RAW MIX AND METHOD FOR PRODUCING RADIATION SHIELDING CONCRETE Russian patent published in 2003 - IPC

FIELD: material science; heavy high- strength shielding concrete for manufacturing spent nuclear fuel shipment and storage containers. SUBSTANCE: raw mix for producing radiation shielding concrete has in its composition cement, cinder filler, superplasticizer, water, and in addition it has thermally treated product of zeolite alkali modification of monoclinic or cubic structure in amount of 0.3-1.0 mass percent. Mix includes grade SELEKS-KM or TsMP-A zeolite of 0.01-0.1 mm fracture, cement of grade not worse than M-500 in amount of 600-640 kg per cu. m, cinder in amount of 3000-3500 kg per cu. m, and water in amount of 150-200 kg per cu. m. Machine flame scaling cinder can be used in the form of mixture of coarse fraction of 5.0 to 20 mm and fine fraction of 0.16 to 5.0 mm in mass proportion of 1.5 : 1, respectively, and superplasticizer based on Na salts of condensation product of sulfonaphthalene acid and formaldehyde in amount of 1%. Method for producing radiation shielding mix includes division of flame scaling cinder into fractions, its thermosetting, step-by-step introduction of water, cement, and superplasticizer, stirring, and weathering; mentioned cinder is pulverized in ball mill; zeolite of monoclinic or cubic structure treated with 2 5% solution of sodium hydroxide and calcined at 400 - 600 C is added to mix. Zeolite can be introduced in the form of granules fractionated to 0.01-0.1 mm in amount of 0.3-1.0 mass percent. Concrete produced from this mix is capable of sorbing Cs 137 and other long-living isotopes; it is noted for fire and explosion safety and can be used to advantage for manufacturing container meeting IAEA requirements with respect to strength, shielding properties, and shipping conditions by means of standard facilities. EFFECT: enhanced radiation safety, water tightness, gas tightness, and mechanical strength. 7 cl, 1 tbl