JPS60194026A - Cold trap device for tank type fast breeder reactor - Google Patents

Abstract

PURPOSE:To reduce the size of a liquid Na cleaning up device for a coolant in a tank type fast neutron reactor by contg. said device into a small-sized cylindrical vessel and feeding liquid Na to the cleaning up device by making use of a main pump for the coolant. CONSTITUTION:A cold trap 36 for cleaning-up liquid Na of a coolant is made smaller in diameter and is suspended from a roof slab 1 in a vessel 38 of a tank type fast breeder. The liquid Na of the coolant contg. an increased concn. of O2, H2 and other impurities after reiterative use enters a main pump 35 from a low temp. plenum 40 in the vessel 38 and passes through a high pressure plenum 42 into a furnace core 34 where the liquid Na is heated and is then fed to a high-temp. plenum 39. Part of the liquid Na in the plenum 42 is at the same time admitted through an introducing pipe 43 into the cold trap device 36 where the Na is cooled by a cooler 46 and the impurities are deposited on and captured by a metallic mesh layer 44. The cleaned-up Na returns again through an outlet 45 to the low temp. plenum 40 in the vessel 38 and acts as a coolant. The trap 36 itself is of a small-sized cylindrical shape and does not require a pump and therefore the reduction in the size of said trap is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cold trap device for purifying impurities in a primary coolant in a tank-type fast reactor.

[Technical Background of the Invention] Generally, a liquid metal such as liquid sodium is used as a coolant for a fast breeder reactor. When liquid metal is used as the coolant, if the concentration of impurities such as hydrogen and oxygen contained in the liquid metal is high, corrosion of piping and equipment through which the liquid metal flows will be accelerated and heat transfer efficiency will be reduced due to corrosion. There are many problems. Therefore, it is necessary to control the concentration of impurities contained in the liquid metal, and the impurities are removed continuously or discontinuously by some means. Various devices have been proposed to purify liquid metal in this way, but all of them basically reduce the saturation solubility of impurities contained in the liquid by cooling the liquid metal. A cold trap method is used to remove supersaturated content by depositing it on the surface of a wire mesh, etc. When purifying the primary system cooling material of a tank-type fast reactor, an integrated cold trap device is used, in which the cold trap device is housed inside the reactor vessel, taking into consideration the problems of radiation wave exposure and radiation interference. There is. A conventional integrated cold trap device will be described below with reference to FIG.

In Figure 1, the symbol @1 partially indicates the roof slab that serves as the upper lid of the reactor vessel.
A cylindrical metal mesh layer 3, which is a trapping part for trapping and removing impurities, is disposed in a cylindrical container 2 with an open top that is suspended from the container. Metal mesh layer 3
A pipe 4 is inserted into the center of the metal mesh layer 3, and the entire metal mesh layer 3 is a cylindrical pipe 7 with a number of inlets 5 provided at the top.
It is stored inside. A pipe 4 with a closed lower end and provided with a large number of outlet ports 6 is provided at the center axis of the metal mesh layer 3. The upper and lower ends of the metal mesh layer 3 are sealed by rings 8.9. A gas cooling coil 10 is wound around the upper side surface of the cylindrical tube 7, and the gas supply pipes 11, 12 of the gas cooling coil 10 pass through the flange 13 on the upper surface of the cylindrical container and are connected to a gas supply system (not shown). ing.

A cylindrical cap 14 is provided on the outer periphery of the gas cooling coil 10.
is installed, and the lower part of the cap 14 is fixed to a partition plate 15.

A heat exchanger 16 is arranged at the lower outer circumference of the cylindrical tube 7. This heat exchanger 16 has heat transfer tubes 17 in a cylindrical double tube structure.
are arranged, and hot zones 18, 19 are located at the top and bottom. The lower high temperature zone 19 is a pipe 2 inserted through the lower end of the pipe 4 in the center of the metal mesh layer 3.
0 through a communication pipe 21. The upper high temperature zone 18 is connected to a pump 22 by a communication pipe 23.

An inlet side flow meter 28 is installed in the communication pipe 23. The inlet side of the pump 22 is provided through the lower end of the cylindrical container 2, and the penetrating portion serves as an inlet 29 for liquid metal. Further, the low temperature region of the heat exchanger 16 is connected to the lower part of the pipe 4 by a communication pipe 25, and the outlet side of the low temperature region of the heat exchanger 16 is connected to the outside of the cylindrical container 2 by the communication pipe 26. It is connected to 27. The communication pipe 26 is provided with an outlet side 1f21i128.

