JP6893203B2 - Ship inspection method, ship manufacturing method - Google Patents

Description

The present invention relates to a method for inspecting a ship and a method for manufacturing a ship.

In order to transport and store radioactive substances such as radioactive waste, the radioactive substances are stored in a storage container made of a material having a radiation shielding property. A ship carrying such radioactive material stores the radioactive material stored in the storage container in a hold (cargo loading section) provided in the ship. The walls, floors, decks, etc. that partition the inside and outside of the hold are formed by a shield having a predetermined radiation shielding performance in order to suppress radiation exposure of the ship's crew. For example, a shield provided on a hold wall or the like may be formed by casting and filling concrete between a pair of steel plates provided at intervals in the horizontal direction.

In such a shield, if there are voids or the like inside, radiation may pass through the shield, that is, a phenomenon called streaming may occur.
For example, Patent Document 1 discloses that streaming occurs through a portion of a pipe provided inside a shield.

Japanese Unexamined Patent Publication No. 60-157093

A shield formed by filling concrete between a pair of steel plates may cause streaming if there is a gap between the concrete joint surface or the concrete and the steel plate. If the shield is manufactured for test purposes, the steel plate covering the surface of the shield can be peeled off and the concrete placement status inside can be visually confirmed. However, in the case of a shield actually installed on the hull, it is not possible to peel off the steel plate and visually check it directly. Therefore, it is difficult to inspect whether or not streaming occurs in the above-mentioned shield.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ship inspection method and a ship manufacturing method capable of easily grasping the occurrence status of streaming without peeling off the steel plate of the shield. And.

The present invention employs the following means in order to solve the above problems.
According to the first aspect of the present invention, a ship inspection method comprises a shield formed of a pair of steel plates and concrete placed between the steel plates to shield radiation from radioactive waste loaded on a hold. an inspection method of a ship having the as abut the surface of the first side of the shield, radiation arranged collimator of the radiation source that emits in the predetermined direction, the surface of the second side of the shield The device arranging step of arranging the radiation detection unit so as to abut against the shield, and the detection unit is continuously moved to a plurality of positions along the second side surface of the shield, and at each of the positions. Based on the detection step of detecting the dose by the detection unit in a state of being abutted against the second surface of the shield and the detection values at the plurality of positions detected in the detection step, the radiation of the shield It includes a determination step of determining whether or not streaming is occurring.

With this configuration, the detection unit detects the dose of radiation emitted from the radiation source and passed through the shield. If the shield is streaming, the dose at that location will be significantly higher than the dose at other locations where streaming is not occurring. Therefore, by continuously detecting the dose by the detection unit at a plurality of positions along the second surface of the shield, it is possible to determine whether or not radiation is being streamed in the shield at each position. It can be determined. This makes it possible to grasp the position where streaming is occurring with high accuracy.

According to the second aspect of the present invention, the determination step according to the first aspect determines that radiation streaming is occurring in the shield when the detection values at the plurality of positions include singular values. You may try to do so.
In this second aspect, the detection unit detects the dose at a plurality of positions along the second surface of the shield. Therefore, when a singular value whose dose detection value is clearly higher than that of other positions is included, the position where the singular value is detected is easily determined as radiation streaming is occurring in the shield. be able to.

According to the third aspect of the present invention, in the detection step according to the first or second aspect, the radiation source is fixed on the first side of the shield, and only the detection portion is of the shield. The dose may be detected by continuously moving to a plurality of positions along the second side surface.
With this configuration, the dose can be detected at multiple positions by continuously moving only the detection unit to multiple positions within the reach of the radiation emitted from the radiation source without moving the radiation source. Can be done. If we try to move not only the detector but also the radiation source on the first side of the shield at all positions where the dose is detected, the radiation source and the detector on both the first and second sides of the shield Must be moved. Therefore, it takes a lot of time and effort to perform the detection work at a large number of positions, and the burden on the operator increases. However, in the third aspect, since only the detection unit is continuously moved, it is possible to reduce the trouble of performing the detection work at a large number of positions.

