The US Army Corp of Engineers Nuclear Cratering Group (NCG) program activities include: (1) cratering calibration of various geologic media and development of techniques designed to provide a desired crater geometry with chemical high-explosive detonations; (2) joint planning of and technical participation in AEC nuclear-excavation experiments; (3) development of data on the engineering properties of nuclear craters; (4) development of civil works nuclear construction technology; (5) accomplishment of engineering studies of nuclear construction feasibility; and (6)execution of joint CE/AEC civil works nuclear-construction experiments. Four conceptual nuclear-construction applications have been identified as having a significant potential for accomplishment: (1) nuclear quarrying to produce rock fill or aggregate; (2) nuclear ejecta dam construction; (3) nuclear harbor construction; and (4) nuclear canal excavation. The nuclear quarry has been identified as the most direct application of present technology. A site is currently being sought for a nuclear quarry experiment.