JPS61137094A - Cooling device for liquid metal cooling type reactor - 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 cooling device for a nuclear reactor secondary cooling system installed outside a nuclear reactor vessel as cooling equipment for a liquid metal cooled nuclear reactor.

[Technical background of the invention and its problems]

In fast breeder reactors that use liquid metal coolant, the reactor coolant, or primary coolant, has high levels of primary radioactivity, so it is necessary to isolate the primary cooling system from the steam generation system. . In addition, heat exchange between liquid metal and water is essential in the process of generating steam to be supplied to a turbine generator. Since the chemical reaction heat generated by contact between the two is enormous, it is necessary to dissipate this heat, so a secondary cooling system is installed between the primary cooling W system and the steam generation system. . A secondary cooling system in a conventional liquid metal cooled nuclear reactor will be explained with reference to FIG. A reactor core 2 is disposed within the reactor vessel 1, and a primary main circulation pump 4 that circulates a liquid metal coolant 3 for cooling the reactor core 2 within the reactor vessel 1, a primary coolant, and a secondary coolant. A primary cooling system consisting of an intermediate heat exchanger 5 that performs heat exchange with the air conditioner is arranged. The secondary cooling system includes an intermediate heat exchanger 5, a steam generator 6 that generates steam to be supplied to a turbine (not shown), and a rigid liquid surface mechanical type 2 that circulates the secondary coolant. Next main circulation pump 8 and piping 7 that connects these devices
It is composed of. In the above conventional example, in the arrangement of the secondary cooling system, each device of the steam generator 6 and the secondary main circulation pump 8 is set to W! It was placed in a separate room by 9. In addition, since both the steam generator 6 and the secondary main circulation pump 8 serve as one anchor point for the connecting piping 7, the piping installed between each device needs to be meandering to absorb thermal expansion. There was a problem with the length being too long.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to simplify the equipment arrangement, shorten the piping length, and reduce the space volume of the reactor building and reactor auxiliary buildings, thereby reducing plant construction costs. An object of the present invention is to provide a cooling device for a liquid metal cooled nuclear reactor.

[Summary of the invention]

In order to achieve the above object, the present invention provides a liquid metal cooled nuclear reactor in which an intermediate heat exchanger disposed inside a reactor vessel and a steam generator disposed outside the reactor vessel are connected by piping. In the cooling device, a liquid metal inlet distribution pipe is provided at the upper part of the main body shell of the steam generator, and a liquid metal outlet riser pipe is provided approximately at the center of the main body shell of the steam generator, and the inside of this outlet riser pipe is provided. A mechanical pump is disposed in the steam generator, and a liquid metal level is provided inside the main body of the steam generator.

In addition, in order to absorb the volumetric expansion and contraction of the inventory in the secondary system due to temperature changes of the liquid metal, a liquid level of the liquid metal is provided on the inlet side inside the steam generator, and the water vapor provided in the steam generator is It is characterized by physically separating the nozzle head and the liquid metal inlet/outlet nozzle head.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a system diagram of a cooling system for a liquid metal cooled nuclear reactor according to an embodiment of the present invention. In the figure, a primary main circulation pump 1 is installed in a reactor vessel 10 that includes a reactor core 11.
A primary cooling system for the nuclear reactor is provided, which includes a reactor 2 and an intermediate heat exchanger 13. The secondary cooling system is composed of an intermediate heat exchanger 13, a steam generator 17, and a pipe 16 passing through the wall 15 to connect the intermediate heat exchanger 13 and the steam generator 17, and A mechanical pump 18 is disposed inside the steam generator 17.

FIG. 2 is a longitudinal cross-sectional view showing details of the steam generator 17. As shown in the figure, the steam generator 17 includes a main body shell 19 and a main body support scar 1-20, including heat transfer tubes 21. Contains structures. The liquid metal inlet section is composed of the liquid metal pipe 16, the liquid gold inlet header 24, and the liquid gold inlet distribution pipe 25.

By the way, a liquid level 28 is formed inside the upper part of the main body shell 19 for absorbing changes in the volume of liquid gold chips.

Further, an outlet riser pipe 26 for liquid metal scraps is disposed at the center of the interior of the steam generator 17, and a heat transfer tube bundle inner shroud 27 is disposed roughly outside the outlet riser pipe 26.

On the other hand, a water inlet section is constituted by a water inlet pipe 29 into which water flows from a water supply pump (not shown), a water inlet header 30, a water inlet distribution pipe 31, and a water inlet water chamber 32. In addition, the outlet steam chamber 33, the outlet steam distribution pipe 34, and the outlet steam header 3
5 and the outlet steam pipe 36 constitute a steam outlet section.

The mechanical pump 18 is inserted and supported through a mounting flange 43 in the upper part of the liquid scrap outlet riser pipe 26 . The pump 18 has a structure in which a drive motor (not shown) is installed on the upper part of the pump 18 via a motor stand 40. Further, the pump 18 is a mechanical type having a free liquid level, and sucks the liquid gold scraps in the lower plenum 23, and is provided with a discharge pipe 42 on the outlet side of the hydro section 41. The secondary system piping 45 in the discharge pipe 42 and the outlet rising pipe 26 is connected to the slide joint 4.
It has a structure connected by 4.

