IAEA safeguards verify the peaceful use of nuclear material in countries across the globe. This includes the verification of nuclear materials associated with the production of radiopharmaceuticals – pharmaceutical drugs that use radioactive compounds to diagnose or treat various diseases – for use in healthcare. At a side event at the IAEA General Conference today, participants learned about several techniques used by nuclear safeguards inspectors to verify the peaceful use of nuclear material, and got an insight into projects carried out by the IAEA with its Member States to strengthen the implementation of safeguards for the production of radiopharmaceuticals.
“The wide variety of techniques we presented today are necessary due to the different types of reactors and processing facilities used in radiopharmaceutical production,” said Bret Grimshaw, Nuclear Safeguards Inspector, IAEA.
The event focused on the production of Molybdenum-99 (Mo-99). Mo-99 is used to produce technetium-99m which, in turn, is used in medical imaging to diagnose diseases and to monitor the spread of cancer. Currently, most Mo-99 is produced at five research reactors across the world.
“This presentation illustrated the level of technical expertise that the IAEA, in collaboration with its Member States, has brought to bear in designing verification tools specially customised to the unique processes used in a variety of radiopharmaceutical facilities,” said Kalman Robertson of the Australian Safeguards and Non-Proliferation Office.
Mo-99 is manufactured by irradiating uranium with an enrichment content of anywhere between 19% and over 90% U-235. However, there is a danger that uranium enriched over 90% could be used to produce nuclear weapons. To verify that the uranium remains in peaceful use, IAEA nuclear safeguards inspectors rely on different techniques, including gamma ray spectroscopy and neutron coincidence counting.
“Gamma ray spectroscopy profiles the gamma energy emitted by the uranium to ascertain the enrichment levels of the material,” said Grimshaw. “Active neutron coincidence counting, on the other hand, measures the rate at which neutrons are emitted from the material. This allows the inspector to calculate the mass of the material.”
The event demonstrated the work undertaken jointly by the IAEA and several countries and operators to build facility-specific solutions to implement safeguards for these facilities. This work has also included commissioning special equipment that helps to improve the verification process. For example, in Australia a neutron coincidence counter, known as the Active Well Coincidence Counter, is installed on site to keep a constant check on the material.
“Working together with States and operational experts is important in safeguarding the production of radiopharmaceuticals,” said Grimshaw. “Events such as this one allow the IAEA to de-mystify some of our practices and communicate directly with the people who we work with to verify the use of nuclear material.”
