JPH07101239B2 - Fast breeder reactor lining equipment - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a lining facility for a fast breeder reactor, which is lined on a concrete surface of a structural material of a concrete building that houses pipes and the like in a power plant for the fast breeder reactor.

[Technical background of the invention and its problems]

In general, metallic sodium used as a coolant for fast breeder reactors is a chemically very active substance and reacts violently with oxygen and moisture. Therefore, if a large-scale sodium leak occurs, a large amount of sodium may react with oxygen or hydrogen in the atmosphere, and a large amount of heat may be released.

Further, when the leaked sodium comes into direct contact with the concrete wall of the room containing the pipes and equipment, hydrogen is generated by the sodium-concrete reaction. Further, the reaction heat heats the concrete to generate water from the concrete, and the water further reacts with sodium,
This also produces hydrogen. In this case, the structural strength of concrete may deteriorate due to hydrogen accumulation or dehydration.

Fast breeder reactor (hereinafter referred to as FBR)
Say. ) Example, the FBR shown in FIG. 3 to FIG.
The prototype reactor "Monju" will be described in more detail as an example. As shown in FIG. 3, in the FBR power generation system, a reactor vessel 3 is housed in a reactor containment vessel 2 surrounded by an outer peripheral concrete wall 1, and the reactor vessel 3 is cooled by the reactor vessel 3. The primary sodium 4 is circulated therein so as to circulate therein, and the primary sodium 4 is provided so as to be capable of exchanging heat with the secondary sodium 6 flowing in the pipe laid in the reactor auxiliary building 5.

The secondary sodium 6 is heat-exchanged in the superheater 7 and the evaporator 8 to generate superheated steam that drives the steam turbine 9. This superheated steam is guided to the steam turbine 9 through the steam pipe 10, where it works to drive the generator 11. The steam expanded by working in the steam turbine 9 is sent to the condenser 12 and condensed to be condensed water. This condensate is a water supply pump 13
Is sent to the evaporator 8.

On the other hand, the secondary sodium 6 cooled by exchanging heat with the feed water in the evaporator 8 passes through the secondary main circulation pump 14 and the primary sodium 4
Sent to the heat exchange system with. Thus, the power generation cycle in the power plant for the fast breeder reactor is configured, and the power generation is performed by operating this power generation cycle. Reference numeral 15 is an air cooler provided in the secondary sodium circulation system, and reference numeral 16 is a circulation pump.

In the fast breeder reactor, the primary sodium 4 that directly transfers the heat of the core is activated, so the sodium leak countermeasure is particularly strict, and not only the reactor vessel 3, but also the pipes and equipment containing the primary sodium 4 The reactor containment vessel 2, which is the primary system atmosphere in which the equipment is installed, is filled with nitrogen that is not reactive with sodium, so that the reaction of sodium is prevented and the sodium fire is prevented. Also,
In order to prevent sodium-concrete reaction, steel liner is stretched all over the wall of each room where piping and equipment are installed.

On the other hand, in the case of secondary sodium 6, since it is not activated, it is not as severe as in the case of primary sodium 4,
Since the reactor auxiliary building 5 in which most of the secondary sodium 6 pipes and equipment are installed is an air atmosphere, it is easy for a sodium fire to occur, and it is very important for plant safety to prevent it. That's right.

In the case of the secondary sodium 6, for example, as shown in FIG. 4, in a room where pipes and equipment such as a superheater 7, an evaporator 8, a secondary main circulation pump 14 and an air cooler 15 are installed. ,
The floor liner 17 is stretched, and the sodium leaked in each room is drained from the floor liner 17 through the communication pipe 18 to the lower room and stored in the storage tank 19, or the fire suppression plate 20.
It is drained into the attached storage liner 21 for suffocation and extinguishing, and further stored in the overflow tank 22.

