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This can be accomplished from a consideration of known
cases of fallout pad transmission from contnimination on grass
to milk and resultant thyroid iodine levels.
Lapp? has made
such a calculation based on the fallout incident at the
Windscale pile No, 1, an experimental nuclear reactor, which
caused the release of 20,000 curies of iodine 131 to the
atmosphere.
The iodine fell +n farms in the area and then
appeared in cows‘
milk in amounts as hish as 100,000 micromicro-
curies per liter.
Though infants did not drink the milk
because it was removed from the market, the thyroid radiation
dose that would result from such concentrations can be caluculated on the basis of standard dosimetry procedures...
The
combined calculation indicates that 1,.c/M@ deposition of iodine
131 results in a dose of 5 rads to an infant thyroid gland.
This is the basis for the lower of our two estizates.
(See Appendix for details)
It should be noted that Lapp was not the first to make
use of the ‘Jindscale experience.
Gordon Dunning estigated
in 1959 the thyroid dose due to raioiodine in fallout.
His
estimate indicates, "Based on '‘Jindscale experience,
petty? 4 o.tuct3yiiter of milk.
of this milk .-—-—>
For one liter
2 rad dose to infant's thyroