JPS6071995A - Combustion inhibitor for leaking sodium - 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 leaked sodium combustion suppression device suitable for a sodium handling room provided in a plant building of a fast breeder reactor, for example.

[Technical Background of the Invention] Generally, in fast breeder reactor plants, heat generated in the reactor is transferred to the steam generator through coolant piping, intermediate heat exchangers, etc., and liquid metallic sodium ( (hereinafter abbreviated as sodium) is often used.

In such fast breeder reactor plants, sodium is used at extremely high temperatures (approximately 300°C to 600°C), and since sodium itself is a highly active substance, it reacts when it comes into contact with air or water, causing a large amount of damage. It will release a lot of energy.

Therefore, in order to minimize the impact on the surrounding area in the event of damage to reactor cooling system equipment and piping, it is necessary to provide a device that quickly contains leaked sodium and suppresses combustion.

A conventional leaked sodium combustion suppression device will be explained with reference to FIG. FIG. 1 shows a leaked sodium storage chamber having reactor cooling system equipment and piping, and FIG. 2 is a plan view taken from A--A in FIG. 1.

That is, the reference numeral 1 in FIG. 1 indicates a building of concrete structure used, for example, in a fast breeder reactor plant, and the inner wall and bottom surface of this building 1 are covered with a lining plate 2 made of, for example, stainless steel. The space in which the lining plate 2 is stretched serves as a storage chamber 4 in which sodium handling equipment 3 is accommodated, and the handling equipment 3 is installed on an equipment installation part 6 by legs 5. The handling equipment 3 is one that stores liquid sodium, such as a dump tank, and may also include a heat exchanger, a steam generator, a pump, etc., which flow and handle liquid sodium, as the case may be. Therefore, the handling equipment 3 is connected to the sodium flow pipe 7, and the pipe 7 is led out of the storage chamber 4. Inside the storage chamber 4, an air supply duct 8 and an exhaust duct 9 are provided facing each other with a slight space between them from the side wall surface. There is a coolant discharge port 10 in the air supply duct 1-0.
However, each exhaust duct 9 is provided with a suction port 11. Further, a corrugated combustion suppressing plate 12 is provided in the storage chamber 4 so as to surround the lower side surface of the handling equipment 3 from approximately the center thereof and divide the chamber into upper and lower sections. Combustion suppression plate 12
A plurality of gaps 13 for inserting the handling equipment 3 and preventing thermal deformation and drain holes 14 for draining liquid sodium condensed from leaked sodium are bored in the housing. In addition, the combustion suppression plate 12 has a hole for penetrating 8.9 into both ducts 1, and both ducts 8.9 and the combustion suppression plate 12
There is a gap M between them as shown in FIG.

Therefore, the combustion suppression plate provided to suppress the contact between the stored sodium and air due to the heat released from the sodium handling equipment 3 and the piping 7 installed in the storage chamber 4 and the heat conduction. 12 or the installation part 6 of the handling equipment 3
In order to prevent the concrete temperature from rising near the concrete, air is flowed in from the supply duct 8 by air conditioning and cooled by forced convection toward the exhaust duct 1 and the exhaust duct 9.

By the way, when sodium leakage occurs in the storage chamber 4 or a room on an upper floor, the leaked sodium is guided to the storage chamber 4 and drained into the storage chamber through a plurality of drain holes 14 provided in the combustion suppression plate 12. It is stored on the bottom of 4. Since the sodium stored in the storage chamber 4 is restricted from coming into direct contact with the air by the combustion suppression plate 12, its combustion is suppressed and the thermal influence on the building is reduced.
It has been proposed to ensure the integrity of the plant and shorten the recovery time of the plant after a sodium leak.

[Problems with backlash technology] By using the combustion suppression plate 12 described above, an effect of suppressing combustion of sodium can be expected. However, in order to make this effect significant, the opening area of the suppression plate, that is, the total area of the drain hole 14 and the gap 130M, must be 0.5% or less of the combustion area of the Nutley → - ram. There is an experimental result that shows that this is not the case, and unnecessary gaps of 130M must be prevented as much as possible.

