Overview
IEC TR 63400:2021 - "Nuclear facilities - Instrumentation, control and electrical power systems important to safety - Structure of the IEC SC 45A standards series" - is a Technical Report from the IEC that explains the overall organization and scope of the IEC SC 45A standards series. Rather than providing new technical requirements, IEC TR 63400:2021 augments the common introductory description used in SC 45A documents by:
- Describing the basic structure of the SC 45A series in diagrammatic form
- Explaining the hierarchy of levels (Levels 1–4) and how documents are subdivided
- Defining broad topic areas and entry-point documents
- Clarifying relationships and liaisons with other standards bodies (e.g., IAEA, IEEE) and related IEC work
This TR is primarily intended to help users - including first-time users - navigate the SC 45A portfolio covering instrumentation, control (I&C) and electrical power systems important to safety for nuclear facilities.
Key Topics and Structure
IEC TR 63400 outlines the SC 45A structure and the main topic areas that the standards series addresses. Key topics include:
- I&C architecture and specifics of I&C (Topic 01)
- Electrical power system architecture and electrics (Topic 02)
- Safety fundamentals (Topic 11)
- Equipment qualification and system performance (Topic 12)
- Human factors engineering (HFE) (Topic 13)
- Cyber security (Topic 14)
- Ageing management (Topic 15)
- Control rooms and human–machine interfaces (HMI) (Topic 21)
- Sensors, measurements and special process measurement (Topics 22–23)
- Radiation monitoring (Topic 24)
- Plant-wide I&C and electrical equipment (Topic 25)
The report also documents normative references, terminology policy, liaison arrangements (internal IEC and external like IAEA/IEEE), and annexed lists of SC 45A and selected SC 45B documents by topic.
Practical Applications - Who Uses It and Why
IEC TR 63400:2021 is a navigation and planning tool rather than a prescriptive standard. Typical users and uses include:
- Standards users and engineers - to identify which SC 45A standard(s) apply to a project or component (I&C, electrical systems, radiation monitoring, etc.)
- Designers and integrators - to map requirements across levels and topic areas when designing safety-important instrumentation, control and power systems
- Regulators and compliance teams - to understand the structure of the SC 45A series and its relationship with IAEA guides and other standards
- Procurement and quality assurance - to select entry-point documents and referenced standards for specifications and qualification programs
- Working groups and standards developers - to maintain consistency in terminology, scope and document hierarchy
Related Standards and Links
IEC TR 63400 explicitly positions SC 45A work relative to other documents and bodies. Relevant references include IEC normative work and other organizations such as the IAEA and IEEE. The TR points users to entry‑point documents, annexed lists of SC 45A/45B standards by topic, and cross‑references (for example to IEC 61508 as a related functional safety framework).
For anyone working on nuclear instrumentation, control, or electrical power systems important to safety, IEC TR 63400:2021 is a concise roadmap to the SC 45A standards landscape.