CS271287B1 - Method of radioactive waste stabilization - Google Patents

Abstract

The proposed method solves the fixation of radioactive concentrates, saturated organic radioactive ion changers and waste arising during the decontamination of metal parts of nuclear power plants to modified bitumen. In the function of modifiers ataxic polypropylene and polypropylene oil are used. The ratio of ataxic polypropylene to bitumen ranges from 0.1:9.9 to 1.5:8.5 and the ration of polypropylene oil to bitumen range from 0.1:9.9 to 1:9.

Description

The invention solves the fixation of liquid radioactive concentrates, saturated organic radioactive ion exchangers, calcinate and sludge resulting from decontamination and metal parts of nuclear power plants into modified bitumen.

BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION The fixation of radioactive waste to bitumen resolves the fixation of liquid radioactive concentrates using a film rotor evaporator and macaque bitumen type. semi-blown or blown bitumen · The use of different types of bitumen for the fixation of various radioactive wastes is mainly due to their different physico-chemical properties. In order to avoid sedimentation phenomena for fixation of saturated, organic, radioactive ion exchangers, calcinate and sludge after decontamination, more viscous types of bitumen, such as macadamous bitumen types, used for fixation of radioactive concentrates in film, rotor scrubs are used. fixation of radioactive waste imposes increased economic costs for construction of heated storage tanks for various types of bitumen, technological operations with sharp bitumen and operation of bituminization equipment ·

The proposed method of fixation of radioactive waste fixes by its nature the fixation of radioactive concentrates, saturated organic, radioactive ion exchangers, calcinate and sludge, resulting from decontamination and metal parts of nuclear power plants into modified bitumen. Atactic polypropylene, polypropylene and polypropylene the bitumen is in the range of 0.1: 9.9 to 1.5: 8 * 5 and the ratio of polypropylene oil to the bitumen is in the range of 0.1: 9.9 to 1; 9. Bitumen may be mixed with additives in a storage tank equipped with a mixing device or directly in a homogenizer or, in the case of a continuous] radioactive waste fixation technology, it may be advantageously metered in the required quantity by suitable dosing equipment. ALIGN! 23032004, 04:02:44 - evaporate the radioactive concentrates, or in a suitable mixing device, the calcinate prepared by evaporating the water from the radioactive concentrates in a rotary horizontal drier; Saturated radioactive ion exchangers, resp. wet sludge must be dried to the extent necessary before fixing to avoid the possibility of leakage of the mixture of bitumen and radioactive waste after its release into the storage container ·

The proposed solution will use one type of soft bitumen for fixation of radioactive concentrates in a film rotor evaporator and for fixation of calcine, organic saturated ion exchangers and sludges after decontamination as well as in a suitable mixing device. of the compounds in the modified bitumen from 40-45% to 50-55% _t , reducing the desorption of salts and radionuclides from the resulting bitumen product by one to two orders. Atactic polypropylene, which is produced as a waste product in the production of isotactic polypropylene, is used to modify bitumen in addition to polypropylene oil. The modified bitumen according to the proposed method is prepared directly in the operation of bitumenisation equipment at nuclear power plants. Such technology makes it possible to operatively prepare modified bitumen with suitable fixation properties

radioactive waste ·

Method of Fixing Radioactive Concentrates, Calcinate, Saturated Organic Radioactive Ion Exchangers, and Sludges into Modified Bitumens with Atactic Polypropylene and Polypropylene Oil This is explained in the following examples without limiting its validity.

CS 271287 Bl

Example 1

For 1000 kg of a bitumen type with a soaking point of 40 to 65 ° C, which is heated in a tank to a temperature of 120 to 140 ° C, 62 kg of atactic polypropylene and 22/6 kg of polypropylene oil are added with stirring. after the addition of these modifying agents, the bituminous, modified mixture is tempered with stirring for 30 minutes to complete melting of the atactic polypropylene and its dispersion in the molten bitumen. Modified bitumen and radioactive concentrate are metered into the film rotor evaporator in proportions such that the resulting bitumen product contains 50% fixed salts (according to the salinity of the radioactive concentrate). Leachability of salts and radionuclides from bituminous samples It is on the order of ´ ° g.cm ”.day (after 63 days of leaching).

Example 2

To 1000 kg of macaque bitumen having a soaking point of 40 to 65 ° C, which is heated in a tank to a temperature of 110 to 130 ° C, 53 kg of atactic polypropylene and 11 kg of polypropylene oil are added with stirring. The treated bitumen is tempered with stirring at temperatures of up to 130 [deg.] C. for half an hour in order to completely melt the atactic polypropylene and disperse it in the bitumen. To the heated mixing tank

3 with a volume of 200 dm, 80 dm of modified bitumen heated to 110-130 [deg.] C. are metered in and 80 kg of a dried mixture of organic saturated radioactive exchangers is added in portions with stirring. Leachability of bituminous radionuclides •• fi - 7 in - 1 samples It is of the order of 10 to 10 g.cm. Day.

Example 3

For 1000 kg of macaque bitumen having a soaking point of 40-65 ° C, which is heated in a tank to 120-140 ° C, 87 kg of atactic polypropylene and 33.6 kg of polypropylene oil are added with stirring. The treated bitumen is tempered with stirring at 120-140 [deg.] C. for half an hour in order to completely melt the atactic polypropylene and disperse it in the bitumen. 80 dm of modified bitumen heated to 120 to 140 ° C is metered into a heated mixing tank of 200 rpm and 53 kg of dry sludge with a maximum bound water content of 5% by weight is added in portions with stirring. The leachability of radionuclides from bituminous samples is of the order of 1θ ”θ to io” ⁷ g.cm ”day ^{2 -} * ¹ .

Example 4

100 100.0 kg of poppy type bitumen having a soaking point of 40-65 ° C, which is heated to a temperature of 120 to 140 ° C in a homogenizer, are simultaneously mixed with 100 kg of a mixture of dried organic radioactive ion exchangers and a melt of atactic polypropylene 8 with polypropylene oil. wherein the ratio of atactic polypropylene to polypropylene oils is 2: 1. The melt of said mixture is prepared in a duplicator vessel equipped with a stirrer and is metered at a temperature of 100 ° C using a gear pump with measurable power to bitumen of 10 kg. The dosing of the organic radio ion exchangers and the melt-modifier must be synchronized so that their addition to the bitumen is terminated simultaneously. The rectility of the radionuclides from the bituminous samples is of the order of 10 ^-6 to 10 ~ ⁷ g-cm ² day ¹ .

Claims (4)

OBJECT OF THE INVENTION Method of fixation of radioactive wastes, saturated organic radioactive ion exchangers and radioactive sludge resulting from decontamination of metal parts of nuclear power plants to modified bitumens, characterized in that the addition of atactic polypropylene in the amount of 0.1: 9.9 to 1.5: 8 is used for bitumen modification. 5 kilograms of bitumen and addition of polypropylene oil in a ratio of 0.1: 9.9 to 1: 9 k of bitumen.