RU1537046C - Radioactive waste processing plant - Google Patents

Abstract

FIELD: processing of radioactive waste. SUBSTANCE: plant has continuous-action filter incorporating casing 1 with bottom 2, conical drain screen 3 fixed through its larger base on lower part of casing 1 with its smaller base facing bottom 2, waste sorbent layer disposal unit, container 8 for waste sorbent layer accumulation, and circulating pump 12. Waste sorbent layer disposal unit is, essentially, conical checker 9 with radial nozzles and perforated disk 10 placed under them; checker is mounted under drain screen 3. Container 8 has drain gauze 11 and communicates with casing 1 on top and with pump 12 at bottom. EFFECT: reduced quantity of radioactive waste; improved reliability of plant. 1 dwg

Description

 The invention relates to nuclear energy, in particular to a technique for managing liquid and solid radioactive waste from a nuclear power plant, and can be used in a waste water treatment plant for pre-treatment, for isolation with the aim of subsequent curing of the most long-lived and most toxic radionuclides of liquid waste storage solutions, additional (warranty) treatment of unbalanced waters from long-lived and most toxic radionuclides to prevent their concentration in places of discharge, for m mechanical filtration of radioactive water.

 The aim of the invention is to reduce the volume of radioactive waste to be disposed of by increasing the coefficient of use of the sorbent in the treatment of radioactive water.

 According to the proposed technical solution, continuous uniform hydraulic discharge of the spent sorbent using purified water is carried out, as well as repeated circulation of this water through a cone-shaped nozzle and a layer of spent sorbent in the container, which ensures the complete production of the sorbent collected in the container. In addition, the installation allows you to continuously remove mechanical impurities into the container from the purified water, which eliminates the clogging of the filter. Impurities are evenly distributed in the volume of the sorbent in the container and practically do not increase the resistance of the sorbent layer. At the same time, the minimum number of installation units is subject to burial with a simple container design, the volume of which is almost completely used to fill it with a sorbent.

 The drawing shows an installation for the treatment of radioactive waste. The installation comprises a continuous filter, including a cylindrical housing 1 with conical broadening in the lower part, a tapered conical bottom 2 conjugated to it, a conical drainage grate 3 fixed by a large base on the lower part of the housing and facing a smaller base to the bottom 2, located on the cover of the housing 1 loading hatch 4, a radioactive water supply unit 5 located in the lower part of the housing, a nozzle 6 for withdrawing a selected sorbent with a ball valve, and a slotted drainage 7 mounted in the middle of the housing for st eye purified water.

 In addition, the installation is equipped with a unit for removing the lower spent sorbent layer and a container 8 for collecting it. The node for removing the spent layer of the sorbent is made in the form of a cone-shaped nozzle 9 with radial nozzles installed under the drainage grid 3 and placed below them with a gap to the body of the perforated disk 10. The size of the gap should be 3-6 grain diameters of the used sorbent. Moreover, the free cross-sectional area of the perforated disk relative to the area of the annular gap as 20: 1.

 The container 8 for collecting the spent sorbent is made with a drainage grid 11 installed with a gap to the bottom of the container, and is connected with its upper part to the pipe 6 and the filter housing 1 of a continuous filter.

 The installation is equipped with a circulation pump 12 associated with the lower part of the container 8 and the conical nozzle 9.

 The container 8 can be equipped with biological protection 13 from concrete 2.8 mlR / h. Instead of a filtering drainage mesh 11, a layer of loose drainage material may be placed at the bottom of the container.

 Installation for the treatment of radioactive waste works as follows.

 The filter housing 1 is loaded through the hatch 4 with an inorganic sorbent selective to long-lived isotopes based on silica gel and transition metal ferrocyanides. In working condition is half the total load of the housing.

Radioactive water is supplied through a radioactive water supply unit 5 (switchgear), passed through a perforated disk 10, a conical drainage grid 3 and a working volume of the sorbent, where water is purified from mechanical impurities and dissolved ions (radionuclides). Purified water through a slit drain 7 is collected in a tank of purified water (not shown in the drawing) or is supplied for further processing. The total area of the slit drain holes 7 is selected from the condition for ensuring the removal of purified water. The pressure of the radioactive water supply through the node 5 should be equal to or higher than the pressure of the circulation pump, and must also be equal to or higher than the hydrostatic pressure of the column of purified water. The filtration rate should not exceed 2 m / h for loading an inorganic sorbent with a bulk density of 0.5 g / cm ³ . The backfill layer adjacent to the drainage grid 3 is poured along its conical surface onto the perforated disk 10.

 The spent sorbent is discharged from the perforated disk by a stream of purified water supplied by a circulation pump 12 to the radial nozzles of the cone-shaped nozzle 9. The sorbent is captured by water jets, transferred to the annular gap between the perforated disk 10 and the filter housing 1, falls onto a conical bottom and together with the circulating water stream through the pipe 6 with a ball valve enters the container 8.

 On the filter screen 11 of the container 8, the sorbent is delayed, and the water flow enters further circulation. In this case, the sorbent is "being finalized."

 After filling the container 8, close the ball valve, the liquid from the container is pumped out by the circulation pump 12. The container is disconnected from the pipe 6 and the circulation pump 12, filled with a curing agent (cement milk, sodium silicate with additives, etc.). The connecting fittings are plugged, the lid of the container is poured with cement mortar.

 The invention provides a reduction in the amount of radioactive waste to be disposed of by increasing the discharge coefficient of the sorbent selected in the filter and repeated contact of the sorbent in the container with the circulating liquid being cleaned, increasing the reliability of the installation due to the absence of moving parts in contact with the sorbent, and eliminating the filter clogging with mechanical impurities due to the continuous removal of them into the container with a stream of purified water.

Claims (1)

 RADIOACTIVE WASTE TREATMENT PLANT, comprising a continuous filter with a casing, a drainage grate and a unit for removing the lower spent sorbent layer, and a container for collecting the spent sorbent associated with the casing, characterized in that, in order to reduce the amount of radioactive waste to be disposed of, by increase the coefficient of use of the sorbent when treating radioactive waters, it is equipped with a circulation pump for the water to be treated, the drainage grill is made in the form of a cone-shaped ring, s mounted on the casing with a large base and facing a smaller base to the bottom, and the unit for removing the spent sorbent layer is made in the form of a cone-shaped nozzle with uniformly located radial nozzles connected under the circulation pump and installed under the drainage grid and placed under them with an annular gap to the perforated disk casing, the container for collecting the spent sorbent is made with a drainage grid installed with a gap to the bottom of the container and is connected with its upper part to the filter housing a continuous and bottom with a circulating pump.