JP2514953B2 - Shielding method for radioactive waste storage facility - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shielding method for preventing radioactive substances from flowing out together with groundwater from a storage facility that stores low-level nuclear waste containing radioactive substances.

[Problems to be solved by the invention]

As a method of treating radioactive waste, land disposal as well as ocean dumping were conducted overseas. As a land-disposal method, there is a method of storing in a storage facility such as a pit whose peripheral surface is covered with a concrete wall and is isolated from the surrounding ground to prevent pollution. However, since the method of burying and storing them underground has a long storage period,
Shielded from the surrounding ground in order to prevent accidents that may occur when radioactive or rainwater penetrates into the pit or radioactive waste dissolves in the water due to damage to the container containing the waste and transfers to the surrounding ground or groundwater. There is a need to.

The present invention has been made in view of the above problems.
The purpose is to propose a method of shielding storage facilities that can prevent the transfer to the surrounding ground even if radioactive materials should leak from storage facilities that store low-level radioactive waste.

[Means for solving problems]

This method of shielding low-level radioactive waste storage facilities is designed to further enclose the storage facilities provided in the ground where the low-level radioactive waste is isolated and stored with underground walls so that radioactive substances should be removed from the storage facilities. When leaking together with groundwater, the radioactive substance is captured and fixed by an adsorbent immediately after leaking, and the groundwater is discharged as harmless water containing no radioactive substance.

That is, the invention according to claim 1 encloses a storage facility, which stores low-level radioactive waste in a separate manner and is buried underground, with a permeable continuous underground wall containing an adsorbent, and the continuous underground wall. Water is collected while passing through the adsorbent the internal groundwater surrounded by a continuous underground wall through a pumping pipe installed in the vertical direction.
The invention according to claim 2 is characterized by pumping water, and a low-level radioactive waste is isolated and stored, and a storage facility that is buried underground is surrounded by a water-blocking wall, and the water-blocking wall is provided. Characterized by collecting and pumping internal groundwater surrounded by a water stop wall through a plurality of water collecting wells along the inside of the water, and then passing the pumped groundwater through an adsorbent layer Is.

 The embodiment will be described below with reference to the drawings.

First, an embodiment of the invention described in claim 1 will be described.

In Fig. 1, a low-level radioactive waste 4 containing low-level radioactive substances filled in a drum container is placed in a rectangular pit 3 of a concrete structure 2 having upper and lower surfaces and four side peripheral surfaces constructed on a bedrock 1. It is stored. A pile-shaped water-permeable adsorbent pile 5 containing adsorbent is formed at a depth reaching the bedrock 1, and it is continuously surrounded horizontally in a rectangular shape around the pit 3 as a continuous underground wall. I am doing it. In the adsorbent pile 5 that constitutes the continuous underground wall, every other one, or
A pumping pipe 6 reaching the lower end of the 5th layer of the adsorbent pile is laid along the central axis at more intervals, and the pumping pipe 6 communicates with a pump 8 via a drain pipe 7 connected to its upper end. .
In FIG. 1, 9 is backfill soil, 10 is surface soil, 11
Is the groundwater level and 12 is the embankment.

The pit 3 accommodating the low-level radioactive waste 4 is surrounded by a continuous underground wall where adsorbent piles 5 are continuous, and groundwater in the pits 3 is collected by the pumping pipes 6 in the absorbent piles 5 at the same time. For example, radioactive substances are adsorbed and fixed by the adsorbent pile 5, sucked by a pump, and discharged to the outside of the system via the drain pipe 7. Therefore, even if the radioactive substance leaks from the pit 3 and is eluted into the groundwater, it is treated by the adsorption treatment, so that it does not move to the surrounding ground or the groundwater and the surrounding pollution can be prevented.

Next, an embodiment of the invention described in claim 2 will be described.

