JP7329084B2 - Guiding devices for systems for locating and cooling core melts in nuclear reactors - Google Patents

Description

The present invention relates to an apparatus for directing nuclear reactor core meltdowns to a melt trap, particularly for the purpose of locating and cooling reactor core meltdowns for the purpose of locating severe beyond design basis accidents. It relates to a system for

The greatest radiation hazards are caused by core meltdown accidents that can occur in the event of multiple errors in the core cooling system.

In such an accident, the core melt (Corium) melts the reactor internals and the reactor vessel and when it flows out beyond the limits, it is the hermetic shell of the nuclear power plant because of the residual heat release that remains there. It is the last barrier on the way to the release of radioactive products into the environment.

To eliminate this, it is necessary to locate the core melt that has flowed out of the reactor vessel and ensure its continued cooling until all constituents of the core melt have fully crystallized. This function is performed by the melt trap and by preventing damage to the hermetic shell of the NPP after the core melt has entered, the melt trap allows the cooling and subsequent melt crystallization to provide a critical protection of the population and the environment from radiation exposure in the event of a serious accident;

After the reactor vessel has melted, the core melt is usually made in the form of a funnel, attached to the truss console, for the purpose of ensuring the supply of melt to the service site, and the reactor is discharged from the outlet from the reactor vessel. Enter the induction device designed to change the direction of travel of the melt towards the axis of the furnace shaft. Combusting through the service platform, the melt enters the melt trap where it interacts with the filler to gradually heat the body of the melt trap. In this case, when the reactor vessel melts, the vessel bottom separates completely, and as a result, the reactor vessel bottom falls into the guide device, greatly reducing or completely blocking the flow of melt into the melting trap. There is a possibility that This can lead to the accumulation of melt in the area of the guide device, the increase in temperature of the melt, the burning of the concrete of the base of the dry shield and the surrounding building, the collapse of the shield to the melt, which can lead to the collapse of the dry shield, drying Chemical interactions between the serpentine concrete of the shield and the melt involve the formation of large amounts of hydrogen, other non-condensable gases and aerosols, among others. The formation of large amounts of hydrogen, other non-condensable gases and aerosols leads to a greatly increased risk of hydrogen explosions and over-engineering of the pressure inside the containment, resulting in the containment being destroyed and over-designed. amount of radioactive fission products could be released outside the containment vessel.

Installed under the bottom of the reactor vessel, resting on the console truss, made in the form of a funnel, consisting of cylindrical and conical parts, its surface is covered with heat-resistant concrete, and the hole conical Known is a guiding device of a system for locating and cooling the core melt of a nuclear reactor (US Pat. No. 5,300,003), which is made centrally of the section.

One of the drawbacks of guide devices is the poor insulation of the walls of the conical and cylindrical parts. In the case of a rapid flow of core melt from the reactor vessel, take into account the acceleration caused by the residual pressure in the reactor vessel when the bottom is torn apart by the full cross-section, and the rotation of the detached bottom in the process of movement. , it is possible to block the hole drilled in the center of the tapered portion. This can lead to core melt accumulation in the area of the conical portion of the guide device, resulting in an increase in temperature in this area. An increase in temperature can lead to penetration of the walls of not only the cone, but also the cylindrical part of the guide device, so that the core melt flows into the outside of the melt trap, i.e. the construction concrete and the serpentinite concrete. If flowed and ruptured, it would form large amounts of hydrogen and non-condensable gases, resulting in the risk of a hydrogen explosion and design overpressure build-up inside the containment vessel. This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

Another drawback of the guide system is the lack of a mechanism for redistributing (leveling) the core melt jet stream. This leads to the fact that the thermal and mechanical loads of the impact are concentrated in the upper and middle zones of the cylindrical part. The concentration of thermal and mechanical loads of the shock can lead to the destruction of the guide devices, the penetration of the core melt into the structures and the serpentinite concrete, their subsequent destruction, hydrogen and non-condensable gases As a result of the formation of a This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

A guiding device for the melt localization and cooling system of a nuclear reactor core, consisting of a cylindrical and a conical part, with a hole in its center and a force rib extending from the central hole to the boundary of the cylindrical part. (Non-Patent Document 1) is known.

