Concerned over fuel rods that were unexpectedly discharged in October, the US has increased spying on Iran's Bushehr nuclear reactor, officials tell the Wall Street Journal. Spent fuel from Bushehr was supposed to be returned to Russia, which commissioned and built the reactor, so the US was surprised when Iran said it would be discharging and storing the nuclear fuel—enough weapons-grade plutonium to produce 24 nuclear bombs—itself. But nuclear experts say safety, not weapons development, is the biggest current concern.
Drones have been a large part of the increased surveillance, say officials, and so far the US has been able to intercept both images and audio from the reactor complex. (But the drone Tehran shot at on Nov. 1—which Iran accused of spying—was not conducting surveillance on Bushehr, US officials say.) Drones are able to intercept phone calls and other communications, which could give officials a clue as to what exactly Iran's nuclear engineers were doing when the fuel rods were discharged. Typically such an action would be taken after 12 to 18 months, but in this case it happened just two months after Bushehr was said to be fully operational. (Read more Bushehr reactor stories.)