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International Generic Ageing Lessons Learned
(IGALL) for Nuclear Power Plants

Welcome to the IAEA Programme on International Generic Ageing Lessons Learned (IGALL). This extrabudgetary programme was established in September 2010, and its first phase was completed in 2013. Its second phase is expected in 2014-2015.


Commercial nuclear power plants have been in operation since 1956. When first commissioned, the projected design life of a plant is calculated in economic terms, based on return on investment. This is generally in the region of 30 to 40 years. However, many plants can be safely operated for decades longer than originally planned. This is advantageous both environmentally in that power is generated without the need to build a new plant to replace the old one at the end of its design life, as well as from an economic standpoint, as it is cheaper to maintain an existing plant than to build a new one.

Systematic ageing management provides for the availability of safety functions throughout the service life of the plant and decommissioning, taking into account changes that occur with time and use. This requires addressing both the physical ageing of systems, structures and components (SSCs), resulting in the degradation of their performance characteristics, and obsolescence of SSCs, i.e. as compared to the latest technology, standards and regulations. Effective ageing management throughout the service life of an SSC requires the use of a systematic approach to managing ageing that provides a framework for coordinating all programmes and activities relating to the understanding, detection, monitoring, control and mitigation of ageing effects of the plant components or structures, including maintenance, in-service inspection, testing and surveillance, as well as operations, technical support programmes (including the analysis of any ageing effects and degradation mechanisms) and external programmes such as research and development.

 600 locations in CE plants
Typical primary circuit mechanical components.

Many IAEA Member States have already taken actions to address the topic of ageing in their nuclear power plants. The US Nuclear Regulatory Commission (NRC) published a compilation of Generic Ageing Lessons Learned (GALL), which is a comprehensive volume of problem areas and relevant countermeasures, used extensively both by regulators and plant operators in the United States. In 2009 the IAEA conducted a Technical Meeting where Member States recommended establishing an international platform for discussion between regulators and utilities regarding implementation of acceptable ageing management programmes (AMPs). The recommendations were to:

  • Develop and maintain a document which can serve as a practical guide for implementing, maintaining and improving AMPs, made up of best practices and universal knowledge on proven AMPs for safety related SSCs;
  • Establish a common basis for discussion between regulators and utilities with regard to implementation of acceptable AMPs.

In response, the IAEA initiated the ‘International General Ageing Lessons Learned’ Programme (IGALL).


The aim of the IGALL Programme is to develop and maintain documents and a database to provide a technical basis and practical guidance on managing ageing of mechanical, electrical and instrumentation and control components and civil structures of nuclear power plants important to safety in order to support the application of the: Specific Safety Requirements on Design, Commissioning and Operation; Safety Guide on Ageing Management; Safety Guide on Periodic Safety Review; and Safety Report on Safe Long Term Operation.

The IGALL database contains the following information relevant for SSCs important to safety:

  • A generic sample of ageing management review tables;
  • A collection of proven ageing management programmes;
  • A collection of typical time limited ageing analyses.

The current publicly available IGALL database consists of 2351 line items in the ageing management review table, 76 AMPs and 27 time limited ageing analyses.

This information is based on approaches developed and implemented in various types of water moderated reactors in participating Member States and is periodically updated.

The IGALL provides an internationally recognized basis for ageing management programmes, as well as a knowledge base for ageing management with respect to the design of new plants, design reviews, safety reviews (such as periodic safety review), etc., and serves as a roadmap for ageing management review and improvement.

The programme is being implemented in coordination with national and international partners on ageing management (the European Commission and the Organization for Economic Co-operation and Development’s Nuclear Energy Agency, etc.).

Programme organization

More than 120 experts representing 23 Members States have already contributed to IGALL’s development and are actively involved in the implementation and further development of IGALL. Programme activities are guided by a steering committee composed of senior representatives from Member States and are implemented by working groups. Working groups focus on collecting and consolidating specific technical data.


Phase 1


  • Scoping meeting/briefing for the PMs of the Member States;
  • Official programme commencement;
  • Organization set-up;
  • Steering group begins activity;
  • Working groups begin activities. 2011-2012:
  • Programme continues with regular group meetings. 2013:
  • Final IGALL Safety Report, including IGALL database, published.


  • Programme continues with regular group meetings.


Phase 2


  • Implementation of IGALL in nuclear power plants;
  • Further enhancement of IGALL completeness.


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| Last update: Tuesday, 15 January, 2019.