Waste Form Evaluation Program. Final report

Abstract

This report presents data that can be used to assess the acceptability of polyethylene and modified sulfur cement waste forms to meet the requirements of 10 CFR 61. The waste streams selected for this study include dry evaporator concentrate salts and incinerator ash as representative wastes which result from advanced volume reduction technologies and ion exchange resins which remain problematic for solidification using commercially available matrix materials. Property evaluation tests such as compressive strength, water immersion, thermal cycling, irradiation, biodegradation and leachability were conducted for polyethylene and sulfur cement waste forms over a range of waste-to-binder ratios. Based on the results of the tests, optimal waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash and 30 wt % ion exchange resins were established for polyethylene, although maximum loadings were considerably higher. For modified sulfur cement, optimal loadings of 40 wt % sodium sulfate, 40 wt % boric acid and 40 wt % incinerator ash are reported. Ion exchange resins are not recommended for incorporation into modified sulfur cement because of poor waste form performance even at very low waste concentrations. The results indicate that all waste forms tested within the range of optimal waste concentrations satisifed the requirements of the NRC Technical Position Paper on Waste Form.