Overview
IEC TR 63400:2025, published by the International Electrotechnical Commission (IEC), provides a comprehensive overview of the structure and relationships of the IEC SC 45A standards series. Focused on instrumentation, control, and electrical power systems important to safety in nuclear facilities, this technical report is essential for professionals seeking to understand how SC 45A standards are organized, how they interrelate, and their links with key documents from other major standards bodies such as the IAEA, ISO, and IEEE.
This second edition reflects updates made to the SC 45A portfolio between 2021 and 2025, including advances in areas like artificial intelligence applications for nuclear facilities. By clarifying the hierarchical structure and providing guidance on the use and development of these standards, IEC TR 63400:2025 facilitates consistent implementation and helps users navigate both existing and newly published standards within the nuclear safety and security fields.
Key Topics
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Hierarchy of IEC SC 45A Standards
The series is structured in four levels, from general requirements at the top to topic-specific standards and technical reports at lower levels.
- Level 1: Core system-level standards such as IEC 61513 (I&C systems) and IEC 63046 (electrical power systems).
- Level 2: General requirements for specialized topics, including cybersecurity, control room design, human factors engineering, and ageing management.
- Level 3: Standards addressing specific equipment, technical methods, and activities, often referring back to Level 2 documents.
- Level 4: Non-normative technical reports, including IEC TR 63400, that provide supporting guidance and structure.
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Integration with External Standards
- Strong alignment with IAEA safety guides (e.g., SSR-2/1, SSG-30, SSG-34, SSG-39, SSG-51, and NSS42-G).
- Incorporation of relevant ISO standards, such as ISO 9001 for quality assurance.
- Coordination with IEEE and close relationships with other IEC technical committees (e.g., SC 65A, SC 45B).
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Topic Areas Covered
- I&C architecture
- Electrical power system design
- Safety fundamentals and equipment qualification
- Human factors engineering and HMIs
- Cybersecurity for nuclear control systems
- Ageing management and modernization
- Sensors, measurement, radiation monitoring, and plant-wide equipment
Applications
IEC TR 63400:2025 is a practical tool for:
- Standard Users: Assisting engineers, regulatory authorities, and nuclear facility operators in understanding how to apply the right IEC SC 45A standard for a specific application, and how these standards fit together for a comprehensive approach to nuclear safety.
- Developers and Committees: Providing a framework for developing, revising, and organizing new SC 45A standards in line with updates in technology and international best practices.
- Quality, Safety, and Security Management: Ensuring robust integration between instrumentation, control, electrical systems, and supporting safety, security, and quality assurance requirements throughout a nuclear facility’s lifecycle.
- International Projects: Supporting harmonization and compliance by mapping relationships between IEC, IAEA, ISO, and IEEE standards.
Related Standards
Professionals referencing IEC TR 63400:2025 should also consider the following closely related standards:
- IEC 61513: General requirements for I&C systems in nuclear power plants
- IEC 63046: General requirements for electrical power systems in nuclear power plants
- IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related systems (industrial safety basis)
- IEC 62645: Cybersecurity for nuclear power plants and related facilities
- IAEA Safety Standards: Including SSR-2/1, SSG-30, SSG-34, SSG-39, SSG-51, NSS42-G
- ISO 9001: Quality management systems
- IEEE Nuclear Standards: Standards developed by IEEE NPEC relevant to nuclear I&C and electrical systems
For detailed lists and breakdowns by topic area, reference annexes within IEC TR 63400 and regularly check updates on the IEC webstore and IAEA library.
Keywords: nuclear facility safety standards, IEC SC 45A, instrumentation and control, electrical power systems, nuclear cybersecurity standards, IAEA integration, IEC TR 63400, IEC 61513, IEC 63046, standardization, nuclear power plant compliance