C 410302 UNIVERSITY OF WASHINGTON SEATTLE, WASHINGTON 98195 August 23, 1974 College of Fisheries Laboratory ef Radiation Ecology Mr. Roger Ray Asst. Manager for Operations USAEC, Wevada Operations Office P. O. Box 14199 Las Vegas, Nevada 89114 Dear Mr. Ray: A second supplement to the 1973-74 Johnston Atoll contract was in amount of $5977 for the analvses of samples collected at Rongelap Bikini in April, 1974. A report of the first results of analyses submitted to Mr. Tommy McCraw, DOS, on 3 July, and a copy of that the and was letter is attached. Following is a report of the results of the analyses for the remaining samples. Plutonium, iron-55 and strontium-90 analyses, except for one strontium-90 sample that was lost, have been completed for 38 samples of soil, fish and _ coconut crabs collected on Bikini Island and Rongelap Atoll in April, 1974. The results of these analyses are given in Tables la, 2a, 3a, 4, 5a and 5h. Relative to the 3 July report, Tables la, 2a, 3a, 5a and 5b supplement Tables 1, 2, 3 and 5, and Table 4 replaces Table 4. In the soil samples, most of the 996, Pu, and gamma-emitting radionuclides werg in the top 25cm of the profiles. Strdnatium-99 levels in the coconut crabs were greater for the Bikini than for the,Rongelap samples and, as exnected, the greatest tissue concentration Sarathe eneskeleton. The levels of 99¢r in the caconnt crab collected ( on Bikini Island in 1974 fall at the lower end of the ranse of values ; §Yeported by Held (1971, NVO-269-8) for coconut crabs collected on Bikini Island in 1969. Two samples, the 0 to 2.5 cm increment from soil profile #2 and the Bikini crab exoskeleton,are being reanalyzed for 29Sr because of inconsistent values for the first two analyses. Island in 1974, Mullet and goatfish collected near Bikini compared with fish collected there in 1969 similar levels of 90Sr but lower levels of 55Fe. (Held, 1971), had Except for the two samples being reanalyzed, this completes the analyses of samples described in the Second Supplement to the 1973~74 Johnston Atoll program. We are presently analyzing the remainder of the samples collected during the April, 1974, trim to Utirik, Rongelap and Bilini Atolls as part of the 1974-75 Johnston Atoll program. Results of these analyses will he forwarded to vou as they hecome available.