JPS63154992A - Heat removing system of fast breeder reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a heat removal system for a fast breeder reactor, and particularly to a fast breeder reactor that can remove decay heat from the outside of a safety vessel. Regarding the heat removal system.

(Prior Art) The containment vessel of a fast breeder reactor generally consists of a reactor vessel that houses the reactor core and the coolant Na (sodium), and a safety vessel that is placed outside the reactor vessel with a gap between them. It has a layered structure, and the gaps are filled with inert gas.

Recently, in order to further improve the safety of such fast breeder reactors, a heat removal system that removes decay heat from the outside of the safety vessel in the event of a failure of the main cooling system has been considered. Consideration is being given to cooling the outside of the safety container with air.

(Problems to be Solved by the Invention) In the conventional concept described above, decay heat from the reactor vessel is transmitted to the safety vessel via the inert gas filled in the gap with the safety vessel, and then air is transferred from the safety vessel to the safety vessel. However, since the heat transfer capacity of inert gas and air is small, it is difficult to remove decay heat only from the outside of the safety container.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a reactor vessel housing a reactor core, a safety vessel disposed outside the reactor vessel with a gap therebetween, and having a plurality of ribs extending vertically in the axial direction on the outer surface thereof; NaK filled in the gap
This is a heat removal system for a fast breeder reactor, comprising a evaporator tube (NAC: sodium-potassium alloy) and an evaporation tube embedded with a conductive material between the ribs.

(Function) Since the gap between the reactor vessel and the safety vessel is filled with NaK, a liquid metal, and the evaporation tube is attached to the safety vessel via a conductive material, the decay heat from the reactor vessel is easily absorbed into the evaporation tube. transmitted to water.

(Example) Examples will be described below with reference to the drawings.

Figure 1 is a diagram showing only the main parts of a fast breeder reactor incorporating an embodiment of the present invention, and Figure 2 is a diagram taken from
It is an arrow view.

The inside of the reactor vessel (2) which houses the reactor core (not shown) is filled with Na (2) as a coolant. A safety vessel (3) is placed outside this reactor vessel with a gap, and one gap is filled with nitrogen.
It is filled with aK (a). A plurality of ribs extending in the axial direction (vertical direction) are welded to the outer surface of the safety container. An evaporation tube 0 is embedded between the ribs with sb (antimony) as a filler. The lower part of the plurality of evaporator tubes communicates with the annular lower header (8), and the upper part communicates with the annular upper part to the ladder 0, and the lower and upper headers are connected to a steam drum (not shown) to form a natural circulation boiler. are doing. And this natural circulation boiler has water (
10) is filled.

Next, the operation of this embodiment will be explained. Decay heat from the reactor vessel is transferred to the safety vessel by natural convection of liquid metal NaK filled in the gap with the safety vessel, and this heat heats the water in the evaporation tube through the conductive material to generate steam. The ribs welded to the outer surface of the safety container serve as conductive material.
In addition to facilitating the casting of b and holding it, it also serves as a thermal fin to transfer the heat of the safety container to the evaporation tube.

By guiding the generated steam to a condenser, decay heat can be released to the atmosphere.

〔Effect of the invention〕

As explained above, according to the present invention, heat can be extracted from the furnace vessel without passing through inert gas or air, which has a small heat transfer ability, so decay heat can be removed only from the outside of the safety vessel. It becomes possible. Furthermore, the heat from the reactor vessel is extracted in the form of steam, which is the most easily used form, and during steady operation of the fast breeder reactor, this steam is used to drive the absorption chiller and the steam turbine system. It also has the effect of being able to.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing only the main parts of a fast breeder reactor incorporating an embodiment of the present invention, and Figure 2 is
- It is a partial sectional view taken along the X arrow.

Claims (3)

[Claims] (1) A reactor vessel that houses a reactor core, a safety vessel that is arranged with a gap outside the reactor vessel and has a plurality of vertical ribs on its outer surface, and a sodium-potassium alloy filled in the gap and the ribs. A heat removal system for a fast breeder reactor, comprising: an evaporation tube embedded with a conductive material between the evaporation tubes; (2) The heat removal system for a fast breeder reactor according to claim 1, wherein the conductive material is a low melting point metal. (3) The heat removal system for a fast breeder reactor according to claim 2, wherein the low melting point metal is antimony.