Keeping the World’s Ageing Research Reactors Running

More than 220 research reactors are in operation, and they provide essential services such as the production of medical radioisotopes and enable scientific research in agriculture and industry. However, these facilities are ageing — the majority of the world’s fleet of research reactors has been operating for more than 50 years. Operators and regulators, with the help of the IAEA, are focused on refurbishing and modernizing these reactors so that they can continue to deliver goods and services while operating safely and securely. 

“In many countries, there are no replacements for these older research reactors and no plans for new ones,” said Ruben Mazzi, Technical Lead for Research Reactor Operation and Maintenance at the IAEA. “We help countries to take the steps to keep these reactors running. Each reactor is different and ages differently. Resources and services provided by the IAEA in support of the global fleet are important for ageing management.” 

The IAEA initiated its Research Reactor Safety Enhancement Plan in 2001, in anticipation of an increasingly ageing fleet of research reactors. This plan aims to help countries ensure a high level of research reactor safety. It includes the Code of Conduct on the Safety of Research Reactors, which provides guidance to countries on the development and harmonization of policies and regulations regarding the safety of research reactors. As part of the plan, countries are working with the support of the IAEA to implement systematic ageing management programmes.  

The IAEA has developed complementary activities to help countries manage their ageing research reactors. It has developed and continues to update safety standards and technical guidelines, while also conducting peer reviews and advisory services, and organizing technical meetings, workshops and training courses.   

The IAEA adapted the methodology of Safety Aspects of Long Term Operation (SALTO) for nuclear power plants to apply to research reactors and completed the first SALTO mission for a research reactor in 2017 at the Belgian Reactor 2 (BR2) research reactor in Belgium. SALTO missions assess a facility’s procedures and practices based on the IAEA safety standards and provide recommendations for further improving safety and effectiveness of modernization and refurbishment projects of such facilities. “In addition to systems and components, refurbishment and modernization also apply to implementing safety upgrades to bring the reactor facility in accordance with up-to-date IAEA safety standards,” said Amgad Shokr, Head of the IAEA’s Research Reactor Safety Section.  

A regular examination of a reactor facility’s structures, systems and components (SSCs) for potential degradation is necessary to assess ageing effects on safety and operation, or to avoid costly repairs. Operating organizations carry out routine maintenance and periodic testing programmes to assure the continuing capability of SSCs to perform their intended functions and to ensure that the reactor functions within operational limits and conditions. In some cases, these examinations require special techniques and additional resources that may not be available to all operating organizations.

The IAEA, upon request, supports countries by providing the needed equipment or expert advice to enable the operator to conduct specific inspection activities through in-service inspections (ISIs). ISIs assess the status of components that are important for the safety and operation of reactors. Specialized equipment can monitor structural defects and damage to a reactor’s physical infrastructure. These examinations identify cracks, other defects or weaknesses in structures at an early stage and over time in a reactor’s concrete and metal parts using radiation resistant underwater cameras and other specialized tools.  

The IAEA plans to release a new publication provisionally entitled Guidelines for Non-Destructive Examination, In-Service Inspection and On-Line Monitoring Programme for Research Reactors in 2024.

Strengthening sustainability 

Another peer review mission that supports countries in managing reactor ageing is the Operation and Maintenance Assessment for Research Reactors (OMARR). OMARR missions are focused on the operational and maintenance aspects that need to be addressed throughout a research reactor’s lifetime, from commissioning to decommissioning. Through OMARR missions, countries can strengthen the sustainability and reliability of a research reactor and optimize utilization of human and financial resources, considering IAEA standards, international good practices and national regulations.  

These missions identify areas for improvement, address specific operational challenges and create a platform for sharing experiences and good practices between international experts and local personnel. Since 2012, OMARR and pre-OMARR missions have been completed or are ongoing in Bangladesh, Chile, the Democratic Republic of the Congo, Indonesia, Italy, the Islamic Republic of Iran, Poland, Portugal, Thailand, the United States of America and Uzbekistan.   

Sammy Malaka, General Manager of Reactor Operations at the South African Nuclear Energy Corporation, participated as an expert on the 2018 pre-OMARR and the 2023 ISI missions at the TRICO II research reactor in the Democratic Republic of the Congo. TRICO II has been in extended shutdown since 2004, and there are now plans to restart the reactor and resume its activities for scientific research, training, radioisotope production and material characterization.  

“The success of both missions will enable the TRICO II facility to establish minimum SSCs to support the programme of restarting the reactor and its long term operation,” Malaka said. “In particular, we emphasized the importance of initiating an ageing management programme to manage ageing SSCs and to track and monitor upgrades, modernization or replacement projects, as this can be beneficial to the facility in the long term following a successful restart programme.” 

In May 2023, an OMARR mission supported by experts from Australia and the Czech Republic was conducted at the Thai Research Reactor-1/Modification-1 (TRR-1/M1) in Thailand, which is used for radioisotope production, research and development, and education and training. “The suggestions from the OMARR mission were helpful to establish and implement systematic and effective maintenance and ageing management programmes for TRR-1/M1 to enhance operation and effective utilization of the reactor,” said Kanokrat Tiyapun, Reactor Manager at the Thailand Institute of Nuclear Technology. “This is key for the sustainable development of nuclear capacity — technological expertise and human resources — and infrastructure required for future nuclear programmes in Thailand.”

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What is research reactor ageing? 

There are two kinds of ageing related to research reactors.

Physical ageing is the degradation of the physical condition of the reactor’s systems and components. Over time, exposure to aggressive environments and operating conditions, such as irradiation, corrosive agents and vibration, degrades some of the materials and components.  

Obsolescence is another type of ageing, in which the technology used for computers, instrumentation and control systems becomes outdated, or safety regulations change and become obsolete.  

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The IAEA offers more than 30 peer review and advisory services to help countries strengthen and enhance their nuclear-related practices. Peer reviews, which are organized upon request, are led by the IAEA and supported by teams of international experts. They assess the country’s national infrastructure and current practices considering IAEA guidance, safety standards and international good practices. These services, often referred to as ‘missions’, focus on an array of specialties, from nuclear safety to the health sector. 

The IAEA provides several peer review missions to assist countries in the safe, secure, reliable and sustainable use of their research reactors. The IAEA peer reviews specific to research reactors are the Integrated Nuclear Infrastructure Review for Research Reactors (INIR-RR), the Integrated Research Reactor Utilization Review (IRRUR), the Integrated Safety Assessment of Research Reactors (INSARR) and the Operation and Maintenance Assessment for Research Reactors (OMARR). The International Physical Protection Advisory Service (IPPAS) related to nuclear security and the Safety Aspects of Long Term Operation (SALTO) cover research reactors, as well as nuclear power plants.