A national shortage of the most widely used radioisotope means thousands of patients are facing delays to diagnostic tests.

The situation is due to a malfunction at the country’s sole nuclear facility — the latest in a long line of incidents at the plant.

Now, nuclear medicine experts are warning shortages will become more frequent unless the facility undergoes an urgent and expensive upgrade.

As you pass through the security gates of Australia’s only nuclear facility, it’s eerily silent. Connected by long snaking roads and security checkpoints, the buildings are scattered across vast stretches of scrubland.