South Korean technicians conduct a ground-penetrating radar survey during investigations into claims of toxic dumping at Camp Carroll, a US army logistics base, in the town of Waegwan in Chilgok county, 216 km (134 miles) southeast of Seoul, June 2, 2011.South Korea and the US are jointly investigating claims by ex-servicemen who said last month they had buried the toxic chemical defoliant Agent Orange at Camp Carroll in 1978.