JPS59112287A - Water seal plug device of reactor vessel - 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] The present invention relates to a watertight lid device for a nuclear reactor vessel.

At nuclear couplers, during annual periodic inspections required by law, sub-cooling water is drained for maintenance and inspection.The conventional maintenance and inspection work is explained using Figure 1. (1) is the cavity, (2) is the reactor vessel lid, (3) is the reactor vessel, (4) is the low temperature side piping, (
5) is the secondary cooling water circulation pump, (6) is the crossover leg piping, (power is the steam generator, (8) is the high temperature side piping, (9)
) is the secondary cooling water injection line, (10) is the secondary cooling water drain line, (111 is the upper core support structure, (+21 is the primary cooling water remaining in the reactor vessel (3), (13) is At the vent line, during operation of the nuclear coupler, reactor vessel (3) low temperature side piping (4) - next cooling J water circulation/P pump (5)
) Crossover leg piping (6) Steam generator (The high temperature side piping (8) is filled with primary cooling water. Normally, the system of the above elements (4) (506B7) (8) is looped. The primary cooling water of this system is called loop water.During maintenance and inspection, the 11th turn of the nuclear coupler is stopped and
Empty the loop water. Then the air is poured into the reactor vessel lid (2)
The loop water is completely drained from the primary cooling water drain line 00) by sending it to the reactor vessel (3).

At this time, the -order cooling water remains only in the portion α2. In this state, perform maintenance and inspection of the loop. After completing maintenance and inspection of the loop, pour shielding water into the cavity (1), remove the nuclear cap vessel lid (2), and remove the upper core support structure. (111 was taken out into the cavity (1) to perform maintenance and inspection of the upper core support structure fill.

Conventionally, as mentioned above, once the maintenance and inspection of the loop was completed, the maintenance and inspection of the upper core support structure (1, 1+) was carried out. There was a problem in that the outage period was prolonged.

The present invention addresses the above-mentioned problems, and includes a water cover that temporarily isolates the inside of the IU reactor vessel from the shielding water sourced from the cavity, and a water cover that is installed upright on the upper end surface of the member on the reactor vessel side. A guide pin for the watertight lid, a double annular dovetail groove provided in the watertight lid so as to face the sealing surface formed on the inside 11111 of the upper flange surface of the reactor vessel, and a seal fitted in each of the annular dovetail grooves. A watertight lid for a nuclear reactor vessel, comprising a ring, an air vent pipe provided in the watertight lid, and a water level pipe provided in the watertight lid so as to communicate with the sealed space between each of the seal rings. Regarding the equipment, its purpose is to provide a watertight lid system for the reactor vessel that can shorten the outage period of the nine-child couplant by allowing simultaneous maintenance and inspection of the loop and the upper core support structure. At the point.

Next, the watertight lid device for the reactor vessel of the present invention is shown in FIGS. 2 to 1.
To explain with an example shown in Figure 0, (1) (3) ~
fl 0) (121 is the same part as above, Section 2.4.6
．． 9.10 country's C5) or key) Shielding water caught in the cavity (1), closing between (1b) or the reactor vessel (3) and the cavity (shielding wall) (I) in Figure 4.6 Seal ring, Fig. 6.4.6.7.8.9 (1'71) or upper flange surface of reactor vessel (3), (1 hook is the same flange surface J
The inner surface of the container has a JR-shaped sealing surface, and the container canister (see (2) in FIG. 1) is attached through a countersunk-shaped sealing part (not shown). In addition, (19) in Figure 6.4.6 is the bolt tap hole, 0υ) or 0'' is the guide 8 stud of the reactor vessel lid, and Ql+ in Figure 4゜6 is the lower core support. Structure (core tank)
, C2l+ is the guide pin of the watertight lid (27) installed on the upper end surface of the lower core support structure (2υ), (231 is the lifting device main body, (24) is the threaded rod, (25) is the threaded rod (241) (261 is the guide 9 scud profiler 41:, (0) is the center line of the reactor vessel (3), and the seal ring (161) and the upper flange surface (17) of the reactor vessel (3) and the seal The centers of the plane 08) and the lower core support structure (2D and Vt are on the center line (01) of the reactor vessel (3). The bolt tap holes (11 are also located on the circle centered on the center line (0) above). Although they are arranged in a uniform manner on the central circle, only a part of them is shown in Fig. 6.

