"The overall program goal is to develop techniques that will lead to predictable and economical recovery of oil from oil shale by a modified in situ process. To achieve this goal, the Phase I project was directed to specific research efforts defined to develop an understanding of and to develop a predictive capability for in situ oil shale fragmentation. These research efforts include: stress wave propagation characteristics of oil shale; oil shale characteristics which control fracture and fragmentation; explosive characteristics which control fracture and fragmentation; geometric characteristics which control fracture and fragmentation; and predictive capabilities of preretort fragmentation design given local geological features and material behavior. A detailed test plan to evaluate the fragmentation characteristics is presented in Table 1."