According to the fourth aspect of the present invention, a method for manufacturing a ship is a shield formed by a pair of steel plates and concrete arranged between these steel plates to shield radiation from radioactive waste loaded on a hold. A method for manufacturing a ship, the shield forming step of forming the shield, a shield inspection step of inspecting the shield by the ship inspection methods of the first to third aspects, and the shield. Includes a repair step of repairing the position where the streaming is occurring in the shield when it is determined that the streaming of radiation is occurring in the shield.

By doing so, the dose is detected by the detection unit at a plurality of positions along the second surface of the shield with respect to the shield, and it is easily determined whether or not radiation streaming is occurring. can do. This makes it possible to grasp the position where streaming is occurring with high accuracy. Further, the radiation shielding performance of the shield at the position where the streaming has occurred can be ensured by appropriately performing the repair work of the shield at the position where the streaming has occurred in the repair step.

According to the fifth aspect of the present invention, in the repair step according to the fourth aspect, the repair steel plate may be attached to the surface of the steel plate at the position where the streaming is generated in the shield.
With this configuration, the shield can be repaired by attaching the repair steel plate to the surface of the steel plate at the position where streaming is occurring. Further, by adjusting the thickness and the number of repair steel plates to be attached, it is possible to appropriately repair the shield according to the degree of streaming.

According to a sixth aspect of the present invention, a ship inspection method comprises a shield formed of a pair of steel plates and concrete placed between the steel plates to shield radiation from spent nuclear fuel loaded on a hold. an inspection method of a ship having the as abut the surface of the first side of the shield, radiation arranged collimator of the radiation source that emits in the predetermined direction, the surface of the second side of the shield The device arranging step of arranging the radiation detection unit so as to abut against the shield, and the detection unit is continuously moved to a plurality of positions along the second side surface of the shield, and at each of the positions. Based on the detection step of detecting the dose by the detection unit in a state of being abutted against the second surface of the shield and the detection values at the plurality of positions detected in the detection step, the radiation of the shield It includes a determination step of determining whether or not streaming is occurring.

According to the seventh aspect of the present invention, in the determination step according to the sixth aspect, when the detection values at the plurality of positions include singular values, it is determined that radiation streaming is occurring in the shield. You may try to do so.

According to the eighth aspect of the present invention, in the detection step according to the sixth or seventh aspect, the radiation source is fixed on the first side of the shield, and only the detection portion is the said of the shield. The dose may be detected by moving it to a plurality of positions along the surface on the second side.

According to the eighth aspect of the present invention, the method for manufacturing a ship is a shield formed by a pair of steel plates and concrete arranged between these steel plates to shield radiation from spent nuclear fuel loaded on a hold. A shield that inspects the shield by the method of manufacturing the ship and the method of inspecting the ship according to any one of the sixth to eighth aspects and the shield forming step of forming the shield. It may include an inspection step and a repair step of repairing a position where the streaming is occurring in the shielding body when it is determined that the streaming of radiation is occurring in the shielding body.

According to the ninth aspect of the present invention, in the repair step according to the ninth aspect, the repair steel plate may be attached to the surface of the steel plate at the position where the streaming is generated in the shield.

According to the above-mentioned ship inspection method and ship manufacturing method, it is possible to grasp the occurrence state of streaming generated from the concrete joint surface and the gap between the concrete and the steel plate with high accuracy.

It is a schematic diagram which shows the whole structure of the ship in one Embodiment of this invention. It is sectional drawing which shows an example of the structure of the shield extending in the lateral direction in the said ship. It is a side sectional view which shows an example of the structure of the shield extending in the vertical direction in the said ship. It is a plan sectional view which shows an example of the structure of the shield extending in the vertical direction in the said ship. It is a flowchart of the manufacturing method of a ship in the said embodiment. It is a flowchart of the inspection method of a ship in the said embodiment. It is a figure which shows the arrangement of a radiation source and a detection part in a detection process. It is a figure which shows an example of the dose detected in the said detection step. It is a side sectional view which shows an example of the state which repaired the shield body in the repair process in the said manufacturing method of a ship.

Next, a ship inspection method and a ship manufacturing method according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing the overall configuration of a ship according to the embodiment of the present invention.
As shown in FIG. 1, the ship 10 of this embodiment includes at least a hull 11, an upper deck 12, and an upper structure 17 having a living area.

