Secondary Pumps and Circuits

Abstract

The secondary circuit, in sodium, has the function to convey the thermal power from the primary circuit to the water circuit, while physically separating the reactor from this water circuit. It is constituted of three types of major components: the steam generator (see Chap. 12 “The Steam Generators”), the intermediate heat exchangers (two in number, see Chap. 11 “Intermediate Heat Exchangers”), and one secondary pump circulating the sodium, getting out cold from the steam generator (345 °C), towards the intermediate heat exchangers, from which it will get out hot (525 °C). In case of sodium/water reaction incident (see Chap. 13 “The Sodium/Water Reactions”), this circuit has to protect the primary circuit. It comprises thus a discharge circuit enabling, in case of pressure rise, to cap this pressure and to drain the circuit. This circuit is also designed to take part in the residual power removal (see Chap. 16 “Decay Heat Removal”), and a sodium/air heat exchanger was placed for this purpose. This chapter is therefore essentially devoted to the secondary pump with its tank, to the sodium/air heat exchanger and to the overall organization of this secondary loop.