Radiation damage effects in candidate titanates for Pu disposition: Pyrochlore

• Published in: Journal of nuclear materials Vol. 345; no. 2-3; pp. 109 - 135
• Main Authors: Strachan, D.M., Scheele, R.D., Buck, E.C., Icenhower, J.P., Kozelisky, A.E., Sell, R.L., Elovich, R.J., Buchmiller, W.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.10.2005; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear fuels; W0200; P0700; T0800; R0400; A0600; Electron microscope; Swelling; Radiation effect; Titanates; Ceramic materials; Dissolution; Isotopes; Radiation damage; Damaging; Nuclear reactor; Crystalline structure
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2005.04.064

Laboratory experiments on titanate ceramics were performed to verify whether certain assumptions are valid regarding the swelling, chemical durability, and microcracking that might occur as 239Pu decays. Titanate ceramics are the material of choice for the immobilization of surplus weapons-grade Pu. The short-lived isotope 238Pu, was incorporated into the ceramic formulation to accelerate the effects of radiation-induced damage. We report on the effects of this damage on the density (volumetric swelling <6%), crystal structure of pyrochlore-bearing specimens (amorphous after about 2×1018α/g), and dissolution (no change from the fully crystalline specimen). Even though the specimens became amorphous during the tests, there was no evidence for microcracking in the photomicrographs from the scanning electron microscope. Thus, although pyrochlore is susceptible to radiation-induced damage, the material remains chemically and physically viable as a material for immobilizing surplus weapons-grade Pu.