When the device is aligned so that its pits are pointing straight at the sun, most of the incident radiation goes down them to their bottoms.

ECONOMIST: Solar power

There were no injuries and little release of radiation from that incident, which remains the worst commercial nuclear accident in U.S. history.

CNN: Pump triggers Three Mile Island reactor shutdown, NRC says

Correspondents say the incident has highlighted the fragility of the rescue operation at Fukushima two years after the meltdowns caused a major release of radiation.

BBC: Fukushima: Rat linked to outage at Japan nuclear plant