Effects of Irradiation on the ß-Thorium Phosphate Diphosphate Structure - Consequences on its Dissolution

The β-Thorium Phosphate Diphosphate (β-TPD), Th4(PO4)4P2O7, can be presented as a potential performant as actinide-bearing phase for nuclear waste storage in geological deposit. This ceramic can be loaded with large amounts of tetravalent actinides like plutonium andexhibits a high resistance to aqueous corrosion and a high thermal stability. Nevertheless selfirradiation by alpha-decays due to the actinides could modify these performances. Thus, it appears necessary to study the effects of self-irradiation on the chemical and physical properties of the ceramic. Self-irradiation was mainly simulated by external exposition to radiation and the dissolution of the matrix was studied trough two kinds of experiments: 1) samples were irradiated then submitted to dissolution tests (post-irradiation dissolution: exsitustudies), 2) samples were immerged during irradiation by γ−rays and α particles which enables to study the effects of radiolysis of the leaching medium on the dissolution of the sample (in-situ studies). Other simulations were performed by internal irradiation through the loading of samples with 239Pu then leaching.

TAMAIN C.;  DACHEUX N.;  OZGUMUS A.;  GARRIDO F.;  THOME L.;  TERRA O.;  BOULET Pascal; 

2005-08-30

University of Vienna

JRC30377

https://publications.jrc.ec.europa.eu/repository/handle/JRC30377,