One of the drawbacks of guide devices is the poor insulation of the walls of the conical and cylindrical parts. In the case of a rapid flow of core melt from the reactor vessel, take into account the acceleration caused by the residual pressure in the reactor vessel when the bottom is torn apart by the full cross-section, and the rotation of the detached bottom in the process of movement. , it is possible to block the hole drilled in the center of the tapered portion. This can lead to core melt accumulation in the area of the conical portion of the guide device, resulting in an increase in temperature in this area. An increase in temperature can lead to penetration of the walls of not only the cone but also the cylindrical part of the guide device, resulting in the risk of hydrogen explosion and over-design of pressure in the containment. This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

Another drawback of the guide system is the lack of a mechanism for redistributing (leveling) the core melt jet stream. This leads to the fact that the thermal and mechanical loads of the impact are concentrated in the upper and middle zones of the cylindrical part. The concentration of thermal and mechanical loads of the shock can lead to the destruction of the guide devices, the penetration of the core melt into the concrete and serpentinite concrete of the building, as a result of which they are destroyed, hydrogen and non-condensed gas may be formed. Among these are the risks of hydrogen explosions and over-designed pressure build-up in the containment. This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

Consists of a cylindrical part and a conical part, with a hole in the center, extending from the central hole to the upper end of the cylindrical part, connecting the cylindrical and conical parts to a sacrificial, heat-resistant The closest approximation to the claimed invention, consisting of power ribs and the like dividing them into sectors covered by a layer of concrete, is the guiding device for the locating and cooling system of the molten core of a nuclear reactor (Patent Document 2- 4).

Such guiding devices are useful for directing the core melt (melt) into the melt trap after destruction or melting of the reactor, for containing bulky debris inside, for fuel assemblies and the bottom of the reactor vessel in the melt trap. To prevent falling, to protect the truss console and its communications from destruction when melt flows from the reactor vessel into the melt trap, to protect concrete shafts from direct contact with core melt, etc. belongs to.

The force rib holds the bottom of the reactor vessel with the melt, so that in the process of its destruction or strong plastic deformation, the bottom overlaps with the flow section of the sector and can interfere with the flow process of the melt. become unable.

Sacrificial concrete that dissolves in the core melt increases the flow area of the sectors of the guide plate when a blockage is formed (when the melt solidifies in one or more sectors), resulting in overheating of the load-bearing ribs and Destruction, ie complete blockage of the flow field and consequent destruction of the guide plate, can be prevented. Thermal and refractory concrete retains the structural strength of the sacrificial concrete as the thickness of the sacrificial concrete is reduced. This concrete protects the underlying equipment from melt attack and prevents the melt from melting and destroying the baffle plates.

One of the drawbacks of the guide device is that when large amounts of metal and oxide melts flow simultaneously, for example when the bottom of the reactor vessel is torn in full cross-section or it is partially destroyed. Sometimes two layers of sacrificial concrete are unable to provide an increase in the flow area of the sector of the guide plate. In this case, the simultaneous interaction of two superheated melts (metals and oxides) and sacrificial concrete (based on aluminum and iron oxides) leads to rapid release of oxygen, violent oxidation, formation of aerosols and complete flow field. leading to slag formation with significant overlap. Due to the fact that the hot vapor gases and aerosol products of the interaction of the sacrificial concrete with the metal and oxide components of the melt tend to be upward and their movement is directed against the flow of the melt From, in the severely restricted space between the bottom of the reactor vessel and the refractory concrete (based on aluminum oxide), a hydrodynamic barrier of foamed sacrificial concrete is formed, preventing melt migration. When a stagnation zone is formed, the refractory concrete overheats rapidly, chemically reacts with the melt constituents, and increases backflow of vapors, gases, and aerosols.

