JPS6179189A - Tank type fast breeder 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 invention 1 The present invention relates to a tank type fast breeder reactor.

[Technical Background of the Invention 1 As is well known, fast breeder reactors are generally classified into tank type and loop type depending on the reactor structure, and usually an intermediate heat exchanger, a coolant circulation pump, etc. are installed inside the reactor vessel. Those with no intermediate heat exchanger and coolant circulation pump installed inside the reactor vessel are called loop types.

Tank-type fast breeder reactors generally have an electrical output of 1 million kW.
In the case of equivalent to e, the reactor vessel has an intermediate heat exchanger, a coolant circulation pump, etc. inside the reactor vessel, so the diameter of the vessel is about 20 m.

For this reason, the roof slab that closes the upper end of the reactor vessel has a large diameter, and the vertical displacement (deflection) of the roof slab tends to increase during earthquakes, especially during vertical earthquakes.

Therefore, in conventional tank-type fast breeder reactors in which the core is supported from the bottom or side of the reactor volume a3, the control rods are moved excessively from the core due to vertical relative displacement between the roof slab and the reactor core that occurs during an earthquake. This is unfavorable for the integrity of the reactor.

On the other hand, in recent years, a tank-type fast breeder reactor has been proposed in which the core is suspended from the roof slab in order to suppress the relative displacement between the roof slab and the reactor core during an earthquake.

FIG. 1 shows a conventional example of this tank-type fast breeder reactor, and in the figure, reference numeral 1 indicates a reactor vessel.

An intermediate heat exchanger 2 and a coolant circulation pump 3 are disposed within the reactor vessel 1, which is comprised of a reactor core 4J3 and a core support structure 5.

The reactor core 6 is suspended from the roof slab 8 to the low-temperature area of the first prince reactor vessel 1 by a suspension shell 7.

A steady rest 9 is provided around the reactor core section 6 and fixed to the inner wall of the reactor vessel 1 for regulating horizontal displacement of the reactor core 4 .

The roof slab 8 is provided with a control rod drive unit 10 for controlling the reactor output, and this control rod drive unit 1'10 extends into the reactor core 4 through the suspension shell 7. There is.

Further, a liquid metal coolant 11 is stored in the reactor vessel 1 up to the level of liquid 1 shown in the figure, and is partitioned by a partition wall 12 into a high temperature region and a low temperature region. This gap g12 is supported by the hanging body 7 and the thermal noise shielding wall 13 by welding.

In addition, from the coolant liquid level in the reactor vessel 1 to the roof slab 8
The cover gas space 14 of the hatch is filled with a cover gas such as argon gas.

The coolant 11 in the reactor vessel 1 is sucked in from the pump suction port 15 by the coolant circulation pump 3, and is drawn into the pump discharge pipe 16.
and is fed into the high-pressure blemish 17 of the reactor core 6. The cold UL material 11 sent into the high-pressure plenum 17 is heated in the core 4 and flows out into the hot pool 18 in the high-temperature region, passes through the flow hole 19 formed in the hanging shell 7, and enters the intermediate heat exchanger inlet 20 to generate intermediate heat. into the exchanger 2.

Intermediate heat exchange 2! The coolant 11 that has flowed into A2 undergoes heat exchange with the secondary coolant, becomes low temperature, and flows out into the cold pool 21 in the low temperature region. The coolant 11 that has flowed out into the cold boule 21 is again circulated 11 through the above-mentioned flow path by the coolant shield lr & pump 3.

In this type of tank-type fast breeder reactor, the reactor core 6 and the roof slab 8 are connected by the suspension shell 7, so that the suspension shell 7 can receive the liquid metal in the hot pool 18 in the high temperature region. A flow hole 19 leading to the intermediate heat exchanger 2 is formed.

[Problem with backweight technology 1. However, in a tank-type fast breeder reactor with such grooves, as shown in FIG. The cold fJI material 111 flows in with a flow vector as shown in the figure.

As is clear from the figure, the coolant 11 flowing from one flow hole hits the free liquid surface F of the coolant 11 at a considerable speed. As a result, the free liquid surface F of the coolant 11 ripples, and the cover gas is drawn into the coolant 11.

The cover gas that has been engulfed in the coolant 11 in this way flows into the intermediate heat exchanger 2, where it is heat exchanged with the cooling material in the secondary system. It flows out to I81 or cold boule 21.

