Shot 1 sample 251.02 (lend station) wes the first processed. Asa result of the observations from that experiment, significant improvements were made in the procedure. Therefore, the results of that run, which gave 10 per cent Np(IV) and $0 per cent Np(V-VI), were not considered signifi-~ cant. On sample 251.04, Shot 1, an attempt was made to shorten the neptunium procedure considerably by eliminating some of the purification steps. However, decay curves of the product indicated impure neptunim which invalidated the results, TABLE 3.)1 - Summary of Analysis of Neptunium Oxidation States Shot Station Np(Iv) Np(V-vI) Sample Source 1250.05 2-74 3-Coca TC 58 LL 66 42 56 34 Lagoon station Free floating buoy Center of lagoon 65 +11 35+ 11 pT 1 2 3 3 4 3-251.02 4-¥39 Average (4) (%) e 20 23 Island station YAG=39 The decay of the various neptunium fractions for all samples was followed for at least three half-lives, In every case, except those specified above, the neptunium showed no indication of any impurities. Decay was followed with a gamma scintillation counter, Gamma ray spectrometer data were also used to help identify the Np samples. 3.3.2 Chemical State of Icdine The chemical state of iodine in the fallout samples was determined for Shots 1 through 4. The procedures and results are given in the following sections, 3430201 Chemical Treatment of Samples Several procedures were used to investigate the oxidation and phase state of iodine in the fallout material. In the first procedure, BaClo was added to the origine) sample to precipitate the sea water sulfate and any iodate present as Bal0,. The sample was centrifuged to separate the solid and liquid phases, “Iodide and iodate carriers were added to the supernatant ani precipitate, respectively, and the iodine oxidized and reduced with NaNO5 and NagS03 alternately while in contact with a CCl, phase to extract the iodine as Ip. This procedure actually gave the amount of iodine in the liquid and solid phases when the two were initially present (as was the case in the samples as received fcr Shots 1 and 3). In anothor procedure, the sample was dissolved in a mininm amount of HCl, divided into two aliquots. 57 Iodide carrier was added to