JP2014013159A - Structure construction method and structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily utilize radioactive debris processed in a disaster area due to a serious accident of a nuclear power plant without transporting the radioactive debris to a place other than the disaster area.SOLUTION: In a structure construction method, radioactive debris 6 is processed by using a radioactive substance absorbing material 5 in a disaster area and a structure 1 such as a tsunami breakwater is constructed using the processed debris 6. Because a large volume of the processed debris 6 is required for constructing the structure, the structure construction method can utilize the processed debris 6 in the disaster area without carrying the same out of the disaster area. In addition, the structure construction method can improve safety of the area against a natural disaster.

Description

  The present invention relates to a structure processing method for reducing the radiation dose of radioactive rubble and using the rubble with the reduced radiation dose as a banking material for a structure such as a tsunami breakwater, and a structure formed by the method.

  When a serious accident occurs at a nuclear power plant, radioactive materials such as cesium diffuse in a large amount around it, and surrounding houses and soil are contaminated over a wide area. In the restoration work, it is necessary to promptly proceed with final disposal such as landfill after reducing the radiation dose of a large amount of radioactive debris. As a method for treating this radioactive rubble (radioactive waste), for example, there is a method disclosed in Patent Document 1. This method is intended to reduce the radiation dose by solidifying radioactive waste with a cement-based solidifying material.

Japanese Patent Application Laid-Open No. 2008-241587

  In the radioactive waste processing method according to Patent Document 1, it is necessary to transport the solidified radioactive waste to a landfill and dispose of it in landfill. However, as described above, in a serious accident at a nuclear power plant, a large amount of debris corresponding to the amount of waste generated in normal times from several years to a dozen years is generated at one time, so the area affected by the accident ( There is a problem that the landfill site cannot be secured only within the disaster area) and the final treatment does not proceed easily. In addition, it may be possible to transport rubble (processed rubble) after radiation reduction treatment to areas other than the stricken area, and landfill it. However, local governments refuse to accept rubble due to safety concerns. In some cases, the acceptance system is not fully prepared. Even if a receiving area is found, it often takes a lot of cost and time to transport a large amount of debris from the affected area. For this reason, the problem that the treatment of rubble, which is the first stage of the restoration work, does not progress slowly, and the reconstruction of the affected areas is greatly delayed, has become a reality.

  Therefore, an object of the present invention is to quickly process radioactive rubble treated in a disaster area of a serious accident at a nuclear power plant without transporting it to a place other than the disaster area.

  In order to solve the above-mentioned problems, the present invention mixes radioactive rubble and a radioactive substance adsorbent that adsorbs radioactive substances, and after the radiation dose of the radioactive rubble falls below a predetermined value, the radioactive rubble and radioactive substance are mixed. A structure was adopted in which a large amount of treated rubble was treated by a method of filling a mixture of substance adsorbents as a filling material inside the structure and creating the structure.

  Depending on the size of this structure, a large amount of embankment material is required for creation. By using treated rubble as the embankment material, a large amount of rubble can be treated at once. Moreover, if the structure is created in the stricken area, it is not necessary to transport the rubble, so the cost and time associated with transport can be reduced. In addition, since it is not necessary to negotiate with the area where rubble is transported, rubble can be processed quickly. For this reason, the reconstruction of the stricken area can proceed smoothly.

  In the said structure, the said radioactive substance adsorbent can be mixed with the retaining wall material which comprises the side wall of the said structure.

  In order to prevent moisture from rainwater, groundwater, etc. from accumulating in the structure, it is common to form a hole through which water passes through the retaining wall material of the structure and drain the water through this hole. . Therefore, by mixing a radioactive substance adsorbent in the retaining wall material itself, even if the radioactive substance remains in the moisture inside the structure, the radioactive substance is absorbed by the radioactive substance adsorbent during the drainage. Adsorbed. For this reason, there is very little risk of radioactive material flowing out of the structure.

