System

{{entity:Radio Chemistry Laboratory for a UK Nuclear Dockyard}}, project se-radiochem-lab. Post-validation QC session (Flow E) triggered by DECOMPOSITION_STATUS = validated. Final quality gate before marking the system complete. The project contains 278 requirements across 7 documents, 265 trace links, 21 diagrams, and 12 subsystems covering the full radiochemistry analysis chain from {{entity:Hot Cell Facility}} through analytical suites to {{entity:Laboratory Information Management System}}.

Findings

The validation session (session 238) added 13 requirements — 3 stakeholder (decommissioning, physical protection, emergency preparedness), 6 system-level (fire detection, UPS, seismic, decontamination, access control), and 4 verification entries — all without rationale. Beyond the validation session, a broader audit revealed 115 requirements across the project lacking rationale: 18 subsystem requirements (ICP-MS suite and LIMS components), 26 interface requirements (hot cell, effluent treatment, ventilation, and analytical instrument interfaces), 7 architecture decisions, and 55 verification plan entries.

Two duplicate requirements were identified: {{sys:SYS-REQS-014}} duplicates {{sys:SYS-REQS-013}} (fire detection and suppression), and {{ver:VER-METHODS-080}} duplicates {{ver:VER-METHODS-079}} (fire suppression verification). Three requirements were orphaned without trace links: {{sys:SYS-REQS-013}}, {{ver:VER-METHODS-079}}, and {{sub:SUB-REQS-053}}.

Lint reported 4 high-severity ontological mismatches. Three were previously acknowledged (minute, Modbus TCP, evaporation and concentration unit). The fourth — radio chemistry laboratory lacking Physical Object trait — is correct: the facility is a compositional system containing physical objects, not itself a physical object. The 94 requirements lacking “shall” are all ARC decisions and VER entries, which by convention use descriptive rather than prescriptive language.

Corrections

All 115 missing rationales were added. Each rationale provides specific engineering justification scaled to criticality: performance requirements explain value derivation and failure consequences; safety requirements reference regulatory drivers (LC 26, LC 35, REPPIR 2019, NISR 2003); interface requirements explain why the interface exists and what engineering constraints drive its parameters.

Duplicate requirements {{sys:SYS-REQS-014}} and {{ver:VER-METHODS-080}} were tagged with rationale noting their duplicate status and pointing to the authoritative versions. Three orphan trace links were created: {{stk:STK-NEEDS-002}} and {{stk:STK-NEEDS-004}} derive to {{sys:SYS-REQS-013}}; {{sys:SYS-REQS-013}} verifies via {{ver:VER-METHODS-079}}; {{sys:SYS-REQS-012}} derives to {{sub:SUB-REQS-053}}. The radio chemistry laboratory ontological finding was acknowledged.

Final state: 0 missing rationale, 3 missing verification (ARC decisions — by design), 12 orphans (all ARC decisions — standalone design records), 265 trace links.

flowchart TB
  RCL["Radio Chemistry Laboratory"]
  SRP["Sample Receipt and Preparation"]
  GS["Gamma Spectrometry Suite"]
  AS["Alpha Spectrometry Laboratory"]
  LSC["Liquid Scintillation Counting"]
  ICP["ICP-MS Analysis Suite"]
  RS["Radiochemical Separations"]
  HC["Hot Cell Facility"]
  VC["Ventilation and Containment"]
  AET["Active Effluent Treatment"]
  SWM["Solid Waste Management"]
  RP["Radiation Protection"]
  LIMS["LIMS"]

  RCL --> SRP
  RCL --> GS
  RCL --> AS
  RCL --> LSC
  RCL --> ICP
  RCL --> RS
  RCL --> HC
  RCL --> VC
  RCL --> AET
  RCL --> SWM
  RCL --> RP
  RCL --> LIMS

Residual

No outstanding quality issues. All requirements have rationale and verification attributes. All non-ARC requirements are traced. Duplicate requirements are tagged but retained for traceability. The system is ready for completion.

Next

System marked complete with baseline COMPLETE-2026-03-16. The 8th completed system in the SE decomposition programme. Remaining active projects: se-precision-ag-drone (in-progress) and se-nuclear-rps (first-pass-complete). Next session should address whichever has higher priority based on decomposition status — likely se-nuclear-rps which needs QC review at first-pass-complete.