JPS59180496A - Pipe penetration structure of reactor biologcal shielding wall - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a structure of a pipe penetration part in a wall of a living body part of a nuclear reactor.

[Prior art]

The internal structure of the reactor containment vessel was constructed using boiling water type (MARK-I)
A description will be given based on FIG. 1, taking the case of a nuclear reactor as an example.

In FIG. 1, 1 is a dry well that constitutes the reactor containment vessel, 2 is a Zapretsunyeon chamber, 3 is a reactor pressure vessel installed in the dry well 1, and 4 is an atom surrounding the pressure vessel 3. Reference numeral 5 indicates piping connected to the pressure vessel 3 on the wall of the furnace body part.

2 is a partially enlarged view of FIG. 1 (an enlarged view of the reactor pressure vessel and its surroundings), and FIG. 3 is an enlarged sectional view taken along the line A-A of FIG. 2.

As is clear from Figures 2 and 3, especially Figure 3,
The pipe 5 is connected to the pressure vessel 3 via a nozzle 6, and the biological barrier wall 4 is provided with a pipe through hole X for drawing the pipe 5 to the outside.

However, the above-mentioned pipe through hole
ISI: In-8service ■n5pec
A large square hole (111) is formed in consideration of securing space during reactor operation, and during reactor operation, this piping through hole During ISi, the door 7 is opened and various tests are performed by temporarily removing the following neutron shield blocks 8, 8, etc., which were previously proposed by the present inventors. That is, in the conventional example closest to the present invention, as shown in FIG.
By stacking a large number of..., an effort has been made to further enhance safety during reactor operation.

Figure 4 is a front view (block structure explanatory diagram) of the above-mentioned reactor connecting wall (around the passage 4), and in the same figure, the neutron connecting walls 8,8...
・ is supported by a ring frame 9 located inside and a square frame 10 located outside, and is 18
1 o'clock, the ring frame 9 and the neutron chain block 8
, 8, etc. will be temporarily removed and resupplied after the ISI ends.

Figure 5 shows the neutron chain block 8°8 shown in Figure 4.
・I have taken out the - piece and shown it,
The iron container 8a is filled with a neutron reactor ag'sb.

The conventional example closest to the present invention has the above configuration,
This configuration is effective in improving safety during reactor operation, but on the other hand, the neutron shield blocks 8, 8...
In constructing the block group 8, 8...
Since the so-called "distortion row" structure in which all the ends of the pipes are aligned, the ring plate 9 that supports the blocks 8, 8... The weight h1- of blocks 8, 8... located in
As a result, the plate thickness of the ring frame 9 is increased to increase the withstand pressure against the block load.
There was a need to prevent the ring frame from deforming.

[Purpose of the invention]

The present invention has been made with the above points in mind, and its purpose is to prevent vertical loads from being applied to the ring frame that supports the neutron shield block from the inside. A nuclear reactor with excellent economic efficiency and workability, which aims to reduce the plate thickness and weight, and allows temporary removal of the ring frame and corner assembly work at the start of TSJ and the end of ISI to be performed more easily than before. The present invention aims to provide a structure for a pipe penetrating part of a biological wall.

[Summary of the invention]

In order to achieve the above object, the present invention surrounds a reactor pressure vessel with a biological wall, and a pipe connected to a nozzle of the reactor pressure vessel is drawn out to the outside of the biological wall. A pipe penetration hole is provided, and the pipe penetration hole V is equipped with a gamma ray shielding function that surrounds the installed pipe, and a neutron shielding block is supported between the inner and outer frames on the inside of the gamma ray passage door. During reactor operation, in the pipe penetration structure of the enclosure wall, among the neutron shielding blocks located inside the comma ray shielding door, at least the blocks located above the horizontal center line of the pipe penetration hole are stacked alternately. It is characterized by:

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on FIG. 6. This figure is a front view 1' (block structure explanatory diagram) of a reactor connecting wall (around the pipe penetration part) showing one embodiment of the present invention. The same reference numerals as in the conventional example shown in FIG. 8,
8... is a neutral premature passage block laminated in large numbers at 111 inside the gamma ray passage door, 9 is a neutron passage block 8,
8... from the inside (+111), 1'(1') shows a square frame that supports the blocks 8, 8... from the outside, and as shown in the illustrated embodiment, the present invention Among the neutron shield blocks 8, 8, etc. located inside the door, at least the blocks located above the horizontal center line of the pipe through hole X are arranged alternately. It is.

