JPS58194742A - Denitration of uranium - Google Patents

Abstract

PURPOSE:Powders of UO2 and/or U3O8 are fed into the fluidized bed of UO3, uranium nitrate is introduced into the bed and the denitration is effected by heating with microwaves, thus conducting denitration without external heaters. CONSTITUTION:UO3 powders, UO2 and/or U3O8 powders are introduced into the fluidized bed 2 and air is fed to make a fluidized state, then uranyl nitrate solution is sprayed from nozzle 4. Microwaves are applied and the powders of UO2 or U3O8 generate heat, because of their large dielectric loss, to gasify the water and nitrogen oxides in the solution and the gases are removed from the exhaust gas treater 5, after UO3, UO2 or U3O8 powders accompanying the gases are separated. In the meantime, the dehydrated and denitrated uranyl nitrate solution is converted into a UO3 powder and the powder is recovered into the recovering tank 9, as it is mixed with UO2 or U3O8 powders. Further, UO3 is converted into U3O8 and UO2 with hydrogen in reductive calciner and UO2 is collected in the vessel 12. A part of the product is contained in the powder feeder 14 for reuse.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a subject! Microwave md by co-feeding materials in a fluidized bed
This invention relates to a method for denitrifying uranium in which a reaction is caused to reduce the amount of material to be treated to m4.

[Technical background of the invention]

1*1 Knee-heated flow excited bed reactor is constructed by forming a double-flow excited bed inside the reaction tower (with a bipartite plate, and above the dispersion plate).
In the IIB bed (introduces two stone holes and heats the material to be treated).

This heating means (second) is a means of pumping hot air from the lower part of the release plate.

The first step is to use OU as an enthalpy rate-determining process for all the woodworkers who are worried about the moisture content (in the second case, it is necessary to use I).
49 in I & Sumire, there is a technical or economic need to find another means of heating.

- One such enthalpy-limited process is denitrification and mue mining, which forms part of the process of reprocessing historical fuel.

This process involves thermally decomposing the cranyl cuprate stock solution to remove moisture and N.
O, gas is released, and uranium oxide (to
l), an enthusiasm of approximately 2000 K cat/# U g K is charged.

In response to such support, the heated flow-bed reactor used in the denitrification reaction process is heated by an external heating method equipped with a double-resistance heater, etc. ing.

[Problems with background technology]

This external heat method (2) is easy to supply the required heat (2) and requires problems that prevent C2 from being carried out effectively.

In other words, since such a method (according to 2) has a limited area of M4 of 42, it is necessary to appropriately select a means to provide the required spacing, and in order to increase the processing capacity to 0, −〇When aiming to scale up, consistency becomes a problem.

On the other hand, in order to secure the necessary amount of heat, the temperature of the device at the level of the 12th grade is lowered. This will result in an increase.

History 4: When the wall temperature of the bed is raised, it becomes difficult to control the particle size of the UOs powder produced, which is a temporary effect of the fluidized bed! II
There is an increased risk of heat transfer failure (such as agglomeration of the fluidized bed, etc.) due to external interference, making it impossible to operate the equipment (2) and other serious troubles.

For this reason, heating means such as resistance heaters are
It is possible to use an internal control system with 42 units installed inside the tower, but since the material to be treated is exposed to radioactive material,
v) It is necessary to pressurize the leakage of ejectable material O. In addition, maintenance and replacement of the heater, etc., may cause structural problems, and in particular, in a general O cylindrical fluidized bed, the particle I51 mobilization state is good (62 to maintain the knee, and the internal heater size is 1
! Due to the Kl limit, the effect of increasing the heat transfer area is limited.

[Purpose of the invention]

The present invention has been made to eliminate the above drawbacks, and increases and thickens the heating efficiency in the R# floor, eliminates the need for external heaters used as indirect heating sources, and requires less maintenance and inspection. C: Yes, to provide a method for easily denitrifying carbon dioxide.

[Summary]

In order to achieve the above object, the present invention introduces uranyl nitrate into a uranium dioxide fluidized bed and heats and denitrates the uranyl nitrate. A micro-serial heating system characterized by heating and denitrifying IItI uranyl by mixing uranium oxide, uranium oxide, or a mixture of these powders. It's a method.

[Start-〇Embodiment] Hereinafter, with reference to Drawing 1, the present invention (microwave heating vL sea bream bed according to 2. Reaction Engineering Ii!4=
This will be explained using an example.

In FIG. 42, the microwave input from the microwave oscillator 1 heats the conductor pipe type A and the floor.

Accent IIt1 bed 2 (= is the nitrate sent from the supply device 3 that converts into uranyl #!! - the injection nozzle 4 and the rising upper air (2 entrains the *# end to the exhaust gas treatment device 5 (= includes) An exhaust line 6 is provided.

