SBIR-STTR Award

Low-level radioactive wastes would be made safe for transportation and ultimate disposal by fixation in high-performance polyethylene modules. The modules would simulate currently employed drums, 30 to 55 gallon, and they would weigh about 400-800 lbs. They would feature tough, load bearing cores to withstand overburden pressures, and 1/4 inch thick, tenacious, resilient, seam-free jackets to manage surface applied stresses. Further treatment of modules would be unnecessary to effect safe manipulation and ultimate disposal. Contaminant particulates are fixed in the cores at high concentration by a matrix of cross-linked polyethylene, prepared from a blend of two commercially available resins: 1,2, polybutadiene and powdered polyethylene. Jackets are fabricated by fusing additional powdered polyethylene upon the surfaces of the cores. The resultant bonding of tough jackets onto core surfaces advances the mechanical performance of modules. In transportation, modules would exhibit performance that exceeds requirements in Department of Transportation regulations governing transportation of hazardous materials and current regulations set forth by the Nuclear Regulatory Commission. Even under extraordinarily severe impact and stresses modules exhibit high damage tolerance. No spillage of hazardous material would occur; modules would remain safely transportable. With ultimate disposal in a landfill, environmental safety would be assured because modules would keep contaminants secure under severe leaching and earth stresses. Because of their performance, a new type of secure landfill can be constructed. Modular landfills, in contrast to plastic lined, secure landfills, would be free-draining. Leachate treatment and maintenance expenses would be mitigated. Furthermore, they would be readily cleared with conventional equipment, if required, for land reclamation or waste consignment recovery.The potential applications as described by the company: Module fabrication would be carried out as final operations of radioactive waste stream treatment processes. Unmanageable toxic residues would be secured in modules, then transported to ultimate disposal sites.

A unique combination of materials is proposed for use in stabilizing low-energy radioactive wastes, and an apparatus is set forth to carry out the stabilization operations. The process is applicable to management of spent ion-exchange resins and salts, thereby addressing the most difficult-to-manage, low-level radioactive contaminants and providing proof of principle of potential general applicability of the process. In Phase 11, contaminant simulants (e.g., ion-exchange resin powders and beads and inorganic salts) shall be stabilized in waste modules of 40-gallon capacity. Each module will weigh about 300 to 600 pounds for powders/beads and salt, respectively. They will duplicate modules proposed for securing low-level radioactive wastes (LLRW). The modules will secure contaminants by agglomeration in resin matrices, those encased by seamless resin jackets. The matrix resins will be chemically equivalent to that of coreacted 1, 2-polybutadiene and polyethylene, a resin mixture shown to have high chemical stability and high resistance to radioactivity. The jackets will be 1/4-in. thick, high-density polyethylene fusion bonded to the surfaces of the agglomerated wastes. The resin jackets provide radiation-stable reinforcement of the resin-fixed contaminants, thus yielding waste forms that assure high performance contaminant stability under harsh environmental conditions.Anticipated Results/Potential Commercial Applications as described by the awardee: In Phase 11, a fixation and encapsulation apparatus will be constructed to fabricate full-size modules containing toxic waste simulants. Phase 11 studies will provide evidence that modules will comply with DOT and NRC regulations concerning transportation and disposal of LLRWs and provide for full-scale LLRW processing. Phase 11 project results will give rise to the necessary equipment and know-how to conduct a full-scale process demonstration addressing low-level radioactive wastes.