JPS59108983A - Thermal shield layer structure - 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 The present invention relates to the structure of a heat shield layer, and particularly to the structure of a heat shield layer suitable for application to a reactor vessel or tank of a fast breeder reactor.

The conventional structure of this type of heat shield layer is used for the walls of nuclear reactors as shown in Figure 1, and its details are as shown in Figures 2 or 3. is well known.

In Figure 1, ■ is a hot plenum, 2 is a cooling layer through which coolant flows, 3 is a vessel wall, 4 is a heat insulator, 5 is a reactor core, 6 is an intermediate heat exchanger, 7 is a low pressure plenum, 8 is a pump, 9 is a high-pressure plenum, an equipment mounted on the IOU reactor. The reactor has a hot plenum 1 with a cooler 11 containing high-temperature sodium gas, and an inert gas 1 such as argon above the cooler 11.
2 is included.

In FIG. 2, a cooling layer 2 through which a coolant flows as a heat shield/iA is provided between a hot plenum 1 and a container wall 3, which is a shielded object. It produces a shielding effect. The thermal cocoon layer A having such a structure has the drawback that when the pump 8 is stopped, such as during a nuclear reactor trip, the coolant flow rate decreases and the heat shielding effect is reduced. there were.

In addition, in FIG. 3, there is a heat shielding layer B and a gas insulation layer J? between the hot plenum 1 and the container wall 3 which is a shielded body. J
13, and this gas insulation layer 13 (heat shielding layer B) provides a heat shielding effect. Although the heat shielding layer B having such a structure can compensate for the drawbacks of the heat shielding layer A having the structure shown in FIG. A certain amount of heat radiation had to be ensured through the material 4.

Therefore, there is a drawback that a separate cooling device must be provided on the outer surface of the container wall 3 in order to control this heat radiation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure of a heat shielding layer that can eliminate the drawbacks of the above-mentioned prior art and can reliably shield the heat of a nuclear reactor.

In order to achieve the above-mentioned object, the present invention provides heat and heat protection by a gas layer sequentially starting from the high temperature region side between the high temperature region and the shielded object.
The present invention is characterized by the provision of a cocoon layer and a thermal side shield provided with a coolant flow path.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 is an explanatory diagram showing the configuration when the implementation train of the present invention is applied to a tank of a fast breeder reactor, and FIG. 5 is an explanatory diagram showing the detailed configuration of the operator implementing the present invention. In these figures, the same components as in the conventional column are given the same reference numerals and will be explained.

In these figures, in the nuclear reactor, sodium heated to high temperature in the core 5 enters the hot plenum 1, then heat exchanges with the secondary side sodium 14 in the intermediate heat exchanger 6, and becomes low temperature. It enters a low-pressure plenum 7, where it is pressurized by a pump 8, and then enters the core 5 again via a high-pressure plenum 9.

The structure of the heat shielding layer in this embodiment is such that a heat shielding layer is formed between the hot plenum 1 as a high-temperature and cold region and the container wall 3 as a shielded body by sequentially forming a gas heat-insulating layer 13 from the side of the hot plenum 1. and a thermal cocoon layer consisting of a cooling layer provided with a coolant flow path to prevent the container wall 3 from becoming high temperature.

In addition, sodium is supplied as a coolant to the cooling layer 2 from the high-pressure plenum 9 via the piping 15, and the sodium that has flowed through the cooling layer 2 is passed through the return path 1.
6 to return to the low pressure plenum 7.

In the case of a nuclear reactor with an electrical output of about 100,100, the thickness of the cooling layer 2 is 100 to 300.
Cn+m), the temperature D+3 of the heat layer 13 is set to 200 to 400 (m+n), and the flow rate of the coolant flowing to the cooling sound 2 is set to several hundred (: m'/h). Obtainable.

The operation of this embodiment configured in this way will be explained below.

During the reactor's rated operation, the discharge pressure of the pump 8 is sufficiently high and enough IJum can be supplied to the cooling layer 2.

Therefore, the temperature inside the cooling layer 2 and the container wall 3 can be maintained at approximately the same low temperature as the primary outlet of the intermediate heat exchanger 6.

Next, if the reactor trips for the same reason, the pump 9 shifts to low-speed operation, so that almost no sodium flows into the cooling layer 2. However, due to the heat shielding effect of the gas heat insulating layer 5 and the heat capacity of the sodium and structural materials in the cooling layer 2, the temperature increase rate of the container wall 3 becomes extremely slow. During this period, the temperature of the hot plenum 1 decreases, and as a result, the temperature of the container wall 3 can be maintained at a low temperature.

FIG. 5 is a temperature change characteristic diagram showing the results of analyzing the temperature change of the vessel wall 3 during a reactor trip when the present invention is applied. In the temperature characteristic diagram shown in FIG. 5, the horizontal axis represents time, and the vertical axis represents the temperature of the container wall. In the figure, reference numeral 100 indicates the temperature change characteristics according to the embodiment of the present invention, and reference numeral 200 indicates the temperature change when only the thermal J body donor shown in FIG. 1 is installed. As explained above, the fL to which the present invention is applied can maintain the temperature of the vessel wall 3 at a low temperature not only during rated operation but also during a reactor trip. In addition, To in the figure is the container wall temperature during rated operation.

In short, the present invention consists of a heat shielding layer A having a structure shown in FIG. 2 and a heat shielding layer B shown in FIG. heat shield 1
-B to heat shielding layer A. In this way, if the coolant flow rate is sufficient, pP1jl
! Due to the cooling effect of the shielding layer B of the shielding layer B and the heat shielding layer A, the temperature of the coolant in the heat shielding layer A and the temperature of the shielded object can be maintained at a sufficiently low temperature.

Next, even if the coolant flow rate becomes insufficient, the heat shield 4B
Due to the shielding effect and the effect of the heat capacity of the coolant in the heat shield layer A, the temperature rise of the shielded object can be made extremely slow.

As described above, according to the present invention, it is possible to maintain the heat shielding effect over the supplementary operating range of the nuclear reactor.
This has the effect of keeping the reactor vessel of a fast breeder reactor at a low temperature.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the general configuration of a conventional high-speed J'a breeder furnace, Figure 2 is an explanatory diagram showing the configuration of a conventional heat shield, and Figure 3 is an explanatory diagram showing the general configuration of a conventional high-speed J'a breeding furnace.
The figure is an explanatory diagram 1 showing the configuration of another conventional thermal J-melt. ig4
Is the diagram an implementation sequence according to the present invention? Fig. 5 is a block diagram showing details of four actual examples according to the present invention, and Fig. 6 is a reactor trip diagram when the present invention is applied to a fast breeder reactor. It is a temperature change characteristic diagram showing a change of 6 degrees and 1 degree of time. 1...Hot plenum, 2...Cold @HA, 3.
... Vessel wall, 4. Insulating material, 5. Core, 6. Medium, 91 Heat exchanger, 7. Low pressure plenum, 8. Bonder, 9. High pressure plenum, 13. ...Gas station heat layer. 1 eye 2 eyes 3rd figure bud 4- eyes / 4 $ 5 eyes S 20 eyes

Claims (1)

[Claims] 1. In the structure of a heat shield layer that provides heat shielding between a shielded object and a high temperature region, a heat shield layer made of a gas heat insulation layer is sequentially installed between the high temperature region and the shielded object, starting from the high temperature region side, and a cooling layer is placed between the high temperature region and the shielded object. A structure of a heat shield layer, characterized in that it is constructed by providing a heat shield layer with a material flow path lAt.