RU2555749C1 - Method of sealing ionising radiation source and apparatus therefor - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of sealing an ionising radiation source includes sealing the ionising radiation source placed in a capsule (19) which is sealed by argon-arc welding. The ionising radiation source used is a cobalt workpiece, wherein the capsule is made in the form of a stainless steel (4) cup. The capsule is sealed by a stainless steel seal cap (20) welded around the capsule. Argon-arc welding is carried out using a nonconsumable electrode without a additives in the medium of a protective gas in radiation-protective hot chambers. The disclosed apparatus includes a capsule with an ionising radiation source and an argon-arc welding device, mounted in a welding head (10) which is mounted on a transfer mechanism (6). The welding head consists of a housing (11), an electricity supply device (12), a socket piece (13) for feeding protective gas and a welding nozzle (14).

EFFECT: enabling remote use of the method and apparatus for sealing an ionising radiation source in radiation-protective hot chambers.

7 cl, 2 dwg

Description

The invention relates to the field of radioactive sources, in particular to the production of ionizing radiation sources.

The well-known "Radionuclide source of radiation for radiation gamma-ray inspection" (see patent RU 2499312, CL G21G4 / 00, publ. 11/20/2013), including a sealed vanadium capsule containing as an emitting substance an irradiated selenium-vanadium alloy, and the irradiated selenium-vanadium alloy additionally contains at least one rare-earth element selected from the group: lanthanum, cerium, samarium, neodymium and gadolinium, in the following ratio of components, wt. %: vanadium 13-20, a rare-earth element from the group: lanthanum, cerium, neodymium, samarium, gadolinium 0.01-0.1, selenium - the rest.

A disadvantage of the known method of sealing radioactive elements is that as highly enriched material use blanks from expensive rare earth elements.

Closest to the proposed invention is the "Method of obtaining sources of gamma radiation based on radionuclide 74Se for gamma-ray inspection" (see patent RU 2444074, CL G21G4 / 00, published on 02.27.2012), which consists in sealing the workpiece of the activated core from highly enriched (not less than 96%) selenium-74 in an ampoule, irradiating the resulting ampoule in a nuclear reactor and subsequent sealing of the irradiated ampoule in the capsule. A solid monolithic blank of an irradiated core, made with a density corresponding to the theoretical one, is placed in a completely disciplining volume. The ampoule cover is sealed by laser welding with simultaneous heat removal, and the outer surfaces of the ampoule are sprayed, followed by sealing and hardening with metal. When a metal is irradiated in the reactor, isotopes are formed that have gamma radiation energy less than the gamma radiation energy of selenium-75 with a half-life of less than 1 h, the thickness of the coating layer of which will compensate for the excess pressure created inside the sealed ampoule during irradiation, irradiated in the reactor heat stream neutrons with a density of not less than 10 ¹⁵ N / cm ² in the mode, ensuring the achievement of the maximum specific activity of selenium-75 (not less than 1250 Ci / g), and sealed by argon-arc welding in a working capsule.

A disadvantage of the known method of sealing radioactive elements is that the highly enriched material is first sealed in an ampoule, and then the ampoule is sealed in a capsule, which significantly complicates the technology for producing a radiation source.

The reasons that impede the achievement of the following technical result when using the known invention include the fact that the method and device are more time-consuming when receiving the same final product.

The essence of the proposed method of sealing the ionizing radiation source (III) is that the III uses a cobalt blank, the capsule is made in the form of a stainless steel cup, and the capsule is sealed by a sealed stainless steel lid welded around the junction of the capsule and the lid.

Argon arc welding is performed by a non-consumable electrode without additives in a protective gas medium and is carried out in radiation-protective “hot” chambers.

The sealing device of the ionizing radiation source includes an argon-arc welding device fixed in the welding head, which in turn is fixed in the movement mechanism, consisting of a base, a rotary mechanism, vertical and horizontal movement carriages, which are moved using handwheels.

The welding head consists of a housing, a device for supplying electricity, a nozzle for supplying a protective gas and a welding nozzle.

The power supply device consists of a housing, a collet, a tungsten electrode and a tightening nut. The capsule with III is placed in the glass of the output shaft of the gearbox, and the gearbox itself is mounted on the base of the device. In addition, the capsule with III is fixed on the output shaft of the gearbox with a manual collet clamp.

The use of the invention provides the following technical result:

- the use of a method and device for sealing a source of ionizing radiation remotely in radiation-protective "hot" chambers.

The specified technical result in the implementation of the invention is achieved by the fact that the proposed method includes sealing III, placed in a capsule, and sealed by argon arc welding.

The peculiarity is that the cobalt blank is used as the III, the capsule is made in the form of a stainless steel cup, and the capsule is sealed by a sealed stainless steel lid welded around the circumference of the junction of the capsule and the lid.

Welding is carried out by an argon-arc method with a non-consumable electrode without additives in a protective gas medium and is carried out in radiation-protective "hot" chambers.

