Overview
IEC 62646:2012 – Nuclear Power Plants – Control Rooms – Computer Based Procedures is an international standard developed by the International Electrotechnical Commission (IEC) to establish requirements for the entire life cycle of operating procedures intended for computerisation in nuclear power plant (NPP) control rooms. This standard guides designers in deciding which operating procedures are suitable for digital transformation into Computer Based Procedures (CBPs), and to what extent such computerisation should be implemented. IEC 62646:2012 focuses on leveraging digital technologies for enhancing operator performance, increasing safety, and improving plant availability.
The standard addresses the integration of CBPs into the main control room (MCR) and other operational environments, providing a framework for the policy, design, deployment, and maintenance of these digital procedures. It also outlines human factors considerations, safety requirements, and the interaction between operators and computerised systems.
Key Topics
1. Computerisation Policy and Decision-Making
- Establishes a systematic policy for deciding which procedures should be computerised in NPP control rooms.
- Defines different "families" of Computer Based Procedures based on their features and guidance levels.
- Emphasizes the need to consider human capabilities, plant operation experience, and technological factors.
2. CBP System and Functional Requirements
- Specifies technical and functional requirements for the digital systems that process and display CBPs.
- Outlines safety and non-safety requirements, as well as requirements for system redundancy and backup in the event of CBP system failure.
- Highlights the importance of continuous operator involvement to maintain human oversight and knowledge.
3. Use and Integration of CBP
- Provides recommendations for using CBPs inside and outside the MCR, including in hybrid or conventional control room setups.
- Covers the interplay between computer-based and paper-based procedures, ensuring smooth transitions and effective backup strategies.
4. Human Factor Engineering
- Sets out principles for integrating human factors into CBP design, focusing on information presentation, navigation, user guidance, and support for both primary and secondary operator tasks.
- Stresses the importance of maintaining ergonomic and intuitive user interfaces for operators.
5. CBP Life Cycle Management
- Details the process from initial project setup, design, verification, and validation through deployment, maintenance, and operator training.
- Ensures that CBPs are kept up to date and that operational staff are proficient in their use.
Applications
IEC 62646:2012 is intended for a range of stakeholders in nuclear power plant operations, including:
- Control Room Designers: Applying the standard ensures the safe and effective computerisation of operational procedures.
- Plant Operators and Utility Staff: Supports more effective and guided operation, especially in complex or abnormal scenarios.
- Systems Evaluators and Regulatory Authorities: Provides a common framework for assessing procedural computerisation and safety compliance.
- I&C System Architects: Aids in integrating CBPs with existing Instrumentation and Control (I&C) architectures without compromising safety or operational continuity.
Typical practical applications include:
- Transitioning from paper-based to computerised procedures in new or retrofitted NPP control rooms.
- Enhancing operator situational awareness and error reduction through better information and guidance systems.
- Supporting regulatory compliance and uniform implementation of operating procedures across international projects.
Related Standards
IEC 62646:2012 is part of a broader suite of standards for nuclear power plant control rooms and I&C systems. Notable related standards include:
- IEC 60964: Control rooms – Design
- IEC 61839: Design of control rooms – Functional analysis and assignment
- IEC 61513: Instrumentation and control important to safety – General system requirements
- IEC 60880: Software aspects for computer-based systems performing category A functions
- IEC 62138: Software aspects for category B or C functions
- IEC 62645: Nuclear power plants – Cybersecurity
- ISO 11064 series: Ergonomic design of control centres
These standards collectively address aspects of safety, software reliability, ergonomic design, function allocation, and cybersecurity for nuclear plant control environments.
By following IEC 62646:2012, organizations can ensure that the development, implementation, and maintenance of Computer Based Procedures in nuclear power plant control rooms meet international best practices, enhancing safety, efficiency, and regulatory compliance.