JP2013002877A - Cooling system for reactor container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool down the inside of a reactor container, steel plates and concrete constituting the container by discharging heat within the container to the outside while maintaining air-tightness inside the container in the reactor container of a steel plate/concrete structure.SOLUTION: In a cooling system for a reactor container where a gap between an inner steel plate 1a and an outer steel plate 1b is filled with concrete 2, an internal outer circumferential surface 4a and an external outer circumferential surface 4b of an annular vessel 4 in which a cooling material 5 is stored, are brought into contact with the inner steel plate 1a and the outer steel plate 1b, respectively.

Description

  The present invention relates to a cooling device for cooling a reactor containment vessel in the event of an accident.

  In recent years, nuclear power plants have used nuclear reactor containment vessels made of reinforced concrete to prevent the release of radioactive materials to the outside in the event of an accident. As such a containment vessel, a reinforced concrete structure with an inner surface lined with a steel liner or a steel plate concrete structure in which a steel plate with studs is arranged on the inside and outside, and no reinforcing bar portion with a concrete portion sandwiched therein is proposed ( Patent Document 1). The steel plate concrete structure is composed of a pair of steel plates composed of an inner steel plate and an outer steel plate, a plurality of stat bolts provided on the inner surface of each steel plate, and a concrete portion filled between the pair of steel plates (FIG. 2). reference).

  Such a steel-concrete reactor containment vessel does not require assembling and building rebars on site, so the construction period can be shortened and the inner steel plate can be an alternative to the conventional steel plate liner. Therefore, it has the function of ensuring the confidentiality in the reactor containment vessel and preventing the release of radioactive materials.

  On the other hand, in the worst case, if the reactor cooling function is lost or high-temperature steam is released into the reactor containment in a severe accident such as a power loss accident, the reactor containment becomes hot. The confidentiality of the containment vessel may be lost. Therefore, in the conventional reactor containment vessel, in order to prevent the containment vessel from becoming high temperature, means for spraying cooling water or cooling air on the outer peripheral wall of the reactor containment vessel and cooling the reactor containment vessel, Reactor by forming a part of steel material with high thermal conductivity and releasing the heat in the reactor containment vessel (Patent Document 2), and by installing a cooling pipe inside the concrete of the containment vessel Means (Patent Document 3) and the like for preventing the containment vessel from becoming high temperature have been proposed.

Japanese Patent No. 3309290 Japanese Patent Laid-Open No. 11-84056 JP 2005-189043 A

  Conventional reactor containment vessels using steel plates or steel liners have a structure in which concrete is filled between the inner and outer steel plates, but the concrete loses strength due to evaporation of internal moisture at high temperatures. In addition, because the heat transfer coefficient of the concrete itself is low, the inner steel liner and the steel plate are buckled and deformed due to heat in the event of a high temperature inside the reactor containment vessel. There is a possibility that voids are generated between the two and the heat transfer performance may be further deteriorated.

  On the other hand, in order to release the heat in the reactor containment vessel to the outside, a part of the reactor containment vessel that becomes the wall surface of the cooling water pool is formed of a material having high thermal conductivity (Patent Document 2), or the reactor containment vessel floor Although it has been proposed to embed a cooling pipe in the concrete part of the surface (Patent Document 3), these heat removal means are used to release the heat of the local high temperature generating part in the reactor containment vessel to the outside. However, it does not have a function of cooling the steel plate and concrete itself constituting the reactor containment vessel. Thus, the conventional reactor containment vessel cooling means is local, has a small heat removal capability, and it has been difficult to cool the steel plate and concrete constituting the reactor containment vessel as a whole.

  The present invention has been made to solve the above problems, and in a nuclear reactor containment of a steel plate concrete structure, by releasing heat inside the containment vessel while maintaining the airtightness inside the containment vessel, It is an object of the present invention to provide a reactor containment vessel cooling apparatus capable of cooling the inside of the reactor containment vessel and the steel plates and concrete constituting the containment vessel.

  In order to solve the above-described problems, a reactor containment vessel cooling apparatus according to the present invention is a reactor containment vessel cooling apparatus in which concrete is filled between an inner steel plate and an outer steel plate. The inner and outer peripheral surfaces of the annular container accommodated are brought into contact with the inner and outer steel plates, respectively.