A secondary system piping 45 within the outlet riser pipe 26 is connected to a piping 16 that is not shown in FIG. 1 and communicates with the intermediate heat exchanger 13.

The outlet portion of the liquid metal is mainly constituted by the outlet riser pipe 26, the annulus space 37 in the mechanical pump 18 portion, and the outlet riser pipe 26.

Next, the operation of the above embodiment will be explained.

By circulating the primary coolant that cools the heat generated in the reactor core 11 using the primary main pump 12, the intermediate heat exchanger 13
It is transmitted to the secondary cooling system via.

A mechanical pump 18 built in the steam generator 17 circulates the liquid metal as the coolant, and the high-temperature liquid metal heated in the intermediate heat exchanger 13 passes through the piping 16 and then enters the liquid metal inlet header 24. Then, after being distributed in the liquid metal inlet distribution pipe 25, it flows into the upper inner side of the main body shell 19 of the steam generator 17. The high temperature liquid metal is transferred to the heat transfer tube 21.
The metal flows down the outside of the metal, gives heat to the water/steam and cools it down, becoming a low-temperature liquid metal. Such low-temperature liquid metal is
It reverses its flow direction in the lower plenum 23 and rises inside the outlet riser 26. It flows into the pump hydro section 41 of the mechanical pump 18 and is pressurized by the impeller 46 in the hydro port section 41. The liquid metal pressurized by the impeller 46 flows from the discharge pipe 42 through the secondary system piping 45, flows out from the steam generator 17, and reaches the piping 16.

On the other hand, on the water/steam side, water sent from a water supply pump (not shown) flows into the water inlet header 30 from the water inlet pipe 29, is distributed through the water inlet distribution pipe 31, and is then divided into a plurality of parts. The water inlet reaches the water chamber 32. This water inlet water chamber 32
The water distributed into the heat exchanger tube 21 from the heat exchanger tube 2
After absorbing heat while rising inside the steam chamber 1 and turning into steam, it reaches the outlet steam chamber 33, passes through the outlet steam distribution pipe 34,
After merging at the outlet steam header 35, the outlet steam piping 36
and reaches a turbine (not shown).

The mechanical pump 18 is provided with an impeller 46 in the pump eight-hydro section 41, and the impeller 46 is rotationally driven by a motor to suck in liquid metal and increase the pressure, and then discharges the liquid metal into the discharge pipe 42.
It is configured so that the water is sent out from there to a secondary system piping 45.

As explained above, according to this embodiment, by integrating a mechanical pump into the steam generator 8, a circulation pump for the secondary cooling system, which is required in a conventional reactor cooling system, can be removed. Since there is no need to install it, the length of piping can be significantly shortened. Furthermore, it is possible to reduce the sodium inventory in the secondary cooling system, and therefore the capacity of drain tanks and the like can be reduced.

Furthermore, by reducing the number of conventional secondary circulation pumps, the number of rooms and space volume of the reactor building can be reduced, and by shortening the piping length, the space volume of the reactor auxiliary building can be reduced. .

〔Effect of the invention〕

According to the present invention, it has become possible to reduce the number of cooling devices in the secondary cooling system in a liquid metal cooled nuclear reactor, that is, to reduce the number of mechanical pumps. It is possible to reduce the drain tank capacity and the space volume of the reactor building and reactor auxiliary building, which in turn has the effect of contributing to a significant reduction in plant costs.

[Brief explanation of the drawing]

Fig. 1 is a system schematic diagram of a cooling system for a liquid metal cooled nuclear reactor according to an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the steam generator of Fig. 1, and Fig. 3 is a conventional liquid metal cooling system. FIG. 2 is a schematic diagram of a cooling system for a nuclear reactor. 10...Reactor vessel, 11...Reactor core, 12...1
Next main circulation pump, 13... Intermediate heat exchanger, 14...
Roof slab, 16... Piping, 17... Steam generator, 18... Mechanical pump, 19... Main body shell, 21.
...Heat transfer tube, 24...Liquid metal inlet header, 26...
・Liquid metal outlet riser pipe, 27...Shroud, 28・
...Liquid metal level, 29...Water inlet piping, 30...
Water inlet header, 33... Outlet steam pipe, 35... Outlet steam header, 36... Outlet steam piping-'37... Annulus space, 40... Motor stand, 41... Pump hydro section , 42...Discharge pipe, 43...Installation flange, 44...Slide joint, 45...Secondary system piping, 46...Impeller.

Claims (1)

[Scope of Claims] 1. In a cooling device for a liquid metal cooled nuclear reactor, in which an intermediate heat exchanger disposed inside a reactor vessel and a steam generator disposed outside the reactor vessel are connected by piping. , a liquid metal inlet distribution pipe is provided at the upper part of the main body of the steam generator, a liquid metal outlet rising pipe is provided approximately at the center of the main body of the steam generator, and a mechanical pump is installed inside the outlet rising pipe. A cooling device for a liquid metal cooled nuclear reactor, characterized in that the steam generator is configured to have a liquid level inside the body shell of the steam generator. 2. The mechanical pump is characterized in that an impeller is provided in the pump hydraulic section, a discharge pipe is connected to the hydraulic section, and a secondary system piping is connected to the discharge pipe. A cooling device for the liquid metal cooled nuclear reactor described above.