In addition, the seal ring (1G) is attached to the reactor vessel (
3) and the cavity (1) [(11) is closed and has a watertight structure.
1 is a surface that has been polished to match the seal T, and its width is not very wide.

Also, the guide stud (2i1! is the bolt tap hole 01
It can be screwed into υ or removed. Also, rotate the threaded rod t24) at a position above the water surface of the shielding water α9, and connect the threaded part □□□ to the upper core support structure ((l) in Figure 1.
The lower core support 441 structure can be taken out from the reactor vessel (3) by screwing it into the screw hole of the lifting device main body (droplet in the downward direction of the arrow). Tracing mechanism (Jt
Since the i+ is guided by a guide stat, the lower core support structure can be lifted or hung straight.Next, the most distinctive feature of this watertight lid device is explained in Section 5.6. .7.8, 9.10 Figure 07) is the water bottle lid, (28) is the lifting boss, and Q! I) is the same boss □□□ with a watertight lid (port attached to 2η), C3
0) is the guide pin access part, (311 is the main vent line, C32+ is the auxiliary vent line, C33) is the Q IJ
(34) is the washer, (3) is the female thread, (36) is the tapped screw hole, Oη is the drain hole, (38) is the outer O-ring, (39) is the inner Q
IJ song (40) is the outer O ring groove, (4υ is the inner O ring groove)
Ring groove, (42) is transparent material hose, (4j is float 1
,・(4 forces are water for leakage monitoring, water leakage M shown in Figures 5 and 6)
(27) is disc-shaped and has the strength to withstand the shielding water that has accumulated in the cavity (1). Note that the watertight lid (27) may be hemispherical, dish-shaped, or the like. Also main vent line C3
υ and the auxiliary vent line (321 and the O-ring vent and water level monitoring line c331 are tubular shapes drawn with lines, and the lower end is installed with watertightness in both directions, and the upper end is the shielding water (I5) It protrudes above the water surface.The guide pin access part (to) connects the watertight lid (5) to the sealing surface ([8
The lifting boss (2) has a depth that does not interfere with the area of the bottle when placed on top of the lid (27). The female thread 051 can fit with the threaded portion (25) of the threaded rod (2). Also, the diameter (D2) of the port (2ω) and the diameter (D2) of the port hole into which the bolt holder fits (
D) is D, > D2, and the boss (281 watertight lid (2
7. The mounting position for η can be adjusted slightly. ). Also, when the Porto (29) is screwed into the watertight lid 0D, the washer (34) is made thicker than usual to stabilize the clamping force. In addition, a boss (', !
At 81, there is a drain hole. Also 0 ring (38
1C39+ is made of solid rubber, and each OII song 38)
091 can contact the QIJ song groove 40 (41) and the seal surface 0 even with its own weight alone. The purpose of providing double O-rings is to make the seal more reliable. In addition, the O-ring groove (4 (1 (411) is dovetail-shaped, and it is easy to insert the O-ring 0I, but it is a trap so that it cannot be easily removed. There is also a vent between the O-rings and a water level monitoring line (towards). and the hose (42) is 011 (38) Cl
It allows the sealed space between I to communicate with the atmosphere, and is flexible, and the lower end of each is attached to the watertight lid C71 in a watertight manner. After placing the watertight lid (2η) on the seal surface 0 mark, insert the hose (42) from above the hose (42).
), adjust the water level in the hose (421) to make it slightly lower than the water level of the thin shielding water θ5 in the cavity (1), and then insert the float +43 into the hose (421). The hose (421) is made of transparent material, and the float (431) can be visually seen from outside the hose (42).

Note that the float (431 is made of styrofoam coated with firewood 0 paint is iR-1).
The primary cooling water drain line (temporary water level monitoring line extending to 101 is a hose made of transparent material).

Next, the operation of the reactor vessel water difference device will be explained. (
I+ The reactor vessel lid (see (2) in Figure 1) is removed, the upper core support structure (see (2) in Figure 1) is also taken out from the reactor vessel (3), and it is shielded in the cavity (1). Water (reluctant to 151. fIII Threaded rod in the atmosphere (
Screw the threaded part (25) of 24) into the female thread (2) of the boss (c) to connect the lifting device body (23) and the water bottle cover 0.
'7) and then the lifting device body (2
(to) is lowered and the watertight lid Qη is placed on the sealing surface 081. C11N - Next cooling water train 8 line <
Drain the loop water from 101, and when the inside of the reactor vessel (3) is filled with only 1 core of residual cold JdJ water (!2), close the valve of the cold water drain line (1@).