  In each said structure, a cavity part can be formed in the inside of the retaining wall material which comprises the side wall of the said structure, and the said radioactive substance adsorbent can be enclosed with this cavity part.

  If a cavity is formed inside the retaining wall material, the cavity serves as a flow path for moisture, and moisture accumulated inside the structure is drained through the cavity. If a radioactive material adsorbent is sealed in the cavity, moisture will directly contact the radioactive material adsorbent, and even if the radioactive material remains in the moisture inside the structure, The radioactive material is adsorbed by the radioactive material adsorbent. For this reason, there is very little risk of radioactive material flowing out of the structure.

  In the configuration in which the retaining wall material is provided, the radioactive substance adsorbing material can be used as a backing material for the retaining wall material.

  When the water inside the structure is drained from the hole formed in the retaining wall material, it flows through the back side of the retaining wall material. Therefore, if a radioactive substance adsorbent is provided on the back side as a backing material, even if the radioactive substance remains in the moisture inside the structure, the radioactive substance adsorbs the radioactive substance during drainage. Adsorbed by the material. For this reason, there is very little risk of radioactive material flowing out of the structure.

  In each said structure, the said radioactive substance adsorption material shall contain at least one from a zeolite, illite, and a barley stone.

  These have been experimentally confirmed to adsorb radioactive substances such as cesium and remove the radioactivity. Among these, illite has been confirmed to have a property of strongly adsorbing radioactive substances, and is particularly excellent as a radioactive substance adsorbent since it is difficult to release once adsorbed radioactive substances.

  The structures created by the above structure building methods are tsunami breakwaters, jetty, river embankments, sluice gates, lock gates, sabo dams, rivers and dams, coastal roads, wind power / hydropower / solar power generation equipment Suitable for use as a foundation, park or green area.

  For example, by constructing a structure such as a breakwater to prevent inundation due to tsunami or storm surge in the area near the coast, and a sabo dam to prevent landslides caused by heavy rain in the mountainous area, Safety against disasters can be greatly improved. In addition, by looking at the transformation of energy policy centering on nuclear power generation, adopting the structure as the basis for various power generation devices, it is also possible to expand new industries associated with the new energy policy. Furthermore, the quality of inhabitants' lives in the area can be improved by creating parks and the like. Thus, by constructing the structure using the treated radioactive rubble, it is possible to achieve both the rapid removal of rubble and the improvement of the safety in the creation area.

  In the configuration according to the present invention, a large amount of radioactive rubble generated in a serious accident at a nuclear power plant is removed using a radioactive substance adsorbent, and the treated rubble is used as a banking material. It was decided to create a structure. Thereby, radioactive rubble can be processed in large quantities and quickly, and it can contribute greatly to reconstruction of a stricken area.

Sectional drawing which shows 1st embodiment of the structure which concerns on this invention Sectional drawing which shows 2nd embodiment of the structure which concerns on this invention

  A first embodiment of a structure according to the present invention is shown in FIG. This structure 1 is a tsunami breakwater provided near the coast. It may be constructed over a length of several kilometers along the coast. This tsunami breakwater is obtained by stacking a plurality of concrete blocks 2 each functioning as a retaining wall material having a groove portion having a substantially U-shaped cross section on both the coast side and the land side. The stacking height h of the concrete block 2 can be appropriately changed in consideration of the maximum tsunami height assumed in the area. The concrete block 2 is installed with a predetermined inclination angle θ with respect to the vertical line. A drainage channel 3 for draining water accumulated in the breakwater is provided inside the concrete block 2 on the land side (land side).

  Between the support walls 4 and 4 provided facing the insides of both stacked concrete blocks 2, a radioactive material adsorbent 5 made of zeolite and illite is mixed with a radioactive material adsorbent 5 to give a predetermined radiation dose. The radioactive rubble 6 (hereinafter referred to as treated rubble 6) having a value equal to or lower than the value is packed as a banking material while being mixed with the radioactive substance adsorbent 5.

