JPS60238796A - Oblique path for fuel transport facility - 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 (Field of Industrial Application) The present invention relates to an improvement of ramps for fuel transfer equipment in nuclear power plants.

(Prior art and its problems) As shown in FIG.
from this fuel transfer cell 3 to the core l of the reactor vessel 1.
slopes 4 and 5 for transferring fuel to the fuel storage tank 2 and the outside fuel storage tank 2, respectively.
are provided, and fuel packets 6 are placed inside the slopes 4 and 5, respectively.
A movable slope 9 is connected to a hoisting device 8 provided in the fuel transfer cell 3 by a chain 7, and a movable slope 9 swings between the extensions of the slopes 4 and 5 in the fuel transfer cell 3. It is.

The spent fuel in the core 18L of the reactor vessel 1 is held by the fuel exchange device 10 and is waiting at the position shown in the figure. On the other hand, the fuel packet 6 is lowered by the hoisting device 8 and slides down the ramp 4 to just below the fuel exchange device 10, and the spent fuel is stored in the fuel packet 6.

The fuel packet 6 containing the spent fuel is lifted up into the movable slope 9 by the hoisting device 8, and then the movable slope 9 is swung and connected to the slope 5. In this state, the fuel packet 6 is slid down and the spent fuel is stored in the extra-core fuel storage tank 2.

The new fuel stored in the ex-core fuel storage tank 2 is stored in a fuel packet 6 by the fuel exchange device 10, and is loaded into the reactor core 1a of the reactor vessel 1 by following the same route in reverse. Once the transfer and exchange of old and new fuel is completed in this way,
The fuel packet 6 is pulled up into the movable slope 9, the slopes 4 and 5 are closed by boat valves (not shown), the movable slope 9 is placed in a vertical state, and the system waits until the next fuel exchange time comes.

By the way, during reactor operation, the temperature at the lower part of the fuel transfer slope 4 connected to the core 1a of the reactor vessel 1 is about 500℃.
℃, and when the reactor is shut down to replace the fuel, this temperature drops to about 200℃ or less. Also, regarding the extra-core fuel storage tank 2, a certain degree of temperature change is unavoidable depending on the amount of spent fuel in the tank.

Because of this temperature change, the ramps 4 and 5 expand and contract due to heat, so consideration is given to absorbing this. That is, as shown in FIG. 4, the guide tube 11, which is the main body of the slope, is divided at the lower part of the slope 4°5, and the other rail 120 is placed at the divided end of the guide tube 11 so as to face each other. rail 1
A joint 15 is provided on which the split end of 2' can slide.

Such a slope configuration can absorb the axial displacement of the rail 12 and improve the safety of the reactor vessel 1 and the extra-core fuel storage tank 2. However, the gap 13 between the divided rails 12' at the bottom of the rail 12 is large, so the fuel packet 6 is attached to the wheel 6a.
When the vehicle travels on the rail 12 through the gap 13 and passes through the gap 13, it receives a large impact.

(Objective of the Invention) The present invention has been made to solve this problem, and it is possible not only to absorb the axial displacement of the slope, but also to absorb the shock even when the fuel packet runs through the divided part at the bottom of the rail. It is an object of the present invention to provide a ramp for fuel transfer equipment that is protected from damage.

(Structure of the Invention) The ramp for fuel transfer equipment of the present invention is a ramp for fuel transfer equipment in a nuclear power plant from the core of a reactor vessel to a fuel transfer cell, and from the fuel transfer cell to an ex-core fuel storage tank. In this method, the lower part of the guide pipe of the slope is divided, the lower part of the channel-shaped rail arranged oppositely in the guide pipe is divided into a plurality of parts, and both sides of each of the divided rails are divided. The present invention is characterized in that a slidable joint with a concave-convex fit is formed in the longitudinal direction of the split end.0 (Embodiment) An embodiment of the ramp for fuel transfer equipment according to the present invention will be explained with reference to FIG. Then, the lower part of the guide pipe 11 of fi1 roads 4 and 5 is divided into a plurality of parts, and the lower part of the channel-shaped rail 12 arranged facing each other in the guide pipe 11 is divided into a plurality of parts, and the lower part of the channel-shaped rail 12 is divided into a plurality of parts. Both sides 12 of each rail 12'
A recess 17 and a protrusion 18 that fit into each other in a recessed and recessed manner are provided in the longitudinal direction of the divided end portion of a, thereby forming a slidable joint 19.

