RU158434U1 - DEVICE FOR STORAGE OF MOLYBDENE-99 IN A NUCLEAR REACTOR - Google Patents

Abstract

1. A device for the accumulation of molybdenum-99 in a nuclear reactor, consisting of a supporting structure, including a cover with end parts, and targets, and the cover of the supporting structure is a square in cross section, and the targets are placed inside the supporting structure. The device according to claim 1, characterized in that the targets are made in the form of plates, rods or rings. The device according to claim 1, characterized in that the connection of the cover with the upper end part is made collapsible.

Description

The claimed solution relates to nuclear engineering and can be used in the core of a nuclear reactor to accumulate Mo-99 and other isotopic products.

A device is known which is loaded into an experimental channel located in the core of a research reactor. It contains targets for producing the Mo-99 isotope, having the shape of a plate and consisting of a uranium-aluminum core and aluminum shell (Gavin Ball. "Status Update on Conversion to LEU Based Mo-99 Production in South Africa." International Conference RERTR, Santiago, Chile, October 23-27, 2011).

The disadvantages of the device include:

the design of the device provides for the possibility of its placement only in the experimental channel, for which in the reactor core there is a small number of irradiation positions, which limits the overall production time of the product;

the need to develop and manufacture special equipment: experimental channels for the placement of irradiation devices, special tools for transport operations, etc.

A device for the accumulation of Mo-99 is known (Svyatkin MN, Izhutov A.L., Klinov A.V. et al. Research nuclear reactors. - Report on the main research work carried out in 2011 - Dimitrovgrad: OJSC “SSC” NIIAR ”, 2012. S. 5-13,). The device consists of a supporting structure containing a central displacer connected to the end parts, and 52 rod fin targets with a square profile of 2.7 mm in size, arranged in a ring in two rows around the central displacer. The target core is made in the form of a dispersion of uranium intermetallide enriched in U-235 to 90% in an aluminum matrix. The mass fraction of uranium in the core is 41.5%, the total content of U-235 in the device is 53.3 g. The neutron irradiation device is loaded into the experimental channel installed in the reactor core.

The disadvantages of the device are:

the design of the device provides for the possibility of its placement only in the experimental channel, for which in the reactor core there is a small number of irradiation positions, which limits the overall production time of the product;

the number of devices that can be loaded into the core is limited by nuclear safety parameters (at the same time, no more than 2-3 pieces can be loaded);

the need to develop and manufacture special equipment: experimental channels for the placement of irradiation devices, special tools for transport operations, etc.

These disadvantages are eliminated in the device for the accumulation of molybdenum-99 in a nuclear reactor, consisting of a supporting structure, including a cover, upper and lower end parts, and targets, and the cover of the supporting structure is a square in cross section, and the targets are placed inside the supporting structure .

The proposed design of the device allows you to:

place the device in any cell of the core instead of the standard fuel assembly i.e. there is no need to develop and manufacture experimental channels for placing devices;

the installation of the device outside the experimental channel reduces its hydraulic resistance, due to the greater flow rate of the coolant, a higher power of the device can be ensured, which will increase the productivity of the target product in a separate device;

device overloading is carried out by a tool for standard fuel assemblies, i.e. there is no need to develop and manufacture a special tool for transport operations.

Targets installed inside the supporting structure can be made in the form of plates, rods or rings.

To enable reusability of the device, the connection of the cover with the upper end part is collapsible.

The attached figure shows an example of a device for the accumulation of molybdenum-99 in a nuclear reactor, which is a square in cross section, where:

1. - upper end part;

2. - a cover;

3. - target;

4. - lower end piece.

The device is assembled and operates as follows. At the assembly site, in the case (2) connected to the lower end part (4), the targets (3) are installed and connected to the upper end part (1). The device is placed in the reactor core, which is brought to power. After irradiation for a predetermined time, the reactor is placed in a subcritical state, the device is unloaded, and with the help of the container it is moved to a protective chamber. In it remotely, using manipulators, the upper end part (1) is disconnected, the irradiated targets (3) are removed and transferred to processing. Fresh, non-irradiated targets are installed instead of the extracted ones, the upper end piece (1) is attached and the device is transferred from the protective chamber to the reactor. Next, the cycle is repeated until the designated service life of the device elements is exhausted.

Claims (3)

1. Device for the accumulation of molybdenum-99 in a nuclear reactor, consisting of a supporting structure, including a cover with end parts, and targets, and the cover of the supporting structure is a square in cross section, and the targets are placed inside the supporting structure. 2. The device according to p. 1, characterized in that the targets are made in the form of plates, rods or rings. 3. The device according to p. 1, characterized in that the connection of the cover with the upper end part is made collapsible.

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