<a CHAPTER8 RUNIT (YVONNE) CLEANUP AND CRATER CONTAINMENT PRECLEANUP CONDITIONS “Ne Runit is the fifth largest island in the atoll, containing approximately acres. The island and adjoining reef were used for nine nuclear events, a nine more were detonated on barges in the nearby lagoon (see Figure 1).! Cleanup of Runit, like other islands with several ground zeros, v complicated by actions taken to prepare for and clean up after someoft ts. eycontamination from the Zebra event of Operation Sandstone on 15 M 1948 was pushedinto the Zebra Crater and covered with clean soil in 19 to prepare for the Dog event of Operation Greenhouse. After | Blackfoot event of Operation Redwingin 1956, the tower area was scrar to reduce radiation to a safe level for personnel reentry. During the sa operation, the Erie event produced heavy contamination with muchof| test device and tower debris remaining in the ground zero (GZ) ar Experimental specimens, propelled by the Erie explosion, were blown deep as 5 feet into the earth andas far as 300 feet west of the GZ. Th recovery required moving a reported 100,000 cubic yards of earth fr depths up to 5 feet and spreading it in 2-inch layers to be searched. 1957, this soil was returned to the excision area which was then leveled. the Quince event of Operation Hardtack I in 1958, only the high explos component was detonated, scattering plutonium over a large area. prepare for the Fig event scheduled 12 days later, 3 to 5 inches contaminated soil were removed from a 60-foot square around the Qui! GZ and disposed ofin the lagoon. The Fig eventitself was a very low or nuclear detonation. It left a highly contaminated crater which wasfill leveled, and covered with clean soil.2 These actions left the same mart cake effect of swirling layers of clean and contaminated soil on Runit was caused (to a lesser degree) by similar actions on Aomon (Sally) < Enjebi (Janet) after several nuclear tests. However, the Fig and Qui shots left numerous plutonium contaminated fragments of centimet range dimensions in addition to fallout contamination. It was th fragments which led to the quarantine of Runit described in Chapter. For the Lacrosse event of Operation Redwing in 1956, massive amou of soil from Runit were used to construct an island and connect causeway on the northern reef. These were vaporized or blown awayin detonation, leaving a crater roughly 55 feet deep and 400 feet in diame