Solubility, speciation and local environment of chlorine in zirconolite glass–ceramics for the immobilisation of plutonium residues

Abstract

Understanding chlorine speciation and incorporation in glass ceramic wasteforms underpins future treatment of contaminated plutonium residues.

Synthesis and characterisation of HIP Ca0.80Ce0.20ZrTi1.60Cr0.40O7 zirconolite and observations of the ceramic–canister interface

“…X-ray absorption spectroscopy (XAS) is a fundamental technique in support of nuclear waste management, as an effective means to probe the local structure and valence chemistry of radionuclides in immobilisation matrices, supporting the safety case towards geological disposal through underpinning the underlying crystal chemistry of actinidecontaining wasteforms [16][17][18]. Accordingly, Ce L 3 and Cr K-edge X-ray absorption near edge structure (XANES) data were collected alongside a series of reference compounds representing Ce and Cr in a variety of oxidation states and coordination environments, allowing the speciation and local environment of Ce and Cr to be inferred.…”

Thermal treatment of Cs-exchanged chabazite by hot isostatic pressing to support decommissioning of Fukushima Daiichi Nuclear Power Plant

“…The changes imposed to the workpiece include the conversion into a passively safe solid monolith product, with exclusion of porosity and voidage (with respect to powder and granular materials) [9]. For these reasons, HIPing is currently under consideration as a thermal treatment process for conditioning radioactive wastes ranging from sludges [10,11] and high level wastes [12,13] to portions of the UK Pu stockpile [14][15][16][17]. Typically, the resulting HIPed wasteform will be a ceramic or glass-ceramic matrix, where the waste is an integral component of the host matrix [18,19].…”