Another drawback of the guide device lies in the insufficient insulation of the walls of the conical and cylindrical parts. In the case of a rapid flow of core melt from the reactor vessel, take into account the acceleration caused by the residual pressure in the reactor vessel when the bottom is torn apart by the full cross-section, and the rotation of the detached bottom in the process of movement. , it is possible to block the hole drilled in the center of the tapered portion. This can lead to core melt accumulation in the area of the conical portion of the guide device, resulting in an increase in temperature in this area. An increase in temperature can lead to penetration of the walls of not only the cone, but also the cylindrical part of the guide device, so that the core melt flows into the outside of the melt trap, i.e. the construction concrete and the serpentinite concrete. If flowed and ruptured, it would form large amounts of hydrogen and non-condensable gases, resulting in the risk of a hydrogen explosion and design overpressure build-up inside the containment vessel. This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

Another drawback of the guide system is the lack of a mechanism for redistributing (leveling) the core melt jet stream. This leads to the fact that the thermal and mechanical loads of the impact are concentrated in the upper and middle zones of the cylindrical part. The concentration of thermal and mechanical loads of the shock can lead to the destruction of the guide devices, the penetration of the core melt into the concrete and serpentinite concrete of the building, as a result of which they are destroyed, hydrogen and non-condensed gas may be formed. Among these are the risks of hydrogen explosions and over-designed pressure build-up in the containment. This could lead to containment failure and release of undesigned amounts of radioactive fission products outside of containment.

Russian Patent Publication No. 2253914 Russian Patent Publication No. 2576516 Russian Patent Publication No. 2576517 Russian Patent Publication No. 2575878

Melt localization device, 7th International Scientific and Practical Conference "Ensuring the safety of NPPs with PWRs", OKB "Gidropress", Russia, Podolsk, May 17-20, 2011

The technical result of the claimed invention is to improve the safety of nuclear power plants by increasing the reliability of melt localization and cooling systems in the reactor core.

The problem to be solved by the invention consists in ensuring the following conditions for the operation of the system for locating and cooling the core melt of a nuclear reactor:
- to exclude occlusion of the hole drilled in the center of the cone;
- to exclude melts from the reactor active zone penetrating the reactor building and serpentinite concrete, with the subsequent formation of hydrogen and non-condensable gases;

The task placed is that the guiding device (1) of the system for locating and cooling the core melt of a nuclear reactor consists of a cylindrical part (2) with a hole (4) in it and a conical part (2). Force ribs (5) arranged radially to the hole (4) dividing the walls of the shaped part (3), cylindrical (2) and conical (3) parts into sectors (7), etc. installed in the reactor underbody and resting on the console truss, according to the invention additionally comprising an outer upper bearing ring (8), an outer lower bearing ring (9), an inner central bearing ring A ring (10), an outer upper load-bearing shell (11), a middle power shell (12) sectored by power ribs (5) and with openings (14) at the top, a lower outer power shell (15), a base ( 16), a support rib (17), a conical bottom (19), a power rib (5) and an upper inclined plate (18) connecting the central power shell (12), and a conical bottom (19), a The load ribs (5), the central load bearing shell (12) and the outer upper load bearing shell (11), attached to the support ribs (17), the inner surface of the central bearing shell (12) and the upper inclined plate ( Lower inclined plate (20) connecting thermal plate metal screen (23) etc. mounted with gaps (22) along 18), collapsible thermal mounted on support ribs (17) and closing holes (4) Through the plate metal shield (13), between the upper and lower inclined plates (18 and 20), and between the central and outer upper powershells (12 and 11), the gap (22) through holes (14) ). There is a cooling channel (21) leaving the manifold (6) between the thermal plate metal screen (23) and the middle power shell (12) and the thermal plate metal screen (23) and the upper sloping plate (18) and the space (24 ), base (16), conical bottom (19), lower sloping plate (20), part of upper outer power shell (11), outer lower power ring (9), outer lower power shell (15). , and the space (25) between the outer upper powershell (11) and the central powershell (12), as well as the space (26) between the upper and lower inclined plates (18 and 20). By comprising a load-bearing frame filled with concrete or ceramic material (27) and consisting of an outer lower power shell (15) and a sealed lower part (28) connected to the supporting ribs (17), etc. resolved.

