ee 5a alOea as
16
3.3-2
Physical-Chemical States and Observations in situ
Lai and Goya (1966) showed that plutonium metal reacts
aly with seawatic
stelding a nonuniform distribution of solid reaction
products of which only about one yo per day went into solution for each mg of
reaction product produced.
Kubose et al. (1968) investigated the dissolution
cf C3E ud. microspheres (Pu02 is formed only at high temperatures) placed in
sea Sediment.
The dissolution rate determined after five months’ exposure
was believed to be dependent on the development of an oraanic encrustation
forming over the 238 Pulo spheres.
The dissolution rate of these microspheres,
assuming a mean microsphere diameter of 100 um, was about 4 ng/me/s (Patterson
et al., 1974).
When similar dissolution rate studes at temperatures of 120
ar4+ 199 C were carried out, large reductions in the dissolution rates were
attributed to the formation of a calcium sulphate coating on the Pu02 spheres
(Yubose et al., 1967a).
Recently, Patterson et al. (op. cit.) reviewed the literature dealing
with the dissolution of Pus under environmental conditions.
These investi-
gators haveehontetst
that the dissolution of Pu, during its first few hours of
contact with seawater is on the order of 100 times higher than that occurring
at later times.
They also showed that the dissolution rate of 239 Pudo is on
te order of 100 times lower than the rate for 238ou0,,
22s
The higher rates for
Fu%2 dissolution can be attributed to the much higher specific alpha radio-
activity of 2385
Linaren (1966) found that when either Pu (III), Pu (IV), PuOo++ or dis.
sci} ve” plutonium
metal was equilbrated with seawater, about 30% of the
resulting species are anionic and about 70% are nonmigrating in an electric
¢
‘4
‘e't.
.
.
:
Wher high fired
Pu0. was dissolved in seawater, however, the distribu-
Line was 22"
anionic, 23% cationic and 55% nonmigrating.
Lingren suggests