Transformation of Cs-IONSIV ® into a ceramic wasteform by hot isostatic pressing

Research output: Contribution to journalArticle

Authors

  • Ewan R. Maddrell
  • Neil C. Hyatt
  • Amy S. Gandy
  • Martin C. Stennett

Colleges, School and Institutes

External organisations

  • Department of Materials Science and Engineering, The University of Sheffield
  • National Nuclear Laboratory

Abstract

A simple method to directly convert Cs-exchanged IONSIV® IE-911 into a ceramic wasteform by hot isostatic pressing (1100 °C/190 MPa/2 hr) is presented. Two major Cs-containing phases, Cs2TiNb6O18 and Cs2ZrSi6O15, and a series of mixed oxides form. The microstructure and phase assemblage of the samples as a function of Cs content were examined using XRD, XRF, SEM and TEM/EDX. The chemical aqueous durability of the materials was investigated using the MCC-1 and PCT-B standard test methods. For HIPed Cs-IONSIV® samples, the MCC-1 normalised release rates of Cs were <1.57 × 10−1 g m−2 d−1 at 0–28 days, and <3.78 × 10−2 g m−2 d−1 for PCT-B at 7 days. The low rates are indicative of a safe long-term immobilisation matrix for Cs formed directly from spent IONSIV®. It was also demonstrated that the phase formation can be altered by adding Ti metal due to a controlled redox environment.

Details

Original languageEnglish
Pages (from-to)33-43
JournalJournal of Nuclear Materials
Volume498
Early online date4 Oct 2017
Publication statusPublished - 1 Jan 2018