N

APPROXIMATE HIGH TIDE LINE, wee
® SOIL SAMPLE LOCATION;
DATUM IS MEAN TRU IN pCi/g

MARY'S

DAUGHTER

LAGOON |

--—_—__—_——_
25m
FIGURE 7-32. COASTLINE AND DATA COLLECTION LOCATIONS FOR ISLAND MARY’S DAUGHTER
1972 Survey

Twenty-five locations were soil sampled during the 1972 survey, and a few vegetation samples were
also collected. Four of the samples were 0-35 em profiles and 21 were 0-15 ecm core samples. Most
of the profiles show a steady decrease in activity with increasing depth for the isotopes, 13%c5,
Osr an 23%240py, the exception was a profile taken on the beach where the activities for 137¢g
and 239,240 py inereased to a depth of 7.5 em and then steadily decreased, and the 90s, activity
dropped at 3.5 em, increased at 7.5 em, and then decreased rapidly with increasing depths.

‘Tables 7-1, 7-2 and 7-3 summarize the results of the 1972 sampling of Nancy for 0-15 cm data on

137Cs, 90sr and 239,240py, respectively.

Characterization

Nancy was measured with the IMP in March 1978 on a 25 m grid because of the small size of this
island. Soil samples were collected at five locations with two composites at each of three depths

for a total of 30 samples. (See Section 4.2.1 for more information on soil sampling.) The results
from these samples were used to estimate a ratio of TRU to 241 am of 2.7 + 0.05 (see Tech Note
2.11). Both the IMP and soil sample locations are shown in Figure 7-33.
~

241

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