A power supply cable 30 of the pump 22 is guided by a cable piping 31 to a small flange 32 through the partition plate 15 and the upper flange 13 of the cylindrical container, and is connected to a pump control panel (not shown) by a cable line 33.

The liquid metal purification apparatus configured in this manner operates as follows.

That is, high temperature liquid metal is pumped into the communication pipe 2 by the pump 22.
3 flows through the upper hot zone 18 of the upper hot zone 16 of the heat exchanger 16, passes through the heat exchanger tube 17, is cooled by the liquid metal in the low temperature zone, and flows into the lower hot zone 19. Furthermore, the gas passes through the pipe 20 via the communication pipe 21, is further cooled by the gas cooling coil 10, and flows into the metal mesh portion 3 from the inlet 5. Impurities in the liquid metal precipitate in this metal mesh portion 3. In other words, mesh part 3
Impurities with solubility at or above the temperature precipitate out in the form of various compounds. Impurities are removed in the metal mesh part 3
The liquid metal descends in the pipe 4 from the outlet 6, passes through the communication tube 25, reaches the low temperature region of the heat exchanger 16, is heated by the heat exchanger tube 17, passes through the communication tube 26, and flows out from the outlet 27. do.

[Problems with Background Art] In the conventional liquid metal purification apparatus as described above, a large number of devices and parts are arranged inside the cylindrical container 2, and the diameter of the cylindrical container 2 is quite large. For this reason,
When installed on the roof slab, the placement relationship with the primary system pump, intermediate heat exchanger, and other communication equipment becomes a problem, and it is desired to place the purification system equipment in a cylindrical container with an even smaller diameter. .

In addition, because electromagnetic pumps are often used for pumps,
There were problems with cooling the coil section, heat-resistant protection of the cable, etc.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and it aims to reduce the diameter of a cylindrical container housing purification system equipment to reduce its size, and to improve the reliability of a pump for circulating liquid metal coolant. An object of the present invention is to provide a cold trap device for a tank-type fast reactor with improved performance.

[Summary of the Invention] That is, the present invention provides a cylindrical container, a liquid metal introduction pipe connected to the lower part of the cylindrical container, and a method for cooling the liquid metal flowing into the cylindrical container from the introduction pipe. a cooler disposed at the lower part of the cylindrical container to remove impurities from the liquid metal cooled by the cooler; and a cylindrical metal mesh layer disposed above the cooler to remove impurities from the liquid metal cooled by the cooler. This cold trap device for a tank-type fast reactor is characterized in that it is equipped with a cylindrical metal mesh H"c and an outlet through which the purified liquid metal flows out.According to the present invention, the primary system main pump A part of the liquid metal sent to the reactor core is guided to the purification system for purification.There is no internal purification system circulation pump, and in order to cool and purify the liquid metal in the low-temperature plenum, The system can be made smaller.

[Embodiments of the Invention] Hereinafter, an embodiment of a cold trap for a tank-type fast reactor according to the present invention will be described with reference to FIGS. 2 and 3. In the figure, the same parts as in FIG. 1 are designated by the same reference numerals, and the explanation thereof will be omitted.

FIG. 2 is a schematic cross-sectional view showing the mounting position of the cold trap device according to the present invention. In FIG. 2, reference numeral 38 indicates a reactor vessel of a tank-type fast reactor, which is suspended from the roof slab 1 within the reactor vessel 38, penetrates the partition wall 37, and reaches the low-temperature plenum 40. A primary system pump 35 is arranged. An outlet pipe 41 of this secondary system pump 35 is connected to a high-pressure plenum 42 at the lower part of the reactor core 34 . This high pressure plenum 42 has a primary system pump 35.
An introduction pipe 43 is connected to introduce a part of the liquid metal sent from the cold trap device 36 into the cold trap device 36 according to the present invention. This introduction pipe 43 is suspended from the roof slab 1 and passes through the partition wall 37 to the low temperature plenum 4.
It is connected at the bottom of the cold trap device 36 where it reaches 0.

However, in the cold trap device 36,
Liquid metal enters the pump 35 from the low temperature plenum 40, and liquid metal pumped out from the pump 35 enters the high pressure plenum 42.
It passes through the high-pressure plenum 42 into the reactor core 34, is heated, and is sent to the high-temperature plenum 39. At the same time, a portion of the liquid metal sent to the high pressure plenum 42 is transferred to the inlet pipe 43.
and into the cold trap device 36. The liquid metal purified within the cold trap device 36 is returned to the cold plenum 40 again.

