Without the water acting as a shield, the irradiated fuel would kill a person almost instantly. The water around the irradiated fuel glows an otherworldly shade of violet-blue. One of the biggest challenges of nuclear power is the disposal of spent fuel. Columbia Generating Station's spent fuel pool is nearly full after 15 refueling cycles, and before the next one Energy Northwest plans to move some of the assemblies out of the in-house pool and into dry cask storage on site, said Rod Webring, an Energy Northwest executive. Eventually, the casks could be moved to a national repository, such as the one proposed at Yucca Mountain in Nevada.
Nuclear plants function much as other thermal power plants.
At Columbia Generating Station, heat is used to boil water for steam, which passes through four turbines connected to a locomotive-sized generator, which makes enough electricity to power a city the size of Seattle. The critical difference is how the plant makes heat. Rather than burning coal or natural gas, nuclear plants produce heat by splitting atoms of uranium. One uranium pellet, about the size of a marble, has the energy equivalent of 149 gallons of oil or a ton of coal, said Alison Ruckhaber, an Energy Northwest spokeswoman. BPA, a federal power marketing agency in Portland, Ore., that sells all of the nuclear plant's electricity, reserved and purchased replacement power in advance of the outage.