GUIDING DEVICE FOR POSITIONING RADIOACTIVE WASTE DRUM IN NEAR-SURFACE DISPOSAL FACILITY

Abstract

 The present invention relates to a guiding device for home position of radioactive wastes drum in near surface disposal facility, and more particularly, to a guiding device for home position of radioactive wastes drum in near surface disposal facility for improving radioactive wastes drum's home position stability and structural stability after home position by installing a guiding device for home position fixing the radioactive wastes drum to vault bottom or grout bottom of a near surface disposal facility of radioactive wastes; designating useful factors in stack-up and correct locations in advance when piling up the radioactive wastes drum; and easily disposing of damaged radioactive wastes drums during an institutional control period for preventing spread of damages.

Description

[Technical Field]

[0001] The present invention relates to a guiding device for home position of radioactive wastes drum in near surface disposal facility, and more particularly, to a guiding device for home position of radioactive wastes drum in near surface disposal facility for improving radioactive wastes drum's home position stability and structural stability after home position by installing a guiding device for home position fixing the radioactive wastes drum to the bottom of vault grout of a near surface disposal facility of radioactive wastes and by designating correct locations in advance when piling up radioactive wastes drums, and for easily extracting only damaged radioactive wastes drums in case of long-term storage of radioactive wastes drums.

[Background Art]

[0002] Coming from nuclear facilities and working areas or laboratories where radioactive materials are handled, radioactive wastes are classified into low and intermediate level radioactive wastes and high-level radioactive wastes depending on degrees of contamination caused by radioactive materials. According to relevant legislations, radioactive wastes are defined as materials to be targeted for disposal, such as radioactive materials or materials polluted by radioactive materials. Low and intermediate level radioactive wastes refer to contaminated work equipment during maintenance in nuclear power plants; they also may be contaminated goods in hospital treatment; and they may be generated through non-destructive inspection at industries. High-level radioactive wastes are remaining nuclear fuels after generating electricity in nuclear power plants. That is, radioactive wastes are generated in all areas, such as schools, hospitals, research institutes, industries, nuclear power plants, etc., where nuclear power is handled.

[0003] As for low and intermediate level radioactive wastes, radioactive wastes are disposed depending on site characteristics of 100-meter underground. Near surface disposal refers to a method for installing a concrete structure on the surface of ground for reclamation. Also, rock cavern disposal is disposed by excavating tunnel/silo into at least tens to hundreds of meters of underground for reclamation. As for high-level radioactive wastes, deep geological disposal is performed in 500 to 1,000 meters underground.

[0004] Different depending on countries, the methods for disposing low and intermediate level radioactive wastes are determined by consideration of national emotion, economy, construction, safety, etc. in all aspects. When disposal facilities are exposed to the air, a shielding device is required for diminishing and blocking radiation which remains inside of the disposal facilities. Also, anti-terrorist measures, enhancement of a shielding structure for decreasing residents' exposure dose, national emotion, and so on require careful consideration. In case of South Korea, rock cavern disposal method has been selected and under construction in areas where both near surface disposal and rock cavern disposal are available.

[0005] Meanwhile, such near surface disposal facility consists of: a vault, a concrete structure, for loading radioactive wastes; a rainfall catchment drainage system for managing rainwater in the disposal facility; a radioactivity drainage system for effective drainage of percolating water, generated after stacking up wastes, in the vault; a crane management system for lifting and piling up radioactive wastes; an underground inspection gallery; and various support buildings.

[0006] As illustrated in FIGs. 1 and 2, the vault(10) comprises vault bottom(11), wall(12), a crane(13) and a roof(15). A slope in the vault bottom(11) is built toward drain holes of the underground inspection gallery(14) and maintains a stable inclination. Porous concrete is built on the top of the vault bottom(11) to perform levelling for home positioning wastes and to drain percolating water.

[0007] Further, when building the wall(12), the vault bottom(11) is firstly chipped for smooth connection to concrete in the vault bottom(11). Wall mould and steel reinforcement are installed and movements are not generated while depositing concrete. The thickness of the wall(12) in the vault is determined by consideration of site characteristics, characteristics of radioactive wastes, etc.

[0008] In addition, the crane(13) stores a radioactive wastes drum(1) to the inside of the vault(1) by lifting up the radioactive wastes drums(1), which are transported near to the vault(10) using a transfer truck(16).

[0009] Meanwhile, when the radioactive wastes drum(1) is home positioned inside the vault(10), empty spaces in the radioactive wastes drum(1) are filled with grout. This functions as leveling for easy home position of the radioactive wastes drum(1).

[0010] When home position of the radioactive wastes drum(1) in the vault(10) is completed, the roof(15) is installed on the top of the vault(10). After installing the roof(15) on the top, a waterproof membrane(not illustrated) is installed to the top and the side of the vault for preventing water penetration. Before installing a final cover for permanent disposal, the waterproof membrane assists in protecting the vault from external climate.

