“q teeTe Le The ships themselves do not pose a_ significant radiation hazard, although the activity of the sediment in the immediate vicinity of some may be as high as 20 pCi/g (Appendix C). accumulating on the ships and a piece of one of the ships The sediment itself will be reported on in Appendix B, Of leaking fuel 26 sunken more concern is conventional tanks or from exploding ammunition. Japanese ships still rest on the contamination from However, at Truk Lagoon bottom of a busy harbor and apparently are not dangerous if left undisturbed (Appendix C). The vessels are being covered with increasing amounts of sediment and coral and are the site of active marine life. Moderate chronic fuel without difficulty by ecosystems owing However, the site Bikini such should be (10) examined by leakage can to divers be borne biodegradation. to ascertain the current state of the sunken ships. The third important event was the Bravo creating the sizeable crater in the lagoon off Nam Island shot in 1954, (Figure 2) which now might be used to store very low-level radioactive materials. 2.1.2 Water. especially after the Bravo Although the levels of contamination were high shot, by 1972 water was Tow enough to meet the Federal the specific-activity of lagoon standard for fresh drinking water (11 N). 2.1.3 (0-4 cm depth) limits. Sediment. The specific-activity of the lagoon sediment is higher than lagoon water but still permissible Cesium-137 activity is generally below 10 pCi/g (Figure 2), and on the lagoon bottom within 15 km of Eneu and Bikini (12). within The levels of other radionuclides in Islands it is 0.1-1 pli/g the Bikini-Eneu area are: cobalt-60, 13 plutonium, 5; americium-241, <5 pCi/g. Analyses of sediment from the northeast corner of the lagoon down to depths of 60 cm have shown that radionuclide levels fall off 5000011 18