PAT-1002-BRIT-PORVARCHETYPE: Brittle Optimization Trap
Deceptive Actuator Status Indicator & Silent Coolant Loss
Sub-Type: Control Command Indicator Misrepresented as Physical Valve State
VEC:AUTH:0.84•COUP:0.92•LAT:0.85•OVR:0.72
Authority Gradient
0.84
Feedback Coupling
0.92
Telemetry Latency
0.85
Override Suppression
0.72
Structural Pattern Audit Brief
Critical Multi-Node (Level 4)PAT-1002-BRIT-PORV
Nuclear reactor relief valve (PORV) sticks physically open, but control room indicator light measures only whether electrical solenoid power is cut, deceiving operators into believing the valve closed while 32,000 gallons of coolant escape.
Failure Invariant Breach
PORV_Valve (Stuck Open) -> Indicator_Light (Reported Closed) -> Operators (Turned Off High Pressure Injection) -> Partial Meltdown
Absent Safety Recovery Mechanism
Direct acoustic flow sensors or physical stem position limit switches
Fundamental Invariant Rules
INV-01:Indicator lights must measure physical position/fluid flow, never merely the electrical command sent to the actuator.
Engineered Resilience & Mitigation Strategies
MIT-01:Direct physical limit switches and acoustic pipe temperature sensors
MIT-02:Symptom-based emergency operating procedures rather than assumption-based routines
Canonical Incident Manifestations (1)
NRC-NUREG-0585Nuclear Power Generation
Three Mile Island Unit 2: Stuck-Open PORV Relief Valve & Deceptive Control Room Indicator
Telemetry indicator measured actuator electrical command rather than physical state. Decision_Nodes disabled high-pressure cooling Buffer_Reserve based on false closed-state telemetry, causing core fuel rod meltdown.
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