Patent Number: 047675942
Section: summary

BACKGROUND OF THE INVENTION This invention relates to sodium cooled reactors. More particularly, this invention relates to an improved reactor vessel auxiliary cooling system sodium flow circuit to supplement heat discharge through the reactor vessel to passing air for residual heat removal from a sodium reactor shutdown under emergency conditions. OUTLINE OF THE DISCLOSURE In certain sodium cooled reactors, the reactor vessel and containment vessel have immediate their exterior an air cooling system. This air cooling system provides for the dissipation of residual heat upon emergency shutdown of the reactor. Since such air cooling systems are well known in the prior art, they will not be discussed further here. This invention is directed rather to the dissipation of heat through the reactor vessel and containment vessel walls where it may reach the air cooling system. In certain sodium cooled reactors, the sodium hot pool is separated from the sodium cold pool by a reactor vessel liner. The purpose of the reactor vessel liner is to separate the reactor hot pool from the reactor cold pool and force fluid flow through the intermediate heat exchanger (IHX) located within the reactor vessel. The reactor vessel liner has a vital secondary function. That function is to short circuit the flow through the IHX to the reactor vessel liner flow gap immediate the reactor vessel wall. Such a short circuiting is required for residual heat dissipation upon loss of normal heat removal systems. The residual heat escapes through the reactor vessel and containment vessel. In such a casualty, it is assumed that reactor control rods are fully inserted. With such full insertion, there nevertheless remains residual heat that must be dissipated. It is the dissipation of this residual heat and the activation of the coolant flow path (here liquid sodium) which is the subject of this invention. In the understanding of this invention, extensive attention will be directed to the prior art normal operation flow path and the prior art residual heat discharge flow path. Emphasis will be placed upon the shortcomings of the prior art residual heat discharge flow path. Thereafter, and once these shortcomings are understood, the improvement constituting the addition of jet pumps from the cold pool to discharge at the slightly higher pressure hot pool will be set forth. It will be emphasized that an improved safety circuit is disclosed.