DE3520230A1 - Nuclear reactor - Google Patents

Abstract

A nuclear reactor is a fast breeder reactor cooled by liquid metal, and has a primary containment 3 with an upper cylindrical section 10 and a lower hemispherical section 12. A tank 13 contains liquid metal 11 and has a wall 13 which is connected at its lower end at the point 14 to the section 12. A hemispherical safety tank 16 is at a distance from the section 12 and the base of a concrete dome 1, and is connected to the primary containment at the lower end 15 of the section 10 at a level above the level 14. The safety tank 16 provides a device for accommodating and determining any leakage from that part of the primary containment which is exposed to the liquid metal. <IMAGE>

Description

-SCHWABE-. ·, -SANDMAN- · MARX '.' ■ ': PATENTANWÄLTE

STUNTZSTFUZE 16 8000 MUNICH 80 OuZUZ JU

Attorney File 34 459 VII June 5, 1985

NATIONAL NUCLEAR CORPORATION LIMITED

Booths Hall, Chelford Road, Knutsford, Cheshire WA16 8OZ / ENGLAND

NUCLEAR REACTOR

Priority: Country: ENGLAND

File number: 8414618 Filing date: June 8, 1984

»(089) 988272-74 Facsimile: (089) 983049 Bank accounts: Bayer. Vereinsbank Munich 453100 (BLZ 70020J70)

Telex: 524560 Swan d KaIIe Infotec 6350 Gr. II + III Hypo-Bank Munich 4410122850 (BLZ70020011) Swilt Code HYPODtMM

Posloiro Munich 65343-808 (BLZ 70010080)

SCWWABE · SANDMAIR- · MARX

STUNTZSTRASSE 16 8000 MUNICH 80

Attorney's file 34 459 VII

National Nuclear Corp., Ltd, Cheshire / England

Nuclear reactor

This invention relates to nuclear reactors and ^; in particular that type of nuclear reactor hereinafter referred to as "of the type mentioned", the nuclear reactor belonging to the type known as liquid metal cooled fast breeder and having a core comprising a number of fuel elements and in a container is attached, which contains a bath of liquid metal, usually of sodium, the heat generated by the fission in the fuel is extracted from the core by a coolant flow of liquid metal and transferred to heat exchangers, and the container is located in a concrete dome over which a roof is attached.

It is common practice, for safety reasons, to use a double-walled container so that any Leakage from the interior of the container can be recorded and identified, and steps to remedy it can be made to reduce the cooling

VII / B / WA

»(089) 988272-74
Telex 5 24 560 Swan d

Fax machines. (089) 983049 KaIIe Inlotec 6350 Gr. II + III

Bank accounts: Bayer. Vereinsbank Munich 453100 (bank code 70020270) Hypo-Bank Munich 4410122850 (bank code 70020011) Swift Code: HYPO DE MM Postgiro Munich 65343-808 (BLZ 70010080)

by means of achieving that, would it go unnoticed Overheating of the core. With a double-walled container, the walls of which extend to the roof, however, the outer container or protective container would have to be manufactured to the same high standard as to the integrity of the inner container or primary container, adding to the weight and cost makes a major contribution to this capital-intensive component of the reactor, and in particular that part of the vessel

₁ q, which extends beyond the design coolant level in the primary container, is superfluous from the point of view of its main purpose, namely in order to record and detect any leakage of coolant from the primary container. Examples are shown in British Patent Nos. 1,307,680 and 1,546,331.

It is also common to use an inner tank, which lies within the primary container and

2Q both the core and the bath of liquid metal contains to avoid any contact between the bath of liquid metal and a cylindrical upper part to prevent the primary container. It is therefore unnecessary to have a protective container that extends over

2g each section of the cylindrical part of the primary container for the same reason as stated in the previous paragraph.

According to the invention, a nuclear reactor of the type mentioned at the outset has a primary container with an upper section and a lower section, the lower section having a partially spherical part, an inner tank which is intended to hold liquid metal and having a wall which has a distance to the _oc primary container and the primary container is affixed with its lower end at the lower portion, a protective container, the outside of the

the lower portion of the primary container is located at a distance from this and with the primary container is connected to a level which is above the lower end of the tank wall.

In such an arrangement, the protective container provides a means for containing and identifying any Leakage from the part in the primary container that is exposed to the liquid metal.

The lower section of the primary container can be partially spherical.

The lower portion of the primary container can be hemispherical.

The protective container can be partially spherical, e.g. hemispherical.

The upper portion of the primary container can be cylindrical be. The protective container can be connected to the primary container at the lower end of the cylindrical upper section be.

The invention includes a nuclear reactor as described.

A structural embodiment of the invention will now be made, for example, with reference to the attached Drawings described in which:

Fig. 1 is a schematic side view of a nuclear reactor of the type mentioned is in the middle section and represents a known construction, and

gg Fig. 2 is a view embodying the invention Represents construction.

