High strength cementized dried resins

One common method for disposal of radioactive resins is to mix them with cement and cast them into monolithic blocks in rigid liners (containers). In some cases, cementized resin samples have reabsorbed water and swelled until the cement crumbled. Therefore, the NRC Branch Technical Position on waste forms requires cementized bead resin to undergo a 0.34 MPa (50 psi) compressive strength test after immersion in water for 90 days in order to qualify as an acceptable radioactive waste disposal form. Many cementized resin waste forms cannot achieve high radioactive waste loading and still qualify as a waste form after the 90-day immersion strength test. It was found that chemically spent resins pretreated in a high efficiency dryer are nearly impermeable to water and will not reabsorb and swell when immersed. The chemical form of the resins was found to be an important factor in water reabsorption. Fresh resins in the H/sup +/ or OH/sup -/ form were susceptible to water reabsorption after high-efficiency drying. However, depleted resins were found to be well-suited for cement solidification and high-strength waste forms were produced with loadings as high as nearly 28 wt.% dried resins (equivalent to 70 wt.% dewatered resins). These waste forms easily withstood the compressive strength test after initial curing and after 90 days of immersion in water