RU109605U1 - DRIVE OF THE REGULATORY BODY OF THE NUCLEAR REACTOR - Google Patents

Abstract

1. Drive of a nuclear reactor regulatory body, including a casing operating under pressure of the primary coolant, a movement mechanism with upper and lower damping devices, a rod connected to the regulatory body, a regulator position control sensor with a flange for installation into the drive, a sealing device casing, sealing the casing by means of a gasket located between the inner surface of the casing, the end and cylindrical surfaces of the housing flange of the said sensor and the end surface of the support sleeve installed on the casing collar, characterized in that the sealing device comprises a split push sleeve and a push flange, while the split push the sleeve has a grip for fixation on the outer surface of the casing and a grip for fixation on the pressure flange. ! 2. The drive according to claim 1, characterized in that a ring is installed on the split push sleeve.

Description

The field of technology.

The utility model relates to actuators of reactive reactors, namely, to actuators of a control and protection system for nuclear reactors with pressurized water (water-cooled nuclear power reactors).

The prior art.

A known actuator of a regulatory body of a nuclear reactor is patent RU 99647, which includes a casing operating under pressure from the primary coolant, a mechanism for moving the rod connected to the regulatory body, a rod, a sensor for monitoring the position of the regulatory body, containing a flange for installation in the drive, a shutter casing, a sealing the casing by means of a sealing device for the shutter of the casing containing a push sleeve with a bayonet catch for fixing on the outer surface of the casing, a support sleeve mounted on mouth of the casing, a sealing gasket located between the end surface of the said supporting sleeve, the inner surface of the casing, the end and cylindrical surfaces of the flange of the housing of the said sensor, in the upper part of the casing between the sealing device and the moving mechanism there is an upper damping device, and in the lower part of the casing between the casing and a moving mechanism has a lower damping device.

The disadvantage of this drive is that for a casing, which under operating conditions is under pressure of the primary coolant, it is necessary to use expensive alloys with high mechanical properties (under conditions of ensuring strength), for example, KhN35VT-VD alloy. This need arises due to the small wall thickness in the area of the bayonet grooves of the casing, and also because the surface area in contact with the pressure bayonet sleeve is reduced due to the grooves. The small wall thickness is due to the fact that the seal assembly must fit into the layout of the reactor equipment in terms of dimensions, which implies the presence of several dozens, and sometimes more than one hundred, of actuators of regulatory bodies. Considering that for bayonet capture, protrusions and grooves on the surface of the casing must necessarily exist, then a small wall thickness is formed in the groove zone. According to the operating conditions of the drive, due to high pressure, large local voltages occur in the bayonet capture zone. The alternation of protrusions and grooves leads to the fact that local stresses are especially high in the zone of protrusions, because the load from the push bayonet sleeve is transferred to them. The use of conventional austenitic steels for bayonet capture, tested by operating experience, in this case, according to the strength conditions, leads to an increase in the wall thickness and thickness of the bayonet capture elements, which is impossible due to the tightness of the layout of the equipment located on the reactor lid. Therefore, the KhN35VT-VD alloy was used in this unit.

However, the machining of such high-strength alloys as KhN35 VT-VD (unlike ordinary austenitic alloys) is difficult due to their high hardness.

Disclosure of a utility model.

Objectives of the utility model:

- improving the reliability and operational properties of the drive of the regulatory body and reactor by reducing the likelihood of damage to the casing during long-term operation;

- reduction of manufacturing costs, as a result of the use of a material that is highly machinable.

The technical result of the utility model:

- reduction of local mechanical stresses in the casing material and, as a result, a decrease in the likelihood of intergranular corrosion cracking and fracture due to stress corrosion;

- reducing the probability of leakage of the coolant of the primary circuit of the reactor installation;

- the possibility of using a wider range of steels, by reducing the requirements for their strength characteristics.

The proposed drive contains a sensor for controlling the position of the regulatory body, a block of electromagnets, a casing, a movement mechanism, a rod, a sealing device of the casing and damping devices. In the proposed drive, in comparison with the prototype, the design of the sealing device is changed.

