Deep Borehole Field Test Specifications

Abstract

This report documents conceptual design development for the Deep Borehole Field Test (DBFT), mainly the test packages (not containing waste) and the system for demonstrating emplacement and retrieval of those packages in the Field Test Borehole (FTB). For the DBFT to have demonstration value, it must be based on conceptualization of a deep borehole disposal (DBD) system for specific waste forms. This document therefore describes a current reference DBD concept, and analyzes key design options for disposal, to guide selection of options for the DBFT. The most important of these options is the emplacement mode, i.e. whether packages are emplaced using a wireline or a string of drill pipe (with a drill rig). This choice is analyzed using cost and risk models, in Sections 5 and 6. Other emplacement mode options are also identified and discussed. The reference DBD concept and the analysis of waste packaging and emplacement options, are used to develop requirements and assumptions for the DBFT and to recommend DBFT specifications. Design issues are identified, and priorities are developed for further conceptual design development and additional engineering analysis, anticipating future design activities. Conceptual design development is part of a process that proceeds in three stages: 1) conceptual design including feasibility studies; 2) preliminary design that includes technical and cost information necessary for final design; and 3) final design sufficient for fabrication or construction. The DBFT engineering demonstration will follow such an evolution. Whereas design evolution typically begins with bench-scale and pilot-scale investigations proceeding to conceptual, preliminary, and final designs, the DBFT can proceed directly to design because of extensive previous work and published literature on scientific drilling, characterization methods, waste packaging and handling, industrial deep-hole drilling and construction, and downhole operations. Hence it is anticipated that this report will lead to completion of conceptual design, then preliminary and final design, fabrication and testing, and demonstration of waste emplacement in a deep borehole.