At Bikini, the early diagenesis toward a steady state condition following
each test was complicated by subsequent testing in similar geographical locations.
Similarly, redistribution of radioactive materials deposited on the
land, reefs, and littoral areas would occur from the action of longshore currents, tides, rainfall, groundwater seepage, waves and storms, including infrequent typhoons in the area.
In the review of the literature, the subject material was categorized in
ane of six general topics, as follows:
(1) the production and occurrence of
transuranium elements; (2) the introduction of radioactivity in fallout from
the different devices detonated at Bikini Atoll; (3) the physical and chemical
properties of plutonium and americium in aqueous solution; (4) plutonium distributions in marine sediments; (5) the physical and chemical nature of Bikini
sediments and hydrological transport process; and (6) previous radiological
surveys of Bikini and Eniwetok sediments.
3.1
Production and Occurrence of Transuranium Isotopes
In 1940 the production and subsequent discovery of plutonium was
made by the nuclear reaction
238), (d,2n) 2384, mar 2385,, and was reported
by Seaborg and co-workers (1946).
al. in 1941 (1946).
Plutonium-239 was discovered by Kennedy et
In 1942 Seaborg and Perlman (1948) demonstrated the nat-
ural occurrence of about 10 -14 ‘g Pu/g U in pitchblende.
In several? subsequent
investigations the Pu/U ratio {n natural materials has been shown to remain
fairly constant at around 107! (Keller, 1971).
The work of several investi-
gations has since indicated that the ee in responsible for naturally
occurring 239Pu is 238 (n,y) 239, ri* Np
cit.).
saa> 239py (Keller, op.
The source of neutrons for these reactions is predominantly from the
spontaneous fission of uranium and from {a,n) reactions of alpha particles
with nuclei of light elements in the uranium-bearing ore.
Small quantities