Overview
ISO 23225:2025 - "Corrosion control engineering life cycle in nuclear power plants - General requirements" is the first-edition ISO standard that defines a holistic framework for corrosion control across the entire life cycle of nuclear power plants. Published in 2025 by ISO/TC 156 (Corrosion of metals and alloys, SC 1), the standard sets out general requirements to identify corrosion sources, select materials and technologies, and manage design, construction, operation, inspection, maintenance, life extension and decommissioning activities with safety, cost-effectiveness and environmental protection in mind.
Key topics and technical requirements
The standard organizes corrosion control engineering around the full lifecycle and specifies requirements for each major element:
- Corrosion source identification: direct (e.g., water chemistries, steam, seawater), indirect (e.g., temperature, radiation, stress), environmental (e.g., stray currents, galvanic contacts) and corrosion-generated sources.
- Materials: selection and validation of metallic, non‑metallic and composite materials (e.g., stainless steels, nickel alloys, coatings) based on corrosion resistance, mechanical and irradiation properties.
- Technologies: environmental conditioning (pH control, oxygen removal), protective layers (coatings, linings, galvanizing) and electrochemical protection (cathodic/anodic systems).
- Design: structural and localized corrosion-strength considerations, accessibility for inspection/maintenance, and allowance for service-life margins.
- Lifecycle processes: development, manufacturing, transport/storage, construction/installation, commissioning/acceptance, operation, testing/inspection, maintenance/repair, life extension and scrapping.
- Management systems: documentation, records, resource management, verification and comprehensive assessment procedures.
- Principles and objectives: holistic, systematic, coordinated and optimized corrosion control to protect public safety, national security and the environment while achieving long-term operation and economic efficiency.
Note: ISO 23225:2025 contains no normative references and recognizes reactor-type differences (schematics in Annex A) and both normal and accident conditions.
Applications and who uses it
ISO 23225 is intended for organizations and professionals involved in nuclear power plant lifecycle management, including:
- Corrosion engineers and materials scientists
- Nuclear design and structural engineers
- Plant operators, maintenance and reliability teams
- Procurement, quality assurance and regulatory compliance staff
- Constructors, fabricators and equipment suppliers
- Safety assessors and decommissioning planners
Practical uses include creating corrosion management plans, specifying materials and coatings, defining inspection regimes, validating mitigation technologies, and supporting regulatory safety cases.
Related standards
ISO 23225 complements broader nuclear and corrosion standards and is aligned with ISO/TC 156 workstreams. For full implementation, users typically reference applicable nuclear design codes, regulatory requirements and industry best practices available from ISO and national standards bodies.
For purchase and official text, obtain ISO 23225:2025 from ISO or your national standards body.