JPS5811894A - Device for storing spheric fuel element - 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] The present invention relates to a containment device for containing spherical fuel elements.

This type of storage device temporarily stores fuel elements discharged from the core of a nuclear reactor system, and is already generally known. This type of containment equipment has a value of effective multiplication factor (k) of
The range ff of ff≦0.9 is configured so as not to exceed the range ff. To fully satisfy this requirement, absorber rods can be placed between all fuel elements.

Of particular importance is that when the core is emptied, all spherical fuel elements within the core can be accommodated by the containment system. Absorption rods are also necessary in cases where the containment device is partially or completely flooded by water ingress. These absorber rods are of particular importance in the event of a failure, when the core of a nuclear reactor must be emptied and, at the same time, water intrusion occurs in the accommodation of the fuel elements.

It is an object of the present invention that both the burnt fuel elements discharged from the reactor during normal operation, and also the fuel elements that are partially burnt with varying degrees of burnout and suitable for recharging when emptying the core. Similarly, it is an object of the present invention to provide a storage device for fuel elements in a high-temperature nuclear reactor that can accommodate fuel elements while maintaining a subcritical state.

The above object is achieved in the accommodation device of the present invention as follows. That is, the spherical fuel elements discharged from the core of the nuclear reactor are distributed by the distribution means depending on their combustion state.
5- configured to be guided into one of at least two silos for containing combusted fuel elements and into one of at least ten wells for containing partially combusted fuel elements; , a spherical absorption element is added to the fuel element depending on the combustion condition.

The containment device of the present invention has a containment section consisting of a silo for containing burnt fuel elements discharged in a predetermined operating state, and a containment section that is only partially combusted when emptying the core of a nuclear reactor. and another accommodating section constituted by a vertical hole for accommodating the fuel element.

Another feature of the invention is that in the silo-shaped containment for combusted fuel elements, at least two silos have a cross section of 9m x 9fn and a height of 6.5 m; An intermediate floor with an inclination angle of 20 degrees is placed approximately 0.8 m above the floor surface. This intermediate bed is then provided with ventilation slits for supplying cooling air during the deposition of the spherical fuel elements.

The shaft-shaped receptacle for the partially combusted fuel element consists of a cylindrical shaft with a diameter of 1.5 m and a minimum height of 1171Z. The wells are filled with helium so that the graphite of the fuel element does not corrode.

In order to facilitate the removal of the fuel elements from the silos and wells, the lower ends of the silos and wells are provided with bulb separators and bulb drain piping. These are then connected to a containment vessel that receives the spherical fuel elements. The container is placed in a sealed transport vehicle.

In order to avoid redundant transport mechanisms between the separator connected to the rear of the reactor and the inlets of the various accommodations, here:
A slope with a slope angle of 6 degrees is provided. Due to this slope, the velocity imparted to the fuel element is further improved by the gas feed flow. Preferably, the separator is connected to the nuclear reactor via a closed armature and to the fuel element housing via a combustion meter, a buffer passage and a second closed armature.

Diverging means are placed in the inclined passage in the receptacle, which are controlled depending on the degree of combustion conditions measured. The premeter and distributor are controlled in a similar manner.

In FIG. 1, spherical fuel elements discharged from a nuclear reactor, not shown here, are sent to an armature block 2 via a separator and piping 1, also not shown here.

Block 2 consists of a closed armature and a ball counter. In addition, the bulb discharge pipe of the nuclear reactor is also provided with a closed armature. The fuel element is sent from the armature block 2 via piping 3 to a combustion meter 4 . Here, the degree of combustion of each fuel element is measured. The fuel element is then passed through the premeter 5' (il-) into the buffer passage 6. The buffer passage 6 is provided with a dart block 7 with another closed armature.

Once the buffer passage 6 is full of fuel elements, the closed armature in the armature block 2
Connection with the reactor is severed.

