JPS61223695A - Melter for nuclear fuel - 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 a melting apparatus for melting nuclear reactor fuel, particularly spent metal-coated nuclear fuel.

(Prior Art) Fig. 4 shows a conventional dissolving device, which consists of a cylindrical dissolving tank (barrel) (01) and a flat liquid storage tank (slab) (02). Oj3b) and the gas phase connecting pipe (08c), and is surrounded by a heating jacket (010) having a steam inlet (011) and a steam outlet (012).

An air or oxygen blowing nozzle (04) is provided at the bottom, and a melting material storage basket (basquera) (05) is mounted in the melting tank (01).

In the conventional dissolving tank, air or oxygen blown from the nozzle (04) moves inside the dissolving tank (Ol) in the direction of the arrow (08).
) direction. As a result, the nitric acid, which is the dissolved solution, is carried by rising bubbles such as air and flows upward.
As shown by the arrow (09), it passes through the upper liquid phase connecting pipe (08a) into the liquid storage tank (02), passes through the lower liquid phase lower connecting pipe (oab), and returns to the dissolution tank (01) again. Form a circulating flow.

Therefore, the material to be melted (06) is placed in the material storage M (05) having a large number of through holes, and fresh nitric acid must be successively supplied to dissolve the material to be melted (06). Must be.

(Problems to be Solved by the Invention) The operation of the above-mentioned conventional device is generally carried out through the following steps. That is, a) Loading the material to be melted, that is, spent nuclear fuel, into the basket, b) Setting the basket in the barrel, c) Injecting the melting liquid, d)
Actual lysis, e) Withdrawal of lysate.

and f) removing the basket.

The above operation method is called a batch method, but it takes a lot of time because each step is followed in series.

(Means for Solving the Problems) The present invention has been made in view of the above-mentioned problems, and includes forming the melting region of the melting tank in an annular shape, and dissolving a plurality of material storage baskets at the same time in the melting region. It is configured to be immersed in liquid and continuously moved through these storage areas.

A device for attaching and detaching the storage section newly loaded with the material to be melted and the storage section empty or containing dissolution residue is provided adjacent to the melting tank at a suitable location.

(Example) The present invention will be explained below based on the illustrated embodiments.

In FIG. 1, a melting region (19) formed in an annular cross section by coaxial side walls (15, 17) is sealed on its upper and lower surfaces. Inside the annular melting tank (21), there are a large number of storage sections (i.e., pass scales) (25
) are arranged. The basket (25) has running rails (26) continuously attached to the side walls (15) and (17).
) is placed on the carrier (27) which moves on the carrier (27).
7) are arranged at equal pitches on an annular drive plate (28) located in the upper space within the dissolution tank (21). A sprocket (29) is fixed to the output shaft end of the drive motor (30), and a plurality of teeth (29) provided on the sprocket (29)
m) is a large number of holes (28 m) drilled in the annular drive plate (28).
) meshes with each other. These conditions are.

This is clearly shown in FIG. On the upper outer surface of two sets of basket replacement devices (45) whose surroundings are sealed.

The hoisting motor (82) was installed and penetrated the side wall.
A hoisting drum (88) is attached to the rotating shaft.

The tip of the wire wound on this drum (88) is connected to the hook (31) which is mechanically connected to the upper part of the basket (25).
)have.

The left side of FIG. 1 shows the basket (25) in a rolled up state, and before that it is at the position indicated by the two-dot chain line.

Referring to FIG. 2, the opening (38) located between the basket replacement space (44) and the basket loading/unloading space (48)
) has double door a (42a) and door b (42b).
(However, the opening/closing device is not shown.)

A lid (48) connected to a lid opening/closing cylinder (41) and a lid opening/closing arm (40) is provided on the ceiling of the basket loading/unloading space (48).
89) is provided.

The cylinder for loading and unloading the basket (86) is a piston rod (85) with a fork-shaped arm (85m) attached to the tip.
Equipped with

The operation of the above-mentioned dissolution tank device (20) will be explained.

Carriers (2
A basket (25) filled with materials to be melted, that is, spent fuel rods, is suspended from the basket support (not shown) in 7), and the drive motor (80) is rotated.

This allows the carrier (27) to move on the traveling rail (26) via the drive plate (28) that meshes with the system processor (29).
moves slowly. In other words, Paskella) (25) moves in the solution (28). The inside of the annular melting tank (21) is rotated once in the time it takes for the fuel rods to complete melting, and the pass scaler (25) is stopped at the bottom of the hoisting hook (31) in the basket replacement space (44) (in the figure). (indicated by the two-dot chain line), connect with the hook (31) that has descended. Vasquera)
(25) was pulled up from the solution (28).

Roll it up to the state shown in (25b) in the figure. Next, open the door a (42a) and door b (42b) provided at the basket entrance/exit opening (88), let out the piston rod (35) from the power cylinder (86) for loading/unloading the basket, and press the fork-shaped rod at its tip. The hook (81) is released by hooking the protrusion (84) on the side of (25b) after winding up (35a) and pulling it toward the slot slot (43). After that, door a, door b,
(42a) and (42b) are closed.Next, the lid (39) is opened using the lid opening/closing cylinder (41), and the hook (31) is opened.
) to lift an empty basket or a basket with dissolved residue.

There are two sets of basket attaching/detaching devices (45) as shown in Fig. 2, and the basket (25) filled with unmelted fuel rods is removed from the annular melting tank (21) by taking out the empty basket and reversing the procedure. immersed in a solution (28) of

(Effects of the Invention) According to the present invention, when the storage section containing the material to be melted passes through the annular melting tank once, the material to be melted is dissolved, and the empty basket is taken out and the undissolved material is filled. The baskets are loaded into the tank adjacent to each other using an attachment/detachment device, allowing continuous melting work.

[Brief explanation of the drawing]

FIG. 1 is an elevational cross-sectional view showing nine embodiments of the present invention. FIG. 2 is a plan view taken along line G in FIG. 1. FIG. 3 is a partial perspective view of FIG. 1, and FIG. 4 is an explanatory diagram of the conventional one. 10... Melting device, 15.17... Side wall, 21.
...Dissolution tank. 28...dissolution liquid, 25...basket, 27...
Carrier, 45... Replacement device. JPJ1 diagram,? 3

Claims (1)

[Claims] In a dissolution tank filled with a dissolving solution and a storage basket for dissolving materials detachably installed in the same tank, an annular dissolution tank in which an annular melting area is defined by coaxially arranged side walls, and A large number of storage baskets are mounted on a transport device that rotates inside the tank,
A nuclear fuel melting device characterized by comprising two sets of storage cage attaching/detaching devices attached to the upper part of the tank.