Further, as shown in FIG. 5, the sodium pipes 25 of the primary and secondary sodium circulation systems are supported by the clamp portions 24 arranged at appropriate intervals. This sodium pipe 25
The interior plate 27 and the exterior plate 28 are covered via the annulus space 26. The inner plate 27 and the outer plate 28 have a double-tube structure, and the annulus space thereof is filled with a heat insulating material 29.

When a large amount of sodium leaks from the sodium pipe 25, the leaking sodium A fills the annulus space 26, fills the heat insulating material 29 from the interior plate 27, and flows downward in the pipe axis direction. When the flow of the leaking sodium A reaches the clamp part 24, the clamp part 24 divides the annulus space 21 in the tube axis direction, so that the leaking sodium A concentrates on the part blocked by the clamp part 24. It collects, pierces through the heat insulating material 29 and the exterior plate 28, and gushes out to the surrounding area.

If this leaking sodium A is jetted out to the surroundings, the leaking sodium A and the concrete wall 30 forming the room may come into direct contact with each other to cause a sodium-concrete reaction. In order to prevent this sodium-concrete reaction, a liner 31 made of steel is stretched over all the sites where the leaking sodium A may come into contact, and measures against leaking sodium are taken.

The above measures against sodium leakage prevent sodium fire and suppress sodium-concrete reaction to secure the strength of building concrete, which greatly contributes to the safety of the power plant.

However, with such conventional equipment, all of the walls, floors, and ceilings of the room where the leaking sodium may come into contact must be covered with the steel liner 31. Further, when the steel liner 31 is adopted, it is necessary to take a shape in consideration of thermal expansion due to leaked sodium, so that a large amount of cost is required for designing the liner shape and manufacturing the liner.

Further, as shown in FIG. 6, when the liner 31 is constructed on the structural material concrete 30, the heat insulating material 35 and the like must be interposed during welding at the site where the anchor 34 is attached,
Installation work is difficult. Therefore, in order to reduce costs, other fire occurrence prevention techniques have become important in place of steel liners, and at present, rationalization of lining equipment is required from the economical aspect.

[Object of the Invention]

The present invention has been made in consideration of the above-mentioned circumstances, and has the same function as that of a steel liner in terms of safety of a power plant, and is a high-speed breeder capable of significant cost reduction as compared with the case of using a steel liner. The purpose is to provide lining equipment for a furnace.

[Outline of Invention]

The lining equipment for fast breeder reactor according to the present invention is, in order to achieve the above-mentioned object, in the lining equipment for fast breeder reactor in a concrete building that houses a pipe or the like for guiding liquid sodium, sodium leaking from the pipe or the like. And to prevent contact with the structural material concrete of the concrete building, a heat insulating layer is coated on the structural material concrete, a sodium-resistant and heat-resistant paint layer is formed on the surface of this heat insulating layer, this paint layer is The coating material is formed by coating a ceramic material with a binder mixed.

Example of Invention

An embodiment of a lining facility for a fast breeder reactor according to the present invention will be described below with reference to FIGS. 1 and 2. In addition,
In FIG. 1, the same parts as those shown in FIGS. 3 to 6 are denoted by the same reference numerals and only the main parts thereof are shown, and the overall structure of the lining equipment is substantially the same and is not substantially different, and therefore omitted. To do.

FIG. 1 shows an example of a lining facility for a fast breeder reactor. In this figure, reference numeral 30 is a part of structural material concrete of a concrete building of a power plant for a fast breeder reactor. 40 is a paint layer having high heat resistance and high sodium resistance. Reference numeral 35 is a heat insulating layer made of a heat insulating material, which covers the structural material concrete 30.

That is, in the embodiment of FIG. 1, the surface of the structural material concrete 30 of the concrete building containing the pipe containing liquid metal sodium inside is covered with the heat insulating layer 35, and the surface of the heat insulating layer 35 is heat resistant and resistant. An example in which a sodium paint is applied to form the paint layer 40 and the lining is lined is partially shown. The heat insulation layer 35 has a thermal conductivity of 1/2 that of the structural material concrete 30.
Since it is as low as ~ 1/3, the paint layer 40 can be made thinner.