When the armature in this block 2 performs a closing operation on the nuclear reactor and the dart block 7 is also closed, the buffer passage 6 becomes in a vacuum state. Then, when the block 7 is opened, the spherical fuel elements are sent to the concentrator 8. From this concentrator 8, the spherical fuel elements are individually distributed to a distributor 9,
Sent to 10. Rolling of the fuel element under gravity can be facilitated by a gas flow. The spherical fuel element is brought into position by appropriate control of the branching means. From the distributor 9 the fuel elements can reach the wells 11.12, 13, 16.17 and the silo 21, while from the distributor 10 the fuel elements can reach the wells 14.15.1B, 19, 20 and the silo 22. . A fuel element suitable for recharging, e.g.
It can be divided into eight combustion classes. The fuel elements with the slightest degree of combustion are, for example, reached by the distributor 9 (
~ Divided into vertical holes. In this case, only these five wells can be pre-supplied with absorbent elements. Both silos 21,22 are fed with burnt fuel elements discharged from the reactor in certain operating conditions. But again,
Even if the reactor core is emptied in the event of a failure, fuel elements that are already highly combusted and suitable for recharging are also accommodated in one of the silos. Approximately 1/3 of the fuel elements housed in the nuclear reactor, in other words, the lower 1/3 of the fuel elements in the reactor are no longer suitable for recharging. This 1/3 fuel element is sent to one of the silos in the event of a failure. The remaining two-thirds of the fuel elements are accommodated in the vertical holes 11-20.

Section 2.3. Figures 4 and 4 show details of the structure of the well and the silo. The accommodation section configured with vertical holes is configured with at least ten vertical holes 11 to 20. These vertical holes are
It has a diameter of 1.5m and a length of approximately 12m. The filling height of the fuel element is always as high as 10. The upper part of the vertical hole is sealed by a sealing member. A separator and a bulb discharge pipe are installed at the lower end of the vertical hole. Each well is filled with an atmosphere of helium, thereby avoiding unnecessary corrosion of the graphite of the reusable fuel element. Cooling pipes for water flow are arranged on the outer wall of the vertical hole for heat dissipation. Heat transfer from the fuel element to the cooling tubes is by free convection of internal gases.

In order to keep the criticality stable, absorption elements must be introduced in the case of only partially burned fuel elements. Absorption elements are continuously supplied depending on the number of fuel elements accommodated.

However, after a certain number of fuel elements have been loaded, a certain number of absorption elements may be supplied to all the wells accordingly.

The silo-like housing consists of silos 21, 22 for accommodating the combusted fuel elements.

Each silo has a cross section of 9m x 9m and a height of approximately 6°5fn. An intermediate floor 23 is provided approximately 0.8 degrees above the silo floor.

The angle of inclination of this intermediate bed with respect to the horizontal plane is 20 degrees. This intermediate floor is provided with ventilation slits. Through this slit, cooling air can be fed into the fuel elements stacked on the intermediate bed. Cooling air is supplied via channel 24'f:. Each intermediate bed 23 of both silos is connected to a bulb discharge pipe 25. Below the silo there is a filling device and a connection station, where the combusted fuel elements can be filled into transport containers and intermediately accommodated in a buffer storage 27 containing a number of containers 26 .

Once the transport containers 26 have been filled from one silo or one vertical hole, these containers 26 are placed on a transport vehicle 28 as shown in FIG. Although not shown here, the transport container is dropped into a shielded transport vehicle 28 by a crane. When the transport vehicle 28 reaches the filling position, the telescopic pipe 29 is lowered into the transport container 26.

This pipe 29 is connected to the bulb discharge pipe 25. By opening the closing armature 30, the separator 31 in operation is connected to the telescopic knob 4b 29. This allows one spherical fuel element to be removed from the silo or well.
One transport container 26 is filled. When one container is filled, the separator is closed and the connection is broken by the closing armature 30. Then, the telescopic guide f29 is pulled up.