[0011] Further, when piling up all wastes and constructing an upper slab, which is the roof(15), grout over a certain thickness is deposited to the top of wastes for minimizing workers' radiation exposure. The roof(15) is installed after depositing grout. Also, when depositing concrete, construction keeps continuing for not making construction joints until the roof(15) pouring is completed. The roof(15) has a thickness, thus forming a slope for draining water(rainfall, etc.) outwards from the vault(10).

[0012] Drums in the vault are home positioned in about 7 to 9 stacks vertically. If radioactive wastes drums are not evenly piled up in the vault by one layer, the amount of disposing radioactive wastes drums in the vault starts decreasing. Also, when grouting, if grout among wastes drums is not evenly built, this is the reason for local weakness, thus causing problems in securing long-term stability.

[0013] In addition, after disposal is completed, in case that the radioactive wastes drums have internal damages during a long-term institutional control period, it is impossible to extract the damaged radioactive wastes drums. Thus, it causes a problem in damaging even surrounding radioactive wastes drums in the vault under the influence of an institutional control period.

<Prior art>

<Patent document>

[0014] 

Patent document 1 : Korean Publication Patent no. 10-1986-0001451

Patent document 2 : Korean Publication Patent no. 10-1990-0015180

[Detailed explanations of the invention]

[Technical Problem]

[0015] The present invention provides a guiding device for home position of radioactive wastes drum in near surface disposal facility for improving radioactive wastes drum's home position stability and structural stability after home position by installing a guiding device for home position fixing the radioactive wastes drum to the bottom of vault grout of a near surface disposal facility of radioactive wastes and by home positioning each radioactive wastes drum, located in the bottom and the top, identically in a vertical direction.

[0016] The present invention also provides a guiding device for home position of radioactive wastes drum in near surface disposal facility for securing continuous home position stability and structural stability after home position by designating useful factors in stack-up and correct locations in advance when piling up the radioactive wastes drum even to the bottom of the grout on the second stage throughout sticking the guiding device out of the bottom of the deposited grout on the second stage while the guiding device is fixed to the top of the radioactive wastes drum when depositing the grout on the first stage after home position of the radioactive wastes drum.

[0017] The present invention also provides a guiding device for home position of radioactive wastes drum in near surface disposal facility for protecting surrounding radioactive wastes drums in the vault during an institutional control period by extracting only column of damaged radioactive wastes drums with vertical drilling after recognizing a damaged location using various measuring instruments in case that radioactive wastes drums are internally damaged after completion of disposal.

[Technical Solution]

[0018] According to an aspect of the present invention, there is provided a guiding device for home position of radioactive wastes drum in near surface disposal facility that is installed on the bottom of a vault or the bottom of grout for designating a location of a radioactive wastes drum which is home positioned in the vault, the guiding device comprising: a ring or circular disk shaped main body whose diameter is smaller than that of the radioactive wastes drum; and a guide protrusion, installed to the outside of the main body, for guiding and fixing an edge which is formed on the bottom of the radioactive wastes drum.

[0019] Here, the guiding device for home position of radioactive wastes drum in near surface disposal facility further comprises a fixing plate for being fixed to the top of the radioactive wastes drum using a magnet, which is fixed on the bottom for exposing the main body to the bottom of the grout, when depositing the grout after home position of the radioactive wastes drum; and a support which is combined vertically using bolts between the main body and the fixing plate for separating the main body from the top of the radioactive wastes drum on a regularly-spaced gap.

[0020] Here, the main body includes an anchor bolt hole for being fixed to the bottom of the vault.

[0021] Here, the main body is diagonally arranged for maximizing the number of the stacked radioactive wastes drums.

[0022] Here, the guide protrusion is formed in all directions with a same angle on the basis of a central point of the main body and has a slope for guiding the edge of the radioactive wastes drum to the outside.

[0023] Here, the guide protrusion is lower than the edge of the radioactive wastes drum while being stuck out at a spot higher than the main body.

[Advantageous Effects]

[0024] According to a guiding device for home position of radioactive wastes drum in near surface disposal facility of the present invention, as constituted above, it enables to improve radioactive wastes drum's home position stability and structural stability after home position by installing a guiding device for home position fixing the radioactive wastes drum to the bottom of vault grout of a near surface disposal facility of radioactive wastes and by home positioning each radioactive wastes drum, located in the bottom and the top, identically in a vertical direction.

[0025] Further, according to the present invention, it enables to improve continuous home position stability and structural stability after home position by designating useful factors in stack-up and correct locations in advance when piling up the radioactive wastes drum even to the bottom of the grout on the second stage throughout sticking the guiding device out of the bottom of the deposited grout on the second stage while the guiding device is fixed to the top of the radioactive wastes drum when depositing the grout on the first stage after home position of the radioactive wastes drum.

