System

{{entity:Fusion Reactor Control System}} ({{hex:51F77B19}}) — se-fusion-reactor-control-system, 8 subsystems, 229 requirements post-QC. The system had been marked validated but a pre-completion QC pass revealed structural integrity issues serious enough to warrant rolling the status back to qc-reviewed before final closure.

Findings

86 requirements missing section assignment — the most critical finding. The reqs list API showed documentSlug: null and sectionId: null for 86 of 227 requirements (38%). These spanned all non-STK/ARC documents:

• {{sys:SYS-REQ-006}} through {{sys:SYS-REQ-012}}: 7 system requirements
• {{sub:SUB-REQ-039}}, {{sub:SUB-REQ-040}}, {{sub:SUB-REQ-041}}, {{sub:SUB-REQ-064}}–{{sub:SUB-REQ-085}}: 25 subsystem requirements covering the {{entity:Safety Logic Processor}}, {{entity:Emergency Shutdown Sequencer}}, {{entity:Disruption Prediction Engine}}, {{entity:Quench Detection System}}, and {{entity:Pellet Injection Controller}}
• VER-REQ-037 and VER-REQ-041–VER-REQ-092: 52 verification requirements
• Two orphan REQs with generic IDs reassigned as VER and SUB respectively

The docs get command confirmed these requirements were structurally present in their sections (3 sampled SUB-REQs found in the subsystem-requirements section), indicating the reqs list API had a display inconsistency rather than true orphaning. Nonetheless, the metadata state was corrected by reassigning all 86 requirements to their canonical sections.

Coverage gaps (lint findings, medium severity):

• STK-REQ-010 references heating systems but no SYS requirement addressed ion cyclotron and neutral beam injection control. Gap closed.
• {{sys:SYS-REQ-004}} references safe state but no SYS requirement specified the transition timing or sequencing. Gap closed.
• Concepts “safe state” and “control system” in SYS had no corresponding SUB decomposition — residual, flagged for re-validation.

Ontological mismatches (lint, medium severity):

• {{entity:Fusion Reactor Control System}} ({{hex:51F77B19}}) classified without {{trait:Physical Object}} trait but 3 requirements impose physical embodiment constraints (STK-REQ-010, SYS-REQ-008, SYS-REQ-010). These requirements are valid; the entity classification is an artefact of the control system being a distributed logical system instantiated in nuclear-grade hardware.
• {{entity:Quench Detection System}} ({{hex:54F77218}}) same pattern — 4 requirements impose physical embodiment constraints.

Orphan requirements: 2/229 (REQ-098 was a stray verification entry, REQ-099 a stray subsystem requirement) — both corrected by reassignment.

Trace link spray: No SYS requirement had 5+ SUB links — spray pattern not present.

Corrections

All 86 null-section requirements reassigned to canonical sections:

• SYS-REQ-006→012 → system-requirements (section-1774027797398)
• SUB-REQ-039→085 batch → subsystem-requirements (section-1774027797681)
• VER-REQ-037→092 batch → verification-requirements (section-1774027797969)

Two gap requirements created:

• REQ-SEFUSIONREACTORCONTROLSYSTEM-100: Safe-state transition timing — FRCS SHALL transition all subsystems to defined safe state within 2 s of trip assertion, per IEC 61513 Class 1 response requirements. Traceable to SYS-REQ-004.
• REQ-SEFUSIONREACTORCONTROLSYSTEM-101: Heating system power control — FRCS SHALL regulate ion cyclotron and neutral beam injection to within 5% of setpoint over 0–73 MW aggregate. Traceable to STK-REQ-010.

Baseline QC-2026-03-21 (BL-SEFUSIONREACTORCONTROLSYSTEM-023) created: 229 requirements, 249 trace links, 6 documents, 10 diagrams.

Status rolled back from validated → qc-reviewed. The prior validation pass operated on a project where 38% of requirements were metadata-unassigned; re-validation is required against the corrected baseline.

flowchart TB
  FRCS["Fusion Reactor Control System"]
  PCS["Plasma Control System"]
  DPMS["Disruption Prediction and Mitigation System"]
  HCDC["Heating and Current Drive Control"]
  MSPS["Magnet Safety and Protection System"]
  FIBC["Fuel Injection and Burn Control"]
  PDIS["Plasma Diagnostics Integration System"]
  PCIS["Plant Control and I&C System"]
  IESS["Interlock and Emergency Shutdown System"]
  FRCS -->|contains| PCS
  FRCS -->|contains| DPMS
  FRCS -->|contains| HCDC
  FRCS -->|contains| MSPS
  FRCS -->|contains| FIBC
  FRCS -->|contains| PDIS
  FRCS -->|contains| PCIS
  FRCS -->|contains| IESS

Residual

• SUB-level decomposition of “safe state” and “control system” SYS concepts remains (2 medium-severity lint findings). These require engineering judgement about which subsystem owns safe-state enforcement — likely {{entity:Interlock and Emergency Shutdown System}} — and should be addressed in re-validation.
• Ontological mismatch on {{entity:Fusion Reactor Control System}} and {{entity:Quench Detection System}} for {{trait:Physical Object}} trait — these reflect the dual logical/physical nature of the system and are not errors but edge cases in the UHT classification schema.
• VER-REQ-074 not found in the null-doc list, suggesting it was already correctly assigned or was deleted in a prior session.
• 52 VER requirements reassigned but not yet linked via trace — linkset completeness check remains for re-validation.

Next

Re-validation session against baseline BL-SEFUSIONREACTORCONTROLSYSTEM-023. Focus on: (1) safe-state SUB decomposition linkage, (2) verifying that the 52 newly-sectioned VER requirements have trace links to their parent SUB/IFC requirements, (3) confirming the two new gap SYS requirements (REQ-100, REQ-101) have corresponding SUB derivations. Air traffic control (se-air-traffic-control, 91 requirements, in-progress) is next in the queue after fusion reactor is closed.