for a specific badge, the exposure of the film badge during the period it was in the
mess hall (H+28.75 to H+35.25) must be added to the calculated film badge dose as of
H+28.75 hours. This "mess hall dose" is approximately 12 rem.
From the personnel interviews it is possible to calculate the H+28.75 film badge
dose for two of the film badges whose readings are given in Table 2 (badge #311 and
#312). In addition, it is possible to calculate the H+28.75 hour dose for the badge that
was hung on the tent post in the Army area (badge #314).
Table 3 compares the
calculated film badge dose at H+35.25 hours (the calculated dose at H+28.75 hours plus
the "mess hall dose”) and the corresponding film badge reading (from Table 2) for these
three film badges.
The activity scenarios or protection factors pertinent to the other
badges are insufficiently known to permit meaningful comparisons.
Table 3. Comparison of calculated film badge doses with dosimetry.
Film
Calculated Dose
@H+28.75 hrs
Calculated Dose
@H+35.25 hrs
Film Badge
Badge
CN
Reading (Table 2)
Ratio
311
416
32 rem
44 rem
40 rem
L.10
312
ali
38
50
44
1.14
314
N/A
100
112
98
[.14
From Table 3, the calculated dose to a specific film badge at H+35.25 hours is
approximately 10-14 percent higher than the actual film badge reading.
That these
ratios are similar under varying circumstances of exposure suggests that there is a
systematic overestimation of dose in the foregoing analysis.
The difference between
the calculated doses and the film badge readings could easily be accounted for in the
uncertainties associated with defining the free-field radiation environment and
protection factors on Rongerik. Thus, the estimated doses in Table | are reduced by a
factor of I.1 in order to be consistent with the dosimetry results.
This adjustment in
the Table | doses yields the best estimates of film badge doses received by the
personnel on Rongerik.
Such an approach provides the most consistency when the
exposures are characterized by a mix of film badge readings and calculated doses.
Results are presented in Section 5.
15