JPS61139794A - Earthquake-proof support structure of reactor vessel - 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 an earthquake-resistant support structure for a nuclear reactor vessel using liquid metal as a coolant.

[Technical background of the invention]

In a conventional nuclear reactor that uses liquid metal as a coolant, as shown in FIG. The reactor vessel 3 is supported by placing its upper 7 flange portion 4 on a pedestal 6 extending from the reactor building base 5. The safety vessel 7 has a similar shape to that of the reactor vessel 3 except for the upper part thereof, except for the supporting legs 8, and is attached to the outside of the reactor vessel 3 at a predetermined interval and concentrically and fixedly suspended from the outer periphery. It is fixed onto the stepped portion of the building base 5 via cylindrical support legs 8 . The space 9 between the reactor vessel 3 and the safety vessel 7 is filled with liquid metal sodium (hereinafter simply referred to as liquid). In addition, in the event that coolant leaks from the reactor vessel 3, the space 9 will receive it.

As the reactor vessel 3 increases in size and volume as the reactor power generation capacity increases, seismic support against earthquakes becomes extremely necessary and important. Therefore, conventionally, as described above, the safety vessel 7 is provided outside the reactor vessel 3, and the space 9 between the reactor vessel 3 and the safety vessel 7 is filled with liquid to form an earthquake-resistant support structure. A method of increasing the earthquake resistance of the reactor vessel 3 by transmitting the seismic force acting on the reactor vessel 3 to the safety vessel 7 using the inertia force of the liquid is adopted. It is known that the seismic support/structure has a greater seismic effect as the distance between the reactor vessel 3 and the safety vessel 7 is smaller. On the other hand, as an in-service inspection (hereinafter simply referred to as inspection) of the reactor vessel 3, visual inspection of the weld line of the reactor vessel 3, continuous leakage monitoring of the coolant in the reactor vessel 3, and weld line of the safety vessel 7 are carried out. A visual inspection of the reactor vessel 3 and the safety vessel 7 is required, and it is necessary to maintain a minimum distance of approximately 300 am between the reactor vessel 3 and the safety vessel 7 in order to carry out these inspections. It is difficult to improve significantly.

Furthermore, since the inspection apparatus for performing the above-mentioned inspection is used in liquid, there are problems such as design difficulties and decreased reliability of the apparatus. Furthermore, during an earthquake, the liquid in the cavity 9 undergoes a high pressure increase in the vibration direction, but if the reactor vessel 3 and the safety vessel 7 are structurally uniformly deformed by this pressure, the seismic support effect is greatly reduced. do. Moreover, although high external pressure acts on the reactor vessel 3 due to the above pressure, there is a possibility that the reactor vessel 3 may buckle due to this external pressure.

[Purpose of the invention]

This invention was made in order to solve the above-mentioned problems in the conventional earthquake-resistant support structure for a nuclear reactor vessel, and is an earthquake-resistant support that increases the effect of earthquake-resistant support of a nuclear reactor vessel and facilitates inspection of the reactor vessel and safety vessel. The purpose is to provide structure.

[Summary of the invention]

The earthquake-resistant support structure for a reactor vessel according to the present invention firmly connects the outer periphery of the reactor vessel and the inner circumferential surface of the safety vessel by ribs separated from each other at multiple locations, and the reactor vessel and safety vessel are installed. A metal plate lining is placed on the inner wall surface of the hole in the building base on the outside of the safety vessel at a predetermined distance from the safety vessel and concentrically in a similar shape to the safety vessel, and between the reactor vessel and the safety vessel and the safety vessel. The above-mentioned object is achieved by filling the space between the lining and the lining with fluid.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, a bottomed cylindrical reactor vessel 10 housing a core 1'', a core support structure 2, etc. has an upper flange 4 that is similar to the conventional nuclear reactor vessel 10 shown in FIG. Like the reactor vessel 3, it is supported by being placed on a pedestal 6 that protrudes from the reactor building base 16.As for its seismic support structure, a 3ooI
At a predetermined interval exceeding IIl, safety vessels 11 having a similar shape to the portion of the reactor vessel 1o except for the upper part are firmly connected concentrically by ribs 12 separated from each other in a plurality of places, and On the inner wall surface of the hole in the building base 16 on the outside of the reactor vessel 11 where the reactor vessel 10 and the safety vessel 11 are installed, a hole similar to the safety vessel 11 is formed concentrically with a narrow predetermined distance from the safety vessel 11. The metal plate lining 14 is tightened to fill the space 13 between the reactor vessel 10 and the safety vessel 11.
The space 15 between the safety container 11 and the lining 14 is filled with a liquid.