  Although only the layer composed of the lowermost radioactive material adsorbent 5 and the treated rubble 6 is shown in the figure, the layers are actually stacked in a plurality of layers. The gap between the treated rubble 6 and the like is filled with cement 7 in which a radioactive material adsorbent 5 such as powdered zeolite or illite is mixed, and the treated rubble 6 together with the radioactive material adsorbent 5 is cemented. 7 is in a state of being enclosed. The concrete block 2 uses zeolite as its aggregate. Further, crushed stone-like zeolite is also filled as the radioactive material adsorbent 5 in the groove portion. A concrete lid 8 is provided on the uppermost portion of the treated rubble 6 and the like to prevent rainwater from entering the structure 1. This concrete lid 8 is also mixed with a radioactive substance adsorbent 5 such as zeolite. In this way, by surrounding the treated debris 6 with the concrete block 2 or cement 7 filled with or mixed with the radioactive material adsorbent 5, the radioactive material remains in the moisture inside the structure 1 temporarily. Even if it is, the radioactive substance remaining at the time of the drainage is adsorbed by the radioactive substance adsorbing material 5. For this reason, the possibility that the radioactive substance flows out from the inside of the structure 1 is very low, and high safety can be secured.

  The structure 1 uses a large amount of treated debris 6 as a fill material, depending on the scale of its construction. For this reason, the debris generated in the stricken area can be disposed of in large quantities at the same time without being transported to areas other than the stricken area, and the restoration / reconstruction work of the stricken area can be proceeded quickly. In addition, by using the structure 1 as a tsunami breakwater or the like in a region near the coast and as a sabo dam or the like in a mountainous region, safety against natural disasters or the like in those regions is greatly improved. Furthermore, in view of the transformation of energy policy centering on nuclear power generation, by adopting this structure 1 as a basis for various power generation devices, it is possible to expand new industries accompanying the new energy policy. In addition, by creating a park or the like on the structure 1, it is possible to improve the quality of inhabitants' lives in the area.

  In this first embodiment, a concrete block 2 having a groove portion having a substantially U-shaped cross section is used, and the radioactive material adsorbent 5 is filled in the groove portion, and the radioactive substance adsorbent 5 is mixed in the concrete block 2 and the lid 8. However, such a configuration is not essential, and a part of the configuration can be omitted as appropriate.

  Next, the construction procedure of this structure 1 (tsunami breakwater) will be described. First, the radioactive material adsorbent 5 is mixed with the radioactive rubble 6 and a treatment (pretreatment) for removing (or reducing) the radioactivity of the radioactive rubble 6 is performed. Prior to this treatment, it is preferable that the radioactive debris 6 is crushed into an appropriate size in advance using a crusher or the like. Moreover, when mixing the radioactive debris 6 and the radioactive substance adsorbent 5, it is preferable to promote mixing and stirring using a stabilizer (stirrer). Furthermore, it is preferable that the radioactive material adsorbent 5 used in this pretreatment is sufficiently dried in advance.

  If the object to be treated contains a lot of water, such as sludge or sludge, add a cement-based or lime-based soil conditioner, mix with the powdered radioactive material adsorbent 5 and mix this radioactive sludge or radioactive Process sludge. It is preferable that the powdered radioactive material adsorbent 5 used in this treatment is forcibly dried in advance. This is because by using the radioactive substance adsorbent 5 that has been forcibly dried, radioactive sludge or radioactive sludge can be easily solidified, and the subsequent creation process can be carried out smoothly.

