JPS608492A - Emergency core cooling pump - Google Patents

Abstract

PURPOSE:To improve the aseismatic performance by projecting a sideboard from the outside of a plurality of ribs projected circumferentially at the outside of a bit with interval while facing the sideboard against the concrete wall at the portion where the temperature will never rise even if the temperature in the barrel is brought high. CONSTITUTION:A plurality of ribs 14 are projected circumferentially with interval at the outside of a bit 2 while a sideboard 15 is projected from the outside of said rib 14. Even if the interior of barrel 3 is brought to high temperature state to transmit the heat to the concrete foundation 1, the foundation 1 at the portion of the sideboard 15 is never heated, so if the barrel 3 is vibrated laterally upon occurrence of earthquake said lateral vibration is received by the concrete foundation 1 having high strength under low temperature through an annular member 13, sideboard 15, etc. Consequently, quite high safety can be assured even if earthquake has occurred when the temperature in the barrel 3 is high.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides an emergency core for ensuring the integrity of the reactor core even in the event of a hypothetical accident in the reactor-subsystem piping in a boiling water nuclear power plant. The present invention relates to a cooling pump device.

[Technical background of the invention]

As mentioned above, if a reactor-to-shipping accident occurs, the coolant inside the reactor pressure vessel will be lost, but if this is left as it is, the inside of the reactor core will become abnormally high temperature. In order to prevent this, the non-special core cooling pump system is activated to supply water from the pressure suppression pool inside the containment vessel into the reactor pressure vessel in an emergency to lower the temperature inside the reactor core. I have to.

By the way, since the pressure suppression pool is located in the containment vessel as described above, the water temperature in the pool will rise after a loss of coolant accident, and therefore the operating conditions of the pump device will become extremely severe. In order to perform stable operation even under such conditions, a pit barrel type pump device has conventionally been used as the emergency core cooling pump device ff.

First, a conventional pit barrel type emergency core cooling pump device will be explained with reference to FIG.

This emergency core cooling pump system is installed on the lowest basement floor of the reactor building of a nuclear power plant, and as shown in Figure 1,
A bottomed cylindrical pit 2 is buried in the concrete foundation 1, and inside this pit 2 is a barrel 3 having a flange 4 at the upper end that is hooked onto the upper surface of the concrete foundation 1.
is stored. A discharge casing 5 is erected above the barrel 3, and a motor 7 is connected to the upper end of the discharge casing 5 via a motor stand 6.
is installed.

A lower part of a pump main body 8 faces inside the barrel 3, and the pump main body 8 includes an inner casing 9 vertically installed on the motor stand 6, and a motor 7 facing into the inner casing 9. It consists of a rotary shaft 10 which is vertically disposed on the rotary shaft 10 and has a number of impellers 11, 11, . . . projecting from its lower end. An annular member 16 is provided protruding from the lower peripheral surface of the internal casing 9, and an annular spacer 17 is interposed between the annular member 16 and the barrel 3.

According to the above-described configuration, the rotating shaft 1 is driven by the motor 7.
0 rotates together with the impeller 11, and pressure-feeds water from a pressure suppression pool (not shown) sucked through the suction port 9a of the internal casing 9 from the discharge port 5a of the discharge casing 5 to the reactor pressure vessel (not shown).

(Problems with Background Art) By the way, in order to prevent the barrel 3 from lateral shaking when an earthquake occurs, an earthquake-resistant support 12 is interposed between the pit 2 and the barrel 3 at a position corresponding to the spacer 17. At the time of an earthquake, the horizontal load acting on the barrel 3 was transmitted to the pit 2 via the seismic support 12, and the pit 2 was able to receive the load from the concrete foundation 1 in its vicinity.

On the other hand, as an operating condition of the emergency core cooling pump device, when the internal fluid is in a high temperature state, the heat inside the barrel 3 is transferred to the concrete foundation 1 via the outer peripheral wall 3a of the barrel 3 and the pit 2. The strength of foundation 1 will decrease as the temperature increases.

Therefore, if there is a large earthquake while the pump equipment is in a high temperature state, the earthquake-induced horizontal shaking of the barrel 3 will be received by the concrete foundation 1 around the outer periphery of the pit 2, which has reduced strength, and there is a risk that the seismic function will deteriorate. Ta.

