If you’re wondering where the smokestacks are at Diablo Canyon Power Plant (below), there aren’t any! Since 1985, Diablo Canyon has generated almost 600 trillion watthours of clean energy – 9% of all the electricity used in California – with zero carbon emissions.

The nuclear fuel in each reactor (Diablo Canyon has two) needs to be replaced about every eighteen months. Though the spent fuel removed from the reactors remains dangerous for hundreds of years, there’s very little of it – the spent fuel from your lifetime electricity needs would fit inside an empty Coke can. All of Diablo Canyon’s spent fuel is stored safely onsite in sealed, dry casks, on a concrete pad about the size of a convenience-store parking lot (it’s to the right of the pool of water above the plant, in the photo below).

Had coal been used to create the electricity Diablo Canyon has over its lifetime, it would have released 4.3 billion tons of ash into the environment (1.47 cubic miles, or roughly the volume of the three closest mountains in the background). Coal ash contains significant quantities of radioactive uranium and barium, as well as toxic arsenic, lead, and mercury. The 50 tons of poisonous mercury released each year by U.S. coal plants doesn’t remain harmful for hundreds of years, like spent fuel – it remains harmful forever.