e

i
ocean beach to lagoon beach, a mean exposure of100 yR/h is probably
on the conservativeside.

|

Table III also gives the estimated fractions of the exposure due
to Cs-137 and Co-60 at the present time based on Gudiksen's soil
sample data.and HASL celculated dose rate ratios.

are alsoeevet
conservative (too much Cs-137).

These ratios

The estimated depth

distribution (relaxation length is the depth the activity is ent

times the surface activity) is: also based on the soil data.

These

quantities are also highly variable and in all cases I tried to
pick ceetees
conservative values.

Contributions to external dose from

isotopes other than Cs and Co are negligible and have been neglected.
4

4,

Table IV gives the calculated values of integrated dose for 5, 10,
30 and 70 year periods.

These are the doses the population dis-

tribution given in Table I would receive assuming an immediate
return to the Atoll.

The doses have been weighted by the population

distribution to account for the fact that different population groups
receive slightly different doses.. In actuality, however, it was
found that the differences in exposure to the various population groups
for the models choseh are minor (see Table V) considering the uncertainties
involved.

Also we note that the dependence on the time breakdown is

also minor since the doses for; cases Ia and Ib are not very different.
Case II indicates that having tne’ vittege area on a "clean" island
lowers the short term doses by, only about 50%, indicating the large
influence of the 25-304 of the time spent on the "hotter" outer islands.

Select target paragraph3