Published 1987 | Version v1
Report Open

Evaluation of the vitreous matrices to include high-level radioactive wastes

Description

The Argentine Nuclear Programme considers a fuel cycle with Pu recycle. This will generate high-level liquid wastes, that should be safely eliminated. With this purpose, primary glasses utilizing three prototipe compositions were prepared. Simulated wastes oxides in the rate of about 10% were added to the vitreous matrices. The mixture was melted in ceramic melting pots in a muffle furnace at 1 100 deg C during 8 hours. Resistance leaching tests were made following an adaptation of the DIN 12 111 standard. Quantitative analysis of the leaching solutions were made to evaluate the solubility of the different elements. Glasses were observed with optical microscopy scanning before and after leaching. In the first, glasses, bubbles and crystalline-phase appear; in the second ones, puncture and embrittlement were detected. By means of differential thermoanalysis, endo and exothermal peaks were identified in glasses supporting gradual heating. X ray diffraction analysis were made in samples with and without wastes. The degree of crystallization of samples was evaluated by photographic and diffractometric techniques. Leaching studies showed the existance of a direct relation between leaching and glass alkaline content. (M.E.L.)

Availability note (English)

MF available from INIS under the Report Number; Also available from Comision Nacional de Energia Atomica, Buenos Aires (AR).

Abstract (Spanish)

El plan Nuclear Argentino contempla un ciclo de combustibles con reciclado de Pu. Esto hace que se generen residuos liquidos de alta actividad, que deben eliminarse en forma segura. Con esta finalidad, se prepararon los vidrios primarios, empleando tres composiciones prototipo. A las matrices vitreas se les agregaron los oxidos de los residuos simulados en un 10% en peso. La mezcla se fundio posteriormente dentro de cristales ceramicos en horno mufla a 1,100 grados C durante 8 horas. Se efectuaron los ensayos de resistencia a la lixiviacion mediante una adaptacion a la norma DIN 12.111. Se realizaron analisis cuantitativos de las soluciones de lixiviacion, para evaluar la solubilidad de los diferentes elementos. Mediante microscopia optica de barrido, se observaron los vidrios antes y despues de lixiviados. En los primeros, aparecieron burbujas y fases cristalinas; en los segundos se detectaron picaduras y resquebrajamiento. Mediante analisis termico diferencial, se identificaron picos endo y exotermicos, que se presentan en los vidrios durante un calentamiento gradual. Se realizaron ensayos de difraccion de rayos X en muestras con y sin residuos. Mediante tecnicas fotograficas y difractometricas, se evaluo el grado de cristalizacion de las muestras. Los estudios de lixiviacion permitieron verificar la existencia de una relacion directa entre ella y el contenido alcalino del vidrio. (M.E.L.)

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Additional details

Additional titles

Original title (Spanish)
Evaluacion de matrices vitreas para inclusion de residuos radiactivos de alta actividad

Publishing Information

Imprint Pagination
15 p.
Report number
CNEA-NT--20/87

Optional Information

Secondary number(s)
CNEA-REPO--24.