300

Soil Cleanup Planning

RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL

assure that doses to
significantly exceed ;
b. What advice can be

intakes of strontium and cesium, both of which were known to exist on

Enjebi. 78

facilitate planning fo:

BAIR COMMITTEE RECOMMENDATIONS

c. What additional infc
the confidence of
transuranics?
d. Can plowing be used
in soils?
The Committee revie:
Division of Occupational
DNA. The draft LLL dos:
which the Committee w:
and to provide advice. Ti
the questions as they per

At the 6 January 1978 conference, Mr. Tommy McCraw, DOE, had
indicated that Lawrence Livermore Laboratory (LLL) was being tasked to
make an Enewetak dose assessment study which could serve as a basis for
associaling island use with concentration of plutonium and other

transuranic elements.79 On 3 April 1978, DNA was briefed on the key

finding of the study. Based on an assumption that the dri-Enewetak would

apportion their time on residence, agricultural, and food-gathering islands
according to 60, 20, and 5 percent, respectively, compliance with the EPA
guideline would be achieved if residence, agriculture, and food-gathering

products, which they un

islands were cleaned to at least 10, 20, 40 pCi/g, respectively.89.8! (The

remaining 15 percent of the time was considered to be spent on the water,

traveling or fishing, or away from theatoll: i.e., Ujelang, Majuro.) This

- finding caused concern at DNA since the stringent criteria might prohibit
some islands from qualifying for their planned use as detailed in the EIS,
and the required cleanup effort wouldbe greatly expanded.
On 4 April 1978, DOE requested that the Bair Committee provide advice
on the soil cleanup questions raised at the 6 January,1978 conference and
on other radiological support matters.82 The Committee, also referred to
as the Enewetak Advisory Group, met with DOE and DNA
representatives at DOE-NV on 13-14 April 1978 and was briefed on the
Status of the cleanup and its current problems. A key topic of discussion
was the recent LLL draft dose estimate study. The principal technical point
of the study related to the unexpected large dose predictions to bone
resulting from inhalation of all transuranics, compared to those from
plutonium alone. The study indicated that inhalation dose to bone might
exceed the dose to lung by a factor of three or more (the ratio of dose
limits for lung and bone). The large dose was due to the less abundant
Am-24l which Dr. William Robison of LLL explained was the result of his

bee we

using a high Am-24] “‘gut transfer coefficient.”’ The high coefficient was

challenged by some Committee members, but Dr. Robison stated that he
felt obligated to use the high coefficient since it had been noted recently by
several experimenters. This draft dose estimate study caused Am-24l to be
considered an important contributor to dose and an important ingredient
tn cleanup evaluations.
The Bair Committee met again on 26-27 April 1978 in Denver,
Colorado, to consider the following questions:
a. Is it possible to develop dose-related cleanup guidance that would

‘

t
|

islands for a number of 5
a. The Bair Committe:
cleanup guidance v
transuranics to futt
guidelines to the e
stringent the cleanu}
uncertainties inhere
precluded absolute
the contamination le
this would be deterr
lifestyle and dietary
islands. Perhaps tr
involved in movem
depositions and rel
well established.
However, the Comm:
cleanup criteria would 1
subsequently exposed f
proposed EPA guideline
equivalent to a lifetime
100,000 persons expose
effects, although thes
assumptions and genera
estimate of i4 cancers pe
chance of one cancer ap

EPA guidance levels fc
probability of one cam
population size).

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