Next, the operation of the earthquake-resistant support structure of the present invention will be explained. In the event of an earthquake, the reactor vessel 1o and the safety vessel 11 vibrate together because they are firmly connected by the ribs 12, but the inertia of the liquid filling the narrow space 15 between the safety vessel 11 and the lining 14 causes Based on this, the reactor vessel 10 and the safety vessel 11 are allocated and support by the building base 16 is maintained safely.

The reactor vessel 10 and the safety vessel 11 are firmly connected by a rib 12, but there is a gap 13 between the two vessels 10 and 11.
The width of the reactor vessel 10 and the safety vessel 11 is more than 300 m, so there is enough space to inspect the leakage weld lines of the reactor vessel 10 and the safety vessel 11 without any problems.

Next, another embodiment of the invention will be described. The configuration of this embodiment is completely similar to that of the previous embodiment, except for the first embodiment.
The only difference is that the space 13 between the reactor vessel 10 and safety vessel 11 shown in the figure is filled with liquid instead of gas.

In this embodiment as well, during an earthquake, the reactor vessel 10 and the safety vessel 11 vibrate together, but the safety vessel 11
Based on the inertial force of the liquid filling the narrow space 15 between the reactor vessel 10 and the lining 14, the vibrations of the reactor vessel 10 and the safety vessel 11 are damped and support by the building base 16 is maintained safely, and the reactor vessel 10 and the safety vessel 11 are By filling the space 15 between the safety vessels 11 with liquid, the reactor vessel 10 is surrounded both inside and outside by liquid with good heat transfer. Further, in this embodiment as well, the space for inspecting the reactor vessel 10 and the safety vessel 11 is secured, just as in the case of the previous embodiment.

〔Effect of the invention〕

The earthquake-resistant support structure for a reactor vessel according to the present invention firmly connects the outer periphery of the reactor vessel and the inner circumferential surface of the safety vessel at a plurality of locations using ribs spaced apart from each other, and also connects the outer periphery of the reactor vessel and the inner circumferential surface of the safety vessel at multiple locations, and A metal plate lining is placed concentrically on the wall at a predetermined distance from the safety vessel in a similar shape to the safety vessel, and fluid is inserted between the reactor vessel and the safety vessel and between the safety vessel and the lining, especially between the safety vessel and the lining. By filling the space between the reactor vessel and the safety vessel with liquid, the space between the reactor vessel and the safety vessel can be used for calibration of the weld lines of the reactor vessel and safety vessel, and for continuous leakage monitoring of coolant from inside the reactor vessel. The space between the safety container and the lining can be made sufficiently narrow as the inspection from this space is no longer necessary, and the fluid seismic effect can be minimized. This improvement has the effect of improving seismic support performance.Furthermore, the outer surface of the lining, which receives liquid pressure in the vibration direction during an earthquake, is supported by the reactor building base, while the reactor vessel and safety vessel are made stronger by the ribs. Since the reactor vessel and the safety vessel are connected to each other, their rigidity is high, and there is no risk of buckling of the reactor vessel and safety vessel due to external pressure during an earthquake, which has the effect of improving the soundness of the earthquake-resistant support structure.

If the same liquid is filled between the reactor vessel and the safety vessel and between the safety vessel and the lining, the reactor vessel will be surrounded both inside and outside by the same fluid with good heat transfer.
The temperature distribution in the reactor vessel becomes uniform, which has a great effect on reducing the thermal stress that occurs.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view of a conventional seismic support structure for a reactor vessel. 10...Reactor vessel, 11...Safety vessel, 12...
- Rib, 14... Lining, 16... Reactor building base. (7317) Agent Patent attorney Kensuke Norichika (and 1 other person) Figure 1 Figure 3

Claims (3)

[Claims] (1) Excluding the bottomed cylindrical reactor vessel containing the reactor core and related equipment and whose upper flange is supported on a pedestal extending from the reactor building base, and the upper part of this reactor vessel. In an earthquake-resistant support structure for a reactor vessel, the structure includes a safety vessel that is similar in shape to the outer circumference of the reactor vessel and is installed concentrically at a predetermined interval on the outside of the reactor vessel. The inner peripheral surface is firmly connected to the inner peripheral surface by ribs spaced apart from each other at a plurality of places, and the inner wall surface of the hole in the building base where the reactor vessel and safety vessel are installed is concentric with the safety vessel at a predetermined distance from the safety vessel. A reactor vessel characterized in that a metal plate lining is stretched in a similar shape to the safety vessel, and a fluid is filled between the reactor vessel and the safety vessel and between the safety vessel and the lining, respectively. Seismic support structure. (2) Claims characterized in that the fluid filled between the reactor vessel and the safety vessel is an inert gas, and the fluid filled between the safety vessel and the lining is a liquid metal. Earthquake-resistant support structure for the reactor vessel described in paragraph 1. (3) The seismic support structure for a reactor vessel according to claim 1, wherein the fluid filled between the reactor vessel and the safety vessel and between the safety vessel and the lining is liquid metal.