Maintenance and inspection of the OM loop and the upper core support structure were performed at 1i/1:00. The depth of the shielding water 09 is about 13 I11, and the sealing surface is 0.
8) is very narrow, and if a scratch is caused here, there is a risk of water leakage 4). In order to do this, the watertight lid (2γ) must be placed on the sealing surface (18iK) with high accuracy.This work is done through a water depth of about 8nL, so special consideration must be given to the calyx.Also, the watertight lid (2γ) A vent line is also required4).Furthermore, from the standpoint of safety, it must be confirmed that there is no water leakage at the joint between the watertight lid 0η and the sealing surface θ~.The present invention also addresses the above points. (4Il!+4chi, as mentioned above, the watertight lid (2
'0 on the sealing surface (181), the watertight lid I
If the 2η is not placed well on the sealing surface (181), water may leak from between them or damage the sealing surface (ilG), but the lifting device body (c) and the watertight 1 ( 27+ is connected to the descending guide stud id 8 stud 9 profiling mechanism (a), so that the watertight lid (27) can be placed on the sealing surface (18) with high precision. If the two threaded rods (241) are installed in the wrong position, and the watertight lid (2η) rides on the flange surface (17), watertightness cannot be ensured, but the watertightness of the boss (28) It is possible to attach the lid (21) by slightly adjusting its position, and this situation can also be prevented. (~41) When removing the loop water, the air inside the reactor vessel (3) must be vented, but This is the main vent line (3j) and the auxiliary vent line C.
'Use i2+ [2 can be done. Also, when the main vent line (31J) is immersed in Yanbai water (]5),
Side! ; The water (I5) enters the reactor vessel (3) through the main vent line 6B, and the air inside the reactor vessel (3) exits to the atmosphere through the auxiliary vent line G2. ) can be easily accessed. It should be noted that the water inside the reactor vessel (3) is brought into a water-deep state by using the water cover Q7.
) when lifting the watertight lid (2), the water head of the shielding water (15)
7) This is to make it easier to lift the watertight lid (9) so as not to overshadow it.

(vlII) Monitor the presence or absence of water leakage from the O-rings (2) (3) as follows. If the sealing performance of the O-rings (to) is impaired, use the vent between the O-rings and the water level monitoring line. (To) The water level of the leak monitoring water (A4) is the shielding water (+
It will be the same as the water level of 51. The float (431) indicates the water level of the leak monitoring water (44), so if you look at the float (431), it will be 0.
It can be determined whether the sealing performance of the ring (2) is impaired. Furthermore, if the sealing performance of the oil song 39) is impaired, the water level of the leakage monitoring water (44) will drop. At this time, you can tell whether the sealing performance of the 0 ring (3ω is impaired or not by looking at the float (43). Usually, the 0 ring C38) (
The sealing performance of 3→ will not be impaired at the same time, and if leakage from either is detected, measures will be taken to prevent water leakage. Water leakage conditions can also be monitored using a temporary water level monitoring line (4-tan).

(IX) The O-ring has a dovetail-shaped O-ring groove (
Since it is fitted to 41Jl (41), the water bottle lid C! η
Even in the middle of hanging it, it never comes out. Also, when trying to lift the watertight lid G2η, if there is no vent between the O-rings, the water level monitoring line C field, and the hose (4), the sealed space between the O-rings (to) 091 will temporarily close like a suction cup. When the pressure becomes negative, the O-ring (To) (To) and the O-ring groove (4[) (41) will also come off easily. If it comes off, remove the O-ring from above the shielding water (151) using another tool.
2◇If you have to make a profit, you should either lengthen the band by 1 sill during work, or use the band between the O-rings, the water level monitoring line (c), and the hose (42 is connected to the atmosphere, and inside it there is a leak monitoring line. Since it contains water (44), close the watertight lid (2).
When trying to lift η, the sealed space between Q IJ ring candle 09 temporarily did not become negative pressure
O-ring groove (40 (41j) can be prevented from coming off.

