RU2310931C2 - Central irradiating apparatus - Google Patents

Abstract

FIELD: nuclear engineering; central neutron trap of reactor for irradiating targets of test specimen during their refueling without pressure release in reactor.

SUBSTANCE: proposed central irradiating apparatus has device with targets in the form of zirconium-tube separators. These tubes are disposed in three rows and coupled by common input and output headers. There is bottom header for mixing coolant. Central compensating element is made in the form of absorbing rods with displacers in third-row subchannels. Central compensating element is connected to drive by means of locking device.

EFFECT: enlarged useful irradiated space in central neutron trap, enhanced operating reliability of central compensating element.

1 cl, 2 dwg

Description

The central irradiation device (DOC) relates to nuclear engineering and is intended for use in the central neutron trap of the SM reactor for irradiating targets with experimental samples when they are overloaded without pressure relief in the reactor.

A significant number of irradiation devices (OC) are known that are used to study materials and accumulate isotopes (Tsykanov V.A., Samsonov B.V. Technique for irradiating materials in reactors with high neutron flux, M., Atomizdat, 1973; "Experimental and research facilities ", SSC RF NIIAR, Dimitrovgrad, 2000;" Reactor methods of materials science ", M., Energoatomizdat, 1991).

The use of each of them is limited to a specific irradiated material, a certain volume in which the op-amp can be placed, and the fact that when they are serviced, it is mainly required to shut down the reactor or relieve pressure in it. By their design, they are individual, therefore, only DU can be taken as analogs of the DSP by coincidence of their purpose.

The claimed device is devoid of these disadvantages and is a separator design (see figure 1) of 40 zirconium tubes 14 ⌀ 14 × 0.5 mm (19 cells of the 3rd row, 13 cells of the 2nd row, 7 cells of the 1st row and one central cell) connected to the housing 4 using tubes 21 made of 12X18H10T steel, in which the input 3 and output 16 collectors are arranged, and the lower collector 11 is located for mixing the coolant and supplying it to cool the targets 12 suspended on reeds 7, 15, on the output collector. The feed system is equipped with a shut-off valve 19.

In addition, the device has a central compensating organ (CTC) in the form of 8 absorbing rods 20 with displacers 10 in the cells of the 3rd row. CSC is equipped with an electric drive 1, attached to the upper flange 2 of the housing 4, and a locking device 18 for connecting the absorbing rods 20.

The claimed device works as follows: the coolant through the inlet manifold 3 from the cell 13 through the open valve 19 enters through 19 cells of the 3rd row of the device, while cooling both the targets 12 and the absorbing rods of the CTC 20 with rods 5 located in this row.

After passing through the peripheral cells, the coolant through the lower collector 11 enters the remaining 21 cells and then into the output collector 16, while cooling the corresponding targets. Then, through the corresponding valve 6, the coolant enters the pipeline of the gas purge system 9 to the degassers, and the CSC and targets are cooled by the coolant of the main circuit of the switchgear having shut-off valves 6, 19 at the inlet and outlet, to allow targets 12 to be reloaded from the DOC without pressure relief in the reactor.

The reeds located in the 2nd and 1st row and in the central cell are equipped with seals 17 to prevent leakage between the inlet and outlet headers.

Overloading is carried out as follows. The reactor stops, the device is cut off from the primary circuit by valves 6, 19. The trip is disconnected from the CTC rods 20 using the lock 18 and the riser 8 is decompressed, the CTC 1 electric drive is removed, and then the targets are overloaded. Loading targets and preparing the device for operation is performed in the reverse order.

The technical effect of using this device is very diverse:

1. The useful irradiation volume in the central neutron trap is increased by ≈20%.

2. There is the possibility of overloading the COU without depressurizing the main loop of the reactor, which leads to lower loads on equipment, lower dose loads on personnel, and reduced radioactive emissions into the environment.

3. Increases the reliability of the operation of the CSC by reducing the likelihood of its mashing and jamming.

4. The proposed technical solution will allow the use of cells occupied by the working bodies of the CEC to place targets in case of refusal to use it when replacing a standard fuel assembly with fuel samples from SVP. In this case, the experimental volume will be increased by 50% in relation to the existing one.

Claims (1)

A central irradiating device containing a device with targets in the form of a separator from zirconium tubes arranged in three rows and connected by common input and output collectors, with a lower collector for mixing the coolant, as well as a central compensating organ in the form of absorbing rods with displacers in the third row cells, connected to the drive by a locking device.

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