System

Radio Chemistry Laboratory for a UK Nuclear Dockyard — {{entity:Laboratory Information Management System}} decomposition, the final subsystem in the first-pass decomposition. Status advanced from in-progress to first-pass-complete. The project now contains 257 requirements across 6 documents, 100 classified entities, 91 PART_OF relationships, and 100 CONNECTS facts.

Decomposition

The {{entity:Laboratory Information Management System}} ({{hex:50AD7B58}}) was the last undecomposed subsystem — and architecturally the most cross-cutting, with 11 other subsystems feeding data into it. It was decomposed into 8 components reflecting the real structure of a LIMS serving a UKAS-accredited nuclear analytical laboratory:

• {{entity:LIMS Central Database Server}} ({{hex:50853158}}) — high-availability Oracle/SQL Server cluster with 30-year retention for ONR LC28 compliance
• {{entity:Instrument Data Acquisition Gateway}} ({{hex:50A57118}}) — middleware bridging 15+ instruments from Canberra, Agilent, PerkinElmer, and Ortec via TCP/IP, RS-232, and file exchange, with 72-hour store-and-forward buffering
• {{entity:Sample Tracking and Chain of Custody Module}} ({{hex:40B57B58}}) — real-time sample lifecycle management across 12 laboratory zones with fissile material inventory tracking per area
• {{entity:Results Validation and Reporting Engine}} ({{hex:50E77B58}}) — GUM uncertainty propagation, MDA per ISO 11929, two-stage review workflow for ISO 17025
• {{entity:Quality Assurance and Audit Trail Module}} ({{hex:40A57B58}}) — Shewhart/CUSUM control charts, instrument lockout on 3-sigma exceedance, tamper-proof audit trail per MHRA Annex 11
• {{entity:Regulatory Compliance and Discharge Reporting Module}} ({{hex:40A77B59}}) — cumulative discharge tracking against EA permit limits with 80%/90% alerts, REPPIR reporting
• {{entity:LIMS Network Infrastructure and Cybersecurity Layer}} ({{hex:50A53858}}) — physically segregated network per NIS Regulations and NCSC CAF, encrypted backups with 4-hour RPO
• {{entity:LIMS Operator Workstation Array}} ({{hex:D68D1018}}) — sealed keyboards in active areas, glove-compatible keyboard-only navigation, role-based access with 4 distinct roles

flowchart TB
  DB["LIMS Central Database Server"]
  IDAG["Instrument Data Acquisition Gateway"]
  ST["Sample Tracking Module"]
  RV["Results Validation Engine"]
  QA["QA and Audit Trail Module"]
  REG["Regulatory Reporting Module"]
  NET["Network and Cybersecurity Layer"]
  WS["Operator Workstation Array"]
  IDAG -->|validated instrument data| DB
  ST -->|sample records| DB
  RV -->|authorised results| DB
  QA -->|audit trails| DB
  REG -->|regulatory queries| DB
  WS -->|client sessions| NET
  NET -->|authenticated connections| DB
  IDAG -->|raw analytical data| RV
  ST -->|sample metadata| RV
  RV -->|authorised results for aggregation| REG
  QA -->|calibration status| IDAG

The key architectural decision ({{sub:ARC-DECISIONS-012}}) documents why a centralised client-server architecture was chosen over distributed/microservices — data consistency and audit trail integrity outweigh scalability for a bounded-throughput laboratory. The instrument gateway is separated as a distinct middleware component rather than relying on each vendor’s native LIMS integration, creating a single point of protocol translation and store-and-forward buffering across the heterogeneous instrument fleet.

Analysis

With the LIMS decomposition complete, all 12 subsystems of the {{entity:Radio Chemistry Laboratory for a UK Nuclear Dockyard}} have been decomposed into components with PART_OF and CONNECTS relationships. Lint reports 5 findings: 3 high-severity ontological mismatches on context fragments (“minute”, “modbus tcp”, “evaporation and concentration unit”) — all acknowledged as classification artifacts rather than real engineering issues. The 82 requirements lacking “shall” are correctly all ARC decisions and VER entries. 13 orphaned requirements: 12 ARC decisions (which are design records, not traceable requirements) and {{sub:SUB-REQS-053}} which needs a trace link to {{sys:SYS-REQS-012}}.

VER coverage stands at 70/155 (45%) of SUB+IFC requirements — below the 50% target. The QC session should close this gap, particularly for the LIMS subsystem requirements which currently have no VER entries beyond the 5 IFC verifications created this session.

Requirements

12 subsystem requirements ({{sub:SUB-REQS-094}} through {{sub:SUB-REQS-105}}) cover database availability (99.9%, 60s failover), 30-year data retention, instrument gateway store-and-forward buffering (72 hours), sample tracking with 30-second custody transfer recording, two-stage results review workflow, GUM uncertainty calculation at k=2, tamper-proof audit trail, discharge permit tracking with 80%/90% alerts, network segregation with 4-role RBAC, backup with 4-hour RPO and 8-hour RTO, fissile material inventory tracking with 80% threshold alerting, and contamination-resistant workstations.

5 interface requirements ({{ifc:IFC-DEFS-048}} through {{ifc:IFC-DEFS-052}}) define the internal LIMS data flows: instrument gateway to database (ACID transactions, 50 records/min), sample tracking to results engine (referential integrity enforcement), results engine to regulatory module (read-only database views), QA module to instrument gateway (control chart lockout), and workstation to network (TLS 1.2+ mutual auth, 15/30-minute session timeouts).

All 5 IFC requirements have corresponding VER entries ({{sub:VER-METHODS-066}} through {{sub:VER-METHODS-070}}) with quantified pass/fail criteria.

Next

First-pass decomposition is complete. The next session should be a full QC review (Flow C, DECOMPOSITION_STATUS = first-pass-complete) focusing on: closing the VER coverage gap to 50%+, adding VER entries for the 12 LIMS SUB requirements, linking orphan {{sub:SUB-REQS-053}}, and reviewing all 257 requirements for testability and completeness. The Gamma Spectrometry Suite has only 5 requirements tagged gamma-spec and may need additional subsystem requirements during QC.