DE1767184C - Process for the concentration and storage of radioactive boron waste water and facility for carrying out the process - Google Patents

Description

of existing foam storage container 7 above the concentrate, the total volume of which

intended. _{about emer} pyjiung of 1 corresponds Eindickungsgefäßes

In order to further develop the facility for implementation, it is to be filled. Subsequently, this tion of the method incorporating the invention, storage vessels can be driven directly to the storage location with the trolley 8, as is recommended in the last-mentioned literature. The point filled into the storage container is known per se, for condensation of the solidified solution solidifies after cooling, since the vaporized liquid contains a subsequent thermal trium borate solution only the integrable crystal exchanger and condensate water for its collection.
holder to be provided. _{During the} thickening from the thickening

In the storage containers there is advantageously a steam vessel 1 flowing off via a line 9

Load cell arranged for level measurement. a heat exchanger 10 supplied, in which the

On the basis of a schematic drawing, vapor is condensed. Then the condensate

construction and mode of operation of an exemplary embodiment sized steam in a condenser container 11

the method having the invention and the catch and finally via the line 12 to one

Establishment for its implementation explained in more detail. x ₅ waste water tanks are discharged.

The core of the system is a cylindrical inlet thickening vessel 1, the sodium borate solution provided with a stirrer 2 above the liquid level is and can form in the lower area from the outside via heating foam, is not shown in detail devices 3 is heated. It is essential to provide a measuring device based on the principle that the lowest water level in the vessel works above the electrical conductivity measurement. There half of the uppermost heating zone is located to a local this foam if necessary radioactive stock-overheating and thus to avoid crust formation. can contain parts, can thus be avoided, For this reason, the thickening vessel 1 with that this foam with the steam flowing off in a lower limit indicator 13 is provided, which controls the heat exchanger 10 and the condensate container The heater switches off when the liquid level 15 11 flows off.

drops below this minimum value. The use of sodium borate solution has proven to be effective

borrowed water level as well as the density of the concentrate proved to be particularly advantageous and simple,

are with a measuring device 14, which after the bubbling there among other things in chemically controlled reactors

method works, measured. The boron is usually already contained in the primary circuit by the measuring device.

14 outgoing measuring probes 15 and 16 extend up to 30. However, it is also possible, if necessary, instead

to use a different salt at the bottom of the vessel or below the surface of the sodium borate,

at minimum liquid level. in which part of the water in solution is

Is bound via a feed line 4 in the cover of the thickener so that the. appropriate

Vessel 1 first flow the radioactive waste water solution after evaporation of the excess water

solidified from concentrate containers not shown in detail in 35.

the thickening vessel. After evaporation of the process described and the excess The water content is the at high thickening plant it is possible to simple and temperature still liquid sodium borate solution over an economical way on the one hand the final volume of the to reduce regulated drain 5 at the bottom of the vessel 1 via sewage and on the other hand this Abeine the downstream filling lines 6 to thicken in a 40 water without additives and in the solid the storage container 7 is filled. The level transfer this state. The plant described is Storage container 7 is extremely reliable with a load cell compared to conventional ones because 17 measured. If, for example, the first storage area is simple and there is no risk of explosion like container 7 is filled, the supply valve closes in the case of Bitufnieranlagen. In addition, is also of the first line 6, and the corresponding valve in 45 a corrosion of the storage container in the final storage feeder The next line opens, so that one after the other the stands are excluded.

