A new IAEA publication on international best practices in the ageing management of nuclear power plants will support operators in improving their processes, help enable longer operating lifespans of reactors and contribute to nuclear safety worldwide.
Nuclear power reactors in use today were typically designed to run for 30-40 years. Given the enormous investment it takes to build a new plant, many operators and governments are seeking ways to extend the lives of their current facilities toward long term operation (LTO). This requires rigorous ageing management procedures, which are subject to regulatory oversight and licensing. Extending the life of a nuclear power plant involves determining if it can safely, securely and cost-effectively continue operating past its original retirement date. When a plant’s life is extended, operations often continue for an additional 20 to 40 years.
The initial version of International Ageing Lessons Learned (IGALL) Safety Report Series No.82 was published in 2015 and included experience gathered within the IGALL Programme between 2010 and 2014. The recently published IGALL Safety Report Series No.82, Rev.1 includes experience up until 2017, and the corresponding web site is updated annually.
“More data and more experience lead to a higher number of best practices that operators from around the world can use,” said Greg Rzentkowski, Director for Nuclear Safety of Nuclear Installations at the IAEA. “The IGALL Programme is effective in identifying proven ageing management programmes (AMP), time limited ageing analyses and generic ageing management review tables and sharing them with the nuclear community.”
Ageing management from the U.S. to the world
The IAEA has been coordinating international cooperation and the sharing of best practices in this area since 2010, when it launched the IGALL Programme. The Programme deals both with the physical ageing of systems, structures and components, resulting in the degradation of their performance characteristics, and technological obsolescence of such components, i.e. lack of spare parts, technical support, suppliers and industrial capabilities.
IGALL is based on the experience in the United States, where the Nuclear Regulatory Commission (NRC) initiated a process for operators to share their experience and best practices in ageing management and establish guidelines based on these. This in turn facilitated the work of the NRC, which had a common set of approaches to evaluate when considering licensing renewals. It is this model that was adapted and brought to the international scale by the IAEA in 2010. NRC has supported this process, including financially, since.
“Our involvement in IGALL and in Safety Aspect of Long Term Operations (SALTO) review missions have enabled us to better understand the approaches used by other countries to regulate long-term operation and the programmes implemented for ageing management at international plants,” said Allen Hiser, Senior Technical Advisor for License Renewal Aging Management at the NRC, and Chairperson of the IGALL Steering Committee. “International sharing of operating experience is an important part of maintaining informed ageing management worldwide. The information provided by our international counterparts in the IGALL meetings has provided us with an important source of information that we evaluate for potential improvement of our guidance.”
The US-based Electric Power Research Institute (EPRI), which has been performing research on materials ageing management for decades and also participates in IGALL, has concluded that IGALL’s work is broader than what is available in the U.S. Their report, entitled 2020 Update to EPRI Product Mapping to International Atomic Energy Agency (IAEA) International Generic Ageing Lessons Learned (IGALL) Aging Management Program Categories published in June 2020 states that the IGALL process goes beyond the U.S. experience in “identifying passive systems, structures, and (or) components for AMPs and includes specific programs for active equipment, such as motors, pumps, and valves and for reactor types that are not operated in the United States.”
“EPRI considers sharing ageing lessons learned internationally within the IAEA IGALL Programme as essential for further improvement in this area. EPRI worked in cooperation with the IAEA on the technical basis for the IGALL by participating on the working groups and Steering Committee,” said Sherry Bernhoft, senior technical executive of EPRI, also IGALL Steering Committee member. “International utilities might need to implement IGALL guidance according to directives from their national regulatory bodies. Useful EPRI technical information is now mapped to those AMPs to assist utilities in implementing AMPs.”
The IGALL programme has been funded by voluntary contributions from participating countries, with substantial part of the funding coming from the United States. Currently, over 200 experts from all 30 countries operating nuclear power plants are contributing to the programme.
“IGALL presents an excellent example of cooperation of regulators, operators and research institutes of all 30 countries operating nuclear power plants,” Rzentkowski said.