JPS6396598A - Lining facility for fast breeder reactor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a fast breeder reactor power generation plant in which a concrete building housing piping, etc. in a fast breeder reactor power plant is lined with a built-up concrete surface. Regarding lining equipment.

(Prior Art) Metallic sodium, which is generally used as a coolant for fast breeder reactors, is a chemically very active substance that reacts violently with oxygen and moisture. Therefore, when a large-scale sodium leak occurs, the leaked sodium reacts with oxygen and hydrogen in the atmosphere, releasing a large amount of heat. In addition, when leaked sodium comes into direct contact with the concrete walls that form pipes and equipment storage rooms, hydrogen is generated by the sodium-concrete reaction. Furthermore, the concrete is heated by the reaction heat and moisture is generated from the concrete, and the moisture reacts with sodium, which also generates hydrogen.

In this case, there is a risk that the structural strength of the concrete will deteriorate due to hydrogen accumulation and dewatering.

This will be explained in more detail by taking as an example the case of the prototype reactor "Monju" of a fast breeder reactor (hereinafter referred to as FAR) shown in FIGS. 4 to 6. As shown in Figure 4, the power generation system is made of concrete iX! A reactor vessel 3 is housed in a reactor containment volume 32 surrounded by i, and this reactor vessel 3 contains primary sodium 4 for cooling the inside of the reactor vessel.
The secondary sodium 4 is installed so as to be able to exchange heat with the secondary sodium 6 flowing through the piping connected to the reactor auxiliary building 5.

The secondary storium 6 undergoes heat exchange in a superheater 7 and an evaporator 8 to generate superheated steam that drives a steam turbine 9. This superheated steam is guided to the steam turbine 9 through the steam pipe 10, where it performs work and drives the power generation 1a11. The steam that has been subjected to work in the steam turbine 9 is sent to the condenser 12, where it is condensed and becomes condensed water. This condensate is sent to the evaporator 8 by the water supply pump 13.

On the other hand, the secondary sodium 6 cooled by heat exchange with the feed water in the evaporator 8 is sent to the heat exchange system with the primary sodium via the secondary main circulation pump 14. In this way, a power generation cycle in the rapid multiplication power generation plant is configured, and power is generated by operating this power generation cycle. In addition, the code|symbol 15 is an air cooler provided in the secondary sodium circulation system, and the code|symbol 16 is a circulation pump.

Therefore, the primary sodium 4, which directly transfers the heat of the reactor core, is
Because it is radioactive, leakage countermeasures are particularly strict, not only in the reactor vessel 3 but also in the reactor containment vessel, which is the primary atmosphere where the piping and equipment containing sodium chloride 4 are installed. The inside of the chamber is filled with nitrogen, which is not reactive with sodium, to prevent sodium fires. Additionally, to prevent sodium-concrete reactions, the walls of each room where piping and equipment are installed are entirely lined with steel liners.

On the other hand, in the case of secondary sodium 6, it is not activated, so in the case of negative sodium 4, although it is not as severe,
The interior of the reactor auxiliary building 5, where most of the piping and equipment for the secondary sodium 6 is installed, is an air atmosphere, making it easy for sodium fires to occur, and preventing such fires is extremely important for plant safety. That's true.

In the case of this secondary I-Rium 6, for example, in the room where piping and equipment such as the superheater 7, evaporator 8, secondary main circulation pump 14, and air cooler 15 are installed, as shown in Figure 5. As shown in the figure, a floor liner 17 is installed, and sodium leaked from each room is drained from the floor liner 17 to the lower room through a communication pipe 18 and stored in a storage tank 19, or is stored in a fire suppression plate 20. The water is drained into an attached storage liner 21 to extinguish the fire by suffocation, and then stored in an overflow tank 22.

Further, as shown in FIG. 6, the sodium pipes 25 of the secondary and secondary sodium circulation systems are supported by clamp portions 24 arranged at appropriate intervals.

This sodium pipe 25 is covered with an interior plate 27 and an exterior plate 28 via an annulus space 26. The interior plate 27 and the exterior plate 28 have a double structure, and the annulus space thereof is filled with a heat insulating material 29.

However, from the sodium pipe 25, a large set of sodium is 1Tili! J! In the case of leakage, the leaked sodium Δ fills the annulus space 26 and further fills the heat insulating material 29 from the interior plate 27, and flows downward in the tube axis direction. When the flow of this leaked sodium A reaches the clamp part 24, the leaked sodium A flows to the clamp part 24 because the clamp part 24 partitions the annulus space 21 in the tube axis direction.
It collects concentratedly in the part blocked by 4, breaks through the two heat insulating materials and the exterior plate 28, and ejects into the surrounding area.

In order to prevent the thorium-concrete reaction that occurs when this leaked sodium 8 comes into direct contact with the concrete wall 30 forming the room, all parts that may come into contact with the leaked sodium A are made of steel. Made of liner 31
is stretched.

