Patent Number: 061608637
Section: claims

1. A volume control system for a nuclear reactor comprising: a primary coolant circuit for cooling a nuclear reactor, said primary coolant circuit including a pressurizer connected thereto;  a secondary coolant circuit connected to said primary coolant circuit comprising:  a pressurizer level control system connected to each of said first and second variable speed charging pumps to independently control the speed of each of said first and second charging pumps in accordance with a level of coolant in the pressurizer. 2. The volume control system of claim 1, wherein said pressurizer level control system includes a processor for monitoring and controlling the level of pressure and flow rates in the volume control system. 3. The volume control system of claim 1, wherein said variable speed drive is an AC variable speed drive, said power supply is an AC power supply bus and said motor is a synchronous AC motor. 4. The volume control system of claim 1, wherein a rate of charging flow into said primary coolant circuit is approximately the same as the rate of letdown flow.