal_classify tool evaluates against a scenario's projected time-series state.

Predicate grammar (v1) — single-tag comparisons with optional DURATION dwell, composed with AND / OR and explicit parens:

«TAG» <op> <value> [for >= <duration>]

<op> ∈ { <, >, <=, >=, ==, != }
<value> is a number, quoted string, or bareword
DURATION units: s (seconds), min (minutes), h (hours)

Rules below are organised by class (UE → Alert → SAE → GE). Each row must declare a unique IC code within its class. Rules marked ic: manual are placeholders for ICs the v1 grammar cannot yet express (set-of-conditions, multi-tag correlations) — these are evaluated by an operator, not by the classifier.

Unusual Event¶

ic	predicate	source
SU4	`«PT-455» < 1815`	NEI 99-01 SU4 (RCS leakage / inventory loss)
SU8	`«CTMT-PR» > 3`	NEI 99-01 SU8 (containment pressure indication)
HU1	`«BUS-A-EMERG» == DEAD AND «BUS-B-EMERG» == DEAD for >= 15 min`	NEI 99-01 HU1 (loss of all offsite AC ≥ 15 min)

Alert¶

ic	predicate	source
SA1	`«NIS-PR-AVG» > 50 AND «TRIP-BKR-A» == CLOSED AND «TRIP-BKR-B» == CLOSED`	NEI 99-01 SA1 (RPS failure to scram — ATWS surrogate predicate: power > 50% with trip breakers still closed)
SA5	`«PT-455» < 1500`	NEI 99-01 SA5 (significant RCS depressurization)
HA1	`«BUS-A-EMERG» == DEAD AND «BUS-B-EMERG» == DEAD for >= 30 min`	NEI 99-01 HA1 (extended loss of AC ≥ 30 min)
SA9	`«CTMT-RAD» > 100`	NEI 99-01 SA9 (containment radiation rise)

Site Area Emergency¶

ic	predicate	source
SS3	`«CET-AVG» >= 1200 for >= 15 min`	NEI 99-01 SS3 (core exit thermocouples ≥ 1200 °F sustained)
HS1	`«BUS-A-EMERG» == DEAD AND «BUS-B-EMERG» == DEAD for >= 1 h`	NEI 99-01 HS1 (loss of all AC ≥ 1 hour)
SS5	`«CTMT-RAD» > 1000`	NEI 99-01 SS5 (high containment radiation, fuel-clad damage)

General Emergency¶

ic	predicate	source
SG1	`«CET-AVG» >= 1200 for >= 30 min AND «CTMT-RAD» > 1000`	NEI 99-01 SG1 (core damage + containment radiation indicates release path)
HG1	`«BUS-A-EMERG» == DEAD AND «BUS-B-EMERG» == DEAD for >= 4 h`	NEI 99-01 HG1 (SBO ≥ 4 hours)

Notes¶

Predicates are deterministic and time-aware. A DURATION clause resets if the underlying comparison is violated for any sample in the series — addressing the post-Fukushima emphasis on sustained-condition EALs.
The classifier returns the highest class reached over the scenario timeline, with the moment first reached + the IC code that triggered it. NEI 99-01's persistence rule ("once SAE is declared, it persists until termination criteria are met") is preserved.
Tags used in predicates must exist in the canonical tag catalogue. The wiki validator enforces this at build time.
This rule table is the source of truth for eal_classify. Build step emits _eal-rules.json next to _manifest.json; samsinn fetches the JSON.

References¶

NEI 99-01 Revision 6: Methodology for Development of Emergency Action Levels
10 CFR 50.47 (Emergency planning)
NUREG-0654 Revision 1 (Criteria for preparation and evaluation of radiological emergency response plans)