The hull 11 has a pair of broadsides 14. The hull 11 includes a bow portion 11c, a hold (cargo loading section) 15, and a stern portion 11d. The hold 15 is provided on the bow portion 11c side of the superstructure 17. The hold 15 is formed so as to be sandwiched between a pair of side 14s. The hold 15 can accommodate a plurality of storage containers containing radioactive waste inside the hold 15.

The upper deck 12 is an all-deck exposed to the outside, and is provided so as to cover the upper part of the hold 15 together with an openable and closable hatch cover (not shown) installed on the upper part of the hold 15. The above-mentioned upper structure 17 is formed on the upper deck 12 on the stern portion 11d side of the hold 15.

The hull 11 has a shield 20 that shields radiation from radioactive waste loaded on the hold 15. The shield 20 includes a lower shield 20A, an upper shield 20B, a side shield 20C, a deck upper shield 20D, and an upper structure shield 20E.
The lower shield 20A is provided so as to extend laterally along the floor portion 15a located below the hold 15. The lower shield 20A may form the floor portion 15a itself, or may be provided on the upper side or the lower side of the floor portion 15a separately from the floor portion 15a.
The upper shield 20B is arranged above the hold 15 so as to extend laterally along the upper deck 12. The upper shield 20B may form the upper deck 12 itself, or may be provided on the upper side or the lower side of the upper deck 12 separately from the upper deck 12.
The side shields 20C are provided on the hold 15 on both sides in the stern direction Da and on both sides in the ship width direction, respectively, extending in the vertical direction Dv (vertical direction).

The shield 20D on the deck is formed on the upper deck 12 so as to extend in the vertical direction Dv. A plurality of shields 20D on the deck are provided on the upper deck 12 at intervals in the stern-tail direction Da. Of the plurality of deck upper shields 20D, the deck upper shield 20Da provided at the position closest to the bow portion 11c has a protrusion height from the upper deck 12 in the vertical direction Dv more than the other deck upper shields 20Db. Is big.
The superstructure shield 20E is provided so as to extend in the vertical direction Dv so as to cover the entire front of the superstructure 17 in the stern direction Da.

FIG. 2 is a cross-sectional view showing an example of the configuration of a shield extending in the lateral direction in the ship. FIG. 3 is a side sectional view showing an example of the configuration of a shield extending in the vertical direction in the ship. FIG. 4 is a plan sectional view showing an example of the configuration of a shield extending in the vertical direction in the ship.
As shown in FIG. 2, the lower shield 20A and the upper shield 20B that are installed so as to extend in the lateral direction include a steel plate 21 and concrete 22 laid on the steel plate 21 with a predetermined thickness, respectively. ing.

As shown in FIG. 3, the side shield 20C, the deck upper shield 20D, and the superstructure shield 20E, which are installed so as to extend in the vertical direction, are each provided in pairs at intervals in the horizontal direction. A steel plate 23 and a concrete 24 cast and filled between the steel plates 23 are provided.

As shown in FIG. 4, a plurality of rib plates 25 are provided between the pair of steel plates 23 at intervals in the horizontal direction along the surface of the steel plates 23. Each rib plate 25 is joined to each of the pair of steel plates 23. As a result, the space between the pair of steel plates 23 is divided into a plurality of compartments A by the rib plates 25. The concrete 24 is filled in each section A between the pair of steel plates 23 and between the rib plates 25 adjacent to each other.

Further, as shown in FIG. 1, a plurality of partition walls 18 are provided in the hold 15 at intervals in the stern-tail direction Da. The partition wall 18 may also have the same configuration as the side shield 20C and the like.

Next, the manufacturing method of the ship 10 and the inspection method of the ship 10 as described above will be described.
FIG. 5 is a flowchart of a ship manufacturing method according to the present embodiment.
As shown in FIG. 5, the manufacturing method of the ship 10 according to the present embodiment includes at least a shield forming step S1, a shield inspection step S2, and a repair step S4.

