wo Runit (Yvonne) Cleanup and Crater Containment 445 roward identifying the appropriate disposition of each item. During the September 1978 survey, it was estimated that there were approximately 10,000 cubic yards of debris on Runit and its associated reef areas, 4,100 of which should be disposed ofin the crater, !00 A resurvey 2 monthslater the crater. 101 estimated that only 2,200 cubic yards need be disposed of in Someofthe higher levels of gamma contamination (maximum intensity of 25 milliroentgens per hour) were found in a twisted metal debris pile on the reef just north the old runway. Other metal located in the area of the Blackfoot GZ had gamma readings up to 17 milliroentgens per hour, !02 Debris underwater and on thereef had to be surveyed and markedseveral times because wave action removed both the paint and the engineer ribbon used to code its radiological condition. Efficiency of this operation could have been increased greatly if the USAE had been taskedto provide ~ equipment to remove debris as it was being surveyed.!03 By the end of 1978, only 1,724 cubic yards of debris had been cleaned up on Runit, most of it by the WBCT or during the removal of contaminated debris from South Runit in 1977, 104 The delays in accomplishing Runit debris cleanup had adverseeffects. The landing craft which had been beached near Station 1310 during the testing period to provide shore protection were sufficiently exposed in 1977 to have permitted complete demolition and removal. However, by late 1979, due to settling and shifting sands, only portions of the superstructures were exposed, and major excavation would have been ~ required to remove them. These landing craft were not contaminated; therefore, it was decided to remove the exposed hazards only. The most serious adverse effect of the delays, however, was that red debris continued to be located after containment operations had been completed, requiring extraordinary measures for containment. These are described in a subsequent section. [n all, 4,120 cubic yards of contaminated debris and 11,482 cubic yards of noncontaminated debris were removed from Runit andits reef. RUNIT SOIL CLEANUP ~ Several alternatives for cleanup of contaminated soil on Runit were considered at the 4 May 1978 Enewetak Cleanup Planning Conference including: a. No cleanup; b. Clean all concentrations over 160 pCi/g immediately; c. Clean all concentrations over 160 pCi/g after all other soil cleanup was complete; and