atoll

Island

Date

Ur Air

1
2

Rongelap
Rongelap

8 Mar

300

3

Rongelap

& Mar

350

h

Rongelap

8 Mar

400

5

Utirik

Rongelap (central cistern)
Rongelap (North part of
village)
Rongelap (Northernmost
cistern)
Rongelap (Southernmost
cistern)

8 Var

220

Sample No.
.

é

Utirik

"

Rongerik

Utirik (cistern near church)
Utirik (cistern at south of

9 Mar

village)

9 Mar

Eniwetak (Distillation water) 10 Mar

L0
LO

24,0

In addition to the above, a sample of foilage was taken at the winc

ward side of Bikar Island,
at

this

The radiation field was 180 mr/hr on 9 March 195
.

point.

Conclusions and Recommendations

8.

| a.

The radiological survey proved that a large yicld surface deto.

t4on can produce extremely serious radiological contamination over a distanc*

more than 120 miles downwind and important contamination about 250 miles dov.
7~

wind.

b.

The center of the contamination pattern from the BRAVO Shot lic

somewhat north of Rangelap and Rongerik Atolls and probably not far froma l

between Bikini and Bikar.

c.

Although the fall-out was serious on Rongelap Island located at

the extreme southeast tip of the atoll, the contamination was about ten tim

greater at the north side of the atoll, twenty miles away.

d, The cotamination decreased by a factor of about eight over the
downwind distance of 50 miles between Rongelap and Rongerik,

e.

Standard military field housing provides a significant degree o

f.

The AN/PDR-39 proved to be a very satisfactory instrument for

protection to personnel inside.

field survey work under rigorous environmental conditions.

-

g, A single DDE with two (2) whale. boats is not a completely satie

factory method of conducting a broad radiological’ survey of the type jud

completed, Future surveys should consider using vessels capable of entering
more of the atolls and of handling a helicopter and several smi boats,

6 Incls:

1, Rad. Survey Rongelap
2, Rad. Survey Utirik
3. Rad. Survey Bikar

Lh. Rad. Survey Rongerik

5. Rad. Survey Ailinginae

-

/s/ Herbert Scoville
_ DR. HERBERT SCOVILLE
Technical Directo

. AFSWP

6. Summary of Rad. survey

,

Select target paragraph3