One of the features of the claimed invention is that, in the guide device (1), an outer upper power ring (8), an outer lower power ring (9), an inner central power ring (10), an outer upper power shell (11) ), intermediate load-bearing shell (12) divided into sectors by force ribs (5) and with holes (14) on top, outer lower power shell (15), base (16), support ribs (17), conical bottom (19), power rib (5), and upper inclined plate (18) connecting the central power shell (12), conical bottom (19), power rib (5), central power shell (12), and the melt locating and cooling system of the load-bearing frame consisting of the lower inclined plate (20) connecting the outer upper powershell (11) and so on. According to the claimed invention, the presence of the load-bearing frame makes it possible to reliably retain large size debris inside and on the bottom of the reactor vessel from falling into the melt trap, thereby protecting the trap from damage. melt the

Another feature of the claimed invention is that in the guide device (1), the gaps ( 22), a collapsible thermal plate metal screen (13) attached to the supporting ribs (17) closing the hole (4), etc. A thermal plate metal screen (23) is provided to eliminate blockage formation associated with overlapping flow areas by the melt, provided by the flattening and melting of the thin elements of the thermal plate metal screen (23). , for a rapid increase in effective flow area, ensuring gravity flow to the filler of the core melt after rupture or melting of the reactor vessel, protecting the truss console and its communications from destruction during melt transfer, core melt direct contact with the reactor shaft and construction concrete installations, the reliable exclusion of the direct radiation action from the core melt on the installation of the reactor shaft and the fixed elements of the reactor vessel, etc. .

Another feature of the claimed invention is that in the guide device (1) of the melt localization and cooling system, the upper and lower inclined plates (18 and 20) exit the collector (6). Cooling channels (21) are provided passing between and between the central and outer upper powershells (12 and 11), between a metal screen (23) such as a thermal plate and the central powershell (12) , and through holes (14) with gaps (22) forming a space between a metal screen (23) such as a thermal plate and an upper inclined plate (18). The provision of cooling channels (21) ensures thermal stabilization of the entire guide arrangement (1) when the reactor is powered under normal operating conditions.

Another feature of the claimed invention is that in the guide device (1) of the melt localization and cooling system, a base (16), a conical bottom (19), a lower inclined plate (20), an upper A space (24) limited by part of the outer powershell (11), the outer lower power ring (9), the outer lower powershell (15), etc., and the outer upper powershell (11) and the middle powershell. The space (25) between (12) and the space (26) between the upper and lower inclined plates (18 and 20) are each filled with concrete or ceramic material (27). The use of concrete and ceramic materials (27) in the indicated spaces can thermo-mechanically protect the force elements of the guide device (1) against destruction and during reactor vessel destruction. It securely holds the bottom and its large pieces, keeps the large pieces inside from falling into the melt trap, and protects the body of the melt trap from damage when large pieces occur. It protects the console truss and its communications from destruction during the fall and ensures the elimination of direct contact between the core melt and the reactor shaft and construction concrete installations.

Another feature of the claimed invention is that in the guide device (1) of the melt localization and cooling system, a closed power shell (15) connected to the outer lower power shell (15) and supporting ribs (17) The presence of the lower part (28). The presence of the sealed bottom (28) allows the drainage of water from the surface of the bottom (28) so that there is no steam explosion the moment the melt enters the filler and during the entire period of normal operation and maintain the integrity of fillers and structural materials in the event of violation of normal operation or a design basis accident.

In summary, this design of the guiding device allows:
- allow the slow flow of core melt (Corium) after the reactor breaks down or melts and enters the melting trap;
- Reliable protection of concrete shafts and serpentine concrete dry shields from direct contact with core melt.

1 shows a nuclear reactor core melt locating and cooling system guide apparatus made in accordance with the claimed invention; 1 illustrates a cross-sectional view of a nuclear reactor core melt location and cooling system constructed in accordance with the claimed invention; FIG. 1 shows a fragment of a guiding device of a melt localization and cooling system for the active zone of a nuclear reactor, made in accordance with the claimed invention;

As shown in Figure 1, the guiding device (1) of the core melt localization and cooling system of a nuclear reactor, installed below the reactor vessel and placed on the console truss, consists of a cylindrical section (2) and a conical portion (3). A hole (4) is drilled in the base of the conical portion (3). Strength ribs (5) radially arranged with respect to the holes (4) extend along the conical and cylindrical parts (2 and 3). Force ribs (5) divide the walls of the cylindrical (2) and conical (3) sections into sectors (7). The guide device (1) contains a load-bearing frame consisting of the following main (load-bearing) elements: an outer upper bearing ring (8), an outer lower bearing ring (9) and an inner central bearing ring. (10), outer upper load-bearing shell (11), middle load-bearing shell (12). The middle load-bearing shell (11) is divided into sectors by force ribs (5) similar to the walls of the cylindrical part (2). The structure of the load-bearing frame also includes an outer lower load-bearing shell (15), a base (16), supporting ribs (17) and an upper sloping plate (18). The upper sloping plate (18) connects the conical bottom (19), the load-bearing ribs (5) and the central load-bearing shell (12). The lower inclined plate (20) connects the conical bottom (19), the load bearing ribs (5), the middle load bearing shell (12) and the outer upper load bearing shell (11).