FIG. 3 is a longitudinal sectional view showing the cold trap device 36 in detail. In FIG. 3, the reference numeral 36 designates a cylindrical container, which is suspended from the roof slab 1, and has a cylindrical metal mesh layer with the central portion removed along the central axis. 44 are arranged. The part of the cylindrical container 3 that comes into contact with this mesh layer 44
A plurality of outflow ports 45 are provided in the body of No. 6. A cooler 46 is disposed below the mesh layer 44 1, and a heat insulating layer 48 is installed on the outer periphery of the cooler 46 with a vibrator 47 in between.

A liquid metal inlet nozzle 50 having a hollow portion 49 is attached to the lower end of the cylindrical container 36 .

The inflow nozzle 50 has a guide tube 51 whose upper end is open in a trumpet shape.
It is connected by pressing it onto the liquid gold Iil inlet pipe 43 having a. The liquid metal inlet pipe 430 inlet is connected to the high pressure plenum 42 . Moreover, the metal mesh layer 44
An upper partition plate 52 is provided at the upper end, and the tip of the thermal lightning pair 60 is set in the metal mesh layer 44 through the upper partition plate 52. A doughnut-shaped lower partition plate 53 is provided at the lower end of the metal mesh layer 44. The cooling pipe 54 of the cooler 46 passes through the upper partition plate 52 and the upper flange 55 and is connected to a coolant supply system installed outside (not shown).

Thus, the cold trap device 36 having the above configuration operates as follows.

That is, as shown in FIG. 2, liquid metal in the low-temperature plenum 40 is sucked in by the primary pump 35 and sent to the high-pressure plenum 42 through the pump outlet piping 41.

A portion of the liquid metal in the high pressure plenum 42 is transferred through the inlet tube 43 from the inlet nozzle 50 to the cooler 46 . The liquid metal is cooled while passing through the cooler 46, and impurities in the cooled liquid metal in the metal mesh layer 4i'' are precipitated and captured. It is returned to the low temperature plenum 40 through the outlet 45 of the section.

The cold trap device 36 does not use its own pump for circulation as a purification system equipment, so the device is small, and the cooling system can be small because it cools and purifies the liquid metal in the low-temperature plenum. The diameter can be made small, and since a primary system pump is used to circulate the liquid metal, the speed is extremely high.

FIG. 4 is a sectional view showing another embodiment of the cold trap device [36a] according to the present invention. Figure 4, Figure 2, Figure 3
The same reference numerals are used for the same parts as those in the figures, and the explanation thereof will be omitted.

In FIG. 4, a metal mesh layer 44 with a central shaft portion removed is disposed inside a cylindrical container 36 that is suspended from the roof slab 1.
has a plurality of inflow ports 56a and outflow ports 56 on the inside and outside.
It is housed in a double-tube structure container 57 having a diameter of 1.b. The upper end of this container 57 is connected to an upper flange 59 by a pipe 58.
It is connected to the. A thermocouple 6° is suspended from the upper flange 59 and set in the metal mesh layer 44 (
There is. [A receiving plate 61 is provided at the lower part of the container 57, and this receiving plate 61 is connected to the vibro 2, and a cooler 46 is disposed inside the vibro 2.

The cooling pipe 54 of the cooler 46 is connected to the vibro 2 and the heat insulating material 6.
3 and further through the upper flange 55 to be connected to a coolant supply system installed outside.

A baffle plate 64 is provided at the bottom of the cooler 46, and an orifice 68 of the baffle plate 64 connects the cooler 46 and the outlet of the lower heat exchanger 65.

The inlet side of the heat exchanger 65 is connected to an inflow nozzle 50 , and the inflow nozzle 50 is connected to a guide pipe 51 and pressed against the IC introduction pipe 43 .

A liquid metal outlet 66 and a drain port 67 are provided at the bottom of the cylindrical container 36 .

The cold trap device M36a having the above configuration operates as follows. That is, the liquid metal fed through the inlet pipe 43 is sent through the injection nozzle 50 to the coil 65 of the heat exchanger 65, cooled by the heat exchanger 65, and passed through the orifice 68 of the baffle plate 64 to be cooled. into the vessel 46. It is further cooled by the cooler 46 and passes through the orifice 69 of the receiving plate 61 before reaching the metal mesh layer 44 .

