RU9332U1 - DEVICE FOR IRRADIATION OF SAMPLES IN A NUCLEAR REACTOR - Google Patents

Abstract

A device for irradiating samples in a nuclear reactor, containing a cylindrical body with holes made in it, a sleeve installed inside the body with the ability to move in the axial direction, upper and lower units for sealing the holes of the body and the separator collector, reeds with ampoules placed in the separator, flow regulator coolant, a drive, characterized in that the lower valve is made in the form of a membrane of a hollow spherical layer of variable cross-section, smaller on the wings and increasing towards the center, and the drive performs two reverse opposite translational forced movements and adjustment of the coolant flow rate.

Description

DEVICE FOR IRRADIATION OF SAMPLES IN A NUCLEAR REACTOR

The inventive device is intended for use in nuclear / engineering.

In the technology for the production of radionuclides, materials science, a number of devices are known, for example, according to a.c.W 680499, No. I6I8I77 and others for irradiating samples and targets. Thus, the device according to A.Is.If 680499 contains separator tubes made V-shaped with different heights of the knees and combined with a tube plate installed at the level of the lower ends. In this case, a pipe for introducing the coolant is installed in the area where the upper ends of the pipes are located, and the channel in the region of the active zone is surrounded by a heat-insulating jacket forming a stagnant zone communicating at the lower end of the channel and near the second tube plate with the reactor coolant.

When using this device, the experimental capabilities of the reactor are somewhat increased due to the increase in the number of separator tubes, the flow rate of the coolant is reduced. This undoubtedly can be attributed to the advantages of the device.

However, the maintenance of the device is inconvenient, overloading involves shutting down the reactor, which leads to an increase in labor costs.

62IC 17/06

for the coolant passage, the upper and lower valves for sealing the reactor vessel, the lower one being spring-loaded — two autonomous actuators for performing 2 functions: for regulating the coolant flow rate and raising the ampoule into the cooling zone. The device allows you to overload the ampoule without reducing the pressure in the reactor and stopping the flow of coolant, which greatly increases the safety of the reactor.

However, the disadvantages of the device are very significant, limiting its use. So the device is equipped with two standalone drives for adjusting the flow rate of the coolant and lifting the ampoule into the cooling zone. When the lower valve is locked at the fit-in place, there can be a shift in the valve seat relative to the seat in the body, which leads to leakage of the coolant from the reactor main circuit. The device is made of a thick-walled steel case, which leads to a decrease in the flux density of the heat flux of neutrons in the irradiated samples by an additional 15%.

While the needs of society were limited to the use of nuclides with a sufficiently long half-life, irradiation was carried out according to a 20-day cycle of overloads.

In connection with the expansion of the nuclide product range, the transition to the accumulation of short-lived radionuclides, the task was to create an irradiation device that would simplify and discharge the irradiated samples (targets) every, for example, 10 days without pressure relief in the reactor and without significant labor costs, which is practically impossible using all known irradiating devices.

The solution to this problem - to simplify the design of the irradiation device while increasing its reliability - is the goal of creating the inventive device.

This is achieved by the fact that in an irradiating device containing a housing, a sleeve placed axially movable inside the housing, the upper and lower seal assemblies of the housing openings relative to the coolant, 10 tubular reeds with ampoules in which irradiating samples or source blanks are placed, drives , the lower valve with a spring, this valve is made in the form of a hollow ball layer membrane with a variable cross section, smaller on the wings and increasing towards the center, and the actuator performs two opposite, translational forced movement of the ampoule and adjustment of the coolant.

The presented drawing shows the irradiation device claimed as a utility model. It contains a housing I with holes 2, a sleeve 3 connected to the upper screw 4 with a left-hand thread, which in turn is connected to the lower screw b with a right-hand thread. In the lower part of the housing I, there is a sealing assembly 5. In the upper flange 15, the head 17 is sealed with a union nut 7 by a sleeve 8 and a sealing assembly 9. The lower part of the device is equipped with a separator 10 of 10 zirconium tubes that pass into the collector II, ending in a cone 12, which houses the bottom valve 18 connected to the bottom screw 6. In the separator 10 are installed

reeds 13 with ampoules 14 in which irradiated samples or source blanks are placed.

The device operates as follows:

Housing I with a separator 10 are installed in the reactor and the bottom flange of housing I, the device is sealed on the cover of the reactor. 10 reeds 13 with ampoules 14 are loaded into the separator. A flange 15 with a valve 16 and a head 17 connected to the upper screw 4 is mounted and sealed with pins and nuts on the upper flange of the vessel I. After that, the reactor vessel is sealed normally and the pressure inside it is brought to the worker (5 MPo). Further, the head 17 is rotated counterclockwise by hand with a tool or by means of an electric drive, thereby the sleeve 3 is lifted and removed from the upper seal assembly, equalizing the pressure in the reactor and in the device. At the same time, the bottom valve 18 moves away from the seat, thereby organizing the flow of coolant through the device. The nominal flow rate is set by moving the upper sleeve 3 by rotating the head 17, while the holes 2 overlap or open within 10 mm, with the lower valve 18 open by approximately 50 mm. The device is ready for irradiation, the reactor is brought to power in an intermittent mode.

After the required irradiation time, the reactor is stopped and the head is rotated counterclockwise for the head 17, thereby sealing with the sleeve 3 along the sealing assembly 5 and simultaneously along the cone 12 with the valve 18 using screws 4, 6. By opening the valve 16, the tightness of the device relative to the primary circuit is checked the reactor. In the presence of tightness, the upper flange 15 is decompressed and the reeds 13 with irradiated ampoules 14 are unloaded and new ampoules are loaded. Then the flange 15 is sealed, the valve 16 is closed and the above operations are performed in the reverse order.

Director of Inst

V.B. Ivanov

Claims (1)

A device for irradiating samples in a nuclear reactor, comprising a cylindrical body with holes made therein, a sleeve mounted axially movable inside the body, upper and lower seal assemblies for the openings of the body and the separator collector, reeds with ampoules placed in the separator, and a flow regulator coolant, an actuator, characterized in that the lower valve is made in the form of a membrane of a hollow spherical layer of variable cross section, smaller on the wings and increasing toward the center, and the actuator There are two opposite opposite translational forced movements and adjustment of the coolant flow rate.