In addition to power elements, thermal elements are used as part of the guide device (1): thermal plate metal screen (23), folding thermal plate metal screen (13). A thermal plate metal screen (23) is attached to the support ribs (17) and gaps (22) along the inner surface of the intermediate load bearing shell (12) and the upper sloping plate (18). A collapsible thermal plate metal screen (13) is attached to the support ribs (17) and closes the holes (4).

Cooling channels (21) extend between the upper and lower inclined plates (18 and 20) and between the central and outer upper powershells (12 and 11). The cooling channels (21) exit the collector (6) through holes (14) between the thermal plate-like metal screen (23) and the middle power shell (12) and the thermal plate-like metal screen (23 ) and the upper sloping plate (18) at the gap (22) forming the space.

Confined by base (16), conical bottom (19), lower sloping plate (20), part of upper outer power shell (11), lower outer power ring (9), lower outer power shell (15) etc. space (24) and the space (25) between the outer upper powershell (11) and the middle powershell (12), and the space (26) between the upper and lower inclined plates (18 and 20). ) are each filled with concrete or ceramic material (27).

From below, the closed bottom (28) is welded to the outer lower powershell (15) and support ribs (17).

The claimed guiding device operates as follows.

As shown in Figures 1 to 3, a guide device (1) mounted on the truss console below the bottom of the reactor vessel, in accordance with the principles of the claimed invention, guides the reactor vessel and the underlying reactor shaft. and between the bottom of the reactor vessel and the melt trap below the guide device (1). The presence of a thermal barrier makes it possible, during normal operation, to provide thermal insulation of the bottom of the reactor vessel, and in the event of a severe accident, upon failure of the reactor vessel by core melt, the initiation of melt entering the trap. provide conditions for diagnosing

To ensure thermal insulation of the bottom of the reactor vessel during normal operation, the insulation is a lamellar metal heat screen (23 ) is attached to a guide plate consisting of Such a package has, in addition to the walls (6) of the cylindrical and conical parts (2 and 3), the inner surfaces of the central load-bearing shell (12) and the upper inclined plate (18), normal operation, Provides mutual thermal displacement of the insulation package and guide plate frames during interruptions in normal operation, and in the event of design basis accidents.

A collapsible thermal plate metal screen (13) is installed beneath the pole at the bottom of the reactor vessel to provide access to the outer surface of the reactor vessel when required. A hatch with a displacement insert is made in the lower part of the guide device (1) from the side of the service platform to access the folding thermal plate metal screen (13). This design eliminates the accumulation of water in the hatch when normal operation is violated, during design, and beyond design-based accidents.

Space (5, 8, 11, 9, 15, 16, 19, 18, 12) guides between load-bearing elements to ensure thermal insulation of building concrete and console trusses in the event of an accident exceeding the design basis The device is filled with heat-resistant concrete. Depending on their function, the power elements (5, 8, 11, 9, 15, 10) and the concrete and ceramic materials (27) are funnel-shaped and of the connecting surface between the bottom and the cylindrical part (2). A guide vane is formed that provides a cladding for the lower portion of the upper reactor vessel. During melt exit, the guide device (1) is subjected to both relatively slow loads during plastic deformation of the reactor vessel and impact loads when the bottom of the reactor vessel tears under the influence of residual pressure. there is a possibility. These loads are taken up by each power element (5, 8, 11, 9, 15, 10) and guide vanes formed by concrete and ceramic material (27). This design provides:
- Gravitational flow of core melt into the filler after reactor vessel failure or melting;
- prevent large internal debris and reactor vessel bottoms from falling into melt traps;
- protection of the body of the melt trap from damage when large fragments fall;
- protection of the truss console and its communications from destruction during melt transfer;
- elimination of direct contact between core melts and reactor shafts and construction concrete installations;
- Elimination of direct radiation effects from the core melt on the reactor shaft equipment and reactor vessel fixing elements.

