Verification of the safety control system for nuclear waste logistics & handling

Context:
In the buildings for storage, internal transport and controlled treatment of radioactive waste, safety relies on a coordinated safety control system: conveyors, lifting/handling systems and valves must come together in a single safety matrix with the main PLC. The operator requested a demonstrable verification of these safety functions.

Approach:

Prohead Engineering carried out a document-based and on-site verification (best practice from IEC 61511 and EN ISO 13849-1/-2):

• Document review & traceability:
  Matching the risk assessment, safety requirements, safety matrix and PLC implementation. Check of emergency stop chains, interlocks, reset philosophy, diagnostic tests and safe states.
• Logic and interfacing check:
  Cross-check with interlock and alarm lists, IO lists and network plan. Particular attention to cross-line functions (e.g. blocking between logistics sections and guards/gates).
• On-site verification & test protocol:
  Practical tests for stop category, hold-to-run, restart conditions and fault injection tests; recording of findings with prioritisation and MOC flow.
• RAM perspective:
  Assessment of the reliability, availability and maintainability of safety-critical components; recommendations for fault detection, redundancy and spare parts policy.

Result:

• Verification reports per subsystem (logistics, handling, main PLC).
• List of corrective actions (e.g. clarified reset sequences, additional diagnostics, redundancy where needed).
• RAM recommendations with impact on availability and maintenance.

The operator has a traceable, verifiable verification file that demonstrates both compliance and practical operational reliability — crucial in an environment where the safe handling and control of nuclear waste are paramount.