Decommissioning a nuclear installation or facility is an essential step in ensuring safe closure of its lifecycle, so that the site can be reused. It involves safely dismantling the facility, managing all radioactive and non-radioactive materials and waste arising from decommissioning and ensuring workers, the public and the environment are protected from radiation and from associated non-radiological hazards. This process happens at large installations, such as nuclear power plants, as well as at small medical, industrial and research facilities, and depending on the size and complexity of the facility, it can take from several months to several decades to complete. Helping countries improve their infrastructure for the safe decommissioning of small facilities is the key focus of an international IAEA project-MIRDEC (Decommissioning of Small Medical, Industrial and Research Facilities) launched in 2018, and based on the IAEA's Specific Safety Guide No. SSG-49.
"While international cooperation in decommissioning often focuses on large nuclear facilities, such as nuclear power plants and research reactors, most facilities worldwide to be decommissioned are smaller in size and less complex, such as laboratories, diagnostic radiology and radiotherapy hospital departments, industrial facilities using radiation sources," said Vladan Ljubenov, Acting Head of the IAEA Decommissioning and Remediation Unit.
"This project covers critical areas of attention for small facilities, for example, having appropriate regulatory frameworks, characterization of facilities, management of radiation sources and radioactive waste, and how to safely apply decommissioning techniques."
Strengthening safety
The project is organized into five working groups, addressing facilities with sealed sources such as irradiators; facilities with unsealed sources such as research laboratories; waste management facilities; accelerators and small research reactors. Serving as a community of practice it brings together operators, regulatory bodies, national authorities, policy makers and technical support organizations involved in decommissioning to enhance their capacities and exchange best practices and lessons-learned in implementing the IAEA safety guide.
"The project provides many opportunities for operators and regulators responsible for small facilities to improve their knowledge and understanding of different aspects of decommissioning and to benefit from exchange of experiences and collaborative work," said Samira Marques de Carvalho, a participant from the National Nuclear Energy Commission (CNEN) in Brazil.
MIRDEC is a collaboration of around 50 professionals from 30 countries from all the regions. The next meeting of the MIRDEC project will be held from 1 to 5 November 2021 as a virtual event.
"We are now at an exciting point in the project where we are collating some excellent decommissioning case studies, such as a hot cells facility in the Nuclear and Energy Research Institute (IPEN) in Brazil, an experimental waste incinerator at Jaslovske Bohunice site in Slovakia, a complex of disused waste management facilities in South Africa and a telecobaltotherapy unit in a hospital in Romania," said Anna Clark, Head of the IAEA Waste and Environmental Safety Section. "These case studies are among those that will form the basis of practical guidance and training materials for the decommissioning of small facilities to cover topics such as regulations, technologies, management of waste, safety and protection aspects."
The MIRDEC project is expected to conclude in 2023 with practical guidance and illustrative case studies on how to achieve and sustain safety during decommissioning of small facilities.
IAEA safety standards
At the heart of the MIRDEC project is the promotion of the IAEA safety standards, including those dedicated to the decommissioning of small facilities. These standards are the bedrock of regulatory activities conducted worldwide. They reflect an international consensus on appropriate levels of safety and serve as a global reference for protecting people and the environment.
General information on decommissioning of facilities can be found in the IAEA publication on General Safety Requirements No. GSR Part 6, and specific information on decommissioning of small facilities can be found in the IAEA publication on Specific Safety Guide No. SSG-49.