For this reason, in the conventional example shown in FIG. There is a concern that a sufficient combustion suppression effect may not be expected, and there is a demand for a device that can be expected to have a more suppressive effect.

That is, when installing the ducts 8 and 9 in the storage chamber 4, the ducts 8 and 9 are placed in the combustion suppression plate 12 in order to prevent the ducts 8 and 9 from coming into direct contact with the combustion suppression plate 12 and being deformed due to thermal expansion. A through hole is provided so as to have a gap M from the outer diameter. Similarly, a through hole is provided in the device that is larger than the outer circumference of the sodium handling device 3 so as to have a gap 13 therebetween.

However, if the total area of these clearance gaps M and 13 becomes larger than the floor area, the amount of oxygen flowing in will increase. The greater the inflow of oxygen, the faster the reaction with leaked sodium, and the greater the danger. Therefore, it is necessary to reduce the total area of these gaps M and 13 as much as possible.

"Object of the Invention" The present invention has been made in response to such conventional circumstances,
By suppressing the combustion of the stored sodium in the containment chamber that contains sodium leaked from reactor cooling system equipment and piping, the atmospheric temperature in the containment room or surrounding rooms is suppressed, and the temperature rise in the building is further reduced. The present invention aims to provide a leaked sodium combustion suppression device that can ensure the integrity of a building and shorten the recovery time of a plant after a sodium leak.

[Summary of the Invention] The present invention includes a storage chamber for accommodating sodium handling equipment, and a storage chamber that is provided upright on the inner wall of the storage chamber and has a coolant supply port at the top and a coolant discharge port at the bottom. and a coolant supply panel in which a coolant distribution path is formed, a coolant discharge panel that absorbs the coolant discharged from the supply panel and discharges it to the outside, and a coolant discharge panel in the vicinity of the sodium handling equipment. A combustion suppression device for leaked sodium characterized by comprising a combustion suppression plate provided therein and having a drain hole for draining liquid sodium in which leaked sodium is condensed.

[Embodiment of the Invention] Hereinafter, an embodiment of the leaked sodium combustion suppression device according to the present invention will be described with reference to FIGS. 3 and 4.

In FIG. 3, a lining plate 2 made of, for example, stainless steel is stretched over the inner wall and bottom surface of a building 1 having a concrete structure. Inside the building 1, there is constructed a storage chamber 4 in which sodium handling equipment 3 is housed. A cooling material supply panel 16 is erected on the left inner wall surface of the storage chamber 4 and has a space in which a cooling material distribution path 15 is formed. This coolant supply panel 16 has a coolant supply duct 17 attached to its upper side, and a coolant discharge port 18 provided at its lower side. Further, on the right inner wall surface of the storage chamber 4, a coolant discharge panel 20 is erected, facing the coolant supply panel 16 and having a space in which a coolant distribution path 19 is formed. . This coolant discharge panel 20 is provided with a coolant suction port 21 at the bottom and a discharge duct 23 at the top.

A corrugated combustion suppression plate 12 is disposed between the panels 16, 20 and the sodium handling equipment 3 so as to cover the central part of the outer surface of the handling equipment 3, as shown in the plan view of FIG. It is provided. The combustion suppressing plate 12 is supported by receiving ribs 22 attached to both panels 16 and 20 to maintain airtightness between them.

However, there is a slight gap 13 between the handling equipment 3 and the combustion suppression plate 12 in order to prevent distortion and deformation due to thermal expansion and the like. Further, the combustion suppressing plate 12 is provided with drain holes 14 scattered in the troughs. The sodium handling equipment 3 is installed in the equipment installation part 7 on the legs 5 at 10-8-.

Although both panels 16 and 20 are shown with the coolant supply system on the left side and the coolant discharge system on the right side, they can be reversed so that the right side is the supply system and the left side is the discharge system. Although both ducts 17 and 23 are not shown, they are connected to the air supply and exhaust systems outside the building 1, respectively.

