JPH02130499A - Sampling device of sand cushion - Google Patents

Abstract

PURPOSE:To sample and of a sand cushion of a desired position and inspect it for moisture by having an edge portion having a conical shape an a sand rake, and a cover capable of opening and closing by remote control in the neighborhood of the edge portion to form a sampling opening sampling the sand. CONSTITUTION:An edge portion 14 is easy to dig sand, formed conically and has a sand rake 15. A sampling opening 17 with a cover 16 supported by a guide 20 on the cylindrical side face of a body 13 and the cover 16 is connected to the upper portion of a rod 18 through a guide 21. A handle 19 for sinking the device into ground is set on the upper portion of the body 13. At first, the edge portion 14 of the device body 13 is turned downward to stand vertical to the upper end of a sand cushion so as to apply downward force with the handle 19 rotated. The device is dug deep into ground down to sampling points by the operation. The cover 16 is opened and sand is allowed to flow into the body 13 by pulling up the rod 18 upward.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a sand cushion sampling device for collecting sand from a sand cushion disposed in a nuclear reactor containment vessel.

(Prior Art) Nuclear reactor equipment can be roughly divided into a reactor pressure vessel 1 that houses the heart of the electronic reactor such as fuel rods and control rods, a reactor pressure vessel 1, and recirculation equipment, as shown in Figure 3. The reactor containment vessel 2 houses the reactor-related equipment such as the reactor, and the concrete frame 3 of the reactor building surrounding the reactor containment vessel 2.

The pressure vessel 1 is installed on a support wall 4 within the containment vessel 2, and there is a space between the support wall 4 and the containment vessel 2 to prevent radioactive materials from leaking from the reactor subsystem due to an accident. A pressure suppression chamber 5 is formed in which the pressure is confined so as not to leak to the outside. Further, each concrete frame 3 is divided into many auxiliary equipment rooms 6 by concrete walls, and the equipment entrance between each of these rooms and the containment vessel 2 is closed with a plug 7.

Of the concrete frame 3 that houses the containment vessel 2,
The portion above the portion of the containment vessel 2 adjacent to the flange portion 8 is usually referred to as a reactor well 9.

And the spent fuel pool 1 is located on the top of the concrete frame 3.
0 and equipment pit 11 are being made.

Next, referring to FIG. 4 which shows an enlarged view of part A in FIG. 3,
The sand cushion 12 of the reactor containment vessel 2 will be explained. In Fig. 4, the bottom of the reactor containment vessel 2, which is made of steel plates, has a part filled with sand around the outer periphery of the reactor containment vessel 2 to serve as a fixed point and to relieve stress corresponding to each load that occurs. This is called the sand cushion 12.

This sand cushion 12 usually includes dry sand 1
2a is packed and does not get damp.

Furthermore, even if moisture does get in, there is a drain pipe (not shown) installed at the bottom to handle the water, so it usually remains sufficiently dry.

(Problems to be Solved by the Invention) In the above configuration, if moisture seeps into the sand due to condensation or pipe breakage, and the drain pipe is blocked and water no longer flows out, the sand will absorb moisture. It will remain in the retained state.

At this time, depending on the composition or content of this moisture, there is a possibility that the steel plate of the reactor containment vessel at the contact portion with the sand cushion may undergo corrosion.

In addition, water is stored inside the reactor containment vessel at the same level as the Nandoction, and water is stored to condense the steam generated during an accident, so in the unlikely event that the outer surface of the reactor containment steel plate corroded At present, there is no way to recognize this situation.

In order to solve the above-mentioned problem, an object of the present invention is to detect whether the sand is moist or not, with respect to moisture in the sand cushion part of the reactor containment vessel, which may cause corrosion of the sand cushion part. Therefore, it is an object of the present invention to provide a sampling device for a sand cushion section that collects sand.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention has a cone-shaped tip with a sand shovel, and a device that can be remotely opened and closed near the tip. A sampling device for a sand cushion part is provided, characterized in that it has a sampling port for collecting sand from a sand cushion part disposed in a nuclear reactor containment vessel.

(Function) In the lean cushion collecting device configured as described above, a cone-shaped tip with a sand scraper is rotated from above the sand cushion provided in the reactor containment vessel to a predetermined position. Dig to the position of , then open the collection port lid to collect the sand from the sand cushion and pull it up. Therefore, it is possible to sample sand from a sand cushion at a desired position and test the moisture content.

(Example) The configuration and usage state of a sand cushion part collecting device according to an example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 (0, υ is a configuration diagram of a sand cushion part sampling device of the present invention.

The device main body 13 has a cylindrical shape so as to be less susceptible to sand resistance when digging the device deep into the sand, and is configured to store collected sand in the cylinder.

This tip part 14 has a circular shape so as to easily dig sand, and has a sand shovel 15.

A sampling port 17 with a lid 16 supported by a guide 20 is provided on the cylindrical side surface of the main body 13, and the lid 16 is connected to the top by a rod 18 via a guide 21. Furthermore, a handle 19 is installed on the top of the main body 13 for sinking the device into sand.

FIG. 2 shows a state in which the device main body 13 described above is actually digging into the sand cushion portion 12 at the bottom of the reactor containment vessel 2 to collect sand.

The method for collecting sand using this sampling device is shown below.

First, the device main body 13 is placed vertically on the upper end of the sand cushion 12 with the tip 14 facing down, and the handle 19 is rotated while applying downward force. This action burrows the device deep into the sand to the point of zampling.

Here, by pulling up the rod 18, the lid 16 opens and the sand 12a flows into the main body 13.

When the sand 12a has been stored in the main body 13, the lid 16 is closed by returning the rod 18 downward. Thereafter, by rotating the handle 19 and applying an upward force, the device main body 1 is pulled up to the upper end of the sand cushion 12, and the sand collection is completed.

(Effects of the Invention) As described above, the sand cushion part sampling device according to an embodiment of the present invention makes it possible to collect sand from the sand cushion part of the reactor containment vessel, and it is possible to recognize whether the sand is wet or not. .

Furthermore, based on the sampling inspection results, it is possible to determine whether the sand cushion portion of the reactor containment vessel and the outer surface of the steel plate are corroded, thereby ensuring the integrity of the reactor containment vessel.

[Brief explanation of the drawing]

FIG. 1(2) is a side view of a sand cushion collecting device according to an embodiment of the present invention, FIG. FIG. 3 is a longitudinal sectional view showing a nuclear reactor building to which the present invention is applied, and FIG. 4 is an enlarged view of section A in FIG. 3. 2...Reactor containment vessel 12...Sand cushion 13...Device body 14...Tip 15...Sand shovel 16...Lid 17...Sampling port agent Patent attorney Nori Chika Yudo Daishimaru Kano diagram diagram diagram

Claims (1)

[Claims] It has a cone-shaped tip with a sand shovel, a lid near the tip that can be opened and closed remotely, and a sampling port for collecting sand from the sand cushion provided in the reactor containment vessel. A collecting device for a sand cushion portion, characterized in that it is formed by forming a sand cushion portion.