JP2941845B2 - Radioactive waste inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a radioactive waste inspection facility for performing various inspections required to carry out a radioactive waste generated at a nuclear power plant or the like outside a facility.

[Prior art] Radioactive waste generated at a nuclear power plant or the like is solidified by a solidifying agent such as cement into a stable state and then stored and stored on the site of each power plant. It is planned to take the body off site and centrally manage and dispose of it. In order to implement this, it is necessary to confirm that the target waste meets certain requirements for burial for transportation and disposal.

Regarding the requirements for waste solidified in 200 drums of radioactive waste, etc., refer to the Prime Minister's Ordinance “Rules on the Project for the Burial of Nuclear Fuel Materials, etc.” and the Notification of the Science and Technology Agency “ The "Notice on Measures, etc." and the like indicate the extent to which waste is buried, and the laws and regulations, such as the Reactor Regulation Law and the Enforcement Order, indicate the extent to which waste can be transported.

Based on these laws and regulations, it is considered necessary to conduct inspection work to confirm that the waste discharged from facilities such as nuclear power plants satisfies some requirements. It is thought that it is necessary to confirm the following items and the like, when concretely illustrating.

(1) Weight of waste (2) Surface contamination density (3) Surface / m dose rate (4) Radioactivity concentration (5) Uniaxial compressive strength of cement solidified ing.

It will take a considerable amount of time to carry out the series of inspections described above for each waste body. Although the quantity is somewhat different for each business establishment, the number is quite large, from several thousand to several tens of thousands, so that it is required to perform an efficient inspection operation and improve the inspection processing capacity.

As a means to improve the inspection processing capacity of waste, a method of arranging a plurality of inspection devices in a series and making them work in parallel or a method of making parallel work by using multiple inspection devices for those that require time for inspection items etc. Is being considered.

[Published by Nikkan Kogyo Shimbun, Nuclear Industry 1989 (Vol. 35, No. 4
No.), pp. 60-64, “Techniques for Unloading and Inspection of Low-Level Radioactive Waste”] [Problems to be Solved by the Invention] However, some wastes that are subject to inspection are out of the scope by inspection. Assuming that
In the above method, when these non-standard wastes are excluded as a result of the inspection, there is a concern that the processing capacity of the entire inspection apparatus is reduced by that much. What is called non-standard here is not a defect. For example, at present, the surface dose rate of the waste body is above a certain standard, so it is necessary to consider using a special shielding container. This is mainly used to refer to wastes and the like that can be rationally transported out several years later due to the attenuation effect of radioactivity.

If wastes are sequentially provided to an inspection device composed of a plurality of inspection equipment as in the above technology, and assuming a case where the wastes are found to be out of regulation in the last inspection item, Most of the inspection work and the time required for them are wasted, so that the processing capacity of the entire inspection apparatus is reduced and the work efficiency is deteriorated.

As described above, the above technology does not take measures to prevent a reduction in the processing capacity of the entire inspection apparatus due to the generation of an unspecified waste body in a series of inspection work, and as a result of the inspection, However, there is a problem that the efficiency is inevitably reduced as the number of wastes increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a radioactive waste inspection facility that can be executed without deteriorating the processing capacity of the entire inspection apparatus even if a waste out of the specified range is generated by the inspection.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a radioactive waste inspection facility described in the claims.

[Operation] In the inspection equipment described in the claims, inspection equipment corresponding to the inspection item that is most likely to be determined as a non-regulated waste in a series of inspection work is installed at the most upstream side of the inspection line. This makes it possible to improve the efficiency of inspection equipment by finding out-of-spec wastes as early as possible, and excluding the wastes from a series of inspection steps and collecting them separately. In particular, if the surface dose rate is high and there are many wastes that need to be handled according to transportation standards, etc., the inspection equipment installed on the most upstream side of the inspection line should be a device that roughly measures the surface dose rate of the wastes. Before conducting a series of full-scale detailed inspections after that, by separating and excluding it, it is possible to improve the efficiency of search work and standardize the means to carry out in-standard waste from inspection equipment. It can be used as a means to carry out external waste and is simplified in terms of equipment.

[Embodiment] An embodiment of the present invention will be described below with reference to Fig. 1. Fig. 1 shows a radioactive waste generated in a nuclear power plant or the like.
The following shows the inspection items and inspection procedures for confirming the soundness of the waste generated by solidifying it in a 200-drum can when it is carried out from a facility such as the nuclear power plant.

