ISO 12749-1:2020

Overview

ISO 12749-1:2020 - "Nuclear energy - Vocabulary - Part 1: General terminology" is an international vocabulary standard that defines the basic terms and cross‑cutting concepts used across nuclear energy, nuclear technologies and radiological protection. The document provides terms, definitions, notes to entry and examples to promote unambiguous communication and harmonization of terminology across standards, regulatory documents and technical literature.

Key topics and technical content

• Scope and structure
  • Covers basic and cross‑cutting concepts only (general terminology), with structured concept systems to show relationships among terms.
  • Organized into subject groups: basic nuclear/radiological terms, nuclear energy, safety, measurement, radioactive waste management and decommissioning.
• Types of entries
  • Each entry includes a clear definition, supporting notes to entry and, where appropriate, examples to clarify use.
• Representative concepts included
  • Radioactivity, activity (Becquerel), radiation, ionizing radiation, radionuclide, half‑life, decay and decay constant.
  • Nuclear energy concepts such as nuclear fission, fusion, chain reaction, nuclear fuel, nuclear fuel cycle and nuclear reactor.
  • Safety and protection terms: radiological protection, radiation safety, radioactive contamination, radiological monitoring, dose and radiation risk.
  • Measurement concepts: measurement, measurand, measurement uncertainty.
• Source alignment
  • Terminology is harmonized with IAEA Safety Glossary, ICRU, JCGM (metrology) and other technically validated references. Annex A documents the methodology used to build the vocabulary.

Practical applications and who uses it

ISO 12749-1 is designed to be a reference for professionals who require consistent, internationally harmonized nuclear terminology:

• Standards developers and technical committees drafting nuclear and radiological standards.
• Regulators and licensing bodies that need precise term usage in rules and guidance.
• Nuclear industry professionals (operators, engineers, safety specialists) for clear technical communication.
• Radiation protection officers, health physicists and emergency responders for consistent operational and safety language.
• Educators, trainers and researchers building teaching materials or scientific publications.
• Procurement and legal teams drafting contracts, specifications and compliance documents where exact definitions matter.

Related standards

• ISO 12749 series (other parts cover specific subdomains such as instrumentation, waste management and decommissioning).
• IAEA Safety Glossary, ICRU reports and JCGM metrology guides are key referenced vocabularies.

Using ISO 12749-1:2020 supports clarity in nuclear terminology, reduces ambiguity in documentation and improves interoperability of international standards, regulatory texts and technical communication in the nuclear sector.