  The reactor containment vessel cooling device according to the present invention is a reactor containment vessel cooling device in which concrete is filled between an inner steel plate and an outer steel plate, and a concrete portion between the inner steel plate and the outer steel plate. A plurality of water sprinkling / steam collecting pipes provided in the water, a plurality of openings provided in each water sprinkling / steam collecting pipe, and a drain tank connected to the lower part of each water sprinkling / steam collecting pipe via a pipe; It is characterized by having.

  According to the present invention, in a severe accident or the like, by releasing the heat inside the containment vessel to the outside while maintaining the airtightness inside the containment vessel, the steel plates constituting the containment vessel and the containment vessel, and Concrete can be cooled efficiently.

The schematic diagram of the nuclear reactor containment vessel provided with the cooling device which concerns on 1st Embodiment. Sectional drawing of the cooling device which concerns on 1st Embodiment. The whole block diagram of the nuclear reactor containment vessel provided with the cooling device which concerns on 2nd Embodiment.

  Hereinafter, an embodiment of a reactor containment vessel cooling apparatus according to the present invention will be described with reference to the drawings.

(First embodiment)
A reactor containment vessel cooling apparatus according to a first embodiment will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic diagram of a reactor containment vessel 1 in which a cooling device according to the present embodiment is arranged, and an inner steel plate 1a and an outer steel plate 1b having a plurality of ribs 3, and a concrete portion 2 filled therebetween. It is comprised from the cooling device which consists of the annular container 4 installed between the inner side steel plate 1a and the outer side steel plate 1b.

  The annular container 4 is made of a highly heat conductive member and has a substantially parallelogram shape as shown in FIG. 2 and is arranged so that the inner outer peripheral surface 4a is in contact with the inner steel plate 1a and the outer outer peripheral surface 4b is in contact with the outer steel plate 1b. The coolant 5 is enclosed inside. Moreover, it is comprised so that the upper end part of the outer peripheral surface 4b may be located higher than the upper end part of the inner outer peripheral surface 4a so that the coolant 5 in the annular container 4 forms a circulating flow by convection.

  In the first embodiment configured as described above, heat from the inner steel plate 1a is transmitted to the coolant 5 through the inner peripheral surface 4a, and the coolant 5 circulates in the annular container 4 by convection. Heat is radiated to the outside through the outer peripheral surface 4b and the outer steel plate 1b.

  According to the first embodiment, when the temperature in the reactor containment vessel becomes high due to an accident or the like, the reactor containment vessel is passively configured without using dynamic devices such as a power source and a drive device. The heat of the steel plate and the concrete constituting the containment vessel and the heat of the concrete can be radiated to the outside, and the inside of the reactor containment vessel and the containment vessel can be cooled.

  A plurality of annular vessels 4 are provided in the circumferential direction and the vertical direction over the entire reactor containment vessel 1. Further, the cooling device is not limited to the parallelogram-shaped annular container 4, and may have an oval shape or the like as long as the inner and outer side surfaces can be in contact with the steel plate. You may comprise from a pipe-shaped member.

Further, a circulation device such as a fan that is driven by an emergency or ordinary power source may be provided in the annular container 4 (not shown) to promote circulation of the coolant 5.
In addition, a storage container (not shown) for storing water such as rainwater is provided on the outer steel plate 1b of the reactor containment vessel in which the annular container 4 is installed, and the water in the storage container is discharged outside when the coolant 5 is radiated. The steel plate 1b, particularly in the vicinity of the place where the annular container 4 is disposed, may be dispersed to promote the cooling function.

(Second Embodiment)
A reactor containment vessel cooling apparatus according to a second embodiment will be described with reference to FIG.
In the present embodiment, as shown in FIG. 3, a plurality of sprinkling / steam collecting pipes 6 are arranged in the circumferential direction in the concrete portion 2 between the inner steel plate 1a and the outer steel plate 1b.

  Each water sprinkling / steam collecting pipe 6 has substantially the same height as the side wall of the reactor containment vessel 1, and a plurality of openings 8 for collecting or sprinkling steam are provided in the longitudinal direction. In addition, a reservoir 9 for storing steam is provided at the upper part of each water sprinkling / steam collecting pipe 6, and the lower part is connected to a drain tank 12 via a pipe 11.