'Also, if the lower end of the fluidized bed 2≦2, the dispersion value 15 and the air supply device 7
An air supply line 8 that supplies air 42 from the air supply line 8 and a mixed powder of 2-year-old uranium or impregnated uranium or a mixed powder of these and a denitrification product is collected and recovered 94; A 2-in-10 plowing discharge is provided.

On the other hand, from the mixed powder, uranium dioxide is transferred from the waste disposal equipment 111m to 92 ton oxidation (2 conversion IA), and further (unionized uranium oxide (:; 41 ton) is converted to product storage vessel 12 (2 conversion. The material 1Il passes through the powder supply device 13,
Powder feeding device 14 (second feed and reuse).

Note that numerals 16 and 17 in the figure indicate pulp.

In the Al11 as described above, the tri-condensed powder and uranium dioxide or uranium oxide or a mixed powder thereof are placed in the vt excimer 2 (in the designated nursery case, the one sent from the Air is supplied at a constant rate, and the solanyl nitrate bath f& is supplied from a 4N spray nozzle to a 4N spray nozzle.

On the other hand, the microwave is guided d'jF type fE, - in the bed 2 (2), so the -4 body loss (atanJ) is large for uranium dioxide or injected uranium oxide powder, and UO3 powder is Energy that could not be generated by the technical department is also generated by the technical department,
The water and water added to the nitric acid solution become water vapor, NO, and gas.

This exhaust gas containing water vapor and NO rises,
Since this exhaust gas is accompanied by fine powder of UOsO rice powder uranium dibanide or injected uranium oxide, this fine powder is removed by exhaust gas 36*t5 and released into the atmosphere.

On the other hand, the H8 product dehydrated and denitrified nitrate-1 uranyl solution is U
The Os powder is mixed with uranium dioxide or injected uranium oxide powder and passed through a discharge line 10 to be collected by a crystallization device 9 (two collection devices).

In addition, 42 recovered Ichigobanfu were mixed with I72 trioxide by roasting 7A 4 parts 1 and 1 hiuran (Yu, Sara ζ dihydroA).
Uranium dioxide (diconverted) in a gas atmosphere.

- The product is collected in the product storage vessel 12. In addition, the tin produced by Youhou passes through the scraper J device 13 and is supplied with powder IIi.
! 1 device 14 and used again.

The above m1-A example is especially for the -4 of the tangent process of the fuel for convenience.
Denitrification reaction process (IJ1)
Suitable for treating 1# Cranil hemorrhoid fluid).

In other words, the width of such a single bed is limited to the column diameter or width of the fluidized bed due to criticality safety issues, but the width U is limited to the column diameter or width of the fluidized bed.
The dimension of 1- of one bed shown by A-A' arrow is 100~
If the distance is set to 150 m, there will be no criticality safety issue.

〔Effect of the invention〕

In the above-mentioned reaction of Sogo Nihon Kaimei] Toho 62, 4
Inside the corrugated tube-shaped fluidized bed (: the mixed carbon dioxide and the carbon dioxide contained in the dui-in tama-seikan itself absorbs microwaves and heats them up, becoming an indirect FA source.
However, by mixing uranium nitride or cemented uranium powder, the energy loss will be reduced and the heating efficiency will be increased.

Therefore, it is possible to easily heat the solution in the fluidized bed or the water that is dispersed in the fluidized bed.

The effects of the present invention are summarized as follows.

(1) Since uranium dioxide or pentoxide itself absorbs microwaves and generates heat, the material to be treated can be salted for a short time. I can do it.

(2) Maintenance and inspection of the scissors 11L becomes easier because an external heater, etc., which was conventionally used as indirect heat 1, is no longer required.

[Brief explanation of the drawing]

The drawing shows a microphone wave heating flow for carrying out the method of the present invention.
The bed reactor is 3 public (required in the block diagram shown in two cross sections. l...Microwave 9?i Stainless steel 2... Waveguide/υ type gn, -bed 3...Liquid supply device 4...Mist nozzle 5...Boat waste processing device 7...Air supply device 9...Mixed powder Unrecovered device 11... Roasted arm S and bowl 12... Raw collection storage container 13... Powder transfer diaphragm 14... Powder storage device 15・・・・・・Dispersion plate

Claims (2)

[Claims] (1) Introducing ζ dinitrate trioxide in a uranium trioxide fluidized bed, and using microwave irradiation (42), the nitrate in the fluidized bed was exposed to cranyl. 11' In the heating and denitrification process, heat denitrification of the ζ22, uranium chloride, or a combined powder of these in the fluidized bed. A method for denitrification of uranium. (2) The fluidized bed 42 is a powder recovery tcit1 rotor reduction device,
The uranium denitrification method A Dankaden according to claim 1, where *a' is defined as the provision of a powder transfer device and a powder supply device.