CZ16465U1 - Internal lining of emergency, regulating and compensating sockets of cover of pressurized-water reactor upper block - Google Patents

Description

(54) Utility model name:

Inner lining of emergency, control and compensating sleeves of the upper block of pressurized water reactors

(0 <0

N

O

CZ 16465 Ul

Inner lining of emergency, regulating and compensating sleeves of the upper block of pressurized water reactors

Technical field

The technical solution concerns the inner lining of emergency, control and compensating sleeves of the upper block of the pressure block reactors, eg of the VVER 440 type, and falls within the field of nuclear engineering, namely the design of nuclear reactors with a focus on the upper block lid.

BACKGROUND OF THE INVENTION

The spherical lid of the upper block of the VVER 440 reactors is in the current design solution welded by electro slag welding from a spherical canopy and a flange. The inner and outer surface of the cover and the flange surfaces as well as the flange surfaces are covered with anticorrosive weld. In the lower part of the flange on the outer circumference, a torque compensator with a foot is welded by means of a special weld deposit and a pressure ring with a ring is established. The sealing surfaces of the lid are the lower face of the spherical lid flange and the lower face of the torus compensator foot. In the upper part of the lid flange there is a bearing surface on which the loose flange is set. On the lid canopy there are 37 sockets for emergency, control and compensating drives, 12 sockets for thermocouple outlets and 6 sockets for neutron flux outlets.

Emergency, control and compensating sleeves are fitted tightly (without play) in the lid openings and welded to the liner on the inner spherical portion of the lid. They are made of manganese steel and the inner surface is covered with austenitic steel housing to protect the inner surface of the sleeve from the corrosive effects of the primary circuit. Inside the emergency, control and compensating sleeves, austenitic steel tube shielding is provided to reduce the effect of refrigerant temperature changes on emergency, control and compensating sleeves. There are threaded holes for 6 M36 bolts on the flanges of emergency, regulation and compensating sleeves and bearing surfaces for two sealing rings. The primary ring, nickel, is used for sealing and the secondary graphoil is used to detect possible leakages due to leakage of the primary seal.

A disadvantage of the original design solution of the emergency, control and compensation sleeves of the upper block lid is the too high casing stiffness, which is then stressed by the compressive force caused by different thermal expansion of the sleeve material and the emergency, control and compensating sleeve.

As a result, the welds of the sleeve connection to the emergency, control and compensating sleeve are also stressed.

The essence of the technical solution

The technical solution relates to the inner liner of the emergency, control and compensating sleeves of the upper block of the pressurized water reactors, eg of the VVER 440 type. The emergency, regulating and compensating sleeve is formed by the emergency body.

The essence of the invention consists in that the inner lining consists of a housing whose walls are weakened in the central part, further comprising a shield and a ring. In the upper part of the housing, there is a ring for strengthening the joint between the upper end of the housing and the emergency, regulation and compensating sleeve. The sleeve and the ring are welded to the front weld of the emergency, regulating and compensating sleeve by welding. On the other hand, the ring is welded to the weld deposit of the emergency, regulation and compensating sleeve by fillet weld. At the base of the sleeve, the sleeve is welded with butt weld to the weld of the emergency, regulation and compensation sleeve.

-1 CZ 16465 Ul

In an advantageous solution to the outside diameter of the emergency, control and compensating sleeve, an opening is formed into the interstice between the emergency, regulating and compensating sleeve and the housing. The test piece is welded to the hole and is equipped with a plug.

During reactor operation, the sleeve is subjected to axial compressive force caused by different thermal expansion of the sleeve material and the emergency, control and compensating sleeve. The technical solution is based on the requirement to reduce the above-described operating load at the weld joints of the sleeve and the emergency, control and compensating sleeve. It is therefore a reduction of the stiffness of the sleeve by reducing its thickness to the technological minimum and carrying out the reinforcement of the upper weld by welding the ring with the connecting weld and the additional fillet weld.

Outside the emergency, control and compensating sleeve, a test sleeve is welded to the opening leading into the interspace between the emergency, regulating and compensating sleeve and the sleeve, by means of which the tightness of the interspace can be checked. After the test, the test sleeve is brought to its final shape and closed with a welding plug.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the proposed solution is described with reference to the drawings, in which Fig. 1 shows the overall construction of the inner liner of the emergency, control and compensating sleeve, the solution with a test sleeve.

Fig. 2 shows a sleeve of a sleeve whose walls are weakened in the central part.

FIG. 3 shows a shield.

Fig. 4 is a detail of the ring; Fig. 5 is a detail of the plug; and Fig. 6 is a detail of the test nipple.

Fig. 7 shows the final shape of the test sleeve.

Examples of technical solution

Example 1

The inner liner of the emergency, regulating and compensating sleeves of the upper block of the pressure block 25 of the water reactors, in this case the VVER 440 type reactor consists of a housing i, see Fig. 1, machined to an outer diameter of max. up to 124 mm.

Shielding 2 is also part of the lining, see Fig. 2, whose outer diameters of max. 135 mm are adapted for installation in emergency, control and compensating sleeves and inner diameter min.

95 mm for flawless movement of the inner part of the emergency, regulation and compensating sleeve.

The inner lining further comprises a ring 3 which reinforces the upper welds 7 and 8 and has dimensions corresponding to the sleeve 1.

Example 2

Alternatively, a test sleeve 4 can be welded outside the emergency, control and compensating sleeve to the opening 9 opening into the interspace 10 between the emergency, regulating and compensating sleeve and the sleeve 1, see Fig. 6.

With the aid of which the tightness of the intermediate space 10 can be checked. The test sleeve 4 is adjusted to the final shape after the test, see Fig. 7 and closed with a welding plug 5, see Fig. 5.

Therefore, the main functions of the inner lining are:

- protection of the internal surface of the emergency, control and compensating sleeve from the corrosive effects of the coolant of the primary circuit;

- reducing the effect of refrigerant temperature change on emergency, control and compensating sleeves.

-2EN 16465 Ul

Industrial applicability

The practical application of the proposed solution is considered for all existing emergency, control and compensation sleeves of the upper block of pressurized water reactors, preferably of the VVER 440 type.

Claims (2)

PROTECTION REQUIREMENTS 5 1. Inner liner of emergency, regulating and compensating sleeves of the upper block of pressurized water reactors, wherein emergency, regulating and compensating sleeve is formed by its own body (6) of emergency, regulating and compensating sleeve and internal liner, characterized in that the inner liner consists of a housing (1), the walls of which are weakened in the central part, of the shield (2) and of the ring (3), the housing (1) being supplemented at the top by a ring (3) for 10 a reinforcement of the connection between the upper end of the sleeve (1) and the emergency, control and compensating sleeve, where the sleeve (1) and the ring (3) are welded to the front weld of the emergency, control and compensating sleeve by connecting weld (7); on the other side welded to the weld of the emergency, control and compensating sleeve by fillet weld (8), at the foot of the sleeve the sleeve (1) is welded butt weld to the weld of the emergency, regulating and compensating sleeve15. An inner liner of the emergency, control and compensating sleeves of the upper block of pressurized water reactors, according to claim 1, characterized in that an opening (9) is formed into the outer diameter of the emergency, regulating and compensating sleeve. and the compensating sleeve and the sleeve (1) and to the bore (9) are 20 is welded to the test sleeve (4), which is provided with a stopper (5). 2 drawings -3EN 16465 Ul FIG FIG FIG