# US 5,702,608 A · Process and installation for the decontamination of radioactive nitric effluents containing strontium and sodium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,608 A - Document ID: US5702608A - Status: Granted - Kind: A - Application number: 08/571,847 - Filed: 1996-02-05 - Granted: 1997-12-30 - Earliest claimed: 1993-07-08 - Assignees: Compagnie Generales Des Matieres Nucleaires - Inventors: Jacques Foos; Alain Guy; Marc Lemaire; Bruno Leclere; Gerard Le Buzit; Pierre Doutreluingne - Web page: https://patentgrep.com/patent/US5702608A ## CPC - G21C 19/46: Aqueous processes {, e.g. by using organic extraction means, including the regeneration of these means} - B01D 11/0457: {comprising rotating mechanisms, e.g. mixers, mixing pumps} - G21F 9/125: {by solvent extraction} - Y02E 30/30: Nuclear fission reactors - Y02W 30/50: Reuse, recycling or recovery technologies - Y10S 210/912: Heavy metal - G21C: NUCLEAR REACTORS (fusion reactors, hybrid fission-fusion reactors G21B; nuclear explosives G21J) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - G21F: PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR (radiation protection by pharmaceutical means A61K8/00, A61Q17/04; in cosmonautic vehicles B64G1/54; combined with a reactor G21C11/00; combined with X-ray tubes H01J35/16; combined with X-ray apparatus H05G1/02) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract The invention relates to a process and an installation for the decontamination of radioactive nitric effluents containing strontium and sodium. According to this process, contacting takes place in 1 of the aqueous effluent with an organic phase incorporating a crown ether such as DCH18C6 and a diluent such as CHCl.sub.3, in order to selectively extract the strontium with respect to the sodium, followed by the reextraction of the strontium in an aqueous solution in 3, followed by fixing in 5 on a cation exchange resin. This leads to a high strontium decontamination level with a very high concentration factor. ## Claims ### Claim 1 Process for the decontamination of a radioactive nitric aqueous effluent containing strontium and sodium, wherein the effluent has a nitric acidity of 0.5 to 2N, a strontium concentration up to 2 .mu.g/l and a sodium concentration of 0.01 to 0.2 mol/l, comprising the steps of: a) contacting the aqueous effluent with an organic phase incorporating a crown ether and a diluent, chosen so as to obtain an extraction selectivity of strontium compared with sodium such that the D.sub.Sr /D.sub.Na ratio, in which D.sub.Sr and D.sub.Na respectively represent the strontium and sodium distribution coefficients, is equal to or above 100 and D.sub.Sr is at least equal to 1, b) reextracting the strontium present in the organic phase in an aqueous solution, and c) fixing the strontium reextracted in said aqueous solution on a cation exchange resin. ### Claim 2 (depends on 1) Process according to claim 1, wherein the crown ether complies with the formula: ##STR3## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 which can be same or different represent a hydrogen atom or an alkyl group with 1 to 18 carbon atoms, or in which R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 form with the two carbon atoms to which they are linked, a saturated or aromatic hydrocarbon cycle with 6 carbon atoms. ### Claim 3 (depends on 1) Process according to claim 1, wherein the crown ether is DCH18C6 of formula: ##STR4## ### Claim 4 (depends on 1) Process according to claim 1 wherein the diluent is chosen from among 1,1,2,2-tetrachloroethane, chloroform, dichloromethane, 1,2-dichloroethane, nitrobenzene, benzonitrile, chlorobenzene, bromobenzene, 1,2-dichlorobenzene and 1-chloronaphthalene. ### Claim 5 (depends on 3) Process according to claim 3, wherein the organic phase is constituted by the crown ether DCH18C6 in the form of a mixture of its isomers or in the form of its cis-syn-cis isomer and in that the diluent is chloroform. ### Claim 6 (depends on 1) Process according to any claim 1 wherein the crown ether concentration of the organic phase is 10.sup.-3 to 0.15 mole/l. ### Claim 7 (depends on 1) Process according to claim 1 wherein the aqueous strontium reextraction solution has an acidity below 0.1N. ### Claim 8 (depends on 1) Process according to claim 1 wherein the cation exchange resin is sulphonated polystyrene. ### Claim 9 (depends on 1) Process according to claim 1 wherein the strontium fixed to the cation exchange resin is recovered by washing it with a 1 to 5N nitric acid solution. ### Claim 10 (depends on 1) Process according to claim 1 wherein the aqueous effluent has a nitric acidity of 0.5 to 2N, a strontium concentration up to 1 .mu.g/l and a sodium concentration of 0.01 to 0.2 mole/l. ### Claim 11 (depends on 3) Process according to claim 3, characterized in that the diluent is chosen from among 1,1,2,2-tetrachlorethane, chloroform, dichloromethane, 1,2-dichloroethane, nitrobenzene, benzonitrile, chlorobenzene, bromobenzene, 1,2-dichlorobenzene and 1-chloronaphthalene. ### Claim 12 (depends on 1) Process according to claim 1, wherein step (a) includes circulating the effluent and the organic phase in a first liquid-liquid extraction device, and withdrawing organic phase from the first liquid-liquid extraction device, step (b) includes circulating the organic phase withdrawn from the first liquid-liquid extraction device into a second liquid-liquid extraction device wherein the aqueous solution is circulated to reextract strontium from the withdrawn organic phase into the aqueous solution, recycling the organic phase from the second liquid-liquid extraction device into the first liquid-liquid extraction device, and step (c) includes circulating the aqueous solution from the second liquid-liquid extraction device into a cation exchange resin column for fixing the strontium on the cation exchange resin, withdrawing aqueous reextraction solution from the cation exchange resin column and recycling the aqueous reextraction solution from the cation exchange resin column into the second liquid-liquid extraction device. ### Claim 13 (depends on 12) Process according to claim 12, wherein a portion of the aqueous reextraction solution is recycled from the second liquid-liquid extraction device into the first liquid-liquid extraction device, and water is added to the aqueous reextraction solution.