Method for separating and determining Pu, <241>Am and <90>Sr in low-radioactivity sample

Abstract

The invention relates to a method for separating and determining <238-240>Pu, <241>Am and <90>Sr in a low-radioactivity sample, which comprises the following steps: (1) sample pretreatment; (2) separation and enrichment of <238-240>Pu, <241>Am and <90>Sr: after ascorbic acid and sodium nitrite are added into a solution obtained in step (1) to regulate the valence state of plutonium into tetravalence, the solution passes through a TEVA, TRU and SR tandem extraction chromatography resin column, and the flow velocity is kept at 1mL / min to 1.2mL / min; at the moment, <238-240>Pu is adsorbed on the TEVA column, <241>Am is adsorbed on the TRU column, and <90>Sr is adsorbed on the SR column; 20mL to 25mL of hydrochloric acid solution which is 0.02mol / L is used for eluting <238-240>Pu on the TEVA column, 15mL to 20mL of hydrochloric acid solution which is 3.0mol / L is used for eluting <241>Am on the TRU column, and 15mL to 20mL of nitric acid solution which is 0.01mol / L is used for eluting <90>Sron the SR column; (3) determination of <238-240>Pu, <241>Am and <90>Sr: a cerium fluoride micro-deposition method is adopted to prepare an Alpha source, and the <238-240>Pu eluent and the <241>Am eluent are measured on the Alpha energy spectrum; the <90>Sr eluent is placed for 14 days, and after <90>Sr<-><90>Y is balanced, determination is carried out by the Cerenkov counting method. The analysismethod can be adopted to separate and enrich Pu, <241>Am and <90>Sr in a sample, and the period of analyzing Pu, <241>Am and <90>Sr is shortened.

Description

technical field [0001] The invention belongs to the technical research field of decommissioning of nuclear facilities and the treatment of three wastes, and in particular relates to Pu, 241 Am and 90 Sr separation and determination method. Background technique [0002] In the decommissioning of nuclear facilities and the treatment of three wastes, the number of samples to be analyzed is large, there are many analysis items, the level of radioactivity varies, and the analysis cycle is tight. It will face problems such as large sample volume, long analysis cycle, and high exposure dose to personnel. [0003] Currently Pu, 241 Am, 90 The three analysis methods of Sr can only refer to the environmental-level sample analysis standards. The three analysis standards are independent, and the sample pretreatment and separation conditions are different, which makes the analysis cycle long and cannot meet the analysis needs of a large number of samples for nuclear facility decommiss...

AI Technical Summary

Problems solved by technology

[0003] Currently Pu, 241 Am, 90 The three analysis methods of Sr can only refer to the environmental-level sample analysis standards. The three analysis standards are independent, and the sample pretreatment and separation conditions are different, which makes the analysis cycle long and cannot meet the analysis needs of large numbers of samples for nuclear facility decommissioning and three wastes treatment.

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