Drop calorimetric measurements on a versatile monazite phase loaded with simulated radioactive waste

Monazite is one of the candidate ceramic matrices for the immobilization of high level radioactive waste (HLW) from the reprocessing of spent nuclear fuel. The monazite phase, Ce 0.8 Ca 0.2 PO 4 , can accommodate cations of different valences due to the mixed valence state (+3 and +4) of Ce in this...

Full description

Saved in:
Bibliographic Details
Published in:Journal of thermal analysis and calorimetry 2014-09, Vol.117 (3), p.1151-1156
Main Authors: Asuvathraman, R., Joseph, Kitheri, Joseph, Jose, Krishnaiah, M. V., Govindan Kutty, K. V.
Format: Article
Language:English
Subjects:
Analytical Chemistry
Calorimetry
Chemistry
Chemistry and Materials Science
Crystals
Inorganic Chemistry
Measurement Science and Instrumentation
Nuclear industry
Oxides
Phosphate minerals
Phosphate rock
Physical Chemistry
Polymer Sciences
Radioactive pollution
Radioactive wastes
Reactor fuel reprocessing
Structure
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Monazite is one of the candidate ceramic matrices for the immobilization of high level radioactive waste (HLW) from the reprocessing of spent nuclear fuel. The monazite phase, Ce 0.8 Ca 0.2 PO 4 , can accommodate cations of different valences due to the mixed valence state (+3 and +4) of Ce in this compound, by facilitating the oxidation and reduction of the Ce 3+ and Ce 4+ as required by the in-coming cation. This will assist in accommodating HLW of different compositions in the monazite crystal structure even if the average valence of the HLW elements is other than 3. Therefore, the monazite phase, Ce 0.8 Ca 0.2 PO 4 , can be a versatile host for the immobilization of HLW. The enthalpy increment and heat capacity of this versatile monazite phase and a simulated waste form based on it with 20 mass% HLW oxides were measured by drop calorimetry in the temperature range from 373 to 873 K, and the results are compared with those measured for CePO 4 .
ISSN:1388-6150
1588-2926
DOI:10.1007/s10973-014-3873-5