Renovation of the ventilation instrumentation and control system of a nuclear research site

Industrial control systems Nuclear France

Context and challenges

This client is a leader in the nuclear research sector. Its facilities include a particle accelerator complex consisting of above-ground buildings, tunnels and, in particular, a 27 km collider with its experiment caverns. The control of the air conditioning and ventilation in these facilities directly affects the performance of the machine and the experiments.

The system includes 500 functional units, a mix of underground infrastructures (at a depth of 100 to 150 m) and surface units. It controls the air conditioning and ventilation, as well as some safety functions related to smoke extraction from the tunnels.

This set is controlled by almost 200 PLCs (Programmable Logic Controllers) within a centralised system infrastructure requiring control devices distributed in the various control rooms and technical areas. To ensure long system life and mitigate component obsolescence, it was necessary to renovate the system.

This customer asked Assystem to renovate the instrumentation & control system and provide long-term (10 years) maintenance for the renovated system.

Project scope

  • Initial audit of the instrumentation of the existing units
  • Safety analysis of safety-related functions (smoke extraction, etc.)
  • Set up of a programming standard for the HMIs (Human-Machine Interfaces) and for the automated functions (based on functional models in LogSim)
  • Replacement of 40 Siemens S5 PLCs with S7 PLCs to control ventilation units
  • Architecture design based on VMWare virtualisation solutions and advanced hot redundancy functionality by PCVue
  • SCADA integration of the units controlled by the 40 renovated PLCs and by 150 existing PLCs:
    • 1200 displays, 85,000 tags, 20,000 alarms
    • PCVue SCADA infrastructure with redundancy based on an Oracle database
    • 20 WTS (Windows Terminal Server) clients, 8 thick clients and Webvue clients
    • Local industrial HMIs via Siemens TP177 touch panels
    • Fireman's switch boxes to control the forced operating modes for emergency situations
    • VMWare virtualisation mechanisms
    • Communication via Ethernet/Profibus gateways
    • OPC (Open Platform Communications) data exchange
    • Performance characteristics: less than 2 s per command and less than 5 s per alarm
  • Drawing up the overall validation strategy
  • Platform and on-site testing, deployment of system components, training of users and maintenance personnel

Client benefits

  • Rationalisation of operations and maintenance via the implementation of a uniform solution based on dedicated automation and imaging standards
  • High system availability thanks to high-performance architecture based on advanced virtualisation and redundancy mechanisms
  • Meeting a schedule constrained by intensive coactivity and critical deadlines related to the machine start-up
  • Impressive stability of the system following its commissioning thanks to the overall validation strategy implemented (many tests during the integration phase, to reduce the number of post-commissioning failures as much as possible).

In figures


functional units


programmable Logic Controllers


graphical operating displays

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