(Function) The fuel transfer slope of the embodiment configured as described above is capable of handling temperature changes in the reactor vessel 1 due to operation and shutdown of the reactor, and temperature changes in the external fuel storage tank 2 due to storage of spent fuel. Expansion and contraction occur due to heat due to changes, but since the guide tube 11, which is the main body of the slope, is divided and separated at the lower part, it can freely expand and contract without any restraint in this separated part.
Further, the rail 12 in the guide tube 11 is divided into a plurality of parts at the lower part, and a recess 17 and a projection 18 are provided on both sides 128 of each divided rail 12, that is, in the longitudinal direction of the wheel passage part, to fit into each other. Since a slidable joint 19 is formed, the joint 19 can freely expand and contract without being restricted in any way. The ramp is therefore capable of absorbing axial displacements.

However, when exchanging old and new fuel, the fuel packet 6 is moved up and down the ramps 4 and 5 via the chain 7 by the drive of the hoisting device 8 (see FIG. 3); 5
Since this is the structure of the fuel transfer slope of the above embodiment, the fuel bucket 6 runs on the rail 12 via the wheels 6a, and the uneven fitting between the divided ends of the lower divided rail 12' is carried out. Since the vehicle travels on the slidable joint 19, it is not subjected to impact.

That is, the channel-shaped rail 120 is divided into a concave portion 17 and a convex portion 18 in which both sides 12a of each divided rail 12 are fitted with concave and convex portions.
Since the wheels 68 of the fuel packet 6 are continuous in the longitudinal direction, the wheels 68 of the fuel packet 6 can run over both sides of the recess 17 and/or the protrusion 18 without falling into the gap between the divided ends of each rail 12. Since it rolls, the fuel packet 6 runs smoothly and is not subjected to impact.

Note that the concave portion 17 and convex portion 18 of the joint 19 in the above embodiment
is rectangular in plan, but may be trapezoidal in plan as shown in FIG.

(Effects of the Invention) As can be seen from the above explanation, the slope for fuel transfer equipment of the present invention has a channel-shaped structure in which the lower part of the guide pipe, which is the slope main body, is divided, and the guide pipe is disposed opposite to each other in the guide pipe. The lower part of the rail is divided into multiple parts, and slidable joints with uneven fitting are formed in the longitudinal direction of the divided ends on both sides of each divided rail, so axial displacement due to heat is prevented. This can be absorbed by the pipe and rail moving relative to each other at the split part, and the wheels of the fuel packet running on the rail can smoothly run over the sliding joint that fits in the unevenness without falling into the gap between the rail split parts. Since it rolls, it does not receive any impact.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main part showing one embodiment of the ramp for fuel transfer equipment of the present invention, Fig. 2 is a perspective view of the main part showing a partially modified example, and Fig. 3 is the fuel transfer equipment of a nuclear power plant. FIG. 4 is a perspective view of a main part showing a conventional slope in a fuel transfer facility. 1...Reactor vessel II! L...Core 2...External fuel storage tank 3...Fuel transfer cell 4.5...Slope
1,1...Guide tube 12...Le/l/12...
Divided rail 12a...Both sides 17...Concave portion 18...Protrusion 19...Joint Applicant: Kawasaki Heavy Industries, Ltd. Applicant: Central Research Institute of Electric Power Industry

Claims (1)

[Claims] In the slope for the fuel transfer equipment of a nuclear power plant from the core of the reactor vessel to the fuel transfer cell and from the fuel transfer cell to the ex-core fuel storage tank, the lower part of the guide pipe of the slope is divided and guided. The lower part of a channel-shaped rail placed opposite each other in the pipe is divided into multiple parts, and a slidable joint with a concave-convex fit is installed in the longitudinal direction of the divided ends on both sides of each divided rail. A slope for fuel transfer equipment, characterized in that a slope is formed.