JP3540306B2 - Radioactive solution sampling method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for sampling a radioactive solution flowing in a pipe.
[0002]
[Prior art]
For example, in a nuclear fuel reprocessing plant, a radioactive solution containing a radioactive substance such as uranium or plutonium flows through a pipe, and it is necessary to perform periodic sampling for the purpose of monitoring the concentration thereof. For this reason, conventionally, a movable glove box was moved to the position of a sampling nozzle provided in a pipe, a vacuum vessel for sampling called a jug was placed inside the glove box, and a tip of a stainless steel hose attached to the sampling nozzle was placed. Was inserted into a vacuum container inside the glove box to perform sampling.
[0003]
However, such a conventional method has a problem in that the large glove box must be moved every time sampling is performed, and work inside the glove box is required.
[0004]
[Problems to be solved by the invention]
The present invention has been made to solve the conventional problems described above, and to provide a radioactive solution sampling method and apparatus capable of sampling a radioactive solution in a pipe with good workability and safety in a vacuum vessel. is there.
[0005]
[Means for Solving the Problems]
The radioactive solution sampling method of the present invention made in order to solve the above-mentioned problem, a box is installed above the sampling nozzle protruded from the radioactive solution pipe, first with the elevator provided inside this box Lower the needle and fix it to the box with its lower end inserted in the pipe, then raise the elevating platform and set the vacuum container, then lower the vacuum container together with the elevating platform again and place it on the upper end of the needle. It is characterized by piercing and sucking a radioactive solution from inside a pipe.
[0006]
Further, the radioactive solution sampling device of the present invention is provided with a lift table with a handle that can move up and down along a guide rod inside a box with a door installed above a sampling nozzle protruding from a pipe of the radioactive solution. A needle holder is provided in the lower half of the elevating table, and a holder for the vacuum container is provided in the upper half thereof. It is preferable that the needle holding portion is separated from the lifting platform and can be fixed to the lower portion of the box.
[0007]
According to the present invention, since the radioactive solution can be sampled from inside the pipe inside the box with the door instead of the conventional glove box, there is an advantage that the workability is excellent. Also, a method of lowering the needle inside the box and fixing the needle with the lower end of the needle inserted into the sampling nozzle, and then lowering the vacuum container for sampling inside the box to pierce the upper end of the needle Therefore, there is no possibility that the radioactive solution leaks to the outside, and the radioactive solution can be safely sampled in the vacuum vessel.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
1 and 2 are views showing a sampling device of the present invention. 1 is a pipe through which a radioactive solution flows, and 2 is a sampling nozzle protruding above the pipe. A radioactive solution containing a radioactive substance such as uranium or plutonium flows inside the pipe 1. The upper end of the sampling nozzle 2 is always closed by a cap (not shown), but this cap is removed before sampling. However, since the ball valve 3 is provided in the sampling nozzle, the radioactive substance does not leak to the outside just by removing the cap.
[0009]
Reference numeral 10 denotes a cylindrical box that is a main body of the sampling device. The box 10 has a bottom plate 11 and is installed above the sampling nozzle by screwing a threaded portion 12 formed at the center of the bottom plate 11 onto the upper end of the sampling nozzle 2 from which the cap has been removed. A door 13 that can be opened and closed is provided on the upper side surface of the box 10 as shown in FIG. A hole is formed in the bottom plate 11 to penetrate a lower end of a screw rod 18 described later.
[0010]
A plurality of guide rods 14 are fixed inside the box 10, and a lift 16 having a handle 15 at an upper portion is provided so as to be able to move up and down along the guide rods 14. The elevating table 16 is provided on the lower surface of a flat plate 17 also serving as an upper lid, and an annular packing 25 is attached around the flat plate 17 to seal the periphery.
[0011]
The lift 16 has a needle holder 19 suspended below a flat plate 17 by a plurality of screw rods 18. In FIG. 1, the wing nut 20 is attached to the upper part of the screw rod 18, but the wing nut 20 at the upper part of the screw rod 18 can be removed and replaced with the lower part of the screw rod 18 as described later. I have. The needle holding portion 19 includes a rubber block 21 and can hold the upper portion of the hollow needle 22 as shown in FIG.
[0012]
As described above, the needle holder 19 is provided in the lower half of the lift 16, and the holder 23 of the vacuum vessel as shown in FIG. 3 is provided in the upper half thereof. As shown in FIG. 3A, the holding portion 23 of the vacuum vessel has a shape in which a side surface of a bottomless cylinder is cut off, and is fixed to the lower surface of the flat plate 17. As shown in FIG. 3B, a sampling vacuum container 24 called a jug can be easily mounted inside the holding portion 23, but the mounted vacuum container 24 should not be moved in the vertical direction inside the holding portion 23. Keep it.
The method for sampling a radioactive solution according to the present invention will be described below with reference to FIGS.
