JPS5952790A - Shock absorbing device for equipment in 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 invention] The present invention relates to a device for stabilizing equipment in a fast breeder reactor.

[Technical background of the invention]

A tank-type fast breeder reactor will be explained with reference to FIG. In the figure, numeral 2 denotes a reactor vessel, and a reactor core 4 is configured within this reactor vessel 2, and this reactor core 4 is supported by a core support plate 6. The reactor vessel 2 contains metallic sodium 8 as a liquid metal coolant. Further, the upper opening of the reactor vessel 2 is sealed with an upper shield 10 called a roof slab. An inert gas 12 called cover gas is filled in the space between the upper shield 10 and the metal sodium 1, 8.

A core upper mechanism 14 is provided above the core 4, passing through the upper shield 10. A control rod drive mechanism (not shown) is attached to this core upper mechanism 14 and is configured to control the reactivity of the core 4.
A primary coolant pump 16 is installed around the core 4 through the upper shield 10 . In-furnace equipment such as an intermediate heat exchanger 18 is arranged.

The intermediate heat exchanger 18 is suspended within the reactor vessel 2 with the flange 2o engaged with the upper shield 10. Further, the lower part of the intermediate heat exchanger 18 passes through the core support plate 6, and a predetermined gap exists between the core support plate 6 and the intermediate heat exchanger 18, and the intermediate heat exchanger 18 is maintained in a loosely inserted state. . The intermediate heat exchanger 18 installed in this manner allows the high temperature metal sodium 8 to flow into the interior through the opening 22, and after heat exchange, the low temperature metal sodium 8 is returned to the reactor core 4 from the outlet pipe 24 at the lower end. It is configured as follows.

[Problems with background technology]

In the conventional fast breeder reactor, the metal sodium 8 reaches a high temperature of about 500'C to 600'C during reactor operation. Therefore, the reactor vessel 2 thermally expands in the radial direction. At this time, the upper shield 1° Since the amount of thermal expansion of the reactor vessel 2 is relatively small, the lower part of the reactor vessel 2 expands and deforms more radially than the upper part, as shown in Figure 2. In order to absorb thermal deformation of the vessel 2, the core support plate 6 and the intermediate heat exchanger 18 are maintained in a loosely inserted state.

However, in the event of an earthquake, intermediate heat exchanger 1
8, the lower part vibrates greatly due to earthquake vibrations, and if there is a gap between the core support plate 6 and the intermediate heat exchanger 18 at this time, the vibration of the intermediate heat exchanger 18 cannot be prevented.

For this reason, there has been a need for a steady rest device that can absorb thermal deformation and prevent geological vibrations.

[Purpose of the invention]

An object of the present invention is to provide an in-reactor equipment steady resting device that can absorb thermal deformation of an in-reactor equipment holding part during operation of a fast breeder reactor and can prevent the in-reactor equipment from vibrating in the event of an earthquake. There is a particular thing.

[Summary of the invention]

The in-core equipment steady rest device according to the present invention has a plurality of upper protruding peripheral walls protruding from the lower end surface of the in-core equipment housed in the reactor vessel of a fast breeder reactor, and has a predetermined gap in the radial direction. A lower circumferential wall protruding toward the reactor vessel is inserted into the gap between the circumferential walls.

[Embodiments of the invention]

Embodiments of the present invention will be described and explained with reference to FIGS. 3 and 4. In addition, in the diagram, the same ministry name is used for the same line as the conventional one to avoid duplication in the explanatory text.

In FIG. 3, reference numeral 18 denotes an intermediate heat exchanger which is one type of in-core equipment, and a core support plate 6 is provided around the outflow pipe 24 of this intermediate heat exchanger 18. A triple upper projecting circumferential wall 3o is provided on the lower end surface of the intermediate heat exchanger 18 in a protruding manner. The upper projecting peripheral wall 3o is formed concentrically around the outflow pipe 24 at equal intervals in the radial direction. On the other hand, a lower projecting peripheral wall 32 is provided on the core support plate 6 side. The lower projecting peripheral wall 32 is inserted into the gap between the upper projecting peripheral walls 30 and combined with the upper projecting peripheral wall 30 as shown in FIG.

The lower projecting peripheral wall 32 is also formed concentrically with equal intervals in the radial direction.

The effects of the device configured as above will be explained.

First, the side projecting peripheral wall? 0 and 32 are inserted into the gap between the opposing projecting peripheral walls and combined, so that the displacement due to thermal deformation of the reactor vessel 2 as described above can be absorbed.

In the event of an earthquake, the side projecting peripheral walls 3θ, 32
A damping force is generated that damps the relative movement of the side projecting peripheral walls 30 and 32 due to the flow resistance of the metallic sodium 8 filling the gap. Therefore, this damping force can attenuate the excitation force that causes the intermediate heat exchanger 18 to vibrate, and the vibration of the intermediate heat exchanger 18 can be prevented.

Moreover, the side projecting peripheral wall 30, ? 2 are formed in a multiple shape in which they are combined with each other, so that the outer diameter can be reduced by k/J% and can be constructed compactly.

Note that the present invention is not limited to the following embodiment. For example, the in-core equipment is not limited to the intermediate heat exchanger 18, but may be any equipment that is accommodated in the reactor vessel 2 and immersed in the metallic sodium 8, such as the refueling material pump 16. Furthermore, the present invention is applicable not only to tank-type fast breeder reactors but also to loop-type fast breeder reactors.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to absorb thermal deformation of the in-reactor equipment holding part during operation of a fast breeder reactor, and also to prevent damage to in-reactor equipment in the event of an earthquake. is large.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a conventional example, FIG. 2 is a vertical sectional view showing a state during thermal deformation, FIGS. 3 and 4 are views showing an embodiment of the present invention, and FIG. The longitudinal sectional view and FIG. 4 are perspective views showing the upper projecting peripheral wall 30 and the lower projecting peripheral wall 32. 18... Intermediate heat exchanger (furnace equipment), 30... Upper projecting peripheral wall, '32... Lower projecting peripheral wall, 24... Outflow pipe. Applicant's agent Patent attorney Takehiko Suzue Jl! 1 Figure 2 Figure 1!3

Claims (2)

[Claims] (1) In-reactor equipment housed in the reactor vessel of a fast breeder reactor containing liquid metal coolant inside and immersed in the liquid metal coolant; It is characterized by comprising a plurality of upper projecting peripheral walls formed with predetermined gaps in the direction, and a lower projecting peripheral wall inserted into the gaps between these upper projecting peripheral walls and protruding toward the reactor vessel side. Furnace equipment steady rest device. (2) The upper projecting circumferential wall is formed concentrically around the outflow pipe of the furnace equipment, that is, the intermediate heat exchanger. Stop device 0