IEC 63147:2017

Overview

IEC 63147:2017 - Criteria for accident monitoring instrumentation for nuclear power generating stations establishes functional and design criteria for accident monitoring instrumentation used in new plant designs or when modifying existing nuclear power plants. Adopted from IEEE 497-2016, the standard defines selection, performance, qualification and display requirements for instrumentation used during anticipated operational occurrences, design-basis events and severe accidents. It applies to instrumentation needed for planned operator actions, assessing plant conditions and safety system performance, and for achieving and maintaining safe shutdown. It does not cover instruments intended solely for historical recording or maintenance.

Key topics and technical requirements

IEC 63147 organizes technical requirements into clear subject areas (see table of contents) that form the core of compliant implementations:

• Selection criteria - classification of monitoring variables (Type A through F) and documentation of selection rationale.
• Performance criteria - required range, accuracy, response time, operating time and reliability expectations for monitoring channels.
• Design criteria - requirements for single-failure tolerance, common-cause failure mitigation, independence/physical separation, isolation, calibration, testability, power supply resilience, and maintenance considerations.
• Qualification criteria - environmental and operational qualification levels for different variable types and portable instruments, plus operating time requirements.
• Display criteria - human factors and information presentation: display characteristics, trend/rate information, identification, location, ambiguity avoidance and recording/validation of digital signals.
• Quality assurance - lifecycle documentation and QA practices to support regulatory and safety cases.

The standard also includes informative annexes with accuracy guidance, example displays, operational state diagrams and references.

Practical applications and users

IEC 63147 is used by:

• Nuclear plant designers and OEMs specifying accident monitoring systems for new builds or design modifications.
• Reactor operators and plant safety engineers defining instrumentation requirements for emergency response and severe-accident management.
• Systems integrators, control-room designers and human factors engineers implementing displays and validation logic.
• Regulatory bodies and licensing reviewers evaluating instrumentation adequacy for safety cases.

Practical uses include selecting sensor types and channels for emergency monitoring, defining qualification tests, designing fault-tolerant signal paths, and specifying control-room displays for operator decision-making during abnormal events.

Related standards

• IEEE 497-2016 (original source document)
• IEC TR 63123 - to be used jointly in IAEA / IEC environments for international application and implementation guidance

Keywords: IEC 63147, accident monitoring instrumentation, nuclear power, design criteria, qualification criteria, display criteria, IEEE 497.