  Next, the concrete blocks 2 are stacked and installed so that the support walls 4 face each other, and a predetermined amount (for example, the total amount) of the treated rubble 6 whose radiation dose has been reduced by the pretreatment is placed between the opposing support walls 4 and 4. 1). And the treated debris 6 etc. which were thrown in are compressed with a compression device. After this compression, cement 6 (cement milk) mixed with radioactive material adsorbent 4 such as zeolite or illite is poured to fill the gaps remaining after compression. The process of charging, compressing, and filling the cement 6 with the treated rubble 6 and the like is repeated, and when reaching a predetermined height, the lid 8 is provided to complete the structure 1.

  FIG. 2 shows a second embodiment of the structure according to the present invention. This structure 1 is a river dike for river revetment and flood prevention. This river dike is mixed with radioactive material adsorbent 3 made of zeolite and illite, and radioactive sludge 9 (hereinafter referred to as treated sludge 9) having a radiation dose of a predetermined value or less is buried in the riverbank and this treated A plurality of concrete blocks 2 for preventing sludge 9 from flowing into the river are stacked to give a revetment action.

  The concrete block 2 is formed with a hollow portion 10 having a water flow action, and crushed stone zeolite is enclosed as a radioactive substance adsorbing material 5 in the hollow portion 10. The concrete block 2 is formed with a water passage hole (not shown) for draining moisture such as rainwater collected on the landfill side to the river side through the cavity 10. Further, crushed stone zeolite is provided as a backing material 11 between the concrete block 2 and the treated sludge 9. Suction to prevent the treated sludge 9 from flowing out into the river etc. between the backing material 11 and the concrete block 2 and in the gap on the surface side (river side) of the concrete block 2 above the water surface A preventive material 12 is provided. The uppermost part of the treated sludge 9 is covered with concrete 13. Plants P such as aquatic plants are planted on the surface side of the concrete block 2, and the greening of the dike is planned.

  In the second embodiment, a configuration is adopted in which the cavity 10 of the concrete block 2 is filled with the radioactive material adsorbent 5 and crushed stone zeolite is used as the backing material 11. Is not essential, and a part of the configuration may be omitted as appropriate.

  In each of the above embodiments, zeolite and illite are employed as the radioactive material adsorbing material 5, but in addition, various minerals that have been confirmed to adsorb radioactive materials such as barley stone are employed. can do. Moreover, as a shape of this radioactive substance adsorbent 5, not only a crushed stone shape but a thing of various shapes, such as particle shape, fine powder shape, flake shape, can be employ | adopted.

1 Structure 2 Retaining wall material (concrete block)
3 Drainage channel 4 Support wall 5 Radioactive material adsorbent 6 Radioactive rubble (treated rubble)
7 Cement 8 Lid 9 Radioactive sludge (treated sludge)
10 Cavity 11 Backing material 12 Suction prevention material 13 Concrete h Stack height θ Inclination angle

Claims (7)

  After mixing the radioactive rubble (6) and the radioactive material adsorbent (5) that adsorbs the radioactive substance, the radioactive rubble (6) and the radioactive rubble (6) and radioactive A structure creation method in which a mixture of the substance adsorbing material (5) is packed into the structure (1) as an embankment material to create the structure (1).   The method for constructing a structure according to claim 1, wherein the radioactive substance adsorbing material (5) is mixed with a retaining wall material (2) constituting a side wall of the structure (1).   A cavity (10) is formed inside a retaining wall material (2) constituting a side wall of the structure (1), and the radioactive substance adsorbing material (5) is enclosed in the cavity (10). Or the structure production method of 2.   The method for constructing a structure according to claim 2 or 3, wherein the radioactive substance adsorbing material (5) is used as a backing material (11) for the retaining wall material (2).   The method for producing a structure according to any one of claims 1 to 4, wherein the radioactive material adsorbent (5) contains at least one of zeolite, illite, and barleystone.   A structure formed by the structure forming method according to claim 1.   A tsunami breakwater, jetty, river dike, sluice gate, sluice gate, sabo dam, hill and valley dam, river lake dam, gulf road, wind power / hydropower / solar power generation foundation The structure described in 1.

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