Countless things can go wrong, starting with the first step.
The worldwide supply of moly-99 relies on a fleet of government-subsidized nuclear research reactors built mostly during the Khrushchev-Eisenhower era.
Regular maintenance and major repairs can shutter the reactors, sometimes for months, and so-called “scrams” — caused by anything from a hiccup in a reactor’s cooling system to an errant lightning strike — frequently halt production. “It’s a nuclear reactor,” Mr. Charlton said. “The only thing you can do is shut it off.”
Even the Mayo Clinic in Rochester, Minn., a prestigious cancer treatment center, can be left waiting for shipments of the so-called generators that contain the imaging agent. “We’ve had days when no generator comes in at all, or…