JPH0672952B2 - Spent fuel transportation container - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a shipping container for spent fuel, in particular spent nuclear fuel.

Conventional Technology Conventionally, for example, spent nuclear fuel (hereinafter simply referred to as fuel)
Loading of fuel assemblies into transportation containers is generally performed in a spent fuel pool under water of about 10 m. Therefore, the inner container as shown in FIG. 8 has been used. That is, the thick lid 52 was simply attached to the tubular container body 51 with the bolts 53.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, in a fast breeder reactor, if a damaged fuel should occur, it is carried to a post-irradiation test facility for various tests to investigate the cause of damage. At this time, it is necessary to keep the fuel surface condition as it is for the purpose of investigating the cause of damage, and therefore, do not wash the sodium adhering to the fuel surface,
It will be stored dry in a shipping container. Therefore, the method of loading the fuel assembly in the spent fuel pool in the prior art cannot be used, and it is necessary to adequately shield and seal the lid after performing dry sealing and airtight inspection of the lid. There is.

Therefore, an object of the present invention is to provide a spent fuel transportation container that can solve the above problems.

Means for Solving the Problems In order to solve the above problems, the spent fuel transportation container of the present invention has an enlarged stepped portion at the upper part of the inlet of the fuel storage chamber formed in the inner container inserted into the transportation container body. And forming engagement holes on both sides around the inlet, forming a contact surface for contacting the enlarged stepped portion on the plug closing the inlet, and providing a sealing material for sealing these contact portions, A swinging member having engaging and disengaging engagement protrusions is provided in each of the engaging hole portions, and opposing ends of these swinging members are connected to each other by a center-folding link connected by a connecting pin, The plug is provided with a tubular member connected to the connecting pin so as to be able to move up and down, and a spring body for urging the tubular member upward to project the engaging protrusion of the swinging member to the engaging protrusion. And a lid that closes above the plug. It is a digit.

Operation In the above configuration, after the spent fuel is stored in the storage chamber, the plug is placed on the enlarged step portion. After that, the tubular member provided in the plug is pressed against the spring body by the holding device of the plug, and the engaging protrusion of the swinging member is retracted. By pulling out, the tubular member is biased upward, so that the engaging projection of the swinging member enters the engaging hole of the inner container, and the plug is firmly fixed to the inner container. Of course, the gas inside is sealed by the sealing material, and even if the internal pressure rises, the floating member is prevented from floating due to the engagement of the rocking member. Then, after this, a lid may be used for sealing.

Embodiment One embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, reference numeral 1 denotes a transportation container for spent nuclear fuel (hereinafter referred to as fuel), and an inner container 3 for safely containing the fuel is arranged inside a container body 2. The inner container 3 has a cylindrical storage chamber 5 in which the fuel assembly 4 is inserted and arranged. At the upper part of the entrance of the accommodation chamber 5,
The enlarged step portion 6 is formed. A plug 7, which is an inner lid for sealing the storage chamber 5, is arranged in the enlarged step portion 6.

As shown in FIGS. 2 to 7, the plug 7 is composed of a lower small-diameter portion 8 and an upper large-diameter portion 9 which enter the storage chamber 5, and also has a lower small-diameter portion 8 and an upper large-diameter portion 9. The annular circumferential surface between the two is made into a contact surface 10 that contacts the enlarged stepped portion 6, and a sealing material 11 is arranged on this contact surface 10. Further, a groove 12 having a predetermined width is formed in the central portion of the upper large diameter portion 9 (fifth
A circular hole 13 is formed in the center of the groove 12 as well. Further, in the groove 12, engaging hole portions 14 formed on both sides of the peripheral wall above the enlarged step portion 6 of the inner container 3, respectively.
A mounting member 16 having a pair of swingable members 15 that can be engaged and disengaged is arranged. That is, the plug 7 is provided at the center of the mounting member 16.
A central space portion 18 into which a holding metal fitting 17 (see FIG. 3) of a holding device for holding is inserted is formed, and side space portions 19 are formed on both side portions. The oscillating members 15 each having an engaging projection 15a that can be engaged with and disengaged from the engaging hole portion 14 are oscillatably supported via horizontal pins 20. The swing members 15 are connected to each other via the center-folding link 21 and the connecting pin
The swing member 15 is swung via 22. That is, the lower part is inserted and guided in the hole 13 on the plug 7 side, the upper part is positioned in the central space 18, and the intermediate member is provided with a cylindrical member 23 through which the connecting pin 22 is inserted so as to be able to move up and down. ing. Then, the tubular member 23 and the connecting pin 22
A compression spring (spring body) 24 which is connected to the cylindrical member 23 and urges the tubular member 23 upward is arranged in the hole 13 and, at the horizontal position of the connecting pin 22, the engaging projection of the swinging member 15 is formed. 15a is designed to project into the engaging hole portion 14. Reference numeral 25 is a guide portion of the tubular member 23 provided on the mounting member 16, and 26 is a positioning bolt for the center-folding link 21. Also,
The mounting member 16 has a split structure in assembly, is connected to each other by a connecting bolt 27, and is further mounted on the plug 7 side by a mounting bolt 28. Further, an inner lid 29 and an outer lid 30 that cover the entire storage chamber 5 are provided at the entrance of the inner container 3. Inner lid 29 is bolt 31
With this, a communication hole 32 is formed which is attached to the inner container 3 and communicates the inside and the outside thereof. The outer lid 30 is screwed to the inner container 3, and the outer lid 30 is provided with a coupler 33 for supplying a gas for leak detection to the inner lid 29 side.

