JP2635856B2 - Protective equipment inside the PCV - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor containment for preventing a communication hole of a pedestal erected in a containment vessel of a boiling water reactor from being blocked by, for example, a fallen object when a pipe breaks. It relates to a protective device in a container.

[0002]

2. Description of the Related Art A reactor containment vessel of an improved boiling water reactor has a rectangular shape as shown in FIG.
And the reactor pressure vessel 3 erected on the pedestal 2
And a suppression chamber 4 is provided below.

[0003] A vent pipe 5 is provided in the suppression chamber 4, and the vent pipe 5 communicates with a communication hole 6 formed in the pedestal 2. The communication hole 6 has a fan-shaped cross section similar to a base having an upper side of about 2 m, a lower side of 1.5 m, and a height of about 1 m, and has a length of about 8 m and supports the reactor pressure vessel 3. The pedestal 2 is provided vertically. The inside of the reactor containment vessel 1 is divided into a dry well 8 and a wet well 9, and the dry well 8 is divided into an upper dry well 8 a and a lower dry well 8 b, and both are communicated by a communication hole 6. A discharge pipe 7 immersed in the suppression chamber 4 is provided in the wet well 9.

[0004]

The jet at the time of a pipe break in the containment vessel 1 does not directly act on the communication hole 6 communicating with the vent pipe 5 of the improved boiling water reactor. However, there is a possibility that facilities in the containment vessel 1 damaged by the jet may block the communication hole 6.

[0005] The communication hole 6 of the improved boiling water reactor containment vessel
Is very narrow due to the arrangement equipment in the containment vessel, and it is very difficult to install a protective structure in the communication hole 6. In addition, pipes, cables, ducts, and the like communicating from the upper dry well 8a to the lower dry well 8b pass through the communication hole 6, and
These installations need to be supported at the entrance of the communication hole 6. Further, the upper dry well 8a and the lower dry well 8b have a role of temporarily absorbing energy released when the built-in piping is broken. Normally upper dry well 8
a and the lower dry well 8b are connected by the communication hole 6, and the released energy is absorbed in both spaces.

However, assuming that the pipe is broken in the upper dry well 8a and the communication hole 6 is closed due to this effect, only the upper dry well 8a has a space for absorbing energy, which is disadvantageous in energy absorption efficiency. There is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a protection device in a reactor containment vessel capable of avoiding blockage of a communication hole even in an assumed accident.

[0008]

According to the present invention, a support structure unit is provided in a communication hole of a pedestal erected in a containment vessel of a boiling water reactor, and the support structure unit projects on the support structure unit into an upper dry well. A protective structure is provided.

[0009]

[Action] When the communication hole is closed due to the fall of the reactor containment vessel damaged by the pipe break jet in the reactor containment vessel, the atom from the pipe break port guides the vapor to the suppression pool to condense and reduce the pressure. Although it becomes difficult to secure the function of the furnace containment vessel, this function is secured by providing a protective structure. In addition, by integrating the protection structure with the support structure unit, installation work of the protection structure on site can be significantly reduced. When the protection structure is installed, the structure of the protection structure can be simplified by disposing the piping break jet.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a protection device in a containment vessel according to the present invention will be described with reference to FIGS. FIG. 1 shows only a main part of the present invention, and a primary containment vessel 1 is shown.
The structure inside is the same as that of FIG. Also,
FIG. 2 is an enlarged perspective view of a main part of FIG. That is, as shown in FIG. 1, the reactor containment vessel 1 having the upper dry well 8a and the lower dry well 8b and having the communication hole 6 communicating the dry wells 8a and 8b is provided in the pedestal 2 as shown in FIG. A stepladder-like support structure unit 10 is provided in the communication hole 6, and a protection structure 11 is installed on the support structure unit 10. The protection structure 11 is configured to be used as a support device for piping cables, ducts, and the like. That is, the piping cable 13 and the like are attached to the protective structure 11 via the support 12, and the protective structure 11 has an arrangement level that is not affected by the equipment 14 in the containment vessel and the pipe break jet 15. ing. The support structure unit 10 has a steel plate 16 and a horizontal beam 17 between the support structure unit 10 and the protection structure 11 as shown in FIG. 2, and the distal end of the protection structure 11 has a communication hole on the upper dry well 8a side. 6 project at the entrance site.

Thus, according to the above embodiment, it is possible to prevent the communication hole 6 from being blocked at the time of an assumed accident. That is, since the entrance of the communication hole 6 is narrow, the protective structure 11 having the communication hole 6 protruded is fixed by using a part of the structural material inside the reactor containment vessel already installed. Have been. Further, the pressure reducing function of the containment vessel 1 is secured by the protection structure 11, the structure can be extremely simplified, and the installation work on site can be reduced. In addition, by forming the platform by the steel plate 16 on the upper surface of the protection structure 11, access to the installation installed above the communication hole 6 becomes easy. Also, the protective structure
When installing the protection structure 11, the structure of the protection structure 11 can be simplified by avoiding the pipe break jet 15.

[0012]

According to the present invention, by providing a protective structure, the pressure reducing function of the containment vessel can be secured, the structure can be simplified, and in addition, the installation work on site can be reduced. Can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a protection device in a containment vessel according to the present invention.

FIG. 2 is a perspective view showing a main part in FIG. 1;

FIG. 3 is a longitudinal sectional view schematically showing the inside of a conventional reactor containment vessel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Containment vessel, 2 ... Pedestal, 3 ... Reactor pressure vessel, 4 ... Suppression chamber, 5 ... Vent pipe, 6
... communication hole, 7 ... discharge pipe, 8 ... dry well, 9 ... wet well, 10 ... support structure unit, 11 ... protective structure, 12
… Support, 13… Piping cable, 14… Containment equipment,
15 ... jet, 16 ... steel plate, 17 ... horizontal beam.

Claims (1)

(57) [Claims] 1. A support structure unit is provided in a communication hole of a pedestal erected in a boiling water reactor containment vessel, and a protection structure is provided on the support structure unit so as to protrude into an upper dry well. A protection device in a containment vessel, characterized in that: