LSuschena wrote at 2012-11-08 21:49:51
To answer the question. Yes, there are 2 steam generators and yes 2 hot legs. But, there are 4 cold legs, two to each steam generator and one hot leg to each steam generator.
The reason is very simple, there is a lot of water being circulated, which a single hot can handle adequately since it is just a huge pipe. The reactor coolant pumps, that circulate the water from the reactor through the steam generator and back to the reactor are in the cold legs. There is a huge volume of water circulating continuously, which requires very large pumps. If only one pump was used it would be massive and require lots of power. So, they use two smaller RCP's instead of one huge one. Now when I say "smaller" these pumps are still monsters, largest canned-rotor/canned-stator pump ever built and if I remember, the pump and motor are like 20 to 30 feet tall. Imagine the size a single pump would be.