In both figures only so much of the reactor is shown, as is necessary to understand the invention; other parts and components necessary for the actual operation required are well known to those of ordinary skill in the art. Same reference numbers refer to the same parts in both figures.

Reference is first made to FIG known construction shows: A concrete dome 1 has a roof 1a and carries in its interior by means a conical strut 2, a primary container 3, which contains the reactor core C, which has a plurality of Having fuel elements. The container 3 is closed by a roof 4 which is part of the roof 1a forms and has a shield. The bracing

2 also carries a protective container 5, which is outside the Primary container 3 is arranged, has a distance from this and · a device for determining any leakage from the container 3 and provides a receptacle for this. Trays 3 and 6 have cylindrical upper sections and hemispherical lower sections on. The hemispherical part 6 of the protective container 5 faces the bottom and the Inner surface of the dome or the arched cavity 1 at a distance. An inner tank 7 is on one conical strut 8 borne by the primary container 3 from such that the cylindrical part 9 of the tank 7 opposite the cylindrical part 10 of the container 3 is at a distance, and contains a coolant bath 11, preventing the bath 11 from contacting the upper cylindrical part 10 of the container 3. That Bath can, however, the hemispherical part 12 of the container

3 touch and do so.

Reference is now made to Figure 2; the dome or the vault-like structure 1 has a primary container 3, which is inside it by a conical arrangement

aspiration 2 is supported, and a roof 4 closes the container 3. An inner tank 13 is cylindrical, has relative to the upper cylindrical part 10 of the container 3 at a distance and fulfills the same function as the part 9 of the inner tank 7 of the construction of Fig. 1. The tank 13 has a wall 13a for the lower one Section on that sealingly in place with the hemispherical section 12 of the container 3 at an annular Point 14 is welded,

A protective container 16 is only hemispherical and is outside and at a distance from the section 12 of the Container 3 arranged, its upper end being welded on site to the container 3 at point 15,

! 5 i.e. the lower end of the cylindrical portion 10 of the container 3, which is higher in level than the weld point 14. Thus, the protective container 16 is outside that portion of the cylindrical portion 12 of the pressure vessel arranged with the coolant

2Q 11 is engaged.

The sections 12, 16 could be partially spherical or have the shape of a spherical part. The upper cylindrical Section 10 could extend to a level 14, with section 16 shaped accordingly would be to deliver a double-walled container up to level 15.

The merits of a design embodying the invention. OQ bodies have the following:

- Saving in time and costs of on-site assembly, there only one container (3, 12, 16) now requires fitting into the dome, instead of two containers (3, 5),

- only one container requires transport to the construction site, gc - some circumferential welds between the containers and supports are unnecessary,

-9-

1 - reduction in dome diameter, - Maintaining higher, sodium-free levels or Free Natriuittnivectus ia leakage situations, and Cost and weight savings of part of the protective B container.

/ tO

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Claims (7)

Expectations 1. Fast breeding nuclear reactor cooled by liquid metal, with a core having a number of fuel elements and arranged in a container which has a bath of liquid metal, usually sodium, with the heat passing through Fission in the fuel is created by a stream of liquid metal coolant being withdrawn from the core and is transferred to heat exchangers, and wherein the container is located in a concrete dome which is provided by is covered by a roof, with the following features: - A primary container, which has an upper and a lower one Having section, wherein the lower section has a partially spherical part, - An inner tank for holding liquid metal and with a wall that faces the primary container Having distance, and * (089) 988272
Telex: 524 560 Swan d -74 '' telecopier (089) 98 3049 KaIIe Infotec 6350 Gr. II + III Bank accounts: Bayer. Vereinsbank Munich 453100 (BLZ 70020270) < Hypo-Bank Munich 4410122850 (BLZ 70020011) Swift Code HYPO DE MM Postgiro Munich 65343-808 (BU 70010080) - a protective container outside the lower section of the primary container and at a distance from it, characterized in that the wall (11) with its lower end at the lower portion of the Primary container (3) is attached, and that the contactor container (16) with the primary container in one level (15) above the upper end (14) of the tank wall (11) connected is. 2. Nuclear reactor according to claim 1, characterized in that the lower section (12) of the primary container forms part of a sphere. 3. Nuclear reactor according to claim 2, characterized in that the lower section (12) of the primary container is hemispherical is. ^v 4. Nuclear reactor according to one of the preceding claims, ft characterized in that the protective container (16) the Has shape of part of a sphere. 5. Nuclear reactor according to claim 4, characterized in that the protective container (16) is hemispherical. 6. Nuclear reactor according to one of the preceding claims, characterized in that the upper section (10) of the primary container is cylindrical. 7. Nuclear reactor according to claim 6, characterized in that that the protective container (16) with the primary container (3) is connected to the lower end (15) of the cylindrical upper section (10). ö. Nuclear reactor, essentially as above and with reference to Fig. 2 of the accompanying drawings and shown therein. f 9. Nuclear reactor as described.