The device for sealing the ionizing radiation source includes a capsule with III and an argon-arc welding device.

The peculiarity lies in the fact that the sealing device includes an argon-arc welding device fixed in the welding head, which in turn is fixed in the movement mechanism, consisting of a base, a rotary mechanism, carriages of vertical and horizontal movement, which are moved using handwheels.

The welding head consists of a housing, a device for supplying electricity, a nozzle for supplying a protective gas and a welding nozzle.

The power supply device consists of a housing, a collet, a tungsten electrode and a tightening nut. The capsule with III is placed in the glass of the output shaft of the gearbox, and the gearbox itself is mounted on the base of the device. In addition, the capsule with III is fixed on the output shaft of the gearbox with a manual collet clamp.

The analysis of the prior art by the applicant, including a search by patents and scientific and technical sources of information and identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find an analogue characterized by features identical to all the essential features of the claimed invention.

Therefore, the claimed invention meets the condition of "novelty."

The design of the invention is presented in the figures:

Figure 1 - appearance of the device.

Figure 2 - appearance of the welding nozzle.

The sealing device of the ionizing radiation source (Fig. 1) consists of a base 1, a reducer 2, an electric drive 3, a cup 4 of the output shaft of the reducer, a manual collet clamp 5, a movement mechanism 6, which in turn includes a rotary mechanism 7, a vertical movement carriage 8, horizontal carriage 9, welding head 10, which consists of a housing 11, a device for supplying electricity 12, a fitting for supplying a protective gas 13, a welding nozzle 14, which consists of a housing 15, a collet 16, a tungsten electric 17 and a tightening nut 18. The object of sealing the capsule 19 is covered with a lid 20.

The device operates as follows. The device is installed in a radiation-protective "hot" chamber and, using a manipulator, remotely actuate actuators. Before starting work, an ionizing radiation source is assembled. For this, the capsule 19 is filled with radioactive components, and then closed with a cap 20. After that, the assembled capsule 19 is placed in the cup 4 of the output shaft of the gearbox 2 and fixed there using a manual collet clamp 5. Before positioning the capsule in the cup using the rotary mechanism 7, the welding head 10 removed from the welding zone to provide free access to the arm of the manipulator to load the capsule. After fixing the capsule 19 in the cup 4, the welding head 10 is returned to its working position, and then, using the handwheels of the vertical 8 and horizontal 9 carriages, the electrode 17 is tuned to the annular welding seam of the capsule 19 and the cover 20. After adjustment, the electric drive 3 is turned on, which provides a circular the movement of the welded products (capsules 19 and caps 20). Power to the tungsten electrode 17 is supplied through the electricity supply device 12. Argon shielding gas is supplied to the weld zone 13 through the nozzle 13.

Welding mode:

Current strength - 180 A

Voltage - 48 V

The gap between the capsule and the electrode is 1 mm

Circular feed rate - 10 rpm

The number of passes - 1, 5

Gas consumption - 6 dm ³ / min

Gas Pressure - 0.3 MPa

Thus, the foregoing description indicates the fulfillment of the following set of conditions when using the claimed invention:

- a tool embodying the claimed invention, in its implementation is intended to seal the source of ionizing radiation and can be used in atomic engineering;

for the claimed method and device in the form described in the claims, the possibility of its implementation using the means and methods described in the application is confirmed;

the means embodying the claimed invention in the implementation is able to achieve the technical objectives perceived by the applicant (using the method and device for sealing the ionizing radiation source remotely in radiation-protective "hot" chambers with a view to their further use).

Claims (7)

1. A method of sealing an ionizing radiation source (III), including sealing an III placed in a capsule sealed by argon-arc welding, characterized in that the III uses a cobalt blank, the capsule is made in the form of a stainless steel cup, and the capsule is sealed with a sealed cap stainless steel, welded around the circumference of the junction of the capsule and lid. 2. The method according to p. 1, characterized in that the argon-arc welding is performed by a non-consumable electrode without additives in a protective gas environment. 3. The method according to p. 1, characterized in that the argon arc welding is performed in radiation-protective "hot" chambers. 4. A device for sealing an ionizing radiation source, including a capsule with III and an argon-arc welding device, characterized in that the argon-arc welding device is fixed in the welding head, which in turn is fixed in the movement mechanism, consisting of a base, a rotary mechanism, vertical carriages and horizontal movement, which are moved using handwheels. 5. The device according to p. 4, characterized in that the welding head consists of a housing, a device for supplying electricity, a fitting for supplying a protective gas and a welding nozzle.
5 . The device according to claim 4, characterized in that the device for supplying electricity consists of a housing, a collet, a tungsten electrode and a tightening nut. 6. The device according to p. 4, characterized in that the capsule with III is placed in the glass of the output shaft of the gearbox, and the gearbox itself is mounted on the base of the device. 7. The device according to claim 4, characterized in that the capsule with III is fixed on the output shaft of the gearbox with a manual collet clamp.

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