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A polyphase titanate ceramic incorporating sodium-free simulated high-level nuclear waste was doped with 0.91 wt% of 244Cm to accelerate the effects of long-term selfirradiation arising from (Y decays. The ceramic included three main constituent minerals: hollandite, perovskite, and zirconolite, with some minor phases. Although hollandite showed the broadening of its X-ray diffraction lines and small lattice parameter changes during damage ingrowth, the unit cell was substantially unaltered. Perovskite and zirconolite, which are the primary hosts of curium, showed 2.7% and 2.6% expansions, respectively, of their unit cell volumes after a dose of 12 X l O I 7 (Y decayvg-'. Volume swelling due to damage ingrowth caused an exponential (almost linear) decrease in density, which reached 1.7% after a dose of 12.4 X l O I 7 a decaysg-'. Leach tests on samples that had incurred doses of 2.0 X 1017 and 4.5 X l O I 7 a decays.g-' showed that the rates of dissolution of cesium and barium were similar to analogous leach rates from the equivalent cold ceramic, while strontium and calcium leach rates were 2-15 times higher. Although the curium, molybdenum, strontium, and calcium leach rates in the present material were similar to those in the curium-doped sodiumbearing titanate ceramic reported previously, the cesium leach rate was 3-8 times lower.

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