First, as shown by (1) in FIG. 4, the box 10 is fixed to the upper end of the sampling nozzle 2 from which the cap has been removed. At this time, the lift 16 is pulled up to the upper end of the box 10. In this state, the upper part of the hollow needle 22 is held by the needle holding part 19 of the lift 16. Thereafter, the ball valve 3 of the sampling nozzle 2 is opened. However, since the box 10 is already fixed to the upper end of the sampling nozzle 2, no radioactive substance leaks to the outside. As the needle 22, a stainless steel tube having an inner diameter of about 1 mm can be used. The upper end shall be sharpened.
[0014]
Next, as shown by (2) in FIG. 4, the handle 15 is pushed down to lower the elevator 16 to the lower end of the box 10, and the lower end of the needle 22 is inserted into the pipe 1. Since the elevating table 16 descends straight along the guide rod 14, the fine needle 22 also descends inside the sampling nozzle 2 without bending. At this time, the lower part of the screw rod 18 penetrates the hole formed in the bottom plate 11 of the box 10 and projects to the lower surface of the bottom plate 11. Then, the wing nut 20 at the upper part of the screw rod 18 is removed and fitted to the lower end of the screw rod 18 projecting from the lower surface of the bottom plate 11. Thus, the needle holding portion 19 of the lift 16 is firmly fixed to the bottom plate 11 of the box 10 together with the needle 22.
[0015]
Next, as shown by (3) in FIG. 5, the elevator 15 is pulled up to the upper part of the box 10 by grasping the handle 15. Since the wing nut 20 above the screw rod 18 has been removed in the previous step, the lift 16 is moved up while leaving the needle holder 19. Then, the door 13 is opened, and the vacuum container 24 is set on the holding portion 23 of the vacuum container as shown in FIG. 3B. The vacuum container 24 is a container made of a synthetic resin, and the bottom surface thereof has a thickness that allows the upper end of the needle 22 to easily penetrate.
[0016]
Next, as shown by (4) in FIG. 5, when the elevating platform 16 is pushed down again toward the lower portion of the box 10, the upper end of the needle 22 fixed to the bottom plate 11 of the box 10 is moved downward. It penetrates the bottom surface and reaches the inside of the vacuum vessel 24. At the same time, the radioactive solution flowing in the pipe 1 is sucked into the vacuum vessel 24 using vacuum pressure.
[0017]
Next, as shown in (5) of FIG. 6, the elevator 16 is raised to the upper part of the box 10, the door 13 is opened, and the vacuum container 24 is taken out from the holding portion 23 of the vacuum container. At this stage, the needle 22 is still fixed to the lower part of the box 10.
[0018]
Then, as shown by (6) in FIG. 6, the elevator 16 is again pushed down toward the lower part of the box 10, and the upper end of the screw rod 18 is made to penetrate the flat plate 17. Then, the wing nut 20 is removed from the lower part of the screw rod 18 and fitted to the upper part. As a result, the connection between the needle holding portion 19 and the bottom plate 11 of the box 10 is released, and the needle holding portion 19 is fixed to the lift 16.
[0019]
Then, as shown in (7) of FIG. 6, when the elevating platform 16 is pulled up, the needle 22 moves up into the box 10 together with the needle holding part 19, and returns to the state of (1). Thereafter, the ball valve 3 of the sampling nozzle 2 is closed, and the box 10 is removed from the sampling nozzle 2. Then, the cap of the sampling nozzle 2 may be fitted.
[0020]
Thus, according to the present invention, the radioactive solution can be sucked into the vacuum container 24 inside the box 10 and sampled. Since a series of operations are performed inside the box 10, no radioactive substance leaks outside. In addition, since the vacuum container 24 can be attached and detached by opening the door 13 of the box 10, workability is better as compared with the conventional operation inside the glove box.
[0021]
【The invention's effect】
As described above, according to the radioactive solution sampling method and apparatus of the present invention, the radioactive solution in the pipe can be sampled in the vacuum vessel with good workability and safety. In particular, there is an advantage that workability is better than the conventional glove box system, and it is not necessary to move the glove box every time sampling is performed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a sampling device of the present invention.
FIG. 2 is a plan view of FIG.
3A and 3B show a holding portion of the vacuum vessel, wherein A is a perspective view, and B is a view showing a state of attachment to a lift table.
FIG. 4 is a process chart of the sampling method of the present invention.
FIG. 5 is a process chart of the sampling method of the present invention.
FIG. 6 is a process chart of the sampling method of the present invention.
[Explanation of symbols]
1 Pipe through which radioactive solution flows, 2 Sampling nozzle, 3 Ball valve, 10 box, 11 Bottom plate, 12 Female thread, 13 Door, 14 Guide rod, 15 Handle, 16 Lifting platform, 17 Flat plate also serving as top lid, 18 Screw rod, 19 needle holder, 20 wing nut, 21 rubber block, 22 needle, 23
Vacuum container holder, 24 vacuum container, 25 packing

Claims (3)

Place a box above the sampling nozzle protruding from the radioactive solution pipe, first lower the needle together with the elevator provided inside this box, and fix it to the box with its lower end inserted in the pipe. Then, the elevating platform is raised to set the vacuum container, and then the vacuum container is lowered together with the elevating platform, pierced into the upper end of the needle, and the radioactive solution is sucked from inside the pipe. . An elevator with a handle that can move up and down along the guide rod is provided inside a box with a door installed above the sampling nozzle protruding from the radioactive solution pipe, and a needle is held in the lower half of this elevator A sampling device for a radioactive solution, characterized in that a sampling part is provided and a holding part for a vacuum vessel is provided in an upper half thereof. 3. The radioactive solution sampling device according to claim 2, wherein the needle holding portion is separated from the lifting platform and can be fixed to a lower portion of the box.

Images