In the shield forming step S1, the shield 20 is formed at a predetermined position on the hull 11.
The lower shield 20A and the upper shield 20B are formed by placing concrete 22 having a predetermined thickness on the steel plate 21 and curing the concrete 22 for a predetermined period of time, respectively. The side shield 20C, the deck shield 20D, and the superstructure shield 20E are filled with concrete 24 placed between two pairs of steel plates 23 provided at intervals in the horizontal direction. , Formed by curing for a predetermined period.

Here, as shown in FIG. 2, when the concrete 22 is placed in a plurality of stages in the lower shield 20A and the upper shield 20B extending in the lateral direction, the concrete 22a is placed and then the concrete 22b is placed. Then, the concrete 22b placed later is placed on the concrete 22a placed earlier. If the elapsed time from the placement of the concrete 22a to the next placement of the concrete 22b exceeds the predetermined time limit, the hardening reaction of the previously placed concrete 22a may proceed. .. Then, the joint portion Z1 is formed between the concrete 22a cast first and the concrete 22b cast later. The joint portion Z1 extends laterally and intersects the thickness direction of the shield 20. In this way, in the case of the lower shield 20A and the upper shield 20B extending in the lateral direction, even if there is a gap or the like in the joint portion Z1, the radiation passes from the inside to the outside of the hold 15 without being sufficiently attenuated. Streaming is unlikely to occur.

As shown in FIG. 3, when the concrete 24 is placed in a plurality of stages, the side shield 20C extending in the vertical direction, the shield 20D on the deck, and the superstructure shield 20E are also placed after the concrete 24a is placed. When the concrete 24b is cast, the concrete 24b to be cast later is cast on the concrete 24a cast earlier. If the elapsed time from the placement of the concrete 24a to the next placement of the concrete 24b exceeds the predetermined time limit, the hardening reaction of the previously placed concrete 24a may proceed. .. Then, the joint portion Z2 is formed between the concrete 24a cast first and the concrete 24b cast later. The joint portion Z2 extends in the lateral direction and is in a direction of connecting the pair of steel plates 23 to each other in the shield 20. Therefore, if there is a gap or the like in the joint portion Z2, there is a possibility that the radiation will pass through the hold 15 from the inside to the outside without being sufficiently attenuated.
Therefore, the side shield 20C, the deck shield 20D, and the superstructure shield 20E extending in the vertical direction are inspected in the shield inspection step S2 described later.

FIG. 6 is a flowchart of a ship inspection method according to the present embodiment. FIG. 7 is a diagram showing the arrangement of the radiation source and the detection unit in the detection step.
As shown in FIG. 6, the shield inspection step S2 includes an equipment arrangement step S21, a detection step S22, and a determination step S23.

As shown in FIG. 7, in the shield inspection step S2, the radiation source 101 and the detection unit 102 are used to inspect the shield 20. The radiation source 101 emits, for example, gamma rays as radiation for inspection of the shield 20. The radiation source 101 includes a radiation source container 101a for accommodating a radiation source, a transmission tube 101b, and a collimator 101c. ^{Radioisotope 60} Co (cobalt-60) or the like can be used as the radiation source contained in the radiation source container 101a.

In the radiation source 101, the radiation source housed in the radiation source container 101a is pushed out to the collimator 101c via the transmission tube 101b and moves. The radiation source moved to the collimator 101c emits radiation in a predetermined direction.
The detection unit 102 detects the dose of radiation. For the detection unit 102, for example, an ionization chamber type survey meter or the like is used.

In the device arrangement step S21, the radiation source 101 is arranged on the first side of the shield 20, and the detection unit 102 is arranged on the second side of the shield 20. Here, the collimator 101c of the radiation source 101 is arranged at a height at which the joint portion Z2 of the concrete 24 may be formed when the shield 20 is formed. The height at which the joint portion Z2 may be formed can be set by managing (grasping) the placing level at each stage in which the concrete 24 is placed in a plurality of stages at the time of construction.
The collimator 101c and the detection unit 102 of the radiation source 101 may be arranged so as to abut against the surfaces 20f and 20g of the shield 20, respectively.

In the detection step S22, the detection unit 102 detects the dose of radiation emitted from the radiation source 101 and passed through the shield 20 at a plurality of positions along the second side surface 20 g of the shield 20.
At this time, the position of the radiation source 101 is fixed on the first side of the shield 20, and only the detection unit 102 is moved to a plurality of positions along the surface 20 g on the second side of the shield 20 by a worker or the like. .. In this detection step S22, the dose is detected by the detection unit 102 at each position.

