Currently there are 104 commercial nuclear reactors operating in United States of America and approximately 63,000 metric tons of spent fuel has been produced by 2014. The United States Department of Energy, Office of Used Nuclear Fuel Disposition is currently investigating repository disposal system in deep borehole environment. Research and development challenges provide opportunities for contribution to the United States of Americas ongoing efforts in this area including but not limited to seal integrity and cement degradation. Deep borehole disposal will be utilizing existing oil and gas well drilling systems and component technologies that pose several unique and significant challenges. Among these are the cement material challenges surrounding the seal integrity of the drilled boreholes. As seen recently, one of the major factors in Gulf of Mexico oil-well explosion was failure of cement and the results were disastrous. If the cement fails when the long-lived radioactive waste has been disposed in deep boreholes, then relocation and re-access will be problematic and the result will be catastrophic with environmental, economic and societal consequences. Moreover, it is recognized that drilling may be the greatest barrier to the development of a suitable deep borehole disposal concept as it will be expensive to carry out such drilling to achieve the desired performance and the success of the concept. Hence, the concept faces both technical and economic challenges. In summary, balancing the structural integrity of the cement and costs associated with drilling is a challenge and driver for the pursuit of new, improved and innovative cementitious materials for the cementing slurry formulations, plugs and grout. This Phase 1 proposal is to pursue a new and innovative approach to obtain cementitious material compositions suitable for deep borehole disposal applications. Applications include cementing in drilling, completion and repair, plugs and grout in boreholes. The cementitious materials will be produced using a selective process technology and the selective composition feed materials. Systematic investigation will be performed to establish optimum process technology operating conditions and physico-chemical composition. Phase 1 Products chemical composition will be free of deleterious impurities present in the current conventional cementitious materials. Chemical and physical properties will provide chemistry/cement of very high strength, very low permeability, durability and thermal stability. Phase 1 Products will simplify design of the current complex cementing slurry formulations and provide more control to the cementing service providers in preparing and applying the cementing slurries. These products will significantly mitigate waiting-on-cement costs, improve economics of construction of boreholes and, thus, combat cost of drilling barrier to the adoption of deep borehole deposit concept. Phase l cementitious products will be produced, characterized, tested and compared with a current potential state-of-the-art commercial product in the market for technical performance. If Phase 1, proof-of- concept, is positive, then Phase 2, proof-of-engineering and Phase 3 commercial demonstration will be pursued. An interdisciplinary team consisting of entrepreneurial company, an academic institute, cement chemistry and process technology consultants and a cementing services providing company will work on the project. In addition to radioactive waste disposal, the proposed cementitious material markets will be in oil and gas industry for cementing of wells during drilling, in carbon dioxide enhanced oil recovery, in carbon capture storage construction, in areas of interest to Department of Defense/Air Force and companion civil applications, i.e., rapid runway or highway repair and in civil structures including tunnel walls and containment for hazardous waste.
