JPS63159796A - Vessel for storage combining transport of radioactive substance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a container for transporting and storing radioactive materials whose lid can be reliably sealed for a long period of time.

(Prior Art) Containers for transporting and storing spent fuel generated at nuclear power plants and the like are stored for a long period of time at a predetermined storage location while containing the spent fuel. For this reason, it is necessary to ensure a long-term seal, and the lid must be removable in case it becomes necessary to reprocess the fuel in the one-way section. Conventionally, as a structure of a container meeting such requirements, as shown in Japanese Patent Laid-Open No. 57-136198, for example, a structure in which an inner and outer double lid is attached to a sealing structure with a gasket is known. This structure has a problem in that if leakage occurs in the seals of the inner and outer lids, the leakage cannot be prevented.

(Purpose of the Invention) This invention was made in order to eliminate such conventional drawbacks, and even if leakage occurs at the sealing portion of the double-layered lid, it can prevent leakage. It provides a container for transporting and storing radioactive materials.

(Structure of the Invention) In this invention, a double lid, an inner lid and an outer lid, is attached to the opening of a bottomed metal cylindrical container body for storing radioactive materials, and the inner lid and the outer lid are different from each other. Each is attached with a sealing structure via a gasket with the end surface of the main body as a contact surface, and the outer cover has a flange that protrudes to the outer periphery. It is held in place by pressing in the direction.

In the above configuration, it is preferable to form a continuous weld groove in the circumferential direction on the flange so that the flange and the end face of the main body can be sealed from the outside by welding, because welding can be performed more easily. .

With the above configuration, if necessary for fuel reprocessing, the inner and outer lids can be removed to take out the fuel inside, and if leakage occurs at the seals of the inner and outer lids, the outer lid can be removed. Leakage can be prevented by seal-welding the outside of the flange to the end face of the main body.

(Example) In Fig. 1, a container body 1 made of a forged product such as carbon steel
is formed into a cylindrical shape with a bottom, and an inner M4 made of the same material as the main body is attached to the opening thereof, and an outer L (protective cover) 5 is attached to the outside thereof.

Further, a neutron shielding material 2 is placed on the outer periphery of the main body 1 so as to be covered by an outer cylinder 3, thereby forming a shielding layer.

A heat transfer member (fin) 30 for transmitting heat from the main body 1 to the outer cylinder 3 is arranged in the neutron shielding material 2 .

A neutron shielding material 40 is also attached to the outer surface of the inner lid 4. 11 is a trunnion used as a handle when transporting the container.

As shown in FIG. 2, the outer circumference of the inner M4 has a gasket 44.
It is crimped to the end face of the main body 1 via the cylindrical body 1 and is tightened with a bolt 42. Further, the outer lid 5 has a flange 50 attached to the outer periphery of the end plate, the flange 50 protruding outward from the end plate, and a gasket 51 is held on the end face of the flange 50.

The flange 50 is pressed down in the direction of the end face with the holding member 7, and this end face is crimped onto the end face of the main body 1, thereby being attached in a sealing structure. The presser members 7 are fixed to a plurality of locations on the end surface of the main body 1 in the circumferential direction with bolts 70 at appropriate intervals. Further, the flange 50 has a welding groove 52 continuous in the circumferential direction on the outer peripheral surface so that the space between the flange 50 and the end surface of the main body can be sealed by welding from the outside.
is formed.

The seal portion of the inner lid 4 is monitored for leakage by a checking means (not shown).

In the above configuration, the inside of the container body is sealed by the seal portions of both the inner lid 4 and the outer lid 5. When it becomes necessary to take out the fuel stored inside the main body 1 for reprocessing, the inner 14 and outer M5 can be removed and opened by removing both bolts 42.70.

In addition, if a leak occurs in the seals of both the inner and outer lids 4 and 5 during long-term storage, or if a leak occurs in the seal part of the inner M4 and double sealing is no longer possible, please refer to Figure 3. Then, as shown in FIG. 4, the groove 52 is seal-welded (welded portion 53). This welding can be performed by welding the groove 52 between the presser members 7 with the presser member 7 attached, and then by removing the presser member 7 and welding the groove 52 in that area.

This makes it possible to reliably prevent leakage at the welded portion 53.

In addition, in order to inspect the leakage of this welded part 53, a conical seal plate 9 is attached to the outer peripheral part of the flange 50.
A space 92 having a triangular cross section can be formed in an annular shape between the flange 5o and the outer peripheral surface of the flange 5o. Also, flange 5
0 is formed with a communication path 55 that communicates with this space 92, and communicates with a helium filling tank 90 through this communication path 55, and a pressure sensor 99 is installed in the helium filling tank 90.

In this configuration, the space 92 is maintained at the same pressure as the helium filling tank 90, so if a leak occurs at the welding part 53, the pressure inside the helium filling tank 90 will fluctuate, and this pressure fluctuation will It can be detected by a pressure sensor 99.

(Effects of the Invention) As explained above, the present invention provides a double lid, an inner and outer lid, and performs a single double seal with the gasket seal portions of the lid, and also provides a seal between the flange of the outer lid and the end surface of the main body. It is designed to be sealed from the outside by welding, and if necessary, the inner and outer lids can be removed to take out the fuel inside, and if a leak occurs at the seals between the inner and outer lids, the fuel can be removed from the outside. By seal-welding the outside of the lid to the end face of the main body, leakage can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of the entire container showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the sealing portions of the inner and outer lids, and FIG. 3 is a sectional view of the outer lid in a welded state. FIG. 4 is an enlarged sectional view of the flange portion. 1... Container body, 4... Inner lid, 5... Outer lid, 44
．． 51... Gasket, 50... Flange, 42.
70... Bolt, 52... Bevel, 53... Welded part. Patent Applicant: Kobe Steel, Ltd. Société Poole, Transport de Lindastry Nuclairs, Transnuclair Agent, Patent Attorney: Etsushi Kotani
Patent Attorney Chief 1) Masayuki Patent Attorney Yasuo Itaya Figure 1 Figure 2

Claims (1)

[Claims] 1. A double lid consisting of an inner lid and an outer lid is attached to the opening of a bottomed metal cylindrical container body for containing radioactive materials, and the inner lid and the outer lid are each The end surface of the main body is attached as a sealing structure via a gasket with the end surface as the contact surface, and the outer cover has a flange that protrudes to the outer periphery. A container for transporting and storing radioactive materials, characterized by being pressed and fixed by a container. 2. The radioactivity according to claim 1, characterized in that the flange is formed with a continuous weld groove in the circumferential direction so that the flange and the end surface of the main body can be sealed by welding from the outside. Container for transport and storage of substances.