Appendix D

ORIGINAL DATA

This appendix contains all the original counting data used in the body of this report, since this
information in unmodified form may be useful for studies not attempted by the project. For

greater convenience, a limited amount of descriptive and analytical material has been included.
D.1 LINEAR FREE-FIELD AND SHIPBOARD RECORDS
A Unear presentation of the gamma records was used in the Interim Test Report (ITR-—1621).
These records are preliminary uncorrected resuits plotted automatically by the GITOUT. Since
ITR’s are destroyed after the final reports are issued, these original linear presentations are
reproduced here. They may be helpful In indicating the relative importance of specific features
of the total gamma record for quick tactical considerations. No particular attempt has been
made to correct these records; therefore, they must be regarded as approximate. Not all records contained in the ITR are reproduced. The discussions in Section 3.3.2 and 3.4.1 are
equally applicable to those records that do appear here.

D.2 METER SURVEY DATA FOR CORACLES
The coracles were surveyed with a Cutie-Pie (CP-3DM beta-gamma survey meter, Reference 103) shortly after recovery. For Wahoo, the meter probe was held 3 feet above the IC

port roughly in the center of the coracle.

Since the coracle background was so lowafter Um-

brella, the meter probe was held 3 inches above the IC port.

The survey meter data may be

converted to approximate std-GITR response bythe factors 2.3 and 0.36 for Wahoo and Um-

brella, respectively. The original and converted data is presented in Table D.1. A plot of this
data versus distance from surface zero (Figure D.34) indicates that the general background for

Wahoo was about a factor of 10 higher than that for Umbrella.

D.3 IC COUNTING DATA
AlL IC trays were counted on Shelf 5 in one of two end-window gamma counters described
in Section 3.3.1. Counter 2 was used at the EPG, and Counter 1 was used at NRDL. The two
counters were nearly identical, no conversion factor from one to the other being necessary.
Upon recovery of the coracles in the field, all IC trays were immediately removed to a laboratory at the site where they were given a preliminary count with a MX-5 survey meter with its
probe positioned exactly ¥, inch above the center of each IC tray. This reading was used to
distinguish trays having significant radioactive deposits, so that maximum counting time could
be assigned to trays having usable data and so that decay counts on the most active samples
could be started immediately. After this initial count at EPG, all IC trays were returned to
NRDL where a second count of all collections was made. Trays were shipped in individual
plastic bags, which precluded cross-contamination during shipment.
The tray counts for a complete set of IC trays (both exposed and unexposed trays in the case
of IC collectors which jammed) were plotted, and a background for the entire set of trays was
determined. These backgrounds for the tray set are reported as “collection bkgd (measured)”
at the beginning of each table of original counts; backgrounds determined from the counts fora
complete IC tray set and backgrounds calculated for other times using the standard decay curve

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