Apparatus for continuous dry chlorination of plutonium dioxide

 

The invention relates to nuclear energy, in particular to the production of plutonium metal and mixed uranium-plutonium oxide fuel. The inventive apparatus for continuous “dry” chlorine dioxide plutonium is made in the form of a horizontal tube, divided into three zones: load compartment 1, the heated reaction volume of compartment 2 and unloading 3. Zones can also be connected and separated by sealed valves 4, 5. Loading and unloading bays are separated from the atmosphere sealed by covers 6, 7. To move products inside the machine has 8 boats. The device is equipped with the evaporator 9 for feeding into the reaction volume of the vapor of carbon tetrachloride. The advantage of the invention lies in the fact that its use will significantly improve performance. 1 C.p. f-crystals, 3 ill.

The invention relates to the field of nuclear energy, in particular the production of plutonium metal and mixed uranium-plutonium oxide (MOX) fuel.

From the published literature devices for dry chlorination, which can be taken as analogues known, for example, laboratory XLERATOR obtained for sky "study of the processes of chlorination of uranium dioxide and plutonium carbon tetrachloride". Proceedings of the second international conference on peaceful uses of atomic energy, Geneva, 1958. Reports of Soviet scientists, "Nuclear fuel and reactor materials", Atomizdat, page 285). This XLERATOR is a closed, horizontally positioned vessel, which put plutonium dioxide. The vessel is equipped with a tube for supplying a reagent in liquid form that is included inside of the vessel by about half its length and above the processed product. This feeding tube is connected to the tank for liquid carbon tetrachloride and provided with a valve to adjust the flow rate of the reagent. For removal of gaseous products provided by the other tube. To heat the vessel to the desired temperature is provided by a horizontal tube furnace. The disadvantage of this charator is the periodic nature of the work and low productivity.

Known also XLERATOR continuous chlorination of plutonium dioxide with phosgene (A. N. Wolski, J. M. sterling "metallurgy of plutonium), Nauka, 1967, S. 145), which is a heated pipe with a slope of 4in the upper end of which serves plutonium dioxide (250-500 g/h), and the bottom serves stream of phosgene. The product inside the pipe prod and a temperature of 450-500With that allows you to use a metal pipe (for example, from an alloy Hastelloy). The disadvantages of this charator are:

the use of phosgene, is extremely toxic and hazardous reagent;

the possibility of driving a full section of pipe products of chlorination and termination of the promotion.

The aim of the invention is to develop charator high performance for continuous dry chlorination of plutonium dioxide.

This objective is achieved in that XLERATOR made in the form of a horizontal tube (see Fig. 1), is divided into three zones: load compartment 1, the heated reaction volume of compartment 2 and unloading 3. Zones can also be connected and separated by sealed valves 4 and 5, such as vacuum valves.

Loading and unloading bays are separated from the atmosphere sealed openable lids 6 and 7.

To move products inside charator provided by the boat 8. The device boats, loaded with product, shown in Fig. 2. The boat is a tank 1, an open top and provided with a double bottom, the upper bottom 2 is made of a porous gas-permeable material, and the lower bottom 3, as the rest of the boat is solid m is the inside pipe of the reaction volume. This device pumps can reduce the time required for chlorine dioxide plutonium. This is due to the nature of the movement of gaseous substances involved in the reaction of chlorination Rio2+CCl4ul3+CO2+1/2l2. Diffusion of gaseous reactant CCL4and gaseous products of reaction of CO2and CL2through the layer of powder is a factor in determining the rate of reaction, so the gas exchange with the two sides of the layer of powder can reduce the duration of the operation. The shape of the boat and the ratio of its size with the diameter of the host pipe does not allow the boat to tip over. The length of the reaction space can accommodate several boats (for example, 6 pieces), their number depends on the duration of chlorination and performance charator.

The evaporator of carbon tetrachloride 9 is connected with the reaction volume of the compartment near the discharge 3 (Fig.1) and the bottom-up part of the line for the exhaust gas (EXHAUST gas) starts from the reaction volume vicinity of the load compartment 1. This inlet and outlet fittings conform to the principle of countercurrent flow of the reacting substances. Ascending part characterized by the capacitor 4 and the separator 5. After the separator neskondensirovannyh EXHAUST gas undergo further cleaning, and line 6 for draining the condensate passes into the evaporator 7 and ends near its bottom (below the level of liquid reagent), here on line 8 takes the spent reagent (carbon tetrachloride). The boiling point of carbon tetrachloride in the evaporator 7 supports the heater 9.

List of drawings graphics

Fig.1 is a schematic representation of apparatus for continuous dry chlorination of plutonium dioxide (oven, the device opening, closing valves and lids, a device for transferring boats, pipes to change the atmosphere in the compartments 1 and 3 not shown).

Fig.2. - cross section of the reaction volume and boats with the product.

Fig.3 - diagram of the recycling of carbon tetrachloride.

XLERATOR works as follows. The apparatus is prepared for operation, is installed in the boot compartment of the boat, which is loaded plutonium dioxide (1 kg). Closing the lid 6, replacing the atmosphere in the compartment 1 on the inert and opening the valve 4, propel the boat in the reaction volume 2, preheated to operating temperature again close the valve 4 and begin filing tetrachloride vapor ugley gas, then connect the reaction volume with the boot compartment and push the loaded boat in the reaction volume.

Through a number of cycles for the installation and promotion of boats to the discharge compartment ideal first boat ready trichloride plutonium boat with the product promoted in the discharge compartment, using the method of sluicing, similar to locking when loading, remove the boat from charator that are discharged into the container, and then load dioxide plutonium and again served in the loading slot.

Next, the process goes with regular replacement of boats performance1 kg/h evaporator of carbon tetrachloride add the required amount of fluid, and the EXHAUST gas is passed through the absorber chlorine and carbon dioxide (solid CP -).

To move boats can be used simple devices (pushers, hooks or other known devices, and to monitor their correct actions (if necessary) wall extreme compartments are made of a transparent material.

Claims

1. Apparatus for continuous dry chlorination of plutonium dioxide, characterized in that the reaction volume is Soane, at the ends of the reaction volume is provided by a sealed valve that separates the loading and unloading bays on the ends of which are mounted sealed cover and inside compartments are tools for moving boats along the pipe, for feeding into the reaction volume of the vapor of carbon tetrachloride provides a heated evaporator, and to return the excess carbon tetrachloride includes a condenser vapors.

2. The apparatus according to p. 1, characterized in that boat for placing products is a tank, an open top and provided with a double bottom, the upper bottom is made of a porous gas-permeable material, and the bottom the bottom, like the rest of the boat is made of solid material, but for the passage of gases has holes are not blocked when moving boats inside the tube of the reaction volume.

 

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