Titre du document / Document title

Ion beam-induced amorphisation of freudenbergite

Auteur(s) / Author(s)

SMITH K. L. ⁽¹⁾ ; BLACKFORD M. G. ⁽¹⁾ ; LUMPKIN G. R. ⁽¹⁾ ; ZALUZEC N. J. ⁽²⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Materials Division, Australian Nuclear Science and Technology Organisation, P.M.B. 1, Menai NSW 2234, AUSTRALIE
⁽²⁾ Materials Science Division, Argonne National Laboratory, 9700 South Cass Ave., Argonne Il, ETATS-UNIS

Résumé / Abstract

Using the HVEM-tandem facility at Argonne National Laboratory, the critical dose of 1.5 MeV Kr⁺ ions for amorphisation of freudenbergite (D_c (freudenbergite)) at room temperature was found to be 1.6±0.3×10¹⁸ ions/m², D_c (freudenbergite) is lower than D_c (zirconolite) and D_c (perovskite) (3.5-5.5 and 3.9-9.2×10¹⁸ ion/m², respectively). Freudenbergite can occur in Synroc-C, a titanate wasteform designed for immobilising high level radioactive waste (HLW). In Synroc-C, zirconolite and perovskite will contain the majority of the actinides in HLW. Freudenbergite will contain less than 0.2 wt% actinides but will experience displacement damage due to the alpha decay of actinides in surrounding phases. In agreement with the experimental findings of previous authors, the calculations show that in Synroc-C, freudenbergite will remain crystalline after zirconolite and perovskite have become amorphous. Neither of the two current parameters (structural freedom, for susceptibility to amorphisation, S) for estimating the relative radiation resistance of different phases is capable of predicting the relative radiation resistance of freudenbergite, zirconolite and perovskite. The low D_c of freudenbergite may result from Na⁺ ions having significantly lower E_d values compared to the other elements in freudenbergite, zirconolite and perovskite, in the electric fields induced by heavy ion irradiation of TEM specimens. If this hypothesis is true, it challenges the assumption that heavy ion irradiation can be used to compare the relative radiation resistance of different phases and will have serious implications for the predictive parameters of radiation resistance.

Revue / Journal Title

Journal of nuclear materials   ISSN 0022-3115   CODEN JNUMAM 

Source / Source

2000, vol. 277, n^o2-3, pp. 159-168 (45 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Amsterdam, PAYS-BAS  (1959) (Revue)

Mots-clés anglais / English Keywords

High level radioactive waste ; Waste treatment ; Conditioning ; Immobilization ; Oxide ceramics ; Quaternary compound ; Titanium Oxides ; Aluminium Oxides ; Sodium Oxides ; Amorphization ; Ion irradiation ; Krypton Ions ; Electron diffraction ;

Mots-clés français / French Keywords

Déchet fortement radioactif ; Traitement déchet ; Conditionnement ; Immobilisation ; Céramique oxyde ; Composé quaternaire ; Freudenbergites ; Titane Oxyde ; Aluminium Oxyde ; Sodium Oxyde ; Amorphisation ; Irradiation ion ; Krypton Ion ; Diffraction électron ; Na2Al2Ti6O16 ; Al Na O Ti ;

Mots-clés espagnols / Spanish Keywords

Residuo fuertemente radioactivo ; Tratamiento desperdicios ; Acondicionamiento ; Inmovilización ; Cerámica óxido ; Compuesto cuaternario ; Titanio Óxido ; Aluminio Óxido ; Sodio Óxido ; Amorfización ; Irradiación ión ; Kriptón Ión ; Difracción electrónica ;

Localisation / Location

INIST-CNRS, Cote INIST : 9265, 35400008155260.0040