The shutdown of shipments from a nuclear reactor in Australia that is a key part of the global supply network for the radioisotope molybdenum-99 (Mo-99) is causing consternation in the nuclear medicine community, particularly in the Asia-Pacific region.
The Australian Nuclear Science and Technology Organisation (ANSTO) announced on June 27 that it had temporarily suspended production of technetium-99m generators due to mechanical problems at the site of the Open Pool Australian Lightwater (OPAL) reactor in Lucas Heights, outside of Sydney, according to an article in the Guardian. As of July 4, production was still suspended.
The generators contain molybdenum-99 and are sent to nuclear medicine facilities at hospitals and imaging centers. The Mo-99 decays into techentium-99m inside the generator and can then be used at imaging sites for a variety of studies, including nuclear cardiology.
The OPAL reactor produces about 10,000 generators a week, and in addition to supplying Australia it also ships generators to New Zealand and other facilities in the Asia-Pacific region. The interruption has forced Australian authorities to implement plans to receive backup supplies of generators from other countries, according to the Guardian.
Australia usually imports backup supplies of technetium-99m generators from South Africa, but a reactor there has been shut down for maintenance, according to the article. Australia received an initial wave of generators from Lantheus Medical Imaging in the U.S., equaling about 39% of what would be used in a week, but a second shipment of 60 generators was delayed and wasn't expected to arrive by plane until July 5, to be distributed to healthcare facilities on July 6, according to a statement by ANSTO.
A third batch of generators is being produced in the U.S. and is scheduled for delivery the week of July 9, the statement noted.
Technetium-99m is being rationed within the country, and patients in rural areas and regional locations are having to fly to major cities to undergo nuclear cardiology tests, the Guardian noted.
The OPAL reactor is part of a fragile network of isotope suppliers around the world in which essentially four sources handle the world's entire Mo-99 supply from fewer than a dozen nuclear reactors. The nuclear medicine community hopes to develop a network of alternative sources for Mo-99 that doesn't rely on reactors and, thus, offers a more stable supply, but it's taking time to get these sources up and running.
The mechanical problem concerns a part called a transfer conveyor, and it does not affect the operation of the OPAL reactor itself or the production of other nuclear medicine products, ANSTO noted.
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