(12i1 problem to be solved by the invention) Conventionally, the strength of building concrete was ensured by preventing sodium fires and suppressing the sodium-concrete reaction by taking measures against leaking 1-lium as described above. It greatly contributes to the safety of power plants.

However, with such conventional installations, all walls, floors, and ceilings of the room that could come into contact with leaked sodium must be covered with a steel liner 31. Furthermore, when the steel liner 31 is employed, it is necessary to form a shape that takes thermal expansion due to leaked sodium into consideration, and a large amount of cost is required for designing the liner shape and manufacturing the liner.

Furthermore, when the liner 31 is processed into the M4 silvicultural concrete 30 as shown in FIG. 7, a heat insulating material 35 or the like must be interposed during on-site welding to attach the anchor 34, making the installation work difficult. For this reason, other fire prevention technologies to replace steel liners have become important due to the desire to reduce costs, and rationalization of lining equipment is currently required from economic considerations.

The present invention has been made in consideration of the above-mentioned circumstances, and is a lining for fast breeder reactors that prevents sodium-concrete reaction, facilitates decontamination in the event of sodium leakage, reduces manufacturing costs, and is easy to manufacture. The purpose is to provide facilities.

Structure of the Invention C) (Means for Solving the Problems) The present invention provides lining equipment for a fast breeder reactor that is lined in a concrete building in order to accommodate piping etc. for guiding liquid metal sodium. In order to prevent sodium leaking from the concrete from coming into contact with the structural concrete of the concrete building, a sodium-resistant and heat-resistant paint layer is formed on the concrete.

(Function) Since a sodium-resistant and heat-resistant paint layer is formed on the structural material concrete of concrete buildings, contact between leaked sodium and concrete can be prevented, and concrete deterioration due to sodium-concrete reaction will not occur. . When sodium leaks, the paint layer turns into a solution, making decontamination easier.

The sodium-resistant and heat-resistant paint layer is easier to apply than conventional steel plate liners, has higher reliability, and can further reduce costs.

(Example) An example of lining equipment for a fast breeder reactor according to the present invention will be described with reference to FIGS. 1 and 2. The outline of the fast breeder reactor power plant is the same as that shown in FIG. 4, so the explanation will be omitted.

In the embodiment shown in FIG. 1, a paint layer 40 coated with a heat-resistant and sodium-resistant paint is formed on the surface of concrete 30, which is a structural material for a concrete building that houses piping and the like containing liquid metal sodium. An example is partially shown.

The raw material for the paint used for this paint layer 40 is a mixture of at least one ceramic material selected from alumina (A, i!203), magnesia (Mgc), and zirconia (ZrO2).

When all of the above ceramic materials are mixed, they are mixed at a ratio of 20 to 40%. Among these ceramic materials, the one that is relatively easy to obtain and inexpensive is alumina (
Δ1203) and magnesia (M2O).

In order to use these ceramic materials as paints, they must be kneaded with a binder to form a paste. When used as a liner for sodium, not only the paint raw material but also the binder itself and the paste-like cured product produced as a result of kneading must be sodium resistant and fire resistant and heat insulating. Furthermore, since the floor liner requires workability, it must have a certain level of strength. For these reasons, an aqueous sodium silicate solution is used as the binder constituting the sodium-resistant and heat-resistant paint. This sodium silicate aqueous solution is prepared by adding 0.5 to 2 times as much water to sodium silicate.

Paints using the above-mentioned ceramic materials as raw materials have long been used as refractory materials for high-temperature furnaces and as fireproofing and heat-insulating materials for various furnaces, but no examples have yet been found of them being used as anti-sodium leakage equipment.

When the above-mentioned ceramic material and an aqueous sodium silicate solution are kneaded, they become paste-like, adhere to each other through the sodium silicate, and become entangled in a chain or network to form a homogeneous structure. This structure has excellent sodium resistance and heat resistance, and does not release chemically bound water and does not deteriorate in physical strength up to about 1200°C. The purity of the above ceramic material requires a chemical composition of 90% or more, and other impurities include silica (SiC2) and calcia (Ca), which are relatively stable against lithium.
b) It is possible to contain inorganic substances such as beryllia (Bed).

When kneading, the amount of sodium silicate used is about 100 d to about 300 d per 1 kg of ceramic material.

Outside this range, as shown in FIG. 2, if it is less than about 10%, it becomes brittle, and if it exceeds about 30%, it will not solidify and will not serve as a binder.

According to the above-described embodiment, there is no need to attach a steel liner to the concrete surface of the building as in the conventional case. That is, since the liner in the above embodiment is a heat-resistant and sodium-resistant paint layer, it can prevent leakage of sodium at openings of 100 g/h or more and temperatures of about 500°C or more, and prevent leakage of sodium. Contact with concrete 1 is prevented so that deterioration of concrete due to sodium-concrete reaction does not occur.