Below the sloping surfaces of the guide vanes, i.e. below the upper and lower sloping plates (18 and 20) where the melt contacts, a layer of sacrificial material of concrete or ceramic is provided: just below the upper sloping plate (18) A sacrificial layer, for example made on the basis of aluminum and iron oxide, is provided, while under the lower inclined plate (20) a heat-resistant layer, for example based on aluminum oxide, is provided.

For example, during melt discharge from the reactor vessel at high flow rates exceeding the throughput of the flow area of the guide device (1), or during melt discharge with core debris, the flow region is blocked and the melt If the increase in effective flow area provided by the flattening and melting of the thin elements of the plate metal screen (23) is insufficient when preventing the free outflow of the sacrificial material under the upper inclined plate (18) , melt into the core melt and increase the flow area of the sector of the guide device (1). Melting the sacrificial material prevents the power ribs (5) from overheating and breaking. When the power ribs (5) are destroyed, the flow section is completely blocked and consequently the guide device (1) is destroyed in sectors.

A heat and heat resistant layer placed under the lower slanted plate (20) reduces the thickness of the sacrificial material placed between the upper slanted plate (18 and 20) and the lower slanted plate (18 and 20). while providing structural strength and stability. The refractory concrete protects the underlying equipment from the effects of the melt and prevents the melt from penetrating the sector and destroying the guide devices.

When the bottom of the reactor vessel breaks, the guide device (1) is subjected to dynamic loads resulting from:
- with lateral outflow of melt under the influence of residual pressure in the reactor vessel;
- when the flow area of the side cavity in the reactor vessel increases and its profile changes during melt outflow;
- when part of the bottom of the reactor vessel is torn as a result of plastic deformation under the action of thermomechanical loads and residual pressure;
- when part of the bottom of the reactor vessel is torn off as a result of a pulsed increase in pressure in the reactor vessel (injection of water into the core melt) and their impact braking against the guide vanes;
- When outside influences and autoshocks in accidents beyond design basis.

Before the melt starts to flow, the filler in the trap body is sealed off by the bottom (28) of the guide device (1), allowing:
- water discharge from the bottom (28), so that there is no steam explosion at the moment the melt enters the filler;
- Maintaining the integrity of fillers and structural materials during the entire period of normal operation and even in the event of violation of normal operation or design basis accidents.
To ensure smooth flow of the melt to the filler, the following is done:
- The sealed bottom (28) is made in the form of an easily breakable membrane.
- Thermal plate metal screens (13 and 23) are made easily breakable by hot melts so as not to impede their movement. When the insulating material melts, the flow area of the melt flowing on the surface of the guide vane increases several times. Different degrees of increase in flow area are provided for vertical and inclined thermal plate metal screens (23), which are related to different shapes of the channels formed by the vertical force ribs;
- in the middle of the guide vanes there is a hole (4) for the passage of the core melt, the dimensions of which limit the spreading of solid and liquid core debris during outflow from the reactor vessel; be done.

Thus, a hot plate metal shield (23) installed under the upper and lower inclined plates (18 and 20) used as part of the guiding device (1) of the reactor core location and cooling system and The sacrificial material performs impact resistance, channeling, and protective functions.

The thermal plate metal screen (23) provides initial damping of shock loads from the disconnected sector of the ruptured bottom, taking into account the acceleration caused by the residual pressure in the reactor vessel. Furthermore, the frangible thermal plate metal screen (23) initially protects the guide device (1) from the impact of molten jets at small residual pressures inside the reactor vessel.

During strong dynamic impacts from isolated sectors of the destroyed bottom of the reactor vessel, the impact loads are applied to the protective layer around the critical load-bearing elements (5, 11, 15, 9) of the guide device (1). and the load-bearing ribs (5) are received by a layer of sacrificial material below the upper and lower sloping plates (18 and 20), especially in the case of the sloping sections. May be protected and partially melted.

Together with the load-bearing elements (5, 8, 11, 9, 15, 18, 20, 12) of the guide device (1), the concrete or ceramic material (27) is Create an impenetrable barrier.

