Pressurizer heaters

Claim 1

A pressurizer vessel for pressurized water nuclear reactor system comprising in combination: a vertically oriented cylindrical shell portion; upper and lower head portions attached to said shell portion; a combined fluid inlet and outlet nozzle disposed in said lower head portion in fluid communication with the pressurized water reactor system; a spray nozzle disposed in said upper head portion and connected to a supply of relatively cool fluid; a plurality of straight tubular electrical heating elements, each of said heating elements having pointed ends and a bulbous end with a heavy wall and electrical leads that connect to an electrical supply; a plurality of support plates disposed in said vessel so as to support said heating elements, said support plates having a plurality of openings for receiving said heating elements; a plurality of heater element nozzles disposed in said lower head portion of said vessel for receiving said heating elements, said heating element nozzles having an enlarged end for receiving said bulbous end of said heating elements; and sealing means disposed to form a seal between said enlarged end of said heater element nozzles and said bulbous end of said heating elements, said heater element nozzles being generally disposed parallel to said fluid inlet and outlet nozzle, and said heating elements being so disposed in said heater element nozzles that said heating elements are connected to said electrical supply external to said vessel and individually accessible, whereby the pressure in the pressurizer and the nuclear reactor system can be controlled by energizing the heating elements to increase the pressure within the system and utilizing the spray to reduce the pressure within the system.