Table 6 (Cont'd)
Sample
Collection
Date
12-3-55
12-3-55
11-26-74
Days Post-
Deconation
642
642
7575
Utirik, pCi guia
60¢,
1255,
1.9x107!
-
-
1.6x107!
4.0x1073
-
1.6xl1075
7575
7575
8240
2.0x107!
9.4x1072
1.8x107!
-
5-8-77
8469
-
-
10-13-77
10-13-77
10-14-77
8627
8627
8628
1.3x107!
-
-
1.3x107!
~
10-13-77
10-14-77
10-14-77
8240
1.6x107!
8627
1.1xi07!
8628
8.6x1072
8628
1.6xl0-4
3.5x107>
-
11-26-74
11-26-74
9-21-76
9-21-76
137¢,
1297
3.7x107>
5.4x1074
2.3x1072
1.8x10°
-
2.2x109
155eu
-
2.5xi07!
=1.4x10°
2.2x109
2.8x10°
2.4x107!
-
1.7x1072
6.7x107!
-
2.0x1072
5.7x107©
l.lxl07>
1.6x109
9.0x107!
7.0x107!
l.lxl07>
1.6x109
-
9.6x107©
-
2.3x1072
7.8x1071
1.2x100
3.2x100
-
-
-
-
“Multiply by 0.037 to obtain Bq gui,
islands after all of the fallout was on the ground.
The fallout decay exponent
was assumed by us to be ~1.2 in order to extrapolate activity present on March
8, 1954, back to activity present on March 1, 1954. The exponent, -1.2, is the
theoretical value for mixed fission products and is considered suitable for
estimating the correspondence of
I soil results with other measuregents. At
Utirik, the focal fallout activity per unit mass of soil was 7.8 x 10° Bq g_
(0.21 uCi g*) at 1.5 days post-detonation.
The ratio of nuclide activity per unit mass of soil to the total beta
activity per unit mass of soil was tabulated in Table 7, column B. This ratio
applies at the times of cessation of fallout. The values in column B were
compared to values estimated from measurements on actual BRAVO fallout and those
estimated by calculation using hypothetical undisturbed fission product yield
data. These estimates for BRAVO fallout activity ratios and those for hypothetical undisturbed fission products were determined as follows.
5.
The Ratio of Nuclide Activity to Fission Product Activity for Thermonu-
clear Fission. Nuclide activity relative to total fission product activity was
estimated from data on thermonuclear fission of 738y given by Crocker (Cr65).
Total activity values given by Crocker do not account for chemical and physical
deletion or enhancement of fission products, production of activation products,
or production of transuranics. Total activity per 10,000 fissions at 0.5 and
-~14-