Next, the operation of the device according to the above configuration will be explained.

Under normal conditions, the temperature rise in the atmosphere below the combustion suppression plate 12 and the equipment installation section 7 caused by heat dissipation or heat conduction from the equipment 3 handling sodium in the reactor cooling system is caused by the increase in temperature of the coolant from the coolant supply air duct 17. It is cooled by the supply air discharged into the storage chamber 4 from the discharge port 18 through the circulation path 15 . The coolant is then exhausted from the suction port 21 through a coolant exhaust duct 23 as shown by the arrow.

If damage occurs to the sodium handling equipment 3 or the piping 7, the sodium contained therein will leak to the outside.
The waste that passes through the drain hole 14 of the combustion suppression plate 12 is stored at the bottom of the storage chamber 4.

Conventionally, in the leaked sodium combustion suppression device configured as described above, the gap M between the combustion suppression plate 12 and the coolant duct 8.9 can be eliminated as shown in FIG. It becomes possible to further suppress the Furthermore, since the coolant flows along the concrete wall, heat removal from the side wall of the stored sodium chamber from the healthy chamber side can be made even more effective.

This suppresses the atmospheric temperature of the leaked sodium storage room 9 where the leaked sodium combustion suppression device is installed as well as the temperature rise of the building 8, and prevents the influence on the building 8, that is, if the temperature of the building 8 becomes too high, As the temperature of the concrete that forms Building 8 increases, hydrogen gas flows out from inside the concrete as the concrete structure breaks down, and this hydrogen gas accumulates, creating a risk of explosion and increasing the possibility that the integrity of Building 8 will be compromised. However, this can be reduced.

[Effects of the Invention] According to the leaked sodium combustion suppressing device of the present invention, air inflow into the combustion section is improved by eliminating unnecessary gaps M-11- when conventional coolant ducts, etc. are provided. It becomes possible to further suppress heat generation, and as an additional effect, it becomes possible to more effectively remove heat from the side wall of the accident room from the side of the adjacent healthy room.

[Brief Description of the Drawings] Fig. 1 is a longitudinal sectional view illustrating a conventional leaked sodium combustion device, Fig. 2 is a plan view taken along the arrow A-A' in Fig. FIG. 4 is a longitudinal cross-sectional view showing one embodiment of the leaky sodium combustion apparatus, and FIG. 4 is a plan view taken along the line BB' in FIG. 3. 1...Building 2...Lining plate 3...Sodium handling equipment 4...Accommodation room 5...Legs 6...Equipment installation part 7...Piping 8...Air supply duct 9 ...Exhaust duct 10...Discharge port 11...Suction port 12...Combustion suppression plate 13...Gap 14...Drain holes 15, 19...Coolant flow path 16... - Coolant supply panel 17... Coolant supply duct 18... Coolant discharge port 20... Coolant discharge panel 21... Coolant suction port 22... Receiving rib 23・・・
・Discharge duct application agent Patent attorney Kikuchi Part 5-1 Part 2 Figure 3 Figure/7 ・、：． ~4~ 23″:・: / , °S. ° W7 8 ./)−'−’7− yq , 2 2 ° 0 pa 4th Fig. 575-

Claims (3)

[Claims] (1) A storage chamber for accommodating sodium handling equipment, and a coolant distribution system installed on the inner wall of this storage chamber, with a coolant supply port at the top and a coolant discharge port at the bottom. a coolant supply panel formed with a coolant, a coolant discharge panel that sucks the coolant discharged from the supply panel and discharges it to the outside; A combustion suppression device for leaked sodium, comprising a combustion suppression plate having a drain hole for draining condensed liquid sodium. (2) The combustion suppression device for leaked sodium as set forth in claim 1, wherein the combustion suppression plate is formed in a corrugated shape and has a plurality of drain holes provided in its troughs. (3) The leaked sodium combustion suppression device according to claim 1, wherein the side surface of the combustion suppression plate is supported by a receiving rib attached to the coolant supply and discharge panel.