The probable error of each reading in the figures besed upon preliminary calibration data, is plus or minus 15%, Fig 2.10-1 is a comparison of the ratios of the average reading under the wasldown with those forward in the unwashed area. A peak activity of over 6 r occurred on H+7 hours and was maintained through H+12. This activity level compared with that under the washdown which averaged 0.8 r gives an efficiency of 84% removal. At H+12 hours, the accumlated free field dose in the unweshed area was 36r. In comparison, the dose under the weshdown everaced 8 r, civing an effective- ness of 75% in dose reduction. (See Fig. 2.10-1) Corrections for dose rate and tots] dose contributed by the air envelope during fallout will be applied to the values presented in Fig. 2.10-1 when they become available. DISCUSSION — WASHDOWN The neture | to thet for th (Tewa) fallout material is quite similar uni), i.e., heavy calcium particles, most of the activity teing associated with insoluable particulate material from 100 to 200 microns in diameter. Fig. 2.71-4 and 2.71-5 show a definite distribution of activity athwartshirs from bow to stern, Leter analysis of post shot surveys and relative wind deta will be made in an attempt to rationalize this anomaly. Final calibration of the cemma-time stations may resolve these apparent differences. Within the limits of present instrumentation error, the effectiveness and efficiency of 75 and 84% here indicated compere favorably with results observed for the iafp), which is the only other land-simulated shot participated in to date, CODb” free ,are n ae L Zo

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