The inner container 3 is fixed to the container body 2 by a plurality of engaging claws 34 arranged around it. 35 is the pushing piece.

Next, the operation will be described.

First, after the fuel assembly 4 is housed in the housing chamber 5 of the inner container 3, the plug 7 is held by a holding device (not shown).
At this time, as the holding member 17 of the holding device is inserted into the central space portion 18, the tubular member 23 is lowered against the compression spring 24 as shown by the chain double-dashed line in FIG. The engaging projection 15a of the member 15 is retracted. When the plug 7 is placed on the enlarged stepped portion 6 in this state and the holding metal fitting 17 is pulled out, the tubular member 2 rises and the engaging projection 15a of the swinging member 15 enters the engaging hole portion 14. , The plug 7 is firmly fixed to the inner container 3. Therefore, the radioactive gas inside is sealed by the sealing material 11, and the floating of the plug 7 due to the rise of the internal pressure is prevented by the swing member 15. After this, the inner lid 29
The outer lid 30 may be attached, and the periphery thereof may be welded 36.
Then, finally, the air inside is replaced with helium gas via the coupler 33, and then a gas leak test may be performed. Of course, the plug has a thickness sufficient to shield radiation. When removing the plug 7, the outer lid 30
When the inner lid 29 is removed and the holding metal fitting 17 is inserted into the central space portion 18 of the mounting member 16, the tubular member 23 is pressed and the swing member 15 is disengaged from the inner container 3 and the plug 7 is removed. It is ready to be removed.

As described above, according to the configuration of the present invention, since the plug that seals the storage chamber is provided, it is possible to sufficiently shield radiation and radioactive substances. Carefully, an operator can approach the lid of the inner container and perform a dry sealing operation and airtightness inspection.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention.
FIG. 2 is an overall sectional view, FIG. 2 is an essential sectional view, FIG. 3 is an essential sectional view for explaining the operation, and FIG. 4 is an AA sectional view of FIG.
5 is a sectional view taken along the line BB in FIG. 3, and FIG. 6 is a sectional view taken along the line C- in FIG.
C sectional view, FIG. 7 is a DD sectional view of FIG. 3, and FIG. 8 is an overall sectional view of a conventional example. 2 ... container body, 3 ... inner container, 5 ... storage room, 6 ...
Enlarged step, 7 ... Plug, 10 ... Contact surface, 11 ... Seal material, 14 ... Engagement hole, 15 ... Swinging member, 15a ... Engagement projection, 21 ... Center bent link , 23 …… Cylindrical member, 24 …… Compression spring, 29 …… Inner lid, 30 …… Outer lid.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Uruwashi 4002 Narita-cho, Oarai-cho, Higashi-Ibaraki-gun, Ibaraki 4002 Power Reactor and Nuclear Fuel Development Corporation Oarai Engineering Center (72) Takahisa Nakatani 1 Edobori, Nishi-ku, Osaka-shi, Osaka 6--14, Hitachi Shipbuilding Co., Ltd. (72) Tsutomu Matsumoto 1-6-14, Edobori, Nishi-ku, Osaka-shi, Osaka Prefecture In-house Hitachi Shipbuilding Co., Ltd. (72) Ken 6-saw, Edobori, Nishi-ku, Osaka-shi, Osaka Prefecture No. 14 Hitachi Shipbuilding Co., Ltd. (56) Bibliographic references Sho 56-110396 (JP, U)

Claims (1)

[Claims] 1. An enlarged stepped portion is formed at an upper portion of an inlet of a fuel storage chamber formed in an inner container to be inserted into a main body of a transportation container, and engaging hole portions are formed at both side portions around the inlet. A plug is provided with a contact surface that contacts the enlarged stepped portion, and a sealing material that seals the contact portion is provided, and the plug has engaging protrusions that can be engaged and disengaged with the engagement holes. An oscillating member is provided, and opposite ends of each of the oscillating members are connected to each other by a center-folding link connected by a connecting pin, and a tubular member connected to the connecting pin is provided on the plug so as to be able to move up and down. At the same time, a spring body for urging the tubular member upward to project the engaging projection of the swing member to the engaging projection is provided, and a lid for closing the plug is provided. Fuel transport container.