Weapons effects test designed to explore the cratering effects of a subkiloton nuclear device detonated in a shallow emplacement about one hour after the detonation radiation intensities of 0.1 R/h and greater were confined within 1000 meters of ground zero except for a broad area to the north where they extended beyond five kilometers by seven days after the detonation the area with radiation intensities of 1 R/h or greater did not extend beyond 980 meters north of ground zero.