1 sheet of drawings

Claims (8)

To incorporate bitumen or cement in order to be able to store them in a solid state. When using the bitumen or cementing systems 1. Method for concentration and storage increases the amount to be stored, however, entirely of radioactive boron-containing wastewater, in the case of 5 considerably, since only a relatively small amount of the wastewater can be bound by adding caustic soda or wastewater. In addition, sodium hydroxide can be converted into a state mixed with sodium borate, especially in bitumen plants, increased risk of fire, as the waste water in the hot addition is characterized by the fact that the stand is mixed with the bitumen,
radioactive, sodium borate solution containing xo The object of the invention is therefore to concentrate wastewater by heating it to such an extent and store it until the remaining water can be found by cooling wastewater in which, on the one hand, possible crystallization as water of crystallization A low final volume is reached and a hazardous trium borate is bound. the environment through fire or decomposition 2. The device is excluded for implementing the procedural ts of the storage container. rens according to claim 1, characterized by a This object is achieved according to the invention by Thickening vessel (1) which is provided with a heating pre-release so that the radioactive, sodium borate solution (3) in the jacket and a stirrer (2) holding wastewater is provided by heating and a regulated inlet (4) is narrowed until the remaining water through the waste water in the lid as well as a regulated 20 cooling crystallization ak crystal water of the Na drainage (5) for the thickened solution is bound to its trium borate,
has the deepest point. It is from U.S. Patent 3,008,904 3. Device according to claim 2, characterized in that a method for concentrating and storing indicates that the single-radioactive waste water is known to crystallize out, in which also the Thickened solution storage container (7) provided as radioactive Absind containing sodium borate solution, into which the thickened solution can be filled. water can be concentrated by heating. With this one 4. A device according to claim 2, characterized in that the method is also used indicates that the thickening vessel (1) is spray-drying the concentrate when it is heated a lower limit indicator (13) for the min and the resulting powder least fill level above the uppermost heating zone (3) 30 mass after a further addition of material to a is provided. solid form melted. In contrast, every 5. Device according to claim 2, marked in the method according to the invention that net by a measuring arrangement (14) for a measuring end product after heating without additional additional the water level and the density of the Kon- liehe measures alone during its Abfüllvorzentrats according to the bubbling method. 35 passed into its solid form, so that the 6. Device according to claim 2, characterized by a powdery intermediate product and indicates that a precaution based on the necessary protective measures and access Conductivity measurement working measuring additional separating devices are avoided, Device for measuring from above the con A device for carrying out the Erfinzentrats occurring foam is provided. 40 manure exhibiting method consists of one 7. Device according to claim 2, characterized in that the thickening vessel is provided with a heating device in the indicates that the condensation jacket and an agitator are provided and one steamed liquid a downstream heat-regulated inlet for the wastewater in the lid as well exchanger (10) and a condenser to collect it - a regulated process for the thickened solution sat container (ll) is provided. 45 at its deepest point. Such a one 8. Device according to claim 2 and 3, although the direction is from the magazine "Kerntechnik", characterized by a load cell (17) for the 8th Jg., 1966, No. 3, pp. 105 to 107, in particular Level measurement in the storage containers (7). Fig. 4, known, but only for a bitumen system, but a different procedure 50 is used. To crystallize out the according to the invention Thickened solution having processes are also known from the last-mentioned literature reference The invention relates to a method for Kon2en- storage containers provided in which the thickened soldering and storage of radioactive solution containing boron 55 can be filled. In addition, the drainage, in which the wastewater by adding a thickening vessel with a lower limit indicator Caustic soda or sodium hydroxide in one with Na- for the minimum height above the top heating zone trium borate solution displaced state are provided and also has a measuring arrangement for den, as well as means for performing this a measurement of the water level and the density of the Procedure. 60 concentrates using the bubbling method. In reactors chemically controlled with boric acid, there is foam when the concentrate is stirred known that the resulting from the primary circuit can and must be prevented that radioactive boron-containing wastewater initially by adding radioactive components to it Set of caustic soda or sodium hydroxide to new foam in a to condense the evaporated neutralize so that the boron as sodium borate or 65 liquid downstream heat exchanger and the Natriunimetaborat is bound. the condensate tank connected to it flows off, For the preparation of this radioactive sodium there is also one based on the electrically conductive borate solution it is also known to measure the wastewater in kcitsmcssimg mhcitcndc for mi ^ iin »