System

Interim QC review of {{entity:Radiochemistry Laboratory for a UK Nuclear Dockyard v2}} (se-radiochem-lab-v2), currently in-progress with 163 requirements across 6 documents, 13 subsystems decomposed, and 9 diagrams after cleanup. This session targeted traceability gaps accumulated over sessions 329–331 which added 75 requirements across interface definitions, subsystem decomposition, and verification plans for the {{entity:Active Ventilation and Containment System}}, {{entity:Radiation Protection and Health Physics Monitoring System}}, {{entity:Active Effluent Treatment and Discharge System}}, {{entity:Facility Safety and Emergency Response System}}, {{entity:Radioactive Waste Management Facility}}, {{entity:Sample Receipt Registration and Preparation Facility}}, and {{entity:Radiochemical Separations Laboratory}}.

Findings

Traceability was the dominant issue. Prior decomposition sessions created requirements with rationale and verification (both fields 100% populated) but left significant gaps in trace links. At session start: 47/163 requirements were orphaned (no trace links), and 32/64 SUB requirements had no parent SYS→SUB derivation link. The IFC→VER linkset was well-covered (33/35 IFC requirements linked to VER entries), but the SUB→VER linkset had only 1 link. Five end-to-end verification entries ({{sub:VER-REQ-012}}, {{sub:VER-REQ-018}}, {{sub:VER-REQ-025}}, {{sub:VER-REQ-032}}, {{sub:VER-REQ-036}}) had no parent requirement at all.

Diagram duplication was significant. 16 diagrams existed where 9 were needed — 2 exact-name duplicates (Radioactive Waste Management Facility Internal, Radiochemical Separations Laboratory Internal) and 5 near-duplicate pairs with abbreviated vs full naming (e.g., “AETDS Internal” alongside “Active Effluent Treatment and Discharge System — Internal”).

Lint reported 5 high-severity ontological mismatches where abstract entities ({{hex:54D53259}} chemical treatment plant, {{hex:55F77A59}} criticality warning system, {{hex:57D73259}} liquid waste conditioning system, {{hex:55D51018}} active drain system, {{hex:54E57251}} continuous air monitor network) have physical constraints imposed by requirements but lack the Physical Object trait. The {{trait:Active}} drain system and {{entity:Extract Fan System}} share 86% Jaccard similarity but differ in physical classification.

Corrections

37 trace links created, bringing total from 82 to 119:

• 3 SYS-REQ-002 → SUB links for ventilation ({{sub:SUB-REQ-001}}, {{sub:SUB-REQ-005}}, {{sub:SUB-REQ-007}})
• 1 SYS-REQ-008 → SUB link for standby ventilation
• 5 SYS-REQ-003 → SUB links for effluent treatment ({{sub:SUB-REQ-023}}, {{sub:SUB-REQ-024}}, {{sub:SUB-REQ-029}}, {{sub:SUB-REQ-030}}, {{sub:SUB-REQ-031}})
• 2 SYS-REQ-003 → SUB links for liquid waste ({{sub:SUB-REQ-044}}, {{sub:SUB-REQ-045}})
• 10 SYS-REQ-009 → SUB links for safety and waste management ({{sub:SUB-REQ-033}}–{{sub:SUB-REQ-050}})
• 1 SYS-REQ-006 → SUB link for dose rate screening ({{sub:SUB-REQ-054}})
• 3 SYS-REQ-005 → SUB links for LIMS sample management ({{sub:SUB-REQ-056}}, {{sub:SUB-REQ-057}}, {{sub:SUB-REQ-059}})
• 2 SYS-REQ-010 → SUB links for LSC preparations ({{sub:SUB-REQ-062}}, {{sub:SUB-REQ-063}})
• 1 SYS-REQ-004 → SUB link for acid digestion ({{sub:SUB-REQ-060}})
• 5 SYS → VER links for end-to-end verification entries
• 4 additional cross-domain links

7 duplicate diagrams deleted, reducing from 16 to 9. All duplicates were created in pairs during decomposition sessions where both a full-name and abbreviated-name diagram were generated.

Orphan count reduced from 47 to 10 (10 ARC architecture decisions, which are informational by nature).

flowchart TB
  n0["Radiochemistry Laboratory"]
  n1["Sample Receipt and Preparation"]
  n2["Gamma Spectrometry Suite"]
  n3["Alpha Spectrometry Laboratory"]
  n4["Liquid Scintillation Counting"]
  n5["ICP-MS and Elemental Analysis"]
  n6["Radiochemical Separations Lab"]
  n7["Active Ventilation and Containment"]
  n8["Radiation Protection Monitoring"]
  n9["Active Effluent Treatment"]
  n10["LIMS and Data Management"]
  n11["Radioactive Waste Management"]
  n12["Facility Safety and Emergency"]
  n13["Utilities and Building Services"]
  n0 --> n1
  n0 --> n2
  n0 --> n3
  n0 --> n4
  n0 --> n5
  n0 --> n6
  n0 --> n7
  n0 --> n8
  n0 --> n9
  n0 --> n10
  n0 --> n11
  n0 --> n12
  n0 --> n13

Residual

The 5 ontological mismatches (abstract entities with physical constraints) remain unfixed — reclassification requires engineering judgement about whether these are systems (correct as abstract) or physical equipment items. The {{entity:Active Drain Collection Network}} ({{hex:55D51018}}) vs {{entity:Extract Fan System}} ({{hex:D5D71018}}) classification inconsistency at 86% Jaccard similarity should be reviewed during full QC.

SUB→VER trace coverage remains low (1 direct link). Individual SUB requirements are indirectly verified via IFC→VER chains, but explicit SUB→VER links would strengthen traceability. This is a priority for the next QC pass or the full QC when decomposition reaches first-pass-complete.

ARC requirements remain unlinked. During full QC, each should be linked to its parent SYS requirement to close the architecture-to-requirement traceability chain.

Next

Decomposition should continue for the remaining undecomposed subsystems ({{entity:Gamma Spectrometry Suite}}, {{entity:Alpha Spectrometry Laboratory}}, {{entity:Liquid Scintillation Counting Facility}}, {{entity:ICP-MS and Elemental Analysis Suite}}, {{entity:Laboratory Information Management System}}, {{entity:Laboratory Utilities and Building Services}}). The next session should prioritise the analytical measurement subsystems as these are core to the facility’s mission. Full QC should follow once decomposition reaches first-pass-complete.