gamma-spectroscopy system and compared them
with the EG&G aerial gamma measurementof
1978. As part of this process, an independent
reviewer, Dr. Herwig Paretzke of the German
Radiation Institute in Munich, Germany,
exposure rate determined from o
gamma
measurements (McGraw and Lynch, 19/73; Robison
unpublished data from Bikini Island, 1987);
based on measurements at Rongelap Island
participated in the measurements to evaluate
our methodology and compare our results with
the EG&G 1978 data. The results of the
measurements made using our in-situ sodium
iodide crystal spectrometer system and the
EG&G data are listed in Table 1. EG&G's data
were listed as ranges for each contour. Our
locations were within the specified contour
ranges.
In addition, in 1988, LLNL staff took more
specific external gamma measurements of
137Cs and Co inside and outside of houses and
other buildings as well as around the village
area. These measurements could not be taken
with the aerial-measurement system used in
1978. The buildings provide shielding so that
the exposure rate is reduced compared to the
maximum effective dose occurs in th first year
and is about 0.11 mSv y-! (11 mrem y-!
Table 1. Comparison of the EG&G aerial gamma measurements with the LLNL in-sigx
measurements for 157Cs.
137Cs5, wR h-!
Island /Site
LLNLa
I
EG&G aerial contqurs4
Rongelap —
R23
2.1
1.6-2.8
R25
35
1.6-2.8
Pit22
3.7
2.8-4.1
R20 »
2.6
1.6-2.8
3.8
1.6-2.8
R9b
2.6
1.6-2.8
R13
1.7
1.6-2.8
0.98
0.51-0.98
1.5
0.98-1.5
R18
R9a
,
:
2.6
1.6-2.8
Ailinginae
C24
C23
a Decay corrected to 1995.
gamma