JPS6049279B2 - Waste gas storage and treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention uses an ionization device with a multi-cylindrical electrode structure to ionize radioactive gas generated during the reprocessing of nuclear fuel, and the polarity of the voltage applied between adjacent electrodes can be adjusted at regular intervals. This invention relates to a multiple cylindrical waste gas storage and treatment device, in which ion bombardment and electrode material sputtering are alternately carried out by changing to the above, and radioactive gas ions are efficiently and cumulatively captured under the surface of each electrode. .

If harmful amounts of radioactivity are released into the environment, nuclear facilities such as nuclear fuel reprocessing plants may have wide-ranging and long-lasting effects, so safety must be ensured far more than in other general industries. Strictly obligated to recover uranium and plutonium, but at the same time the accompanying fission products. Radioactive waste, including radioactive waste, must be disposed of appropriately.

Of the radioactive wastes, Kr-85 is the only gaseous waste, but it has a long half-life of 10.7 years, so if nuclear power generation is expected to increase, it will cause global pollution in the future. Connect. Therefore, in addition to recovery technology, an important issue is how to safely store or dispose of the recovered Kr-85. Conventionally, methods have been considered to permanently preserve radioactive waste gas by sealing it in a pressure vessel such as a bottleneck. However, the treatment method of enclosing the material in a pressure vessel has problems in terms of safe storage over a long period of time. For example, pressure resistance is poor due to gas leakage due to corrosion of the pressure vessel. Additionally, pressure vessels are required by law to undergo periodic pressure tests, which have the drawback of requiring complicated and dangerous work such as transferring stored gas each time. This invention was made in order to solve the above-mentioned need, and its purpose is to store radioactive gas such as Kr-85 generated during nuclear fuel reprocessing in a Kr-85 storage container in which multiple cylindrical electrodes are embedded. make use of,
By changing the polarity of the voltage applied between adjacent electrodes at regular intervals, ion bombardment and sputtering of the electrode material are performed alternately, and a large amount of Kr-85 is deposited on the i-plane of each electrode.
An object of the present invention is to provide a multiple cylindrical waste gas storage and treatment device that improves the processing efficiency of Kr-85 gas by trapping ions in multiple cumulative ways.

The multiple cylindrical waste gas storage device of the present invention will now be described in detail with reference to FIGS. 1 and 2. FIG.

1 and 2 are cross-sectional views for explaining the present invention in detail. To explain its structure, 1 is a radioactive gas Kr.
-85 container, 2 is Kr-85 gas, 3 is a valve, 4 is an operation valve for exhausting Kr-85 gas to vacuum system 5, 6 is a blank rod electrode, 7 and 8 are lead wires. Cylindrical electrodes 10 and 11 are supplied with voltage from a power source (not shown), and 12 is an insulator for insulating the lead wires 9, 10, 11.

Using a device with such a configuration, Kr-85 gas 2 is introduced into container 1 via valve 3, and a voltage is applied to each electrode 6, 7, 8 to immobilize Kr-85 gas. Let me explain the case.

A constant pressure of Kr-85 gas is sealed in the container 1, and the Kr-85 gas 2 is ionized through lead wires 9, 10, 11 to each electrode 6, 7, 8. , 8, a bombardment voltage is applied with sufficient energy to plant ionized Kr-85 under the surface of the ionized Kr-85.

For example, if a positive voltage is applied to electrode 6, a negative voltage is applied to electrode 7, and a positive voltage is applied to electrode 8 for a certain period of time using a DC high-voltage power supply that can change the polarity of the applied voltage for a certain period of time (not shown in the figure). , between the positive electrode 6 and the negative electrode 7, the negative electrode 7, the positive electrode 8
Then, the ionized Kr-85 is bombarded, and Kr-85 ions are injected and captured under the surface of the electrode 7 and the inner and outer surfaces.At the same time, the inner and outer surfaces of the electrode are sputtered to expel the electrode material, and the electrode material is ejected. It adheres to the surfaces of the electrodes 6 and 8. In this manner, bombardment of Kr-85 ions and sputtering of the electrode material are performed between the electrodes 6, 7, and 8 for a certain period of time. Next, when a negative voltage is applied to the electrodes 6 and 8 and a positive voltage is applied to the electrode 7, Kr-85 ions are injected and trapped under the inner surfaces of the negative electrodes 6 and 8 by the positive electrode 7 by bombardment. The electrode materials of the electrodes 6 and 8 are sputtered out and adhered to the surface of the positive electrode 7. In this way, by repeatedly applying voltages of different polarities to the opposing electrodes for a predetermined period of time to alternately bombard Kr-85 and sputter the electrode material, Kr- 85 ion layer→electrode material layer−Kr-85 ion layer and one electrode material layer. In addition, when the Kr-85 gas in the container 1 becomes diluted due to injection and capture into each electrode, the pressure of the Kr-85 gas in the container 1 is constantly maintained by automatically operating the valves 3 and 4. It can be kept constant. After injecting and capturing the desired Kr-85 ions into each electrode in this way, the electrodes are taken out from the container and stored in a capsule, or
Store in separate containers.

The above explanation was about the case where Kr-85 gas is fixed using three electrodes, but it goes without saying that the present invention is not limited to the number of electrodes mentioned above, and the processing gas is also Kr-85 gas.
Of course, it is not limited to r-85. As explained above, according to the multiple cylindrical radioactive gas storage and processing device of the present invention, a large amount of radioactive gas can be efficiently injected and captured onto the electrode surface, and the processing capacity for radioactive gas generated during nuclear fuel reprocessing can be improved. It can be increased, and the practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the multi-cylindrical radioactive gas storage and processing apparatus according to the present invention, and FIG. 2 is a cross-sectional view taken along arrow A-A'' in FIG. 1. ...Container, 2...Radioactive gas, 3,
4...Valve, 5...Vacuum system, 6,7
, 8... Cylindrical electrode, 9, 10, 11...
...Lead wire, 12...Insulator.

Claims (1)

[Claims] 1. A container containing waste gas, a cylindrical outer electrode formed in the container, an inner electrode provided concentrically within the outer electrode, and a predetermined interval between the inner electrode and the outer electrode. and at least one middle electrode provided concentrically,
Voltages of different polarities are switched and applied to each of the adjacent electrodes at regular intervals to alternately bombard the waste gas ions to each electrode and sputter the electrode material, thereby transferring the waste gas ions to each of the electrodes. A waste gas storage and treatment device characterized by trapping multiple accumulated gases on a surface.