JPH035919Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field to which the idea belongs]

This idea is useful for stopping nuclear power supplies, such as a stopper device for fuel buckets that move within a transfer assute, which is installed outside the transfer astute between the fuel exchange pool in the reactor containment vessel and the external fuel storage pool. The present invention relates to the configuration of a stopper device that is installed in a pressure vessel that constitutes an equipment section in a furnace facility and performs locking and release operations for a moving object moving within the pressure vessel.

[Prior art and its problems]

A stopper device installed in a pressure vessel, such as the above-mentioned transfer shaft, which constitutes the second type equipment category in nuclear reactor equipment, is used to prevent the leakage of radioactive materials. It is required that a highly reliable boundary be formed that isolates the inside and outside. Next, FIG. 2 shows the structure of a conventional stopper device constructed in response to the above requirements. In FIG. 2, 1 is the above-mentioned transfer shoot that constitutes the second type of equipment classification in the nuclear reactor equipment, and 2
is a stopper device which is the subject of this invention, and the stopper device is installed on the outer wall surface of the transfer assembly 1, and is constructed so that the stopper portion thereof can be moved in and out of the transfer assembly 1 side.
Here, the stopper device 2 includes an outer cylinder 3, a flange 4 of the cylinder, an operating rod 6 having a piston 5 penetrating the flange 4 and disposed inside the cylinder, and a stopper portion 7 formed at the tip of the operating rod. , a spring 8 that always projects and biases the stopper part 7 toward the inside of the transfer shaft, and double inner and outer bellows 9 and 10 stretched between the piston 5 and the cylinder end plate are assembled as main parts. It consists of an inner and outer bellows 9 and 1.
0 as a pressurized space, and a liquid introduction pipe 11 that uses pressurized water as a working liquid is connected thereto, and the inner circumferential space of the inner bellows 9 communicates with the inside of the transfer shaft 1. It fits. In addition, the operating rod 6 is attached to the valve stem 6a in the part where it passes through the flange 4, and the through hole on the flange side is inserted into the valve seat 4.
A valve mechanism denoted by a is constructed. Note that 12 is an intermediate connecting fitting interposed between the bellows 9 and 10. With this configuration, during normal operation of the reactor, pressurized water is not introduced into the cylinder, and the operating rod 6 is biased by the spring 8 to project the stopper portion 7 into the transfer shaft to maintain the stopper in the operating state. There is. In this state, the rod which also serves as a valve stem is pressed against the valve seat of the flange 4 to seal the opening thereof, and this valve mechanism portion forms the boundary of the transfer. On the other hand, when transferring fuel through the transfer assute 1, the stopper device is operated in and out in accordance with the transfer operation of the fuel bucket moving inside the transfer ascent, and the stopper unit 7 is operated backward when transferring the fuel bucket. to allow the passage of the fuel bucket,
Otherwise, the stopper portion 7 is protruded to hold the fuel bucket in a predetermined position. This retraction operation of the stopper is performed by introducing pressurized water into the cylinder through the pressurized water introduction pipe 11 described above and moving the operating rod 6 to the right against the spring 8. Therefore, in this case, the above-mentioned valve mechanism opens and communication is established between the transfer chute 1 and the inside of the cylinder. It will form and cut off the inside and outside of it. By the way, the conventional structure described above has been found to have the following problems from long-term operation results. In other words, in the conventional configuration shown in FIG. 2, dual bellows 9 and 10 are arranged inside the cylinder to form a boundary on the transfer shaft side and to define a pressurized space for introducing pressurized water. Regarding No. 9, when the cylinder is operated, a large pressure difference due to pressurized water for operation acts between the inside and outside of the cylinder, so excessive stress is applied to the bellows, which may cause fatigue and breakage during long-term use. Regarding the outer bellows 10, this bellows 10 is prone to buckling because the operating pressurized water acts on the inner circumferential surface, and once buckling occurs, it locally contacts the inner wall surface of the cylinder and this Therefore, the amount of expansion and contraction of the bellows becomes uneven, generating excessive stress, which may eventually lead to breakage. An even more serious drawback is that if either the inner or outer bellows is damaged during cylinder operation, the pressure of the operating pressurized water will be lost and the stopper will no longer be able to be operated backwards, making it difficult to subsequently transfer the fuel bucket into the transfer shaft. This will cause a serious problem in which the fuel cannot be recovered during the transfer.

[Purpose of invention]

This idea was developed in consideration of the above points, and improved the structure of the conventional device to eliminate the above-mentioned drawbacks, construct a highly reliable boundary, and in the event of an emergency situation in which the bellows is damaged. To provide a stopper device in which the stopper can be operated backward even when the stopper is operated backwardly.

[Key points of the idea]

In order to achieve the above object, this invention comprises a cylinder including an outer cylinder and an inner cylinder, and the inner cylinder provided inside the outer cylinder;
A boundary chamber and a pressurized chamber for introducing working fluid are defined inside and outside the inner cylinder, and a boundary of the pressure vessel is formed by extending between the inner cylinder and the operating rod in the boundary chamber. This structure isolates the boundary chamber from the pressurized chamber to which the working fluid is applied, preventing high working fluid pressure from acting on the bellows, thus preventing the bellows from being damaged in the event of damage. Even in the event of an emergency situation, the stopper can be operated backward without affecting the cylinder operation.