In this metal mesh layer 44, impurities in the liquid metal are precipitated, captured, and purified. The purified liquid metal flows out from the outlet 56b of the double tube container 57 into the cylindrical container 36, passes around the outer periphery of the cooler 46, passes through the communication port of the baffle plate 64, and reaches the heat exchanger 65. It is heated by a heat exchanger 65 (outflows from an outlet 66 and returned to the cold plenum).

[Effects of the Invention] According to the present invention, only the metal mesh can be replaced,
Metal mesh layer, cooler or heat exchanger provided below the cooler can be arranged in three stages in the cylindrical container.
The diameter of the cylindrical container can be reduced. In addition, since there is no pump, the entire cold trap device can be easily removed.

In general, there are no placement problems when installing it on the roof slab, and it is small and lightweight, making it easy to maintain.
A cold trap device for a tank-type fast reactor that is highly reliable as a purification system can be provided.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional cold trap device for a tank-type fast reactor, FIG. 2 is a schematic view showing the mounting position of the cold trap device according to the present invention in a reactor vessel, and FIG.
4 and 4 are longitudinal sectional views showing respective embodiments of the cold trap device for a tank-type fast reactor according to the present invention. 1・・・・・・・・・Roof slab 2・・・・・・
...... Cylindrical container 3 ...... Metal mesh layer 4 ...
・・・・・・・・・Pipe 5・・・・・・・・・Sodium inlet 6...
・・・・・・・・・Sodium leakage lower・・・・・・・
・・・・・・Cylindrical pipe 8・・・・・・・・・Upper ring 9・・・・・・
・・・・・・Lower ring 10・・・・・・・・・・・・
Gas cooling coil 11...... Gas supply piping (inlet) 12... Gas supply piping (outlet) 13... ...Top flange 14...Cylindrical cap 15...
...... Partition plate 16 ... Heat exchanger 17 ...
...... Heat exchanger tube 18 ...... Upper high temperature area 19 ...
・・・・・・Lower high temperature area 20・・・・・・・・・
・・・・・・Pipe 21・・・・・・・・・・・・Communication pipe 22・・・・・・・・・Pump 23・・・・・・・・・・・・Communication pipe 24 ......Inlet side flow meter 25...
......Communication pipe 26...Communication pipe 27...Purifier outlet 28...
......Outlet side flow meter 29...
・・・・・・Pump inlet 30・・・・・・・・・・Power cable 31・・・・・・・・・・・・Cable piping 3
2...Small flange 33...
・・・・・・Cable line 34・・・・・・・・・・・・
・Furnace core 35... Primary system main pump 36...
・・・・・・・・・Cold trap device 37...
...... Bulkhead 38 ... Reactor vessel 39 ...
・・・・・・High temperature Blenheim 40・・・・・・・・・
...Low temperature blennium 41...Pump outlet piping 42...High pressure blennium 43...Introduction Pipe 44...Metal mesh layer 45...
......Liquid metal outlet 46...
......Cooler 47...Pipe 48...Insulation material 49... Bellow structure part 50...
......Inflow nozzle 51...
... Guide tube 52 ... ... Upper partition plate 53 ...
......Lower partition disc 54...
...Cooler piping 55...Top flange 56a...Inflow port 56b...Outflow port 57... ......Double tube structure container 58...
......Pipe 59...Top flange 60...
......Thermocouple 61...Batch plate 62...Vibro 3... ...Insulating material 64...Baffle plate 65...
......Heat exchanger 66...
・Outlet 67・・・・・・・・・Dorenro, Patent Attorney
Suyama Sa - Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Cave

Claims (3)

[Claims] (1) A cylindrical container, a liquid metal introduction pipe connected to the lower part of the cylindrical container, and a cylindrical container for cooling the liquid metal flowing into the cylindrical container from the introduction pipe. a cylindrical metal mesh layer provided at the top of the cooler for removing impurities from the liquid metal cooled by the cooler; A cold trap device for a tank-type fast reactor, characterized in that it is equipped with an outlet through which liquid metal purified in a layer flows out. (2) The cold trap device for a tank-type fast reactor according to claim 1, wherein the cylindrical container and the introduction pipe are connected so as to be able to be freely connected to and separated from each other. (3) The cold trap device for a tank-type fast reactor as set forth in claim 1, wherein the outlet is formed of a plurality of small holes formed in the body or lower part of the cylindrical container.