An anonymous reader writes: The Tennessee Valley Authority's Watts Bar nuclear power plant began construction in 1973. The plant's first reactor was completed in 1996, and it began operation. Work on the second reactor paused in 1988, and only resumed in 2007. That reactor is now complete — the first newly-operational Generation II reactor since the 1990s. The new reactor has been granted an operational license, and it will soon begin fueling. While the Gen II reactors aren't unsafe, they're much less safe than the Gen III AP1000s. "Compared to a Westinghouse Gen II PWR, the AP1000 contains 50 percent fewer safety-related valves, 35 percent fewer pumps, 80 percent less safety-related piping, 85 percent less control cabling, and 45 percent less seismic building volume. ... If an accident happens, the AP1000 will shut itself down without needing any human intervention (or even electrical power) within the first 72 hours."