The coolant 11 that has flowed into the cold boule 21 flows into the core again by the cold material circulation pump 3, but during such cold cooling, the above-mentioned J: U;
, and the cover dregs that have been introduced into the reactor core, there is a problem in that this cover dregs unnecessarily changes the reactivity in the reactor core.

[Object of the Invention J The present invention has been made in response to such conventional circumstances,
The present invention aims to provide a tank-type fast breeder reactor that can effectively prevent the entrainment phenomenon of cover gas at the free liquid surface of the coolant.

[Summary of the Invention The present invention provides a nuclear reactor vessel containing liquid metal;
a roof slab that shields the upper end opening of the reactor vessel; a reactor core housed in the reactor vessel; a suspension shell having a flow hole on the side surface that suspends and supports the core on the roof slab; In a tank-type fast breeder reactor equipped with a shell and an intermediate heat exchanger disposed in a space formed by the reactor vessel, a nozzle is disposed in the flow hole formed on the side surface of the hanging shell. This is a tank-type fast breeder reactor. .

[Embodiment of the Invention] The details of the present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 2 shows an embodiment of a tank-type fast breeder reactor of the present invention.
A flow hole nozzle 22 having a diameter corresponding to the diameter of one flow hole is formed in one hole so as to protrude toward the intermediate heat exchanger 2 side. This flow hole nozzle 22
The protrusion length to the intermediate heat exchange B2 side is, for example, 25 On
+m. In addition, except for the parts mentioned above,
Since the structure is similar to that of the tank-type fast breeder reactor shown in the figure, the same members are given the same reference numerals and detailed explanations will be omitted.

In the tank-type fast breeder reactor configured as described above, the flow of the coolant 11 flowing from the bottom pool 18 through the flow hole 19 of the suspension shell 7 to the intermediate heat exchanger 2 side is 41 yen.
The flow is as shown in vector diagram 1.

That is, in FIG. 4, the arrow indicates the flow direction of the cold O material 11, and the length of the arrow indicates the speed of this portion.

As is clear from FIG. 4, in the tank-type fast breeder reactor of the present invention, the flow direction of the coolant 11 is corrected horizontally, so the flow velocity of the coolant 11 flowing toward the free liquid level F is reduced accordingly. be done.

As a result, the ripples of the free liquid surface F can be reduced to a greater extent than in the past, and the entrainment phenomenon of the cover gas into the coolant 11 that accompanies this can be reduced to a greater extent than in the past.

As a result, it is possible to prevent fluctuations in the reactivity of the core 4 due to the cover gas passing through the core 4.

[Effect of the invention 1 As described above, according to the tank-type fast breeder reactor of the present invention, the gas entrainment phenomenon at the free liquid level of the coolant can be effectively suppressed by arranging the flow hole nozzle in the flow hole of the hanging shell. It can be prevented. As a result, unnecessary fluctuations in the reactivity within the core due to the entrainment of the cover gas can be prevented.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing a conventional tank-type fast breeder reactor, Fig. 2 is an explanatory diagram showing the flow of cold iJJ material passing through a flow hole, and Fig. 3 is an illustration of a tank-type fast breeder reactor of the present invention. FIG. 4 is a longitudinal sectional view showing the embodiment, and is an explanatory diagram showing the flow of coolant passing through the flow holes of the tank-type fast breeder reactor' shown in FIG. 3. 1・・・・・・・・・Reactor vessel 2・・・・・・
・・・・・・Intermediate heat exchanger 3・・・・・・・・・・・・
Cold member circulation pump 7... Hanging shell 8... Roof slab 19...
・・・・・・・・・Flow hole 22・・・・・・・・・
...Flow hole nozzle agent valve lT engineer Sa Suyama -1 Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] (1) A reactor vessel that accommodates liquid metal, a roof slab that shields the upper end opening of this reactor vessel, a reactor core that is housed in the reactor vessel, and this core that is suspended and supported by the roof slab. In a tank-type fast breeder reactor, the tank-type fast breeder reactor is equipped with a hanging shell having a flow hole on the side surface thereof, and an intermediate heat exchanger disposed in a space formed by the hanging shell and the reactor vessel. A tank-type fast breeder reactor, characterized in that a nozzle is arranged in the flow hole.