In FIG. 2, the surrounding area of the pit 3 containing the low-level radioactive waste 4 is surrounded by a square, and the water blocking wall 13 is the bedrock 1.
It is built to reach a depth. A plurality of water collecting wells 14 are bored at predetermined intervals along the inside of the water blocking wall 13, and a pumping pipe 6 communicating with a pump 8 is provided in each well 14. In addition, the two-way valve 15
2 tanks filled with a series of adsorbents 1 series of adsorption tanks 16,1
6, 17, 17 are connected.

This pit 3 is provided with a water stop wall 13 surrounding the periphery of the pit 3, and groundwater inside the water stop wall 13 is collected in a water collection well 14 and sent to a adsorption tank by a pump 8 for adsorption treatment and discharged. In the normal condition where radioactive material is not detected in the groundwater by collecting water in the water collecting well 14, it is discharged as it is without being subjected to adsorption treatment in the adsorption tank. The adsorption treatment may be performed only when a radioactive substance is detected.

In addition, since this pit is equipped with two series of two tanks and one series of adsorption tanks, one series is subjected to adsorption processing and the other one series is subjected to adsorbent regeneration processing, and alternately used for long-term stable adsorption processing. it can. Further, since one series consists of two tanks in series, it is possible to adsorb a wide range of substances by using two kinds of adsorbents. Of course, the series or the number of connecting tanks can be increased as necessary. Alternatively, it is possible to connect the detector for radioactive material in groundwater and the controller for adsorption treatment to automate the treatment.

The adsorbent used in the present invention has an ability to adsorb radioactive substances such as ion exchange resins and zeolite.
These adsorbents are used after being formed into pellets or the like, if necessary, in order to maintain proper water permeability and contact with water upon filling and use.

〔The invention's effect〕

The present invention is as described above. With this shielding method, even if radioactive material leaks from an isolated storage facility containing low-level radioactive waste and dissolves into groundwater and leaches out, groundwater flow is restricted by the surrounding underground wall, and Since the radioactive substance as the pollution source is adsorbed and removed by the adsorbent, a trace amount of the radioactive substance does not flow out together with the groundwater, and the contamination of the surrounding ground and groundwater can be completely prevented.

[Brief description of drawings]

1 (a), (b), and FIG. 2 (a), (b) are a longitudinal sectional view and a lateral sectional view of a pit accommodating the low-level radioactive waste of the embodiment and its periphery, respectively. 1 ... rock, 2 ... concrete, 3 ... pit, 4
...... Low-level radioactive waste, 5 …… Adsorbent pile, 6 …… Pump pipe, 7 …… Drain pipe, 8 …… Pump, 9 …… Backfill soil,
10 …… Surface soil, 11 …… Groundwater level, 12 …… Embankment, 13…
… Water stop wall, 14 …… Sampling well, 15 …… Three-way valve, 16,17 ……
Adsorption tank.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eizo Fukasawa 2-19-1 Tobita-cho, Chofu-shi Kashima Construction Co., Ltd. (72) Inventor Michio Tsuchihiro 2-19-1 Tobita-cho, Chofu-shi Kashima Construction Co., Ltd. Company Technical Research Institute (72) Inventor Kyoichi Tanaka, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Shibumu Sawauchi 1-2-7, Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Kenichi Otani 1-27 Fukkamachi, Sendai City Kashima Construction Co., Ltd., Sendai Branch (56) Reference JP-A-53-70546 (JP, A) JP-A-61-101288 (JP) , A) JP 62-21100 (JP, A)

Claims (2)

(57) [Claims] 1. A storage facility, which stores low-level radioactive waste in isolation and is buried in the ground, is surrounded by a permeable continuous underground wall containing an adsorbent, and is vertically arranged in the continuous underground wall. A method of shielding a waste storage facility, characterized by collecting and pumping internal groundwater surrounded by a continuous underground wall through an installed pumping pipe while passing the adsorbent. 2. A storage facility that contains low-level radioactive waste in a segregated manner and is buried underground is surrounded by a water blocking wall, and a plurality of water collecting wells are provided along the inside of the water blocking wall. A method for shielding a waste storage facility, which comprises collecting and pumping the groundwater inside which is surrounded by a water blocking wall, and then passing the pumped groundwater through an adsorbent layer.