It's a good thing that the NRC is out there watching over us

From the AP as reported in the Strib:

The Nuclear Regulatory Commission says a spill of radioactive tritium at Xcel Energy's Prairie Island Nuclear Plant was so small the utility wasn't required to report it. 

Excel did report it, though, which is a point in its favor.

The NRC says since it was only 27 gallons of radioactive water that spilled, apparently on the ground, well, no blood, no foul.

But that begs the question, how much radioactive water do you have to pour on the ground before you DO have to report it?