cn ene ne ne tera
GAMMA DOSE RATES AT RONGELAP ATOLL,
1954-1963
INTRODUCTION
Rongelap Atoll, Marshall Islands, was accidentally contaminated on March 1, 1954 with radioactive fallout from a
thermonuclear device detonated at Bikini Atoll some 80 miles
to the west.
Eighty-two natives residing on Rongelap Island
were evacuated and repatriated in June 1957.
The atoll,
its
inhabitants and its economy have been briefly characterizea'?).
decline of gamma dose rates resulting from the fallout is
\discussed in this report.
RESULTS
Department of Energy
et
Dose rates on D+ 1
Historian’s Office
ARCHIVES
Gamma dose rates at Rongelap Atoll on D+ 1
(time of
detonation plus one day) were estimated to be 3.5 r per hour
at the inhabited islet of Rongelap in the south and 35 r per
hour at uninhabited Lomuilal islet in the northern part of
ecient cemtnaS
the ato11 ‘?? ’ Fig.
1.
These estimates were based on extra-
polations of measurements made two days after initial fallout '??
The subsequent decline of gamma dose rates, based on survey
meter readings taken three feet above the ground at Rongelap
i
\
and Kabelle islets, is compared with the theoretical decay 3)
1