〔Effect of the invention〕

Therefore, in the present invention having the above configuration, when focusing on the neutron number range blocks in contact with the ring frame 9 (the neutron number range blocks located above the horizontal center line of the pipe through hole X), these blocks have a downward direction. Even if a load tries to act on it, other blocks located above it (alternately stacked blocks) act to stop the downward load of the blocks in contact with the ring frame 9. In other words, the above-mentioned alternately stacked blocks (This is intended as a vertical load blocking part of the block in contact with the frame 9), and as a result, no downward load is applied to the block with a low number of neutrons in contact with the ring frame 9. For the installation 1 load, it is sufficient to consider the load acting on the blocks 8, 8, etc. due to horizontal seismic force. Therefore, the horizontal seismic force mentioned above is a small value of about 1/2 or less compared to the vertical downward load (dead load l - vertical seismic force), and the ring frame 9 should be designed using this small value. As a result, the thickness of the ring frame 9 can be reduced to almost half of that of the conventional ring frame 9, resulting in a reduction in the weight of the frame 9, which also makes temporary removal and resupply of the frame 9 at the start of IS and the end of ISI easier than before. It can be done. Further, according to the present invention having the above configuration, the thickness of the ring frame 9 is reduced by about 1/2 compared to the conventional one, so that the size of the pipe through hole X can be reduced by that amount.

FIG. 7 is a front view of main parts showing another embodiment of the present invention, and FIG.
This figure is an exploded perspective view of the ring frame shown in FIG. 7. In FIGS. 7 and 8, the same reference numerals as in FIG. 6 indicate the same parts, and in this embodiment, the neutron number block 8. The ring frame 9 that supports 8... from the inside is composed of divided parts paulownia 9a and 91), and if the ring frame 9 is composed of a plurality of divided members as shown in ``2'', ■S ■The temporary removal and resupply work of frame 9 at the start and end of ISI will be further postponed.

As described above, the present invention provides at least the horizontal center line of the piping through hole in the neutron number shield block located inside the gamma ray passage hole in the structure of the piping penetration part of the nuclear reactor biological wall. By stacking the blocks located above the neutron block alternately, the ring frame that supports the neutron number block from the inside is not subjected to vertical load, which reduces the thickness of the frame plate and, in turn, reduces the weight. It is possible to obtain a structure of this type that is superior in economy and workability, and allows temporary removal and resupply of the ring frame at the start of f and the end of ISI to be carried out more frequently than in the past.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the internal structure of the θ1) rising water type (MARK-1 type) reactor containment vessel, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is an enlarged view of A and -A in Figure 2. A cross-sectional view, and FIG. 4 is a front view of the reactor bioshielding wall (piping penetration structure) previously proposed by the inventors (block 1111 + blue explanatory diagram)
, FIG. 5 is a partially cutaway perspective view of the block piece shown in FIG. 4,
FIG. 6 shows a nuclear reactor biological shielding wall (
FIG. 7 is a front view of main parts showing another embodiment of the present invention, and FIG. 8 is an exploded perspective view of the ring frame shown in FIG. 7. be. 1...Trywell, 2...Zapresso 7 Yonchennoku, 3...Reactor pressure vessel, 4...Reactor biological shielding wall, Death...Piping, 6...Nozzle, 7. Gamma ray communication Heino; rl, 8...neutron number block, 8a.
...Iron container, 8b...Neutron beam material, 9...Ring frame, 9a, 9b...Dividing member, 10...Square frame, X...Piping through hole. Agent: Patent attorney: Denio Nagasaki. (1 other person) Certain 1, 3! 2nd $3 Ward Kaya Otsu Figure 0

Claims (1)

[Scope of Claims] J. The reactor pressure vessel is surrounded by a living body wall, and the living body wall has a pipe through hole for leading out the pipe connected to the nozzle of the reactor pressure vessel. The piping through-hole is equipped with a gamma ray shield that surrounds the installed piping, and inside the gamma ray shield is a reactor body that supports a neutron shield between the inner and outer frames. In the structure of the pipe penetration part of the wall, among the neutron shielding blocks located inside the gamma ray shielding hole, at least the blocks located above the horizontal center line of the pipe penetration hole are stacked alternately. Piping penetration structure in the wall of the reactor living body exhibiting lPJ characteristics. 2. In the invention described in Section 4 of the Patent Induction System, the ring frame that supports the neutron flow shield block from the inside is formed of a plurality of divided members. Structure of piping penetrations in the constructed reactor biotransport wall.