An International Atomic Energy Agency (IAEA) Integrated Safety Assessment for Research Reactors (INSARR) team has concluded an eight-day mission to assess the safety of the Miniature Neutron Source Reactor (MNSR) and Heavy Water Zero Power Reactor (HWZPR) in Iran. The team of experts said the operator of two research reactors had improved safety and implemented significant upgrades to modernise systems and components in recent years. The team also provided recommendations and suggestions for further enhancement of the operational organisational structure, safety documents and operational safety programmes.

The five-member team comprised experts from Argentina, China and Jordan, as well as two IAEA officials. The mission was conducted at the request of the government of Iran and hosted by the Nuclear Science and Technology Research Institute (NSTRI), Reactor and Nuclear Safety Research School, the operator of the two research reactors. The team reviewed organisational and management aspects as well as technical areas including safety analysis, operation and maintenance programmes, radiation protection, and safety of modifications and experiments. The team visited the two reactors and associated facilities and met with NSTRI officials.

The MNSR and HWZPR research reactors are located in Esfahan, some 450 kilometres south of the capital Tehran. The 30 kW MNSR was first commissioned in 1994 and is utilised mainly for education and training and neutron activation analysis – a method for the qualitative and quantitative determination of elements. Recently the facility was modified to include the installation of two vertical beam tubes for film-based neutron radiography. This is used to analyse the structure of a sample as well as for calibration of neutron detectors, and for prompt gamma activation analysis to measure elements.

The HWZPR was first commissioned in 1996, with a maximum rated power of 100 W and a normal operating power 10 W. It is utilised mainly for education and training programmes, research and development and applied nuclear science.

“NSTRI has shown a commitment to safety by requesting an IAEA INSARR mission”, said David Sears, INSARR team leader and senior safety officer of the IAEA’s Research Reactor Safety Section. “The recent facility modifications and safety enhancements should extend the service life and utilisation of the reactors. The operating organisation should continue improvements, including revision and updating of safety documents and operating procedures, to maintain continued safe operation of the facility in accordance with the IAEA safety standards.”

The IAEA team noted the effective implementation of refurbishment and upgrades to enhance operational safety performance, ageing management, and procedures for response to abnormal situations. It also observed improvement in the effectiveness of training and maintenance programmes.

The mission also made recommendations and suggestions for improvements, including:

  • Enhancing the operational organisational structure by better clarifying the roles and responsibilities for safety and ensuring the independence of the safety committee from the reactor management.
  • Reviewing and revising the procedures for modification of safety systems and components, as well as of implementation of new experiments.
  • Reviewing and revising the operation and maintenance procedures in accordance with research reactor manufacturer recommendations, design requirements and operating experience feedback.

“We made a lot of efforts to ensure a high level of safety. I am glad to see that noted in this mission” said Dr Seyed Amir Hossein Feghhi, the head of NSTRI. “We are grateful to the mission experts for their professional and valuable support as we strive for continual safety improvement”. NSTRI has indicated that they will request a follow-up INSARR mission in 2027.

Image: Cutaway of the Miniature Neutron Source Reactor (courtesy of IAEA)