Here, the range in which the detection unit 102 is moved along the surface 20 g on the second side of the shield 20 is a range in which the radiation from the radiation source 101 reaches with a sufficient dose. For example, the range in which the detection unit 102 is continuously moved along the second side surface 20g of the shield 20 is centered on the position P0 at which the detection unit 102 faces the collimator 101c of the radiation source 101 with the shield 20 in between. The range can be 20 mm above and below the vertical Dv, respectively. That is, the movement range of the detection unit 102 illustrated in this embodiment is the position P1 and the position P0 which are moved 20 mm above the vertical Dv with respect to the position P0 facing the collimator 101c of the radiation source 101 with the shield 20 in between. It is the range between the position P2 and the position P2 which is moved 20 mm below the vertical Dv. The detection unit 102 detects the dose at a plurality of positions at predetermined pitches in the vertical direction Dv while moving the range between the positions P1 and P2.

The dimension of the range in which the detection unit 102 illustrated in the embodiment is moved is an example, and is not limited to the above-mentioned dimension. That is, the detection unit 102 may be moved above and below the position P0 in the vertical direction within a range of 20 mm or more or less than 20 mm, respectively. Further, the pitch of the position where the dose is detected may be set to any dimension within the range in which the detection unit 102 is moved in the vertical direction Dv. Further, the detection unit 102 may be continuously moved not only in the vertical direction Dv but also in the horizontal direction along the second side surface 20g of the shield 20 to detect the dose at a plurality of positions.

In the detection step S22, the detection of the dose as described above is repeatedly performed in each section A.
Further, in each section A, when there are a plurality of height positions where the joint portion Z2 may be formed in the concrete 24, the collimator 101c of the radiation source 101 and the detection unit 102 are set at the respective height positions. Face each other. In this state, only the detection unit 102 is moved to a plurality of positions, and the dose is detected at each position.

The determination step S23 determines whether or not radiation streaming is occurring in the shield 20 based on the detection values at the plurality of positions detected in the detection step S22.
In the detection step S22, the detection unit 102 detects the dose of radiation emitted from the radiation source 101 and passed through the shield 20. When the joint portion Z2 is formed in the shield 20 and streaming is generated due to a gap or the like of the joint portion Z2, as shown in FIG. 8, the dose at the position where the streaming is occurring is caused by streaming. The singular value Lp is clearly higher than the dose at other positions.
Therefore, when the detection values at the plurality of positions detected in the detection step S22 include a singular value Lp whose dose detection value is clearly higher than that at other positions, radiation streaming occurs in the shield 20. Judge that there is.
The shield inspection step S2 is completed by going through the equipment arrangement step S21, the detection step S22, and the determination step S23.

Returning to FIG. 5, following the shield inspection step S2, the shield 20 confirms the presence / absence of radiation streaming (streaming presence / absence confirmation step S3), and if there is no streaming, a series of operations is completed.
On the other hand, if it is determined in the streaming presence / absence confirmation step S3 that radiation streaming is occurring in the shield 20, the repair step S4 is performed.
In the repair step S4, the shield 20 is repaired at a position where streaming is occurring in the shield 20.

FIG. 9 is a side sectional view showing an example of a state in which the shield is repaired in the repair step.
As shown in FIG. 9, in the repair step S4 in this embodiment, the repair steel plate 30 is joined and attached to the surface of the steel plate 23 at the position Pz where streaming is occurring in the shield 20 by welding or the like. Here, it is assumed that the repair steel sheet 30 to be attached has a thickness necessary for ensuring a predetermined radiation shielding performance based on the dose of the position Pz detected in the detection step S22. The repair steel plate 30 to be attached to the surface of the steel plate 23 is not limited to one, and a plurality of repair steel plates 30 may be laminated and attached to the steel plate 23.

