JPH0812279B2 - Storage and disposal method for industrial waste such as radioactive substances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Industrial field of application” The present invention relates to a storage container for the purpose of disposing or isolating radioactive substances and various other harmful industrial wastes, and a storage pit (hereinafter, referred to as “storage pit” for storing the same). Is referred to as a storage / disposal facility.).

"Problems to be solved by conventional techniques and inventions" At present, industrial waste is in the state of being produced as waste, or in a state of being treated to some extent, in its original form, or in containers, etc. It is stored in and disposed of in the ground.

In this underground disposal, most of them are buried in the excavated ground, and almost no effective measures have been taken against leakage and diffusion of waste in the ground, and leakage of harmful substances Contamination of the living environment due to is a major social problem.

As an exception, steel sheet piles are placed around the area for underground disposal, or impermeable membrane materials are embedded to build an artificial barrier,
Although we sometimes try to prevent the leakage of harmful substances, in the case of this steel sheet pile construction method, the joint structure with a gap between the steel sheet piles has a joint structure and the steel sheet pile is driven into the ground. Since it is often the case that the joints of steel sheet piles are disengaged from each other, it is not possible to achieve perfect water-stopping in this construction method, and when impermeable membrane materials are used. It can be partially damaged, which is very similar. Furthermore, in any case,
Even if a leak occurs, it is almost impossible to identify the location and grasp the situation.

By the way, the storage / disposal method of radioactive materials adopted in other countries is a method that combines artificial storage / disposal facilities such as concrete pits and the ground as a natural barrier, and this method is also proposed in Japan. It is being studied (JP-A 61-159200 and JP-A 60-147700).

However, even with this method, it is not possible to accurately grasp the situation regarding the leakage of radioactive materials from an artificial storage / disposal facility. In particular, it is impossible to build a completely watertight concrete structure due to the occurrence of cracks in the concrete pit and the presence of construction joints, and even if the area around the concrete pit is directly surrounded by the leakage expansion prevention plate, it will eventually There is no big difference.

Therefore, the current storage / disposal methods have the above-mentioned problems with regard to water stoppage and detection of an unexpected leak, so even if a simple measure against leak is taken, its reliability is low and its confirmation. Is also difficult.

Therefore, the present invention is intended to solve such a problem.

"Means for Solving the Problem" In order to achieve the purpose of steam, the present invention provides a predetermined interval from the storage / disposal facility in the surrounding ground where the storage / disposal facility for radioactive substances and other various hazardous industrial wastes is buried. A water impermeable water impermeable membrane and a water impermeable wall incorporating this membrane material are constructed to form a secondary artificial barrier, and the groundwater level is measured and stored inside and outside this artificial barrier, respectively. We have installed a monitoring facility that has the function of detecting leakage of disposed substances and collecting and discharging groundwater that serves as a medium for transferring and diffusing the leaked substances.These monitoring facilities also help to control the groundwater level in the artificial barrier. It is characterized by maintaining a lower water level than the groundwater level outside the barrier.

Due to the above-mentioned structure, monitoring equipment is operated inside and outside the artificial barrier to monitor the leakage of stored / disposed substances by sampling the groundwater, and the groundwater level inside the artificial barrier is controlled. By maintaining a lower water level than the outside groundwater level, the groundwater flow from the inside of the artificial barrier to the outside is eliminated, and the leakage and diffusion of harmful substances outside the artificial barrier is prevented.

“Example” Part 1. FIG. 1 shows an example of a water-stop liner type.

In the figure, 1 is a buried storage pit made of concrete, 2 is backfill soil around the storage pit, and 3 is a secondary wrap around the storage pit and the backfill soil around the storage pit to prevent movement of groundwater and rainwater. The water blocking film is made of a polymer material sheet or the like that constitutes the artificial artificial barrier A.

Reference numeral 4 is a bank that protects the storage pit, prevents inflow of rainfall and the like, and shields radiation, and 5 is a drainage groove provided on both sides of the bank 4 for removing surface water.

6 is sampling and detection for measuring the groundwater level inside and outside the artificial barrier A, and detecting leakage of harmful substances from storage / disposal substances such as radioactive substances,
In addition, the groundwater is pumped and discharged, and the artificial barrier A
Monitoring facility to prevent the leakage and diffusion of harmful substances to the outside of the artificial barrier A by keeping the internal water level inside the artificial barrier A lower than that outside the artificial barrier A and eliminating the groundwater flow from the inside of the artificial barrier A to the outside. Is.

 The construction procedure in this case is as follows.

