The improvement of the mechanical stability and leachability of bituminized waste form of radioactive ash by addition of reused polyethylene

This study was carried out in order to produce bituminized waste forms, whi ch have dimensional and mechanical stability like cement-based waste forms. This paper reports the effects of adding polyethylene (PE) to the bitumini zed waste form. The additive used for the experiment was the spent PE gener ated from agricultural use. The bitumen used in the sample preparation is s traight-run distillation bitumen of penetration 60/70 (paving asphalt). The waste used for the experiment was a bottom ash generated from an industria l (inactive) waste incinerator. Bituminized waste forms with PE contents of 5 wt% or more resulted in maintaining dimensional and mechanical stability . The compressive strength and softening point of bituminized waste forms i ncrease in proportion to the amount of additional PE. The leaching test usi ng ANS 16.1 shows that the principal leaching mechanism of elements (Cs, Sr , Co) from bituminized waste forms is diffusion. Furthermore, it is demonst rated that additive PE of 5-10 wt% does not change the leaching mechanism, and bituminized waste forms maintain a high leach resistance.