JPS6273198A - Cooling device of core tank for 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 [Technical Field of the Invention] The present invention relates to a cooling device for a core barrel that is installed in a reactor vessel of a fast breeder reactor and supports the reactor core in the horizontal direction.

[Technical background of the invention and its problems] Reactor vessel (hereinafter referred to as reactor vessel) of a loop fast breeder reactor
) is structured as shown in Figure 2. That is, the tenth opening of the furnace vessel 1 is closed by a cooling plug 2, and an inlet pipe 3 through which sodium from cold steam flows into the furnace vessel 1 is connected to the lower part. A reactor core 4 is disposed within the reactor vessel 1, and the reactor core 4 is configured such that core components 7 are loaded into an insertion opening 6 provided in an upper support plate 5. Above the core components 7 is an upper plenum 8, and an outlet pipe 9 for cold molten material is installed on the side of the reactor vessel 1 at the position of the upper plenum 8.
or connected. Also, below the core component 7 is a lower blenheim 10, the core (1η component cable 7 is surrounded by a core tank 11, the core'!111 is an upper core support, temporary
2 is supported. /YoJ5, neutron shields 14 are arranged in the outermost layer of the core tank 11, and these neutron shields 1
The five-shell body 14 has substantially the same shape as the core components. Therefore, the flow of coolant in a typical fast breeder reactor will be explained with reference to FIG. The furnace vessel 1 has an upper part m-
It is sealed by a sealing plug 2. The coolant at a temperature of about 200'C flows into the lower brenum 10 from the inlet pipe 3, and is placed in the lower core support plate 5 that vertically supports the core 4 (core inserted into the Φ inlet hole 6). The coolant rises in the trumpet tube of the core component 7 from the En 1 Herance nozzle of the component 7, reaches an ambient temperature in the core 4, becomes about 500'C, and flows out to the upper plenum 8.The coolant in the upper plenum 8 Cold rum [1 Mura flows out from Yamaguchi piping 9.

The core tank 11 that supported the reactor core 4 in the horizontal direction was bordered by the upper core support plate 12, above which it was in contact with the coolant of the high island of the upper plenum 8, and below it was in contact with the coolant of the high island of the upper plenum 8.
It is in contact with a cooler cooler than the top.

For this reason, there is a possibility that a large thermal stress will occur in the core layer 11, and at the same time, as a result of thermal expansion, the effect of supporting the reactor core 4 in the horizontal direction will be reduced because it will spread outward. Ta.

[Objective of the Invention 1] The present invention has been made in consideration of the above-mentioned problems, and is intended to reduce the thermal stress applied to the reactor core barrel, and to reduce the thermal stress applied to the reactor core barrel, and to reduce the thermal stress applied to the neutron shield trumpet tube loaded in the outermost layer of the reactor core components. An object of the present invention is to provide a cooling device for a core tank for a fast breeder reactor, which prevents a gap near the upper pad provided in the core tank from widening, thereby improving the earthquake resistance of the core.

[Summary of the invention] A coolant outflow hole is provided in the trumpet tube of a neutron i5 shell loaded in the outermost layer of the core tank of a fast breeder reactor, in the vicinity of a position facing an upper support body that supports the core tank. This is a cooling device for a core tank for a fast breeder reactor, characterized in that it is provided with:

[Embodiment 1 of the invention Hereinafter, one embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows only the main parts of the present invention, and the same parts as in FIG. 2 are given the same reference numerals, and the explanation of the overlapping parts is omitted.

In FIG. 1, reference numeral 20 indicates a neutron shield loaded in the outermost layer of the core barrel 11. The block 23, the handling head 24 which is connected to the upper part of the trumpet tube 21, the engine lance nozzle 25 connected to the lower part, and the outflow hole 2 (5) installed on the side of the trumpet tube 21. This outflow hole 26 is provided near a position where the core barrel 11 is supported by the upper support plate 12.Although not shown, the trumpet tube 21 is provided with a spacer pad. The size and shape of the coolant outflow hole 26 are determined in consideration of the coolant flow rate of the neutron shield 20, the heat generation base, and the strength of the outer cylinder. As shown by the arrow, the cold material of about 200'CV[1] flows from the top 1 of the neutron shield 20 to the lance nozzle 25, and flows between the inner surface of the wrapper tube 21 and the outer surface of the cladding tube 22. , and flows out from the coolant outflow hole 26. In the outermost layer of the core 4, the δ rays and neutrons are sufficiently low compared to the center of the core. During the break 20, almost no heat is generated.For this reason, the cold material [J material] hardly gets warmed up in the stomach, flows out from the coolant outflow hole 26, and flows into the reactor core (Ql).
Cool the high temperature parts of l.

[Effects of the Invention] According to the present invention, since the upper part of the reactor core tank is cooled, thermal stress is reduced and overall life is improved. In addition, it is possible to prevent gaps in the pad portions provided at the top of the core components from widening due to thermal expansion of the core barrel, thereby improving the earthquake resistance of the core.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing only the essential parts of an embodiment of a cold comb 1 neck of a core vessel for a fast breeder reactor according to the present invention, and FIG. 2 is a schematic view of the interior of the reactor vessel of a conventional fast breeder reactor. Required in the vertical cross-sectional view shown in . 11... Core tank 12... Upper support plate 20... Neutron cotoid body 21... Trumpet tube 22... Cladding tube 23... Neutron absorption block 24... Handling head 25...・Entrance nozzle 26...Outflow hole Applicant: Toshiba T Corporation Figure 1 Figure 2

Claims (1)

[Claims] (1) A core tank supported by upper and lower core support plates inside the reactor vessel, a reactor core disposed within this core tank, and a neutron shield block in a trumpet tube loaded in the outermost layer of this core. a neutron shielding body having a structure, and a coolant outflow hole is provided in the vicinity of the surface of the trumpet tube facing the core tank supported by the upper support plate. Cooling device for reactor core barrel.