Furthermore, when alumina (Ai203) is used as a raw material for a paint, the paint layer exhibits strong hygroscopicity and forms a crystalline compound A12o3.H,20 at temperatures around 200°C, where concrete begins to dehydrate. This compound has little interaction with concentrated alkalis, and can prevent the deterioration of the paint layer due to heating of concrete and the reaction of water released from concrete with sodium.

The paint layer can sufficiently prevent concrete deterioration due to sodium leaking from piping and the like and generation of H2 due to sodium-water reaction.

Further, at the same time that the leaked sodium reacts with moisture in the atmosphere and changes into sodium hydroxide (NaOH), the paint layer becomes a solution and can be decontaminated by an easy method such as suction at the time of decontamination.

Therefore, by providing the above paint layer, it is no longer necessary to design the shape of the steel plate liner in consideration of thermal expansion and the like. moreover,
A paint layer liner formed by applying paint is much easier to construct than a steel plate liner.

Additionally, with conventional steel plate liners, it is necessary to take measures to prevent the steel plate liner from bursting due to water vapor emitted from concrete, but with a paint-layered liner, it is more reliable and can significantly reduce costs.

In the above-described embodiment, the heat-resistant and lium-resistant paint layer 40 was directly formed on the surface of the structural concrete 30. Alternatively, the paint layer 40 may be formed on the surface of the heat insulating material 41 or the #A plate by covering it with a thickening board (not shown), and the same effect as in the above-mentioned embodiment can be obtained.

The present invention can be widely applied to peripheral equipment regardless of whether it is a primary system or a secondary system of sodium.

〔Effect of the invention〕

As explained above, one aspect of the present invention is a lining facility for a fast breeder reactor that is lined inside a concrete building to house piping, etc. that guides liquid metal sodium. In order to prevent contact with structural material concrete, a sodium-resistant and heat-resistant paint layer is formed on the concrete, which prevents sodium-concrete reactions and facilitates decontamination in the event of a sodium leak. Moreover, it is easier to manufacture than conventional methods, and has the effect of reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of lining equipment for a fast breeder reactor according to the present invention, FIG. 2 is a diagram showing the relationship between the kneading ratio of the binder in the paint used in the above example and the hardness of the paint,
Fig. 3 is a diagram showing another embodiment of the present invention, Fig. 4 is a schematic diagram for explaining the outline of a fast breeder reactor, and Fig. 5 is a cutaway perspective view for explaining countermeasures against secondary sodium leakage. , FIG. 6 is a schematic diagram of a conventional steel liner, and FIG. 7 is a partial cross-sectional view showing the installed state of the conventional steel liner. DESCRIPTION OF SYMBOLS 1... External concrete wall, 2... Reactor containment vessel, 3... Reactor vessel, 4... -order sodium, 5...
... Reactor auxiliary building, 6... Secondary sodium, 7...
・Superheater, 8... Evaporator, 9... Turbine, 11.
... Reactor, 12... Condenser, 13... Water supply pump, 14... Secondary main circulation pump, 15... Air cooler, 17... Floor liner, 18... Communication pipe, 19...
・Storage tank, 20... Fire suppression board, 21... Storage liner, 22 River overflow tank, 24... Clamp part, 25... Sodium cooling system piping, 26...
Annular space, 27...Interior board, 28...Exterior board, A...Leaked sodium, 30...Structural material concrete, 31...Liner, 40...Paint layer, 41...
・Heat insulation material. Applicant's agent Hatano Docking Figure 1 Figure 2 Figure 3 Figure 4 87th

Claims (1)

[Scope of Claims] 1. In a fast breeder reactor lining facility in which a concrete building is lined to accommodate piping etc. that guide liquid metal sodium, sodium leaking from said piping etc. and structural materials of said concrete building Lining equipment for a fast breeder reactor, characterized in that a sodium-resistant and heat-resistant paint layer is formed on the concrete to prevent contact with the concrete. 2. The lining equipment for a fast breeder reactor according to claim 1, wherein the paint layer is formed on the surface of a heat insulating material or a steel plate stretched over the structural concrete. 3. The paint layer is made of Al_2O_3, MgO, ZrO_2
The lining equipment for a fast breeder reactor according to claim 1, wherein the lining equipment for a fast breeder reactor is coated with a paint made by kneading at least one ceramic material selected from the following with a binder. 4. The binder is made of an aqueous sodium silicate solution,
This sodium silicate aqueous solution is added to the paint in an amount of about 10 to 3
The lining equipment for a fast breeder reactor according to claim 3, which is kneaded at a ratio of 0%. 5. The paint is a ceramic material in which all types of Al_2O_3, MgO, and ZrO_2 are mixed in a proportion of 20 to 40%, respectively, and is kneaded with a binder.
Lining equipment for fast breeder reactors as described in section.