Raw materials for the paint used for the paint layer 40 include alumina (Al ₂ O ₃ ), magnesia (MgO), magnesium aluminum oxide (MgAl ₂ O ₄ ), thoria (ThO ₂ ), and titania (TiO ₂ ).
₂ ), at least one ceramic material selected from silica (SiO ₂ ), beryllia (BeO), yttria (Y ₂ O ₃ ) and zirconia (ZrO ₂ ) is used.

Generally, alumina (Al ₂ O ₃ ), magnesia (MgO), thoria (ThO ₂ ), yttria (Y ₂ O ₃ ), zirconia (ZrO ₂ ).
As shown in FIG. 2, the ceramic materials such as have a small free energy of formation as compared with sodium oxide, and are chemically stable to sodium.

Of these ceramic materials, the ones that are relatively easy to obtain and inexpensive are alumina (Al ₂ O ₃ ) and magnesia (MgO).
Is. When these ceramic materials are used as paints, it is necessary to knead them with a binder such as water or a solvent to form a paste. When used as a substitute for a steel liner for sodium, not only the raw material of the paint but also the solvent itself or the cured product of the paste resulting from kneading must be sodium resistant and fire resistant.

Furthermore, since workability is required for the floor liner,
Some strength is required. For these reasons, gelled aluminum hydroxide using alumina as the raw material of the sodium-resistant and heat-resistant coating and water as the solvent is desirable.

Paints using alumina as a raw material have been used as a refractory material for high temperature furnaces and as a fireproof / heat insulating material for various kilns, but no examples have been found yet for use as a sodium leakage countermeasure facility. When alumina and water are mixed, a paste-like colloidal solution is formed. The colloidal particles attract water molecules to the surface, and these gel waters adhere to each other as a medium, and are entangled in a chain or a net to form one structure and form a gel aluminum hydroxide compound. This compound is sodium resistant and has excellent heat resistance,
Up to 00 ° C, chemically bound water is not released and physical deterioration does not occur. As the purity of alumina
It is possible that other impurities, such as silica (SiO ₂ ), calcia (CaO), and magnesia (MgO), which require a chemical composition of 90% or more and are relatively stable to sodium, may be included. Water for kneading is used in the range of several 10 ml to several 100 ml per 1 kg.

Therefore, according to each of the above embodiments, it is not necessary to attach the steel liner to the concrete surface of the building as in the conventional case.
That is, since the liner in each example is a heat-resistant and sodium-resistant paint layer, it is possible to prevent contact between leaking sodium and concrete and prevent deterioration of concrete due to sodium-concrete reaction. Since the paint layer 40 is applied on the surface of the heat retaining layer 35,
Since it is not necessary to increase the thickness of the expensive paint layer 40 and the thickness can be reduced, the paint layer 40 can be saved and the cost can be reduced.

Further, at a temperature of around 200 ° C at which dehydration of concrete begins, gel aluminum hydroxide exhibits a strong hygroscopic property and forms a crystalline compound Al ₂ O ₃ · H ₂ O. This compound hardly acts even with a concentrated alkali, and can prevent deterioration of the paint layer due to heating of concrete and reaction of water discharged from concrete with sodium. The above paint layer can sufficiently prevent deterioration of concrete due to sodium leaking from pipes and the like and generation of H ₂ O due to sodium-water reaction.

Further, the paint layer eliminates the need for designing a steel liner shape in consideration of thermal expansion and the like. Further, since the liner of the paint layer formed by applying the paint is close to the coefficient of thermal expansion of the structural material concrete 30, it is not necessary to consider the difference in coefficient of thermal expansion when applying the paint layer 40. Is very easy.