Excavation of water-stop film / storage pit construction part Installation of water-stop film 3 Construction of storage pit 1 Installation of monitoring facility 6 Backfilling Construction of embankment 4 Installation of drainage groove 5 The feature in this case is storage pit 1 and surrounding backfilling Soil
It is in a place where it is completely covered by a waterproof membrane,
Applies regardless of ground conditions.

In this case, by adjusting the mechanical properties and chemical properties of the backfilled soil, it is possible to reliably prevent the leakage and diffusion of industrial waste and radioactive substances.

Part 2. Fig. 2 shows an example of a water blocking wall type.

In the figure, 1 is a buried concrete storage pit, 7 is a trench in the periphery of the storage pit by a mud construction method, and a water blocking film made of a polymer material sheet or the like is installed, It is a water blocking wall that constitutes a secondary artificial barrier A that prevents the movement of groundwater.

Reference numeral 8 is an upper water stop film that prevents the groundwater level in the storage area from rising due to permeation of rainfall or the like.

Reference numeral 4 is the embankment, 5 is a drainage channel, and 6 is a moratoring facility. These are the same as in the previous example, and a description thereof will be omitted.

 9 is a lower impermeable layer.

 The construction procedure in this case is as follows.

Ground investigation (position and spread of impermeable layer) Construction of water blocking wall 7, namely, excavation of water blocking wall construction part (mud construction method), installation of water blocking film, backfilling with excavated soil or imported material Storage pit construction part Excavation and storage pit 1 Construction of monitoring facility 6 Construction of embankment 4 Construction of drainage channel 5 The feature of this case is that when the impermeable layer exists at a relatively shallow depth as shown in FIG. And the surrounding soil,
It will be surrounded by the lower impermeable layer 9, the water blocking wall 7, and the upper water blocking film 8. In this case, in particular, the artificial barrier A over a wide area can be constructed economically.

In addition, when the impermeable layer is at a deep position, the water blocking wall 7
Does not penetrate into the impermeable layer, and as shown in Fig. 4, the groundwater level is lowered by the pumping discharge of groundwater by the monitoring facility 6 to prevent the flow of groundwater toward the direction outside the area. , Prevent the leakage and diffusion of harmful substances outside the area.

[Effect of the Invention] According to the present invention, an impermeable water-stop membrane formed at a predetermined interval from the storage / disposal facility or this membrane material is incorporated in the ground around the buried storage / disposal facility. It is possible to measure the groundwater level inside and outside of the secondary artificial barrier by the water blocking wall, detect leakage of stored / disposed substances, and collect and discharge groundwater as a medium for transferring / diffusing the leaked substances. Since the monitoring equipment equipped with the function is installed and the groundwater level inside the artificial barrier is kept lower than the groundwater level outside the artificial barrier by these monitoring equipment, the inside of the artificial barrier is maintained by maintaining this low water level. The groundwater flow from the outside to the outside can be eliminated, and the leakage and diffusion of harmful substances to the outside of the artificial barrier can be prevented. Therefore, the artificial barrier has some defects such as breakage and peeling of seams. Even if a problem occurs, groundwater in the artificial barrier, which serves as a medium for transporting and diffusing harmful substances, does not flow out of the artificial barrier, and leakage of harmful substances can be effectively eliminated.

Moreover, even in the event of a leak, the situation can be accurately grasped by the monitoring equipment and appropriate measures can be taken, so that safe storage can be performed and contamination of the living environment can be sufficiently avoided.

[Brief description of drawings]

1 is a sectional view of an example, FIG.
FIG. 2 is a sectional view of another example, and FIGS. 3 and 4 are explanatory views. 1 ... storage pit, 2 ... backfill soil, 3 waterproof membrane, 4 embankment, 5 drainage, 6 monitoring facility, 7 waterproof wall, 8 upper waterproof membrane, 9 … Impermeable layer, A …… Artificial area

Claims (1)

[Claims] 1. A water impermeable water impermeable membrane or a membrane material of this type, which is impermeable to the surrounding ground where a storage / disposal facility for radioactive substances and various other harmful industrial wastes is buried, at a predetermined interval from the storage / disposal facility. Built a water blocking wall to build a secondary artificial barrier, measure the groundwater level inside and outside of this artificial barrier, detect the leakage of stored / disposed substances, and transfer / diffuse the leaked substances. It is necessary to install monitoring equipment equipped with the function of collecting and discharging groundwater, which serves as a medium for maintenance, and to maintain the groundwater level inside the artificial barrier at a lower level than the groundwater level outside the artificial barrier. A method for storing and disposing of characteristic industrial waste such as radioactive substances.