The waste body (drum) is first subjected to inspection by an inspection device (ionization chamber type measuring instrument, etc.) that measures the approximate surface dose rate, and whether the approximate surface dose rate of the waste body is below a predetermined level. Is determined (step). This is done from the following perspectives. In other words, as a method of transporting the waste from which various inspections have been completed and its soundness has been confirmed out of facilities such as a nuclear power plant, for example, it is conceivable to put the waste into a container or the like capable of storing eight wastes. However, in order for the surface dose rate of the container to be kept below a certain value in accordance with the transport regulations when these are stored in a container, the surface dose rate of the individual waste to be stored in the container must be adjusted. It is necessary to set the value to a predetermined value or less in advance. For this purpose, the approximate surface dose rate of the waste body is measured at the beginning of the inspection process as described above. Then, the waste body whose measured value is equal to or less than the predetermined value and which is determined to be able to be stored in the eight containers is continuously provided to an inspection process following the next process. On the other hand, if the surface dose rate exceeds a predetermined value and is stored in a transport container having another shielding function instead of the eight containers, or is continuously stored and stored, the surface dose due to the radiation attenuation of the waste itself is reduced. Wastes for which it is deemed appropriate to wait for the rate reduction are sorted and excluded without going through a series of inspection steps following the next step.

For the waste that was determined to be less than or equal to the predetermined value in the above-mentioned approximate surface dose rate measurement process and that was subjected to the inspection process following the next process, as a full-scale inspection for soundness confirmation, details Measurement of surface dose rate (surface / 1m), surface contamination density (measured by smear method), waste weight and nuclide analysis (radioactive concentrations of various radioactive materials in waste) are performed. In addition, for wastes solidified in containers (drums) using radioactive waste as cement solidified material, confirm that they have a uniaxial compression concentration of 15 kg / cm ² or more, which is required by the standard. Inspection is also performed.

In the present embodiment, these tests are performed by distributing the functions for each test and forming a series. However, a method in which two or more tests are collectively performed may be considered.

In each of the inspection processes described above, a waste body determined to be out of the standard in any of the inspections is not sent to the next inspection process, but is separately collected and temporarily stored. After a series of inspection work is completed, the temporarily stored sorted waste is palletized to distinguish it from the waste determined to be within the standard in all inspections.

A waste body determined to be within the standard in all the inspections is sent to a labeling process, and operations such as attaching a color band display or the like according to a predetermined radiation dose rate to the waste body are performed.

In FIG. 1, the time shown on the left side of each inspection step and the steps such as labeling indicate the time required for performing the work in each step.

FIG. 2 shows an example of a specific configuration of a facility for performing a waste body inspection described in FIG. Hereinafter, the inspection equipment of the present embodiment will be described with reference to FIG.

The waste 2 formed by solidifying radioactive waste in 200 drum cans is placed on a pallet 3 which collects wastes usually used for storage and storage in a power plant in units of four, and the inspection apparatus according to the present embodiment. Supplied to The waste 2 transported together with the pallet 3 by a not-shown forklift or the like is moved by the pallet conveyor 1 to a position where the waste lifting device 4 is joined, and the waste 2 is palletized at a predetermined position by the lifting device 4. Is transferred to the waste conveyor 5. The waste body 2 transferred to the waste body conveyor 5 is moved by the waste body conveyor 5 and stopped at a predetermined position with respect to the surface dose rate measuring device 21. The waste 2 whose surface dose rate is measured by the rough surface dose rate measuring device 21 and is determined to be equal to or less than the predetermined value is moved again by the waste conveyor 5 and the next inspection equipment is the surface contamination density / detailed surface dose. It is provided to the rate measuring device 22.

On the other hand, the waste body 2 determined that the surface dose rate measured by the approximate surface dose rate measuring device 21 is equal to or more than a predetermined value,
Without being supplied to the surface contamination density / detailed surface dose rate measuring device 22, the waste is separated and temporarily stored in a separation waste conveyor 6 from a branch point provided in the middle of the waste conveyor 5.

All the wastes 2 to be inspected are sequentially sorted by the above operation so that the surface dose rate is equal to or more than a predetermined value.

The waste 2 which has been inspected by the surface contamination density / detailed dose rate measuring device 22 is sequentially transferred to the weight measuring device 23, the nuclide analysis measuring device 24 and the uniaxial compressive strength measuring device 25 by the same operation by the waste conveyer 5. Then, a series of inspection work for confirming the soundness of the waste 2 is completed. After that, the waste 2 is moved to the labeling device 26 by the same operation, and a work such as attaching a color band display or the like according to a predetermined radiation dose rate to the waste 2 is performed, and all the work is completed. . However,
Waste that is determined to be out of specification in any of these inspection processes is separated as described below without being subjected to subsequent inspection and labeling.

The waste 2 completed up to the labeling operation is moved from the waste conveyor 5 to the waste return conveyor 8 by the waste lateral movement conveyor 7, and is returned to the waste lifting device 4 by the return conveyor 8. After being moved into position,
The waste is lifted by the waste lifting device 4 and transferred to the pallet 3 set on the pallet return conveyor 10.

Here, the pallet 3 for transferring the waste 2 is placed on the pallet conveyor 1 for the inspection work.
The pallet that has been emptied after providing the pallet is slid from the pallet conveyor 1 to the pallet return conveyor 10 so that the pallets can be supplied without excess and deficiency.

