F.

CALCULATIONS OF DOSE to TAKUYO MARU Personnel
Japanese data:

1.

2000 hours JST

14 July

Rainout started

26

2030 hours JST

14 July

Rainout over

36

2200 hours JST

14 July

Highest count of 37470 cpm

he

0530 hours JST

15 July

Start of decontamination

5e

Scintillation background = 2400 cpm

6.

Contamination of scintillation counterprobe was 11,235 cpm

Te

Conversion:

500 cpm = 0.7 mr/wk

Other data:

12.

1230 hours JST

2.

I= yt

12 July

Detonation time

3. Dose= 1, [. lent i-n|

at LA

Where:
“

ta _

+t,

= time of entry

to

= time of exit

I,

= intensity at H + 1 hour

Assumptions:
1.

The suspected event to have taken place at 1230 hours JST, 12 July
NOTE:

The only instance where we are able to attempt an estimate
of the decay rate from the Japanese data is compatible with
the assumed time of detonation of the suspected event.

2.

n=1,.2

3.

Continuous exposure of personnel to indicated dose rate for
tne time period used.

4

Use 2030 hours 14 July for time of highest count:
H + 55 hours = tz

5.

Use 1130 hours 15 July for end of decontamination:

HE + 70 hours # to
6.

Use 0030 hours 27 July as time of monitoring TAKUYO:
my Des

123 days = 3 + 300 hours. = to

CONSIDENTIAL

DOE ARCHIVES

he

2c

Select target paragraph3