Therefore, according to the ship inspection method of the above-described embodiment, the dose is detected by the detection unit 102 at a plurality of positions along the second side surface 20g of the shield 20, thereby shielding at each position. It is possible to determine whether or not radiation streaming is occurring in the body 20. This makes it possible to grasp the position Pz where streaming is occurring with high accuracy. In this way, it is possible to grasp the occurrence state of streaming at the joint portion Z2 or the like of the concrete 24 with high accuracy.

Further, as a result of detecting the dose at a plurality of positions along the second side surface 20 g of the shield 20, when a singular value Lp whose dose detection value is clearly higher than that of other positions is included. , It can be determined that radiation streaming is occurring in the shield 20. This makes it possible to easily determine whether or not streaming is occurring in the shield 20 and grasp the position Pz where streaming is occurring.

Further, in the detection step S22, the radiation source 101 is fixed on the first side of the shield 20, and only the detection unit 102 is continuously moved to a plurality of positions along the surface 20 g on the second side of the shield 20. And detect the dose. As a result, without moving the radiation source 101, only the detection unit 102 is continuously moved to a plurality of positions within the range where the radiation emitted from the radiation source 101 can reach, thereby detecting the dose at a plurality of positions. It becomes possible. When it is attempted to continuously move not only the detection unit 102 but also the radiation source 101 on the first side of the shield 20 with respect to all the positions where the dose should be detected, the first side and the second side of the shield 20 are to be continuously moved. The radiation source 101 and the detection unit 102 must be moved in both of the above. Therefore, it takes a lot of time and effort to perform the detection work at a large number of positions. By moving only the detection unit 102, it is possible to reduce the trouble of performing the detection work at a large number of positions.

Further, in the ship manufacturing method of the above-described embodiment, the dose of the formed shield 20 is detected by the detection unit 102 at a plurality of positions along the second side surface 20 g of the shield 20. This makes it possible to easily determine whether or not radiation streaming is occurring in the shield 20. Therefore, it is possible to grasp the position Pz where streaming is occurring with high accuracy. Further, the radiation shielding performance of the shield 20 at the position Pz where the streaming is occurring is ensured by appropriately performing the repair work of the shielding body 20 or the like in the repair step S4 with respect to the position Pz where the streaming is occurring. be able to.

Further, in the repair step S4, the repair steel plate 30 is attached to the surface of the steel plate 23 at the position Pz where streaming is occurring in the shield 20. As a result, the repair work of the shield 20 can be easily performed, and the radiation shielding performance of the shield 20 can be ensured. Further, by adjusting the thickness of the repair steel plate 30 to be attached, it is possible to appropriately perform the repair work of the shield 20 according to the degree of streaming.

(Other variants)
The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention. That is, the specific shape, configuration, and the like given in the embodiment are merely examples, and can be changed as appropriate.

For example, in the above embodiment, the state of occurrence of streaming at the joint portion Z2 or the like of the concrete 24 is grasped, but the present invention is not limited to this. For example, the streaming that occurs when a gap or the like exists between the concrete 24 and the steel plate 23 can be grasped with high accuracy in the same manner.
The installation position, structure, etc. of the shield 20 can be changed as appropriate. Further, the ship 10 is not limited to the purpose of transporting radioactive waste, and may be used for other purposes.

Vessel 10 may be used for transporting spent nuclear fuel. In the case of the ship 10 carrying spent nuclear fuel, the target radiations are gamma rays and neutron rays. In the case of an inspection targeting a neutron beam, the radioactive source 101 described above may use, for example, a radioisotope ²⁵² Cf (calibornium 252) that emits a neutron beam, and the detection unit 102 can detect the neutron beam. A neutron survey meter or the like may be used. Further, in the case of the application for transporting the used nuclear fuel in this way, the shield 20 described above is replaced with a combination of the steel plate 21 and the concrete 22 or a combination of the steel plate 23 and the concrete 24, and is replaced with the steel plate 21 and the synthetic resin. (For example, paraffin, polyethylene, etc.) may be combined, or the steel plate 23 and a synthetic resin (for example, paraffin, polyethylene, etc.) may be used in combination. In other words, the concretes 22 and 24 of the shield 20 may be replaced with a synthetic resin such as paraffin or polyethylene.

