Patent Number: 040101088
Section: description

In order to illustrate the preferred procedures of the present invention, the following examples are set forth. However, it should be understood that these examples are primarily for the purpose of illustration and any enumeration of detail contained therein should not be construed as a limitation. EXAMPLE 1 Water from a reactor cooling loop containing radioactive isotopes of the iron family is passed through a conduit packed with 1200 mililiters of resin beads, which beads are composed of a cation exchange resin available commercially (specifically a sulfonated styrene-divinylbenzene polymer). In this way, radioactive cationic materials are removed from the water and collected by the resin beads. The water is allowed to drain from the beads and the wet beads are then placed in a five gallon container. A 2000 ml solution or dispersion of urea-formaldehyde resin is then prepared by adding 1200 ml water to 800 ml of a dispersion containing about 63-66% solids. This diluted dispersion is then added to the wet beads in the container, and the mixture stirred by an electric stirrer at a speed sufficient to keep the resin beads substantially evenly distributed in the mixture. 50 ml of a saturated solution of sodium bisulphate is then added gradually with the stirring being continued. After the sodium bisulfate is added and the mixture gels sufficiently to hold the resin beads from sinking by gravity, the stirring is discontinued and the stirring blades disconnected and left in the mixture. The gel is then allowed to set until the cure is complete, whereupon the unit is ready for disposal. EXAMPLE 2 Water from a reactor cooling loop containing radioactive waste is mixed with 1200 ml of powdered ion exchange filter aid available in the trade as Powdex. The Powdex is then filtered and added to a 5 gallon container. A 1200 ml solution or dispersion of urea-formaldehyde resin is then prepared by adding 900 ml water to 300 ml of a dispersion containing about 63-66% solids, and the urea-formaldehyde dispersion added to the five gallon container. The mixture is stirred by an electric stirrer, and 150 ml of a saturated solution of sodium bisulfate is added while continuing the stirring. After the solution gels, the stirring is discontinued and the mixture allowed to cure into a solid thermoset mass. EXAMPLE 3 Water from a reactor cooling loop containing radioactive waste is mixed with 1200 ml diatomaceous earth, and the diatomaceous earth removed by filtration. 1200 ml of urea-formaldehyde dispersion similar to that used in Example 2, and the treated diatomaceous earth is added to a five gallon container. These materials are stirred with an electric stirrer and 100 ml of a saturated solution of sodium sulphate is added. After the solution gels, the stirring is discontinued and the mixture allowed to cure into a solid thermoset mass. EXAMPLE 4 Water from a reactor cooling loop containing radioactive waste is placed in a vacuum and about 80% of the water removed by vacuum evaporation. 900 ml of the evaporated waste water and 1200 ml of a wood celulose flour is added to a five gallon container. 300 ml of a urea-formaldehyde dispersion containing about 63-65% solids is also added. The ingredients are then stirred with an electric stirrer and 150 ml of saturated sodium bisulfate is added. After the solution gels the stirring is discontinued and the mixture is allowed to cure into a solid theremoset mass. EXAMPLE 5 The procedure of Example 4 is repeated, except that the evaporated waste water contains borate moities in the amount of about 20% by weight of the solution calculated as boric acid. Similarly good results are obtained. EXAMPLE 6 Water from a reactor cooling loop containing radioactive waste is flashed in a vacuum to remove about 80% of the water. Another portion of water from the reactor cooling loop is passed through a conduit packed with 1200 ml of ion exchange resin beads similar to those of Example 1. 1200 ml of the evaporated water, the ion exchange resin beads, and 800 ml of a urea-formaldehyde dispersion containing about 63-65% solids are mixed together by an electric stirrer and 50 ml of a saturated solution of sodium bisulphate is added. After the solution gels, the stirring is discontinued and the mixture is allowed to cure into a solid thermostat mass. The samples obtained from the procedures set forth above are compared with similar samples made with Portland Cement. In all cases, the samples made with the urea-formaldehyde were as good as or better than those made with Portland Cement. Of particular note, is the fact that certain of the cement samples did not set at all. Moreover, contact of the other cement samples with sea water caused them to crack, while the resin samples remained intact under similar circumstances. From the foregoing description, it is seen that there has been provided an improved method of disposal of radioactive waste material, and particularly an improvement over the process using cement heretofore in major usage.