  In the present embodiment configured as described above, when the reactor containment vessel 1 becomes high in the event of an accident, the steam generated in the concrete part 2 is sprinkled and collected through the opening 8 as indicated by an arrow 7a. While being collected by the pipe 6, the internal pressure of the concrete part 2 is prevented from rising and the concrete part 2 is prevented from being deteriorated by high heat.

  Further, the collected steam is guided to the storage unit 9 or the pipe 11. At that time, the steam is condensed by the cooling device 4 or natural cooling shown in the first embodiment, and the condensed water is stored in the drain tank 12. Is done.

  On the other hand, when the moisture of the concrete part 2 becomes very low, the concrete part 2 becomes hot and the strength is lowered. Water is then sprayed into the concrete part 2 and cooled (arrow 7b).

Thus, the sprinkling / steam collecting pipe 6 has both water sprinkling and steam collecting functions, and collects or sprinkles steam from the concrete part 2 according to the state of the concrete part.
Further, in order to reinforce the steel concrete structure, a stat or a rib may be provided on the outer surface of each water sprinkling / steam collecting pipe 6, and the water sprinkling / steam collecting pipe may be used as a structural material.

  As described above, according to the present embodiment, when the concrete part becomes hot due to an accident or the like, damage due to an increase in internal pressure of the concrete part by performing timely steam collection or water spraying with water sprinkling / steam collecting piping, Deterioration and strength reduction can be prevented. Moreover, the collected steam can be stored in a drain tank and effectively used as sprinkling cooling water.

In the above embodiment, the water sprinkling / steam collecting pipe 6 has both water sprinkling and steam collecting functions. However, the water sprinkling pipe and the steam collecting pipe are separated from each other, and a plurality of them are arranged in the concrete portion 2 of the reactor containment vessel 1 respectively. You may make it do. At that time, the sprinkler pipe and the steam collecting pipe are connected to the drain tank 12 by pipes having different systems, or an on-off valve (not shown) is installed between each pipe and the pipe 11 to operate the on-off valve. By doing so, water spraying or steam collecting operation may be performed.
Further, the drain tank 12 may store not only steam condensed water but also water from the outside such as rain water.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, combinations, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Reactor containment vessel, 1a ... Inner steel plate, 1b ... Outer steel plate, 2 ... Concrete part, 3 ... Stud, 4 ... Ring container, 4a ... Inner outer peripheral surface, 4b ... Outer outer peripheral surface, 5 ... Coolant, 6 ... Sprinkling / steam collecting piping, 8 ... opening, 9 ... reservoir, 10 ... reactor pressure vessel, 11 ... piping, 12 ... drain tank.

Claims (8)

In the reactor containment vessel cooling device filled with concrete between the inner and outer steel plates,
A reactor containment vessel cooling apparatus, wherein an inner outer peripheral surface and an outer outer peripheral surface of an annular container having a coolant contained therein are brought into contact with the inner steel plate and the outer steel plate, respectively.   2. The reactor containment vessel cooling apparatus according to claim 1, wherein a plurality of the annular vessels are arranged in a circumferential direction and a vertical direction of the reactor containment vessel.   3. The reactor containment vessel cooling apparatus according to claim 1, wherein an upper end portion of the outer peripheral surface of the annular vessel is located higher than an upper end portion of the inner outer peripheral surface.   The reactor containment vessel cooling apparatus according to any one of claims 1 to 3, wherein a coolant circulation device is provided in the annular vessel.   The reactor containment vessel cooling apparatus according to claim 1, wherein a coolant is sprayed on the outer steel plate. In the reactor containment vessel cooling device filled with concrete between the inner and outer steel plates,
A plurality of water spray / steam collection pipes provided in the concrete portion between the inner steel plate and the outer steel plate, a plurality of openings provided in each water spray / steam collection pipe, and each water spray / steam collection pipe A reactor containment vessel cooling apparatus comprising a drain tank connected to a lower portion via a pipe. 7. The reactor containment vessel cooling apparatus according to claim 6, wherein a plurality of water sprinkling pipes and a plurality of steam collecting pipes are provided in place of the plurality of water sprinkling / steam collecting pipes.   The reactor containment vessel cooling apparatus according to claim 6 or 7, wherein a stat or a rib is provided on an outer surface of the sprinkling / steam collecting pipe, the sprinkling pipe or the steam collecting pipe.

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