What is new is that in the drive of the regulator the sealing device comprises a split push sleeve and a pressure flange, while the split push sleeve has a grip for fixing on the outer surface of the casing and a grip for fixing on the pressure flange. Thus, this sealing device, through the use of a split push-in sleeve and a pressure flange of the casing, allows to increase the wall thickness of the casing (due to the absence of grooves) and to reduce local mechanical stresses in the zone of sealing of the casing by increasing the surface area of the casing in contact with the split push-in sleeve. The uniform distribution of mechanical stresses over the entire surface area of the casing in contact with the split push sleeve allows the use of ordinary austenitic steel for the casing.

A brief description of the drawings.

The essence of the utility model is illustrated by drawings, which show the following:

- figure 1 shows a General view of the drive regulatory body of a nuclear reactor.

- figure 2 shows the node with a sealing device

The drive (figure 1) of the regulatory body includes a casing 1, which is under pressure from the primary coolant, a position sensor for controlling the position of the regulatory body 2, comprising a flange 3 for installation in the drive, an electromagnet block 4 mounted outside the casing, and a moving mechanism 5 mounted inside the casing and connected to it through the upper damping device 6 and the lower damping device 7, as well as the rod 8. The casing is mounted on the cover of a nuclear reactor 9 and experiences the pressure of the primary coolant together with the housing m and sealing said sensor device housing. The rod 8 is connected to the regulatory body 10.

The assembly of the sealing device of the casing (Fig. 2) includes a casing 1, a flange 3 of the housing of the sensor for controlling the position of the regulatory body 2, a gasket 11, a support sleeve 12 connected to the upper damping device 6, a support ring 13, a pressure flange 14, bolts 15, a split push sleeve 16 having a grip 17 for fixing it on the casing and a grip 18 for fixing on the pressure flange, ring 19.

Implementation of a utility model.

The installation of the components of the drive and the sealing device of the casing with damping devices is as follows. A block of electromagnets is mounted on the casing 1 (Fig. 1), which interacts with the movement mechanism through the casing wall by means of an electromagnetic field. In the casing 1 (figure 1) on the damping devices 6 and 7, a movement mechanism is installed. The supporting sleeve 12 (figure 2) connected to the damping device 6 is mounted on the upper shoulder of the casing, while the damping device 7 is installed on the lower shoulder of the casing. In the movement mechanism start the rod 8 (figure 1). A gasket 11 is installed on the end of the support sleeve 12 (Fig. 2), the lower part of the regulator position control sensor is inserted into the movement mechanism and in the rod 8, the flange 3 of the said sensor is installed on the gasket, and the support ring 13 is mounted on the flange 3, and the connector is sealed using the pressure flange 14, bolts 15, the split pressure sleeve 16, fixing it on the casing and on the pressure flange using the grippers 17 and 18. Ring 19 is installed as a bandage.

The proposed drive design with a split push-in sleeve and a pressure flange in the sealing device allows the use of a casing made of ordinary austenitic steel, for example, grade 08X18H10T.

The utility model can be applied in the drive of the regulatory body of nuclear reactors.

Claims (2)

1. The drive of the regulatory body of a nuclear reactor, which includes a casing operating under pressure of the primary coolant, a movement mechanism with upper and lower damping devices, a rod attached to the regulatory body, a sensor for controlling the position of the regulatory body with a flange for installation in the drive, a sealing device a casing, a sealing casing by means of a gasket located between the inner surface of the casing, the end and cylindrical surfaces of the flange of the housing of the said sensor, and rtsevoy surface of the bearing sleeve mounted on the casing shoulder, characterized in that the sealing device comprises a split pressure sleeve and the pressure flange, the split pressure sleeve has a catch for fixing to the outer surface of the housing and the grip for fixing on the pressure flange. 2. The drive according to claim 1, characterized in that a ring is mounted on the split push sleeve.