Moreover, the thermal plate metal screen (23) and the concrete or ceramic material (27) forming a protective layer for the power elements (5, 9, 11, 12, 15) of the guide device (1) are the core of the reactor vessel and its It provides damping and interception of internal large debris while ensuring a consistent flow of core melt, internal debris, and the bottom of the reactor vessel into the melt trap.

A frangible thermal plate metal screen (23) provides increased flow area to move the core melt azimuthally with horizontal melt flow in each radial vertical and sloping sector.

Guiding devices (1 ), an increase in flow area occurs when the chemical activity and thermo-mechanical effects on the load-bearing frame of the guide device (1) are reduced and its integrity is maintained.

Moreover, the thermal plate metal screen (23) and the concrete or ceramic material (27) forming a protective layer for the power elements (5, 9, 11, 12, 15) of the guide device (1) are Provides protection of reactor shaft structure and serpentinite concrete from action.

Concrete or ceramic material (27) forming a protective layer around the critical strength members (5, 11, 15, 9) of the guide device (1) creates a thermal and chemical barrier and prevents core melt jets from To prevent damage and destruction of the load bearing elements (5, 8, 11, 9, 15, 18, 20, 12) of the guide device (1) under the thermochemical and thermomechanical effects from , the thermal resistance of the concrete or ceramic material (27) is chosen differently in different directions of core melt flow, resulting in premature failure of the sacrificial material under the upper sloping plate (18) closest to the reactor vessel. is ensured, which leads to faster discharge of the molten resin and less thermochemical and thermomechanical influence on the important power elements (5, 6, 9, 7, 11, 14, 10) of the guiding device (1) Decrease.

In addition, the concrete or ceramic material (27) forming the protective layer of the load-bearing elements (5, 6, 9, 7, 11, 14, 10) of the guide device (1) is suitable for lateral penetration of the reactor vessel. It provides protection of the reactor shaft structure and serpentinite concrete from interaction with the melt as a result of ensuring their strength in some cases.

The use of a guide device (1) with a load-bearing frame with additional thermal elements does not block the central hole drilled in the taper, protects the concrete shaft and protects it from direct contact with the core melt. by ensuring a gradual flow of core melt (melt) after reactor vessel rupture or after penetration into melt traps without the dry protection of serpentinite concrete of the internal , fuel assemblies, and large debris at the bottom of the reactor vessel from falling into the melt trap, thereby keeping the truss console and its communications out of the way as melt flows from the reactor vessel into the melt trap. It made it possible to protect from destruction.

Claims (1)

A guide device (1) installed below the reactor vessel and resting on the console truss, comprising:
dividing the cylindrical part (2) , the conical part (3) with holes (4) and the walls of the cylindrical (2) and conical (3) parts into sectors (7) , power ribs (5) radially arranged with respect to the holes (4),
In addition, including a load-bearing frame,
The load-bearing frame includes:
Sectored by outer upper bearing ring (8) , outer lower bearing ring (9) , inner central bearing ring (10) , outer upper power shell (11) and power rib (5), open at the top Central power shell (12) with section (14), outer lower power shell (15) , base (16) , supporting ribs (17) , conical bottom (19), power ribs (5 ), and an upper inclined plate (18) connecting the central powershell (12) with a conical bottom (19), a power rib (5), a central powershell (12) and an outer upper powershell. lower sloping plate (20) connecting (11) and supporting ribs ( 17) with a gap (22) along the inner surface of the central powershell (12) and the upper sloping plate (18) a collapsible thermal plate metal screen (13) attached to the supporting ribs (17) and closing the holes (4); upper and lower inclined plates (18 and 20); and between the central and outer upper powershells (12 and 11), through holes (14) between the thermal plate metal screen (23) and the central powershell (12), and a cooling channel ( 21) connected with the gap (22) forming the space between the thermal plate metal screen (23) and the upper inclined plate (18) ,
Base (16), Conical Bottom (19), Lower Sloping Plate (20), Part of Outer Upper Powershell (11), Outer Lower Power Ring (9), Outer Lower Powershell (15) ) , the space (25) between the outer upper powershell (11) and the central powershell (12), the upper inclined plate (18) and the lower inclined plate ( 20 ) are filled with concrete or ceramic material (27) and the sealed lower part (28) is connected to the outer lower power shell (15) and supporting ribs (17). guide device (1) of a system for locating and cooling core melt of a nuclear reactor , comprising :

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