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