Radiation damage effects in candidate titanates for Pu disposition: Zirconolite

• Published in: Journal of nuclear materials Vol. 372; no. 1; pp. 16 - 31
• Main Authors: Strachan, D.M., Scheele, R.D., Buck, E.C., Kozelisky, A.E., Sell, R.L., Elovich, R.J., Buchmiller, W.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2008; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; GENERAL STUDIES OF NUCLEAR REACTORS; Installations for energy generation and conversion: thermal and electrical energy; leaching; Nuclear fuels; plutonium disposition; radiation damage; titanate; waste form; zirconolite; Swelling; Alpha decay; Radiation effect; pH; Titanates; X ray; Dissolution; Radiation damage; Damaging; Nuclear reactor; Crystalline structure
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2007.01.278

Results from studies of radiation-induced damage from the alpha decay of 238Pu on the density and crystal structure of a nominally phase-pure zirconolite and two other zirconolite-bearing ceramics are discussed. Macro and micro swelling were found to be temperature independent, whereas the density determined with He gas pycnometry was temperature dependent. Approximately 2.6 × 10 18 α/g were needed to render the specimens X-ray amorphous– more to saturate the swelling. Unlike pyrochlore-based ceramics, we did not observe any phase changes associated with storage temperature and damage ingrowth. The forward dissolution rate at a pH value of 2 for material containing essentially all zirconolite is 1.7(4) × 10 −3 g/(m 2 d) with very little pH dependence and no dependence on the amount of radiation-induced damage. Even after the radiation-induced swelling saturated, the specimens remained physically intact with no evidence for microcracking. Thus, the material remains physically a viable material for the disposition of surplus weapons-grade Pu.