The immobilisation of anion exchange resins in polymer modified cements

Organic anion exchange resins, loaded with⁹⁹Tc pertechnate were incorporated into polymer modified cements and BFS/OPC(9∶1) cements. The composites formed were tested for initial compressive strenghts, underwater and radiation stabilities and leach rates. IAEA standard leach testing was with simulated sea and ground waters. Ground water leaching was also carried out on composites subjected to 1.1 MGy (γ). Polymer modified composites performed better than the BFS/OPC mix under all the conditions studied and, in most cases, were able to encapsulate high resin loading.     

The uptake of radioisotopes onto clays and other natural materials

Montmorillonite and illite clays were examined for their ability to take up cesium and strontium radioisotopes from solution. Uptakes onto near homoionic Na, Ca, Mg and Sr clays were assessed by distribution coefficients measured at different Na, Cs, Mg, Ca and Sr solution concentrations. Some experiments were carried out at different pH, and to check the effect of differing anions. In addition measurements of the uptake of ruthenium species were made.     

Plasma ignition thresholds in UV laser ablation plumes

Ultraviolet (UV) laser thresholds for plasma ignition on solid targets predicted from electron-neutral collisional heating are generally much higher than those observed experimentally. This inconsistency was reconciled by Rosen, et al. [2], who showed that excited-state photoionization played a key role in long-pulse UV laser breakdown. Here we develop a related model but with emphasis on pulses of ~10 ns duration. Experimental results are also reported for titanium, copper, silicon, and ferulic acid targets in vacuum, irradiated with combinations of the XeF, KrF, and ArF lasers for comparison with predictions.