The waste 2 determined to be out of standard in any of the inspection processes from the surface contamination density / detailed dose rate measuring device 22 to the uniaxial compressive strength measuring device 25 does not undergo any further inspection and labeling work. Then, the waste is conveyed to a sorting waste conveyor 6 through a waste conveyor 5, a waste lateral moving conveyor 7, a waste returning conveyor 8, and a non-standard waste conveyor 9 branched from the middle.

The waste 2 separated into the separated waste conveyor 6 by the rough surface dose rate measuring device 21 and the inspection process from the surface contamination density / detailed surface dose rate measuring device 22 to the uniaxial compression strength measuring device 25 are out of specification. The one or more waste bodies 2 separated into the separated waste body conveyors 6 through the conveyors 5, 7, 8, and 9 are determined to be a predetermined number of standard waste bodies that have been subjected to a series of inspection operations. After being collected by the pallet 3 by the waste lifting apparatus 4 and carried out by the pallet return conveyor 10, the separated waste conveyor 6 and the nonstandard waste conveyor 9 are discarded by reversing the above-mentioned separation work. It is returned to the body return conveyor 9. Thereafter, the non-standard wastes are transferred to the pallet return conveyor 10 by the same operation as the above-mentioned standard wastes.
Collected on the upper pallet 3.

Here, in order to separate and collect the in-standard waste and the out-of-standard waste in pallet units, it is desirable to control the pallets so that each pallet has an integral multiple of the number of waste bodies (four in this embodiment).

In this embodiment, a roller conveyor type such as a waste body conveyor 5 is used as a waste body moving means. However, the moving means is not limited to the roller conveyor type, and a hoist or a waste body with a waste body gripping tool is used. It is also possible to adopt a thing like a cart with a gripper.

Next, FIG. 3 shows a time chart of an inspection operation in the waste body inspection apparatus having the configuration shown in FIG. In the figure, the waste bodies (drum cans) indicated by,, etc. are subjected to a series of inspections and operations of Nos. 1 to 6;
Wastes determined to have a dose rate higher than the specified value in the rough surface dose rate measurement in o.1 will be inspected in No.7
Separated into nonstandard drum storage. In the rough surface dose rate measurement, since the time required for inspection per waste body is shorter than the inspection time that is rate-limiting in the following inspection process, it is assumed that two to three consecutive waste doses are determined to be out of specification. Even if there is a body, it is possible to absorb it during play time, so that it is possible to keep the processing capacity of the entire inspection apparatus without lowering.

[Effects of the Invention] According to the present invention, nonstandard wastes can be detected and separated and collected as early as possible in a series of inspection processes. Even in a situation where a considerable amount of wastes are mixed, the processing efficiency of the waste inspection equipment is not reduced, so that the maximum efficiency can be ensured. Furthermore, the separated and collected nonstandard wastes can be carried out of the inspection equipment by using the transportation means for unloading the wastes within the specification, so that the equipment can be simplified.

[Brief description of the drawings]

FIG. 1 is an inspection flow of an embodiment of the present invention, FIG. 2 is a perspective view of the inspection equipment, and FIG. 3 is a time chart of the inspection work. DESCRIPTION OF SYMBOLS 1 ... Conveyor for pallet transfer 2 ... Waste, 3 ... Pallet 4 ... Conveyor for waste disposal 5 ... Conveyor for waste disposal 6 ... Conveyor for sorted waste 7 ... Conveyor for lateral movement of waste 8 …… Conveyor for returning wastes 9 …… Conveyor for non-standard wastes 10 …… Conveyor for returning pallets 21 …… General surface dose rate measuring device 22 …… Surface contamination density and detailed surface dose rate measuring device 23 …… Weight measurement , 24… nuclide analyzer 25… uniaxial compressive strength meter 26… labeling device

Claims (2)

(57) [Claims] 1. A radioactive waste inspection system for performing a necessary inspection on a waste obtained by immobilizing a radioactive waste in a container such as a drum can to carry the waste out of a storage facility. A plurality of inspection devices sequentially arranged in a line, transportation means for sequentially transporting wastes between these inspection devices, and all non-regulated wastes determined to be out of specification by at least one inspection device. A separate transport means for separating and collecting from the regulated waste determined to be within the provisions in the inspection equipment, and corresponds to the inspection item with the highest possibility that the waste is determined to be outside the provision. In the radioactive waste inspection equipment where the inspection equipment is installed on the most upstream side of the inspection line, the specified waste determined to be within the specification by all the inspection equipment is carried out from the inspection line to outside the inspection equipment The separation and transportation means, the classified and collected non-standard wastes, the specified waste in all the inspection equipment is determined to be within the specified waste by the export and transportation means, A radioactive waste inspection facility that can be transported to the above-mentioned transportation means after being carried out of the inspection facility. 2. The radioactive waste inspection equipment according to claim 1, wherein the inspection equipment installed on the most upstream side of the inspection line is an equipment for measuring the surface dose rate of the waste in advance.