[Example of idea]

FIG. 1 shows the structure of an embodiment of this invention, and the same members as in FIG. 2 are given the same reference numerals. In other words, in FIG. 1, the difference from the conventional structure is that the inner cylinder 13 is interposed and sealed between the flange 4 and the operating rod 6 on the side closer to the flange 4 than the piston 5 inside the outer cylinder 3. On the outer circumferential side of the inner cylinder 13 with this inner cylinder 13 as a boundary, there is a pressurized chamber 14 into which working fluid is introduced into a space surrounded by the outer cylinder and the piston 5, and there is also a boundary inside the inner cylinder 13. A chamber 15 is defined, and within the boundary chamber 15, a bellows 9 that forms a boundary on the pressure vessel 1 side is stretched between the inner cylinder 13 and the flange 6b of the operating rod. Furthermore, bellows 9
The inner circumference side space is a communication hole 1 opened to the operating rod 6.
6 and a hole 3a opened in the outer cylinder 3 to communicate with the atmosphere outside the pressure vessel. The operation of the stopper in the above configuration is similar to that in the conventional configuration, and the stopper portion 7 normally projects into the pressure vessel 1 by the biasing force of the spring 8 to restrain the fuel bucket moving inside the vessel. Further, the stopper is released by introducing pressurized water into the pressurizing chamber 14 from the outside and moving the operating rod 6 backward to the right against the spring 8. In this state, the pressure vessel A side boundary is formed by the bellows 9 to isolate the inside and outside of the pressure vessel. Further, according to the above configuration, since the inner cylinder 13 is provided to isolate the pressurizing chamber 14 and the boundary chamber 15, the pressure of pressurized water does not act on the bellows 9 in the boundary chamber 15. In addition, the pressure within the pressure vessel 1 acts on the outer circumferential side of the bellows 9. Therefore, first of all, when looking at the bellows 9, since the pressure on the pressure vessel side acts as an external pressure on the bellows, a self-aligning effect works, and there is no risk of buckling occurring in the bellows. Since the high pressure of pressurized water as a working fluid does not act on the bellows, there is no risk of excessive stress being applied to the bellows, and the influence of aging deterioration of the bellows can be suppressed to that extent, allowing the soundness of the bellows to be maintained for a long period of time. Another great feature is that even if the bellows 9 were to break, the pressure chamber 14 and the boundary chamber 15 are isolated by the inner cylinder 13, so the stopper can be moved back without loss of pressure of the pressurized water. Therefore, even in this emergency situation, it is possible to recover the fuel that is being transferred inside the pressure vessel. Although the illustrated example shows a stopper device for a transfer, it goes without saying that the present invention can be similarly applied to stopper devices installed at other locations of nuclear reactor equipment.

[Effect of the idea]

As described above, according to this invention, a boundary chamber is defined which is isolated from the pressure chamber in which the working fluid is introduced into the cylinder, and on which no working fluid pressure acts, and the bellows is disposed within the boundary chamber to reduce the pressure. By forming a boundary between the inside and outside of the vessel, the bellows that forms the boundary of the pressure vessel will not be subjected to excessive pressure during normal use, and in the event that the bellows breaks, You can also perform stopper release operations, etc.
It is possible to provide a stopper device that provides superior effects in terms of reliability and functionality compared to conventional configurations.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views of an embodiment of this invention and a conventional stopper device, respectively. In the figure, 1... pressure vessel, 2... stopper device, 3...
Outer cylinder, 4...flange, 5...piston,
6... Operating rod, 7... Stopper portion, 8... Spring, 9... Bellows forming a boundary, 13... Inner cylinder, 14... Pressurized chamber for introducing working fluid, 15... Boundary chamber.

Claims (1)

[Scope of utility model registration request] A device that is installed on the outside of a pressure vessel that constitutes an equipment section in a nuclear reactor facility, forms the boundary of the pressure vessel, and locks a moving object that is transferred into the pressure vessel by operating its stopper portion in and out of the pressure vessel. , a stopper device for releasing, which is equipped with a cylinder with a piston that operates the stopper part by controlling the pressurization of the working fluid, and is configured so that a bellows built into the cylinder forms a boundary on the pressure vessel side. The cylinder is composed of an outer cylinder and an inner cylinder, and an operating rod with a piston is arranged to penetrate through a flange of the outer cylinder and has a stopper portion formed at its tip, and a piston-equipped operating rod that extends in a direction in which the stopper portion protrudes from the flange. a spring that biases the operating rod; an inner cylinder connected at one end to the flange side and provided in the outer cylinder; a boundary chamber defined inside and outside the inner cylinder with the inner cylinder as a boundary; and a working fluid introduction. and a bellows extending between the inner cylinder and the operating rod in the boundary chamber to form a boundary of the pressure vessel, and pressurizing the outer space with the bellows as a boundary. A stopper device for nuclear reactor equipment, characterized in that the inner space on the vessel side is communicated with the atmosphere outside the pressure vessel.