Furthermore, conventional steel liners require measures to rupture the steel liner due to water vapor released from concrete, but paint liners are more reliable than before and can significantly reduce costs. .

〔The invention's effect〕

As described above, in the lining facility for a fast breeder reactor according to the present invention, a heat insulating layer is provided on the structural material concrete in order to prevent contact between sodium and structural material concrete of the concrete building that leaks from the pipe or the like. A sodium-resistant and heat-resistant paint layer is formed on the surface of this heat insulating layer, and this paint layer is formed by applying a paint prepared by kneading a binder on a ceramic material. It can be lined with a paint layer of ceramic material that has low free energy and is chemically stable, eliminating the conventional steel plate liner that requires consideration of the difference in thermal expansion. Moreover, the paint layer of ceramic material is close to structural concrete. Since it has a coefficient of thermal expansion, construction of lining equipment is simple and easy, and there is no need to consider the difference in thermal expansion.
Significant cost reductions can be achieved while maintaining reliability.

Further, since the paint layer was formed on the surface of the heat insulating layer coated on the structural material concrete, the temperature of the structural material concrete can be kept below the allowable limit with this heat insulating layer,
By interposing a heat insulating layer, the expensive paint layer can be thinned and the paint layer does not need to be thickened. Therefore, heating and dehydration after coating the paint are not always necessary, and sodium with water remaining in the paint layer is not necessarily required. The reaction can be effectively prevented. Furthermore, the lining equipment can be easily and easily repaired by exchanging only the thin paint layer or overpainting the paint layer, and the repairability is improved and the repair work can be simplified.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a first embodiment of a lining facility for a fast breeder reactor according to the present invention, FIG. 2 is a characteristic diagram showing a relationship between free energy of formation of a typical ceramic material and temperature, and FIG. FIG. 4 is a schematic diagram for explaining the outline of the fast breeder reactor, FIG. 4 is a cutaway perspective view for explaining secondary sodium leakage countermeasures, FIG. 5 is a schematic diagram of a conventional steel liner, and FIG. FIG. 6 is a partial cross-sectional view showing a mounted state of a conventional steel liner. 1 ... Perimeter concrete wall, 2 ... Reactor containment vessel, 3
...... Reactor vessel, 4 ... Primary sodium, 5 ... Reactor auxiliary building, 6 ... Secondary sodium, 7 ... Superheater, 8 ...
… Evaporator, 9 …… turbine, 11 …… generator, 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 plate, 21 ... Storage liner, 22
...... Overflow tank, 24 ...... Clamp part, 25 ......
Sodium cooling system piping, 26 …… annulus space, 27 ……
Interior plate, 28 ... Exterior plate, A ... Leaked sodium, 30 ...
Structural material concrete, 31 …… liner, 35 …… heat insulation layer, 40
…… Paint layer.

Claims (3)

[Claims] 1. In a lining facility for a fast breeder reactor in a concrete building containing a pipe or the like for guiding liquid metal sodium, in order to prevent contact between sodium leaking from the pipe or the like and structural material concrete of the concrete building, A heat insulating layer is coated on the structural material concrete,
A sodium-resistant and heat-resistant paint layer is formed on the surface of this heat retaining layer, and this paint layer is formed by applying a paint prepared by mixing a ceramic material with a binder, and a lining for a fast breeder reactor. Facility. 2. The coating layer comprises Al ₂ O ₃ , MgO, MgAl ₂ O ₄ .ThO ₂ , TiO ₂ .
_The coating material prepared by applying a coating material in which at least one ceramic material selected from ₂ , SiO ₂ , BeO, Y ₂ O ₃ and ZrO ₂ is kneaded with a binder is applied. Lining equipment for fast breeder reactor. 3. The fast breeder reactor according to claim _2, wherein the coating material made of Al ₂ O ₃ as a raw material in the coating layer is made of gelled aluminum hydroxide when kneaded with water. Lining equipment.