[Purpose of the invention]

In view of the above-mentioned points, it is an object of the present invention to provide an emergency core cooling pump device with improved seismic resistance compared to conventional ones.

[Summary of the invention]

According to the present invention, a plurality of ribs are provided on the outside of the pit at intervals in the circumferential direction, and a side plate is provided on the outside of the rib, and this side plate prevents the inside of the barrel from becoming hot. This is achieved by facing the concrete wall in an area where the temperature will not rise even when the temperature rises.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings. Components that are the same as those in the prior art described above are designated by the same reference numerals in the drawings, and their explanations will be omitted.

2 and 3 show a first practical example of the present invention, and since the members inside the barrel 3 are the same as those in FIG. 1, illustration thereof is omitted.

In FIGS. 2 and 3, a cylinder $13 is fitted on the outer peripheral surface of the pit 2 at a portion corresponding to the seismic support 12. A plurality of ribs 14, 14, . . . are provided to protrude apart from each other. The length of this rib 14 is formed so that even if the inside of the barrel 3 becomes high temperature, it reaches the concrete foundation 1 at a portion that is not affected by this heat. Also,
Each of the ribs 14 has an annular side plate 15 projecting from the outside of each rib J4. It goes without saying that each rib 14 and side plate 15 are buried in the concrete foundation 1.

According to the above-mentioned configuration, the inside of the barrel 3 is in a high temperature state, and even if this heat reaches the concrete foundation 1 and heats the concrete foundation 1, the concrete foundation 1 in the area where the side plate 15 is located will not be heated. Therefore, even if an earthquake occurs and the barrel 3 shakes horizontally, the horizontal shaking of the barrel 3 will be transmitted through the torus 13, IJ block 14, side plate 15, etc. to the concrete foundation 1, which is strong at low temperature. can be received by

Therefore, even if an earthquake occurs when the inside of the barrel 3 is at a high temperature, safety can be extremely high.

4 and 5 show a second embodiment of the present invention, in which ribs 14, 14, etc. are directly provided on the outer peripheral surface of the pit 2, without providing the torus 13 in the previously described embodiment. It is a projecting structure.

Even with such a configuration, if the length of the rib 14 is set to penetrate into the concrete foundation 1 to the same extent as in the first embodiment, the same effects as in the first embodiment can be achieved.

FIG. 6 shows a third embodiment of the present invention, in which an independent flat side plate 15 is provided protruding from each rib 14.

Even with such a configuration, similar to the above-mentioned embodiments,
It can be effective.

〔Effect of the invention〕

As explained above, the emergency core cooling pump device according to the present invention has a plurality of ribs projecting from the outside of the pit at intervals in the circumferential direction, and a side plate projecting from the outside of the ribs. The side plate faces the concrete wall where the temperature does not rise even if the temperature inside the barrel rises, which has the excellent effect of improving the rolling resistance compared to conventional ones.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a conventional emergency core cooling pump device, FIG. 2 is a vertical cross-sectional view showing a first embodiment of the emergency core cooling pump arrangement according to the present invention, and FIG. Figure III-
FIG. 4 is a cross-sectional view of the corresponding part taken along the If line, and is the second embodiment of the present invention.
FIG. 5 is a cross-sectional view of a corresponding portion taken along line v-V in FIG. 4, and FIG. 6 is a view similar to FIG. 4 showing a third embodiment of the present invention. 1... Concrete foundation, 2... Pit, 3...
Barrel, 7...Motor, 12...Earthquake support, 1
3... Toric body, 14... Rib, 15... Side plate. Applicant's agent Kiyoshi Inomata Figure 1

Claims (1)

[Claims] 1. A barrel is housed in a pit buried in a concrete foundation, the lower part of the pump body is disposed within the barrel, and an earthquake-resistant support is interposed between the pit and the barrel. An emergency core cooling pump device, characterized in that a plurality of ribs protrude from the outside of the pit at intervals in the circumferential direction, and a side plate protrudes from the outside of the ribs. . 2. The emergency core cooling pump device according to claim 1, wherein the side plate is formed in an annular shape. 3. The emergency core cooling pump device according to claim 1, wherein the side plate is formed independently for each rib. 4. The emergency core cooling pump device according to any one of claims 1 to 3, wherein a cylindrical body is interposed between the pit and the rib.