In the reactor vessel watertight lid device of the present invention, as explained in sections TII to (IV) of the above operation, the reactor vessel lid is removed, the upper core support structure is also taken out from the reactor vessel, and the upper core support structure is installed in the cavity. After draining the water, the watertight lid is lowered using a lifting device and placed on the sealing surface at the upper end of the lower core support structure, leaving only residual secondary cooling water in the reactor vessel. , maintenance and inspection of the loop and the upper core structure can be performed simultaneously, and the shutdown period of the nuclear couplant can be shortened. Also, the above action (
As explained in sections V) to (IX), it is possible to securely place the watertight lid on the sealing surface, place a seal on the seal ring, and hold the seal ring, so maintenance and inspection of the loop can be done safely. This has the effect of facilitating smooth implementation.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a conventional atomic couplant, Fig. 2 is a longitudinal side view schematically showing an embodiment of a water cap device for a nuclear vessel according to the present invention, and Fig. 6 is an enlarged view of the main parts. Fig. 4 is an enlarged longitudinal sectional side view of the arrow ■ part in Fig. 2, Fig. 5 is an enlarged plan view of the watertight lid, Fig. 6 is a longitudinal sectional side view thereof, and Fig. 7 is a longitudinal sectional side view of the watertight lid. Fig. 8 is an enlarged plan view of the lifting boss portion, Fig. 8 is a vertical cross-sectional side view taken along the arrow till-■ line in Fig. 7, Fig. 9 is a longitudinal cross-sectional side view of the air vent pipe portion, and Fig. 1 is an overall system diagram. Yes, (1)...cavity, (3)...reactor vessel, a
η...Flange surface, (!Cap...Seal surface, (2I)...
...Reactor vessel (3) side parts, @...Guide 9 bottle, (21...Watertight lid, C311C!:, D...Air vent pipe, (3:31 (42)...Water level Tube, (: Burnt Oto・
Seal ring, (40) (41)... annular dovetail groove. Sub-representative Patent Attorney Shige Okamoto 2 persons Figure 2 Figure 3 Figure 5 Figure 7 Figure 8 Figure 9 Procedural Amendment January 24, 1981 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of the case 1982 Patent Application No. 222097 2, Title of the invention Reactor vessel watertight lid device 3, Relationship with the case of the person making the amendment Patent applicant name (620
) Mitsubishi Heavy Industries, Ltd. 4, Sub-Agent 5, Amendment Order l] Attached to Showa (1st year""'J-]
[1 Procedural Amendment 11i' (December 8, 1958 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 222097 of 1982, 2, Title of the invention: Watertight lid device for nuclear reactor vessel 3 , Relationship with the case of the person making the amendment 1.1 Name of applicant (
620) Mitsubishi Heavy Industries, Ltd. 4, sub-agent 5, amendment order 1 = 1 request Showa (1 year 4 days (dispatch 1)) 6, subject of amendment Specification 7, contents of amendment Page 12 of the specification "Lower core support structure" in lines 16 and 17 is amended to "to the reactor vessel." Procedural amendment 1981] February 12, Kazuo Wakasugi, Commissioner of the Patent Office, 1, of the case Indication: 1982 Patent Application No. 222097 2, Title of the invention: Reactor vessel watertight lid device 3, Relationship with amendment f1: Patent, Patent applicant name (6)
20) Mitsubishi Heavy Industries, Ltd. 4, Sub-Agent 5, Date of amendment order Showa (100 years 1st day (shipment date) 6, Subject of amendment Details'':! 1 7, Contents of amendment Page 12 of the specification, No. 16 Correct "lower core support structure" in lines to lines 17 to "reactor vessel".

Claims (1)

[Claims] A watertight lid that temporarily isolates the inside of the reactor vessel from the shielding water that has collected in the cavity, a guide bottle for the watertight lid installed upright on the upper end of the reactor vessel side member, and an upper part 7 of the reactor vessel.
A double annular dovetail groove provided on the watertight lid so as to face a sealing surface formed inside the flange surface, a seal ring fitted in each of the annular dovetail grooves, and an air vent pipe provided on the watertight lid. A watertight lid device for a nuclear reactor vessel, comprising: a water level pipe provided in the watertight lid so as to connect a sealing space between each of the seal rings.