10 Ship 11 Hull 11c Nose 11d Stern 12 Upper deck 14 Side 15 Hold 15a Floor 17 Upper structure 18 Section wall 20 Shield 20A Lower shield 20B Upper shield 20C Side shield 20D, 20Da, 20Db Deck shield Body 20E Superstructure shield 20f First side surface 20g Second side surface 21 Steel plate 22, 22a, 2b Concrete 23 Steel plate 24, 24a, 24b Concrete 25 Rib plate 30 Repair steel plate 101 Radioactive source 101a Source container 101b Transmission Pipe 101c Collimator 102 Detection unit A Section Da Ship nose-tail direction Dv Vertical direction Lp Singularity S1 Shield forming process S2 Shield inspection process S3 Process S4 Repair process S21 Equipment placement process S22 Detection process S23 Judgment process Z1 Joint Z2 Joint Department

Claims (10)

A method for inspecting a ship having a shield formed of a pair of steel plates and concrete placed between these steel plates and shielding radiation from radioactive waste loaded on a hold.
Wherein as to abut the surface of the first side of the shield, the collimator of the radiation source which emits radiation in a predetermined direction are arranged, the detection of radiation so as to abut against the surface of the second side of the shield The equipment placement process for arranging the parts and
The detection in a state where the detection unit is continuously moved to a plurality of positions along the second side surface of the shield and abutted against the second surface of the shield at each of the positions. The detection process that detects the dose in the department and
A determination step of determining whether or not radiation streaming is occurring in the shield based on the detection values at the plurality of positions detected in the detection step, and a determination step.
Inspection method of the ship including. The ship inspection method according to claim 1, wherein the determination step determines that radiation streaming is occurring in the shield when the detection values at the plurality of positions include singular values. In the detection step, the radiation source is fixed on the first side of the shield, and only the detection unit is moved to a plurality of positions along the second side surface of the shield to obtain a dose. The method for inspecting a ship according to claim 1 or 2 for detection. A method for manufacturing a ship having a shield formed by a pair of steel plates and concrete placed between these steel plates and shielding radiation from radioactive waste loaded on a hold.
The shield forming step of forming the shield and the shielding body forming step
A shield inspection step of inspecting the shield by the ship inspection method according to any one of claims 1 to 3.
When it is determined that radiation streaming is occurring in the shield, a repair step of repairing the position where the streaming is occurring in the shield and a repair step.
A method of manufacturing a ship, including. The method for manufacturing a ship according to claim 4, wherein in the repair step, the repair steel plate is attached to the surface of the steel plate at a position where the streaming is generated in the shield. A method of inspecting a ship having a shield formed of a pair of steel plates and concrete placed between these steel plates and shielding radiation from spent nuclear fuel loaded on a hold.
Wherein as to abut the surface of the first side of the shield, the collimator of the radiation source which emits radiation in a predetermined direction are arranged, the detection of radiation so as to abut against the surface of the second side of the shield The equipment placement process for arranging the parts and
The detection in a state where the detection unit is continuously moved to a plurality of positions along the second side surface of the shield and abutted against the second surface of the shield at each of the positions. The detection process that detects the dose in the department and
A determination step of determining whether or not radiation streaming is occurring in the shield based on the detection values at the plurality of positions detected in the detection step, and a determination step.
Inspection method of the ship including. The ship inspection method according to claim 6, wherein the determination step determines that radiation streaming is occurring in the shield when the detection values at the plurality of positions include singular values. In the detection step, the radiation source is fixed on the first side of the shield, and only the detection unit is moved to a plurality of positions along the second side surface of the shield to obtain a dose. The method for inspecting a ship according to claim 6 or 7 for detection. A method for manufacturing a ship having a shield formed by a pair of steel plates and concrete placed between these steel plates and shielding radiation from spent nuclear fuel loaded on a hold.
The shield forming step of forming the shield and the shielding body forming step
A shield inspection step of inspecting the shield by the ship inspection method according to any one of claims 6 to 8.
When it is determined that radiation streaming is occurring in the shield, a repair step of repairing the position where the streaming is occurring in the shield and a repair step.
A method of manufacturing a ship, including. The method for manufacturing a ship according to claim 9, wherein in the repair step, the repair steel plate is attached to the surface of the steel plate at a position where the streaming is generated in the shield.

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