[0026] Furthermore, according to the present invention, it enables to protect surrounding radioactive wastes drums in the vault during an institutional control period by extracting only column of damaged radioactive wastes drums with vertical drilling after recognizing a damaged location using various measuring instruments in case that radioactive wastes drums are internally damaged after completion of disposal.

[Description of Drawings]

[0027] 

FIGs. 1 and 2 are pictures showing a general vault.

FIG. 3 is a perspective view showing the constitution of a guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention.

FIG. 4 is a sectional view in which the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention is installed on the bottom of a vault.

FIG. 5 is a view in which a fixing plate and a support are combined to the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention.

FIG. 6 is a sectional view in which the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention is installed on the bottom of grout while combining to the fixing plate and the support.

FIG. 7 is a plan view showing arrangement of the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention and radioactive wastes drums.

FIG. 8 is a partially-sectional perspective view showing arrangement of the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention and the radioactive wastes drums.

[Description of the preferred embodiments]

[0028] The configuration of a guiding device for home position of radioactive wastes drum in near surface disposal facility, according to the present invention, will be described in detail with the accompanying drawings.

[0029] In the following description of the present invention, a detailed description of known incorporated functions and configurations will be omitted when to include them would make the subject matter of the present invention rather unclear. Also, the terms used in the following description are defined taking into consideration the functions provided in the present invention. The definitions of these terms should be determined based on the whole content of this specification, because they may be changed in accordance with the option of a user or operator or a usual practice.

[0030] FIG. 3 is a perspective view showing the constitution of a guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention; FIG. 4 is a sectional view in which the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention is installed on the bottom of a vault; FIG. 5 is a view in which a fixing plate and a support are combined to the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention; FIG. 6 is a sectional view in which the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention is installed on the bottom of grout while combining to the fixing plate and the support; FIG. 7 is a plan view showing arrangement of the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention and radioactive wastes drums; and FIG. 8 is a partially-sectional perspective view showing arrangement of the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention and the radioactive wastes drums.

[0031] Referring to FIGs. 3 to 8, a guiding device for home position of radioactive wastes drum in near surface disposal facility(100) according to the present invention comprises a main body(110), a guide protrusion(120), a fixing plate(130) and a support(140).

[0032] First, the main body(110), made of metal or synthetic resins, is shaped like a ring or circular disk and has a smaller diameter than that of a radioactive wastes drum(1). At this time, it is desirable that the main body(110) includes: an anchor bolt hole(111), shaped like a flat head, for being fixed to vault bottom(11) using glue; and a bolt hole(113) for combining a support(140), explained below, to the lower side. Here, as illustrated in FIG.7, it is desirable that the main body(110) is diagonally arranged for maximizing the number of the radioactive wastes drum(1), which are stacked. Further, the anchor bolt hole(111) may be formed in a center for minimizing the number of the anchor bolt hole(111) of the main body(110).

[0033] In addition, formed to the outside of the main body(110), the guide protrusion(120) guides and fixes an edge(1a) which is placed on the bottom of the radioactive wastes drum(1). Here, it is desirable that the guide protrusion(120) is formed in all directions with a same angle(θ) on the basis of a central point(C) of the main body(110) and has a slope(121) for guiding the edge(1a) of the radioactive wastes drum(1) to the outside. Here, it is desirable that the guide protrusion(120) is lower than the edge(1a) of the radioactive wastes drum(1) while being stuck out at a spot higher than the main body(110) without causing friction against the radioactive wastes drum(1). For example, as for the 1 centimeter-high edge(1a), the guide protrusion(120) has a height of 0.9cm.

[0034] Furthermore, the fixing plate(130), made of metal or synthetic resins, is shaped like a ring or circular disk for exposing the main body(110) to grout bottom(21) when depositing the grout after home position of the radioactive wastes drum(1), and is fixed to the top of the radioactive wastes drum(1) using a magnet(131) which is fixed on the bottom. Here, when the fixing plate(130) is attached to the top of the radioactive wastes drum(1), i.e., a lid, for maintaining a correct location, it is desirable that the outer circumference of the fixing plate(130) has a diameter to close to an edge(1b) of the lid.

[0035] In addition, the support(140) is combined vertically using bolts between the main body(110) and the fixing plate(130) for separating the main body(110) from the top of the radioactive wastes drum(1) on a regularly-spaced gap. Here, the support(140) is spaced at least the grout's height(about 10cm) more on the top of the radioactive wastes drum(1). Here, it is also desirable that the support(140) forms a long hole(141) longitudinally for filling the inside with the grout.

