The Mudcat Café TM
Thread #136314   Message #3112709
Posted By: josepp
12-Mar-11 - 08:50 PM
Thread Name: BS: Japan Nuclear plant disaster, 2011
Subject: RE: BS: Nuclear plant disaster looming
///Okay... yet another perhaps stunned question... if a nuke power plant does not "boil water", how does it create enough kinetic energy to move a turbine to create electricity?///

In the types of plants I worked in, the water in the reactor that heats up and is moved by pumps through a pressurizer and steam generator was never allowed to boil. The pressuirzer prevented that. The water then passes through heat exchange tubes in the steam generator and back to the reactor. This system is called the primary.

On the other side of the tubes is a different, unconnected system of water that received the heat energy from the primary. It is called the secondary. It DOES allow the water to boil inside the steam generator (which is basically a boiler) and that steam is superheated and moving through pipes at a high rate of speed. It must be very dry when it enters the turbine. Very small droplets in the steam will tear up the turbine blades so there must not be any droplets. The spinning turbine then turns the generators to generate power which goes to a power distribution switchboard which is what I operated and oversaw for a number of years.

I take it that in a boiling reactor, there is no secondary system. The water must leave the reactor as steam and go directly to the turbines. That sounds dangerous as hell to me but it is what it is.