-ECOMMENDATIONS FOR RAD-CHEM WORK uN FUTURE OPERATIONS AND SOME Ol
JATIONS MADE DURING OER ECKS
from 10 to 208.
l. Efficiency of Geiger-Mueller tube is about 15%, but some may vary
iun?? source,
2. Check efficiency of G-M tube at least once each week with Stront
3. Alpha counting setup is very poor.
the phosphor will be wiped off tube.
“amples, such as swipes with become stuck in drawer and
Better technique is to use Thyac probe attacked to
Efficiency will be same as Radiac instrument.
Berkeley Scaler.
Use a good plutonium source
for calculated efficiency.
4. Ideal counting tim: for field work is ten minutes.
It is better than several short counts.
Large flat planchets are best to use.
5. ten or fifteen ce is good amount to evaporate.
6. Decide who is to collect the samples.
to observe procedures
7, It might prove educational and interesting to visit other task groups
and
counting techiiques.
8. Use first shelf of lead pig for best counting results.
.
“9, Would be desirable to have mimeograph sheets for counting log.
10, “hen background goes up outside of trailer, backzround in lead pigs will raise.
11, Some of the different types of specimens handled at EPG
were as follows: sda water, food
samples, swipes from mess halls, nose swipes for alpha, urines for tritum, fresh water samples,
air filter samples for Gross Beta and alpha.
Only tritum-analysis was done at Eniwetok atoll.
12, Swipes of mess halls are of no value when you don't know the area covered.
13. No radioiodines were done at EPG.
14. Results of liquid specimens-were reported at Bikini Atoll so many d/m per liter, and at
Eniwetok Atoll so many d/m per cc.
15. Keep out unauthorized people from the trailers.
16, Extremly hot speciens:should not be counted,
17. Counting rain water samples may be of value,
“everal high counts were had on the operatio
18. °ea water will have higher counts in the morning than the afternoon, due to tide changes.
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