JPS58191991A - Reactor container 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 (Technical Field of the Invention) The present invention relates to the improvement of a nuclear reactor equipped with a vibration isolation mechanism, and particularly relates to a nuclear reactor that improves the safety of a φ-down type reactor main vessel against large seismic forces. Regarding the structure of the furnace vessel.

Suspended reactor vessels generally consist of a tank-type main vessel that houses the reactor core and core structures and forms a coolant boundary around them, and a safety vessel that covers the outside of this main vessel. , the main container has been reduced to a roof slab that serves as a lid. The tank-type main vessel has a large-diameter tapered structure for the purpose of alleviating thermal stress and reducing manufacturing costs, so it is necessary to take into account possible vibrations between the built-in fluid and the main vessel wall, such as sloshing and bulging during earthquakes. Especially in the case of a suspended structure, it is necessary to provide support to the outer wall of the main container as a countermeasure against earthquakes* for each container.

However, conventional support structures have various interstices. For example, in a method in which the main container is supported on the safety container by elastic springs or a dashpot using oil, damper mounting parts and their reinforcement parts are required on both the main container and the safety container in order to attach the damper. However, when these attachment parts and reinforcement parts are formed, the main container becomes an unrestricted plate structure, which tends to cause thermal stress, which becomes a hindrance to in-service inspections (III) and the like. If the thickness of the entire main container is increased in order to achieve a uniform plate thickness, the production cost will increase considerably, and an axis of thermal stress will occur.

(Object of the Invention) The present invention has been made to eliminate the above-mentioned drawbacks in conventional IT, and provides a nuclear reactor equipped with a vibration isolation mechanism that is easy to configure and has excellent surface resistance. That is.

(Configuration of the Invention) Hereinafter, the configuration of the present invention will be explained in detail based on the embodiment shown in Figure E. 1 to 3, a safety vessel 3 having a water tank structure with its upper end fixed to the reactor vessel 1 is installed in the reactor vessel 1. Inside this safety container 3, a main container 4 having a slightly smaller diameter and depth is arranged,
Its upper end is fixed to the roof slab 2 to form a hanging structure.

The roof slab 2 has slide pads 7 laid between the vicinity of its periphery and the support part 5, and supports arranged on the circumference to support the support part 5 and the roof slab 2 in the horizontal direction. Multiple springs (for example, formed by Saraba springs)
A structural support mechanism 8 is provided. In addition, the oil damper type damping mechanism 9 is a spring structure J! ! It is installed between the support mechanism 8 and the reactor vessel chamber support section 5. 2 and 3 show individual embodiments of the support mechanism 8 and the damping mechanism 9. FIG.

'JJ''-Gate structure The entire structure is surrounded by liquid thorium 11, which is a coolant.

(Function of the Invention) Next, the explanation mechanism of the reactor vessel structure described above will be explained. In one agricultural mechanism of the present invention, the horizontal natural frequency of the entire reactor system is adjusted to the floor response spectrum of the reactor room Bunchoto 5 by means of the spring support 5 having a flexible structure in response to the ground force in the horizontal force direction. The acceleration is reduced sufficiently below the frequency band where the peak appears, and the damping mechanism 8 reduces the water displacement of the large roots slab that occurs due to the use of flexible springs. It depends on the method. To explain the following using a diagram, the ground truth is given by the acceleration that horizontally shakes the support part 5 of the reactor vessel bit chamber in FIG. 1. The acceleration of this ground wave is shown in the floor response spectrum shown in FIG. 4, where the horizontal axis shows frequency (Hz) and the vertical axis shows acceleration. □This floor response spectrum shows a peak in a certain frequency band (in the figure, between 3 and 15 Hz), and has a large acceleration in the frequency band of this peak.

In other words, if the natural oscillation vJ number of the reactor string extending in the support cap 5 of the Laozi reactor falls within the frequency range where the acceleration peaks, it will be necessary to design an acceleration that is larger than necessary, and the tank-type reactor that is the object of the present invention will have a maximum This does not hold true with acceleration near peak -1, and furthermore, the characteristic JkRm number of the main container itself is 4 to 1.
03-1m, which is in the filler peak region, the block is trying to establish the setting at by somehow designing in a band with a large eigenvalue, which is usually called an open design.

- In the field of force architecture, there is a design method that is the opposite of this method and involves designing in a low force frequency band, which is usually called flexible structure design.

The present invention adopts a flexible structure method as described in "Mi", and for example, a plurality of flexible structure spring supports 8 using flat springs as shown in FIG. 2 are arranged at the end of the roof slab 2 shown in FIG. , the 161 oscillating frequency of the entire reactor is, for example, 3 in Figure 4.
Hz or less. At this time, in order to facilitate horizontal vibration of the roof slab, the slide pad 7 is moved to the support portion 5.
Place it on top of the cloth to make it slippery. If the entire shoji reactor is made into a flexible structure, even if the Ill speed is small, if the spring constant is low, a large amplitude will occur and it will not be easy to operate the reactor. An example of a location is the tIIc damping mechanism 9 of an oil damper as shown in Figure 3.
Arrange a large number of and add 21 more! This method reduces the amplitude of the roof slab by reducing wrinkles.

(Effect of the invention) In the present invention configured as described above, the earth surface is generated and 1
Even if the floor surface of the nine sub-reactors vibrates, the flexible structure of the spring will cause the reactor response to be in the low frequency range where the floor response is small, and the damper damping mechanism will further reduce the acceleration, suppressing the vibration of the main vessel. Acceleration will be small. Therefore, damage to the main vessel against the geological formations is prevented, and the integrity of the entire reactor structure is ensured.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view schematically showing the flexible structure support system in the reactor vessel structure of the present invention, Fig. 2 is a cross-sectional view of the flexible structure spring support mechanism of Fig. 1, and Fig. 3 is the $2 figure. An example of a cross-sectional view of the damper damping mechanism shown in FIG. In addition, Figure 4 is a floor response spectrum diagram of the reactor installation surface. Unsupported rock structure 9: Damper damping mechanism f 7317
(1 person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In addition to suspending the reactor main vessel from the roof slab, a plurality of damper mechanisms are installed horizontally between the peripheral part of the roof slab (1) and the reactor vessel chamber support part (5), and a plurality of damper mechanisms are installed in the lower part of the roof slab. A nuclear reactor vessel structure characterized by having a slide butt arranged therein.