Durability crystalline ceramics

During the past ten years, there has been considerable research devoted to the development of crystalline waste forms for actinide immobilization [7,8,24,27, 28,39,40,67,68,41-43,69]. Many of the phases are based on studies of minerals that contain Th and U, such as pyrochlore [16-18], zirconolite [70,71], zircon [1,72], monazite [73], britholite [74]. Based on their degrees of alteration, most of the minerals are considered to have an acceptable chemical durability. In addition, closely related mineral structures, such as murataite and garnet, which do not contain U or Th have been synthesized with actinides [29,75,76]. Multiphase ceramics. Ceramic matrices were initially designed for the immobilization of non-partitioned HLW from SNF reprocessing and considered... 

Dacheux N, Clavier N, Le Coustumer P, Podor R (in press) Immobilization of tetravalent actinides in the TPD structrrre. Proc 10th Inti Ceramics Congress. Vincenzini P (ed) Techna Publishers, Florence, Italy Davis DD, Vance ER, McCarthy GJ (1981) Crystal chemistry and phase relations in the synthetic miner s of ceramic waste forms. II. Studies of uranirrm-containing monazites. In Scientific Basis for Nuclear Waste Management, vol. 3. Moore JG (ed) Plentrm Press, New York, p 197-200 Day DE, Wu Z, Ray CS, Hrma P (1998) Chemically durable iron phosphate glass waste forms. J Non-Crystalline Solids 241 1-12... 

In the medical praxis, UHMWPE have been used successfully as one half of the bearing couple (against metallic alloys or ceramics) in total hip and total knee joint replacements crosslinked under irradiation [82]. Even y-irradiated UHMWPE at doses higher than 100 kGy presents the incipient ffacmre development [83], the alkyl macroradicals are involved in crosslinking and in a smaller proportion they promote oxidation [84, 85]. The prosthesis manufactures by the irradiation of UHMWPE have long durability, because the application of radiation treatment induces an increased crystallinity and promotes sterilization in the whole volume of material. 

Glass-ceramics contain an amorphous phase and a crystalline phase minimum. Their attractive properties are chemical durability, mechanical strength, lower thermal expansion coefficient compared to glasses, dielectric constant, and electromagnetic radiation transmittance. Because of these properties, they find applications in electronics, military, vacuum technology, households. 

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