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AbstractAbstract
[en] The radiological characterization of radioactive waste and effluents requires the measurement of many radionuclides, including 90Sr. The usual methods for 90Sr analysis are efficient but they are relatively long and require the use of toxic products such as fuming nitric acid and scintillation cocktails. This thesis work consisted in developing new analytical procedures for 90Sr analysis, in particular new separation methods. A first method based on successive selective precipitations was optimized using design of experiments methodology and speciation modelling. Fuming nitric acid was replaced by concentrated nitric acid at 69 % while preserving the separation selectivity between Sr and Ca, and an understanding of the mechanisms involved in this precipitation was provided. A second method using the Sr chromatographic extraction resin was developed by including a new pre-treatment based on the TRU resin, allowing the elimination of problematic interferents for liquid scintillation measurements, such as 241Pu. Finally, a method was developed with a scintillating resin called PS-Sr resin, which enables to isolate Sr, to perform a nuclear measurement by plastic scintillation and thus to be compatible with REACH regulation. The performances of the methods were validated by participation in inter-laboratory comparisons. (author)
[fr]
La caracterisation radiologique des dechets et des effluents radioactifs necessite la mesure de nombreux radionucleides dont le 90Sr. Les methodes usuelles d'analyse du 90Sr sont performantes mais elles sont relativement longues et necessitent l'utilisation de produits toxiques tels que l'acide nitrique fumant et les liquides scintillants. Ce travail de these a consiste a developper de nouvelles procedures d'analyse du 90Sr, en particulier de nouvelles methodes de separation. Une premiere methode basee sur des precipitations selectives successives a ete optimisee a partir de la methodologie des plans d'experiences et de la modelisation de la speciation. A l'issue de ces travaux, l'acide nitrique fumant a ete remplace par de l'acide nitrique concentre a 69 % tout en preservant la selectivite de la separation entre le Sr et le Ca et une comprehension des mecanismes mis en jeu lors de cette precipitation a ete apportee. Une seconde methode utilisant la resine d'extraction chromatographique Sr a ete developpee en integrant un nouveau pretraitement base sur la resine TRU, permettant d'eliminer les interferents problematiques pour la mesure par scintillation liquide, comme le 241Pu. Enfin, une derniere methode a ete mise au point avec la resine dite scintillante appelee resine PS-Sr qui permet d'isoler le Sr, d'effectuer une mesure nucleaire par scintillation plastique et ainsi d'etre conforme a la directive REACH. Les performances des methodes ont ete validees par la participation a des comparaisons inter-laboratoiresOriginal Title
Developpement de methodes radiochimiques innovantes en vue de la caracterisation du strontium-90 dans les dechets et effluents radioactifs
Primary Subject
Source
9 Sep 2022; 244 p; 244 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses; Chimie Physique et Chimie Analytique
Record Type
Report
Literature Type
Thesis/Dissertation
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ACTINIDE NUCLEI, ALKALINE EARTH ISOTOPES, ALKALINE EARTH METALS, ALPHA DECAY RADIOISOTOPES, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, CHEMISTRY, ELEMENTS, EVEN-EVEN NUCLEI, EVEN-ODD NUCLEI, HEAVY NUCLEI, HYDROGEN COMPOUNDS, INORGANIC ACIDS, INORGANIC COMPOUNDS, INTERMEDIATE MASS NUCLEI, ISOTOPES, MATERIALS, METALS, NITROGEN COMPOUNDS, NUCLEI, OXYGEN COMPOUNDS, PLUTONIUM ISOTOPES, RADIOACTIVE MATERIALS, RADIOISOTOPES, SEPARATION PROCESSES, SIMULATION, SPONTANEOUS FISSION RADIOISOTOPES, STRONTIUM ISOTOPES, TESTING, WASTES, YEARS LIVING RADIOISOTOPES
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