Reaction Chamber for Extraction of Uranium Dioxide Powder by Using Method of Uranium Hexafluoride Reductive Pyrohydrolysis

Abstract

Reaction chamber and methods of extraction of metal compounds, specifically tools for uranium hexafluoride (UF.sub.6) conversion into uranium dioxide (UO.sub.2) ceramic powder (up to 5% enrichment of U.sup.235) by applying a method of reductive pyrohydrolysis. In one aspect, the reaction chamber is a shell with upper and lower heads, comprising upper filtration area, equipped with metalceramic filters, regenerating nitrogen, the first reaction zone for conversion of uranium hexafluoride into uranyl fluoride, the second reaction zone with gas-distribution grid for building up fluidization layer for reduction of uranyl fluoride to uranium dioxide with a nozzle of steam, and hydrogen and nitrogen supply. On the side walls of the first reaction zone of the reaction chamber shell there are two nozzles located symmetrically for uranium hexafluoride, hydrogen and water steam supply. The chamber is equipped with a device for discharge of powder.

Claims

1. A reaction chamber for extraction of uranium dioxide powder by method of reductive pyrohydrolysis of uranium hexafluoride, which is a shell with upper and lower heads, comprising upper filtration area, equipped with metalceramic filters, regenerating nitrogen, the first reaction zone for conversion of uranium hexafluoride into uranyl fluoride, the second reaction zone with gas-distribution grid for building up fluidization layer for reduction of uranyl fluoride into uranium dioxide with a nozzle of steam, hydrogen and nitrogen supply and equipped with a nozzle for uranium hexafluoride, hydrogen and water steam supply, located on the back wall of the first reaction chamber, characterized in that the shell of the reaction chamber is additionally equipped with second nozzle for uranium hexafluoride, hydrogen and water steam supply located on the wall of the first reaction zone shell symmetrically to the first one.

2. The reaction chamber according to claim 1, characterized by nozzles for uranium hexafluoride, hydrogen and water steam supply that are movable vertically.

3. The reaction chamber according to clause 1, characterized by one nozzle being an inlet for uranium hexafluoride, and the second nozzle being an inlet for hydrogen and water steam supply.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0017] The essence of the invention is explained by the drawing.

[0018] FIG. shows reaction chamber for extraction of uranium dioxide powder by using method of uranium hexafluoride reductive pyrohydrolysis.

[0019] The reaction chamber comprises shell 1, upper head 2 and lower head 3 with a gas-distribution grid (not shown), sealed between each other with flange connections. On the upper head 2 there are tightly connected replaceable metalceramic filters 4. Each metalceramic filter 4 is equipped with an inlet system 5, installed on the upper head 2, for intermittent nitrogen supply for filter regeneration. In the side wall of compensating volume of the upper head 2 there is a nozzle 6 provided for outflow of discharge gases.

[0020] The shell 1 of the reaction chamber comprises of the upper filtration area 7, where metalceramic filters 4 are installed, located in the upper area of the shell 1, the first reaction zone 8 for converting hexafluoride into uranyl fluoride and the second reaction zone 9 for building up fluidization layer for reduction of uranyl fluoride into uranium dioxide.

[0021] The first reaction zone 8 of the shell of the reaction chamber connects the upper filtration area 7 with the second filtration area 9 of the fluidization layer. In the first reaction zone 8 there are two nozzles 10 and 11 located symmetrically for supply of uranium hexafluoride, hydrogen and water steam. The lower head 3 is equipped with nozzle 12 for supply of steam, hydrogen and nitrogen mixture into it and nozzle 13 of device for powder discharge, tightly connected with gas-distribution grid.

BEST EMBODIMENT OF THE INVENTION

[0022] The reaction chamber works the following way.

[0023] The reaction chamber is preliminarily heated up to temperature of 450°-500° C. in the upper filtration area 7 and in the first reaction zone 8 and to 580°−635° C. in the second reaction zone 9. Into the first reaction zone 8 through nozzles 8 and 11 symmetrically located on the opposite walls of the shell 1 of the first reaction zone 8, uranium hexafluoride, hydrogen and water steam is supplied. Inserted reagent enter into a reaction with each other, while uranyl fluoride powder is formed, large fraction of which goes down to the second reaction zone 9 of fluidization layer and is slowed down by gas-distribution grid of the lower head 3, and fine fraction particles go up, slowed down by metalceramic filters 4 and occasionally regenerated by nitrogen air backflow. Nitrogen-blown particles of uranyl fluoride get into fluidization layer of the second reaction zone 9.

[0024] Through nozzle 12 of the lower head 3 under gas-distribution grid a mixture of water steam, hydrogen and nitrogen is supplied, creating fluidization layer above gas-distribution grid, in which there is reduction of uranyl fluoride to uranium dioxide is performed. As it accumulates, uranium dioxide powder is removed from the reaction chamber through nozzle 13 of device for discharge of powder from the reaction chamber.

[0025] Symmetrical location of nozzles 10 and 11 with equal flows provides flow flattening in the upper filtration area 7 in parallel to its walls and provides equal load on filters 4. As a result increases time between overhaul of the reaction chamber. Exclusion of accumulation of semi-products leads to an increase of th reaction chamber performance.

INDUSTRIAL APPLICABILITY

[0026] Thus, supplying of the reaction chamber structure for extraction of uranium dioxide powder by method of reductive pyrohydrolysis of uranium hexafluoride with additional nozzle allows to solve the set task of increasing time between overhaul of the chamber, increase operating life of filtration components and achieve increase in performance of the chamber at the cost of minimizing semi-product formation.