[0036] Hereinafter, home position processes of the radioactive wastes drum(1) using the guiding device for home position of radioactive wastes drum in near surface disposal facility according to the present invention are described in detail with reference to the accompanying drawings.

[0037] Before home positioning the radioactive wastes drum(1), the main body(110) is fixed to the vault bottom(11) and arrayed as illustrated in FIGs. 7 and 8. At this time, the main body(110) may be arranged in a regular space, and the installation position of the main body(110) may be designated by being shot from a certain height using a laser pointer.

[0038] When the arrangement of the main body(110) is completed, the radioactive wastes drum(1) is home positioned to the vault bottom(11). After lifting up the radioactive wastes drum(1) using crane(reference numeral 13 in FIG.1), the radioactive wastes drum(1) is lifted down consecutively to the place where the main body(110) is installed. Then, the radioactive wastes drum(1) is home positioned by storing the main body(110) and the guide protrusion(120) to the inside of the edge(1a), formed on the bottom of the radioactive wastes drum(1), in accordance with the guide protrusion(120). At this time, the main body(110) is fixed to the top of the radioactive wastes drum(1) using the fixing plate(130) and the support(140).

[0039] When the arrangement of the first stage of the radioactive wastes drum(1) is completed by repeating the above process in sequence, the grout is deposited to the low level of the main body(110), which is placed on the top of the radioactive wastes drum(1).

[0040] Next, when the grout is cured, the arrangement of the radioactive wastes drum(1) is completed by repeating the above process.

[0041] Throughout the guiding device for home position of radioactive wastes drum in near surface disposal facility(100) according to the present invention, as constituted above, the radioactive wastes drum(1) may be home position fixed to the vault bottom(11) or the grout bottom(21) and thus, it is possible to improve the radioactive wastes drum(1)'s home position stability and structural stability after home position by designating useful factors in stack-up and correct locations in advance when piling up the radioactive wastes drum(1).

[0042] Further, according to the guiding device for home position of radioactive wastes drum in near surface disposal facility(100) of the present invention, when the grout is deposited after home positioning the radioactive wastes drum(1) to the vault bottom(11), the grout is deposited while the guiding device(110) is fixed to the top of the radioactive wastes drum(1). Therefore, due to the main body(110) and the guide protrusion(120), which are stuck out of the grout bottom(21), it is possible to designate useful factors in stack-up and correct locations in advance when piling up the radioactive wastes drum(1) even to the grout bottom(21).

[0043] Lastly, according to the guiding device for home position of radioactive wastes drum in near surface disposal facility(100) of the present invention, the radioactive wastes drum(1) is placed in vertical arrangement(up and down) at home position, and the main body(110) may be exposed to the top level of the grout bottom(21) according to choices. Thus, after disposal is completed, damages of the radioactive wastes drum(1) or damages of the vault(10) are recognized by various measuring instruments such as strain gauges, manometers, optical fiber sensors, etc. If damages are detected, only column from the damaged radioactive wastes drum(1) may be extracted by a vertical drilling and thus, it is possible to recover damages and protect surrounding radioactive wastes drums.

[0044] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

<Explanations on reference numeral>

1 : radioactive wastes drum	10 : vault
11 : vault bottom	21 : grout bottom
110 : body	120 : guide protrusion
130 : fixing plate	140 : support

Claims

1. A guiding device for home position of radioactive wastes drum in near surface disposal facility that is installed on the bottom of a vault or the bottom of grout for designating a location of a radioactive wastes drum which is home positioned in the vault, the guiding device comprising: a ring or circular disk shaped main body whose diameter is smaller than that of the radioactive wastes drum; and a guide protrusion, installed to the outside of the main body, for guiding and fixing an edge which is formed on the bottom of the radioactive wastes drum.

2. The guiding device according to claim 1, wherein the guiding device further comprises a fixing plate for being fixed to the top of the radioactive wastes drum using a magnet, which is fixed on the bottom for exposing the main body to the bottom of the grout, when depositing the grout after home position of the radioactive wastes drum; and a support which is combined vertically using bolts between the main body and the fixing plate for separating the main body from the top of the radioactive wastes drum on a regularly-spaced gap.

3. The guiding device according to claim 1, wherein the main body includes an anchor bolt hole for being fixed to the bottom of the vault.

4. The guiding device according to claim 1, wherein the main body is diagonally arranged for maximizing the number of the stacked radioactive wastes drums.

5. The guiding device according to claim 1, wherein the guide protrusion is formed in all directions with a same angle on the basis of a central point of the main body and has a slope for guiding the edge of the radioactive wastes drum to the outside.

6. The guiding device according to claim 1, wherein the guide protrusion is lower than the edge of the radioactive wastes drum while being stuck out at a spot higher than the main body.

Drawing