The Rengelap unexposed group ie expected te remain near the upper range

ef the prospective annual risk limit recommended by ICRP.

Moving away from

Rongelap at this time will not eignifieancly aleer future annual Pigke

Tn

large part, the unexposed group's future gisk will be from radiation exposure
received during the last 27 years.

Reeent Bioassay Results from Pu

The estimates of radiation dese and asseeiated risks given previously doe
not imelude the contriburcion from craneuranic nuclides.

We anticipate this

dose to be negligible based upon estimates by BLiil Rebigon which apply to
former Bikinians, however, thie has sot been verdfted through bicassay. We

have analyzed about 500 test samples using alpha iieuid seintililacion (PERALS)
procedures.

Test samples were run af two outside laboratories in addition te

eur work ec BNL.

fn July 1984 we identified 46 Harshell Islands urine samples

which we suspected as either not containing Po ef es containing lew levels of
Fue

Briefly, we wet ashed these eamples and golvent extracted to obtain pure

Pue

We chen introduced the Pu inte an extractive seintdilater se that the

gample could be counted on PERALS.

The minimum detection limit for this

method is 190 uBq (5 fCi).
& number of these Marshall Islands urine samples shewed alpha counts in
the 2359p region, however, on further investigation we moced that some of this
activity was due to the decay of maturally eceurring 21056,

Experiments done

here end at one other laboratory indicated to we that the solvent extraction
8

procedure unexpectedly allows significant emounts of 2105, te pass into the

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