308

RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL

pCi/g had evolved into requirements to remove concentrations Over I¢

pCi/g from visitation/food-gathering islands, over 80 pCi/g fro
agriculture islands, and over 40 pCi/g from residential islands.92
m

The evolution of island use plans also was reviewed, including 1h,

differences between the desires originally expressed by the people in 1973

and the EIS or AEC Task Group Report:

a. The people desired to collect coconut crabs on all islands while th
EIS and Task Group Report limited such activity to the Southern
islands.

b. The people desired to use Runit as an agriculture island while the Ejs

and Task Group Report only prescribed that Runit would be Cleaneq
and the quarantine removed, without specifying eventual use.
c. The people desired to use Enjebi for residence while the EIS and Task
Group Report did not specify such cleanup but merely indicated jx
might eventually be used for that purpose. The briefer indicated tha
this was a highly desirable goal, unaware that the people had recently
communicated a lack of enthusiasm for such residence.
The pilot soil removal project and its results were described in detajj,
One principal result was the identification of more subsurface
contamination in the soil than anticipated. This discovery, together with
the inclusion of all transuranics, the more stringent soil cleanup criteria,
and the time already lost, resulted in greater demands on cleanup
capabilities to satisfy the people’s desires and openedthe possibility that

someislands might have to be permanently quarantined.93

SOIL CRITERIA BRIEFING
DOEthen presented a briefing on soil cleanup criteria. Following the
1972 radiological survey of Enewetak, which was probably the most
extensive done in any environment, the agency had a dose assessment
study conducted by their contractor, LLL. The assessment consideredall
of the pathways by which radionuclides enter humans, soil being only one
component. This dose assessment was the basis for the original soil
cleanupcriteria. After the cleanup phase had begun, DOE began working
with EPA ontheir development of federal guidelines for transuranic
elements in soil. DOE then recognized the need to review the Enewetak
dose calculations to determine just how their values compared with those

they had helped EPA develop. After some rough comparisons, DOE

tasked LLL to redo the Enewetak dose calculations with additional data
collected in the past 5 years, including some of the in situ survey results
from Enewetak. The new dose assessment included other transuranics as
well as plutonium. (Initial LLL estimates had indicated that Am-241 was an
important contributor to dose; however, the calculations contained an

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