[Brief explanation of drawings]

1 is a schematic diagram showing the configuration of the distributor and various accommodating parts of the accommodating device of the present invention, FIG. 2 is a plan sectional view of the accommodating device taken along the line ■-■ in FIG. The figure is a vertical cross-sectional view of the storage device along the line ■-■ in Figure 2, and Figure 4 is IV-IV in Figure 2.
FIG. 3 is a longitudinal cross-sectional view of the storage device along a line; 2... Armature block, 5... Front measuring device,
8...Collector, 9.10...Distributor, 1-20.
... Vertical hole, 21.22 ... Silo, 23 ... Intermediate floor, 28 ... Transport vehicle. Applicant's representative Patent attorney Takehiko Suzue 13- -1■ 2■FIG, 2RG''3 Continued on page 1 0 Inventor Siegzried Mika Federal Republic of Germany 6944 Hemsbach Gernotstrasse @ Inventor Hans Rubsch Federal Republic of Germany 8706 Hetzchoberg Kister Strasse 1 0 Inventor Wolfgang Roerke Federal Republic of Germany 6834 Ketsch Landstrasse 40 0 Inventor Jasbir Zink Federal Republic of Germany 5170 Jüritz Gutenberg Strasse 22 0 Inventor Helmuth・Shimmer Federal Republic of Germany 6901 Ezpelheim Richard Bachnerstrasse 40 [Phase] Inventor Rudolf Biesel Federal Republic of Germany 6800 Mannheim Landteil Strasse 4 ar 0 Inventor Rudolf Bürth Federal Republic of Germany 6800 Mannheim Glucksburger Bake 41 Procedural amendment (method) % formula % 1, Indication of the case Japanese Patent Application No. 57-73481 2, Name of the invention Accommodating device for spherical fuel elements 3, Person making the amendment Relationship with the case Patent applicant Hoho Temberator - Leaktor Pause Doserschaft Fist Mid Peschlenkta... Yatsurank 4, Agent Address: 17 Mori Building 5, 1-26-5 Toranomon, Minato-ku, Tokyo, Date of Amendment Order: July 27, 1980, 6. Specification subject to amendment 7, contents of amendment as attached

Claims (1)

[Claims] 1. In order to accommodate the spherical fuel elements, the spherical fuel elements discharged from the core of the nuclear reactor are distributed through distribution means (s, s, 9., to) f depending on the combustion state. , at least two silos (21, 22) for containing combusted fuel elements;
or into one of at least ten vertical holes (11-2o) for accommodating the partially burnt fuel element, and depending on the combustion condition, a spherical absorption element is added to the fuel element. A housing device for a spherical fuel element characterized by: 2. Two silos C for storage of burned fuel elements
2J, 22) has a cross section of 9m x 9m and a height of 6.5m, and an intermediate floor (23) with an inclination angle of 20 degrees is arranged approximately 0.8 m above the silo floor surface. The storage device according to item 1. 3. Containment device according to claim 2, characterized in that the intermediate bed (23) is provided with ventilation slits for supplying cooling air during the deposition of the spherical fuel elements. 4. Vertical holes (1
1 to 20) are configured in a cylindrical shape. 5. Accommodation device according to claim 4, wherein each well (11-20) has a diameter of 1.5 ms and a height of at least 11 m, preferably 12 m. 6. The upper part of each of the vertical holes (11 to 20) can be sealed with a hollow member.
Containment device as described in section. 7. At the lower end of the silo or vertical hole, install a ball separator (3
1) and the ball discharge pipe (25) were removed from the transport vehicle (
7. The storage device according to claim 1, wherein the storage device is connectable with a transport container (26) which accommodates all the spherical fuel elements within the container (28). 8. The storage device according to any one of claims 1 to 7, wherein the vertical hole is filled with helium. 9. From the separator connected to the rear of the reactor to the distributor (9
, 1, 0) i or up to the introduction opening of the silo or vertical hole, an inclination with an inclination angle of 6 degrees is provided. containment device. 10. The separator is connected to the reactor via a closed armature (2) and is connected to the combustion meter (4), the buffer passage (6) and the accommodation of fuel elements via a second closed armature (7). The storage device according to any one of claims 1 to 9, which is connected to the front side. 11. Any one of claims 1 to 10, wherein a branching means is provided in the inclined passage in the fuel element housing part, and the branching means is controlled according to the measured combustion state. The containment device described in . 12. A patent claim in which a premeter (5), a collector (8), and a distributor (9, 10) are provided in one group of silos or vertical holes in order to distribute fuel elements according to the combustion state. The storage device according to any one of the ranges 1 to 11. 13. The storage device according to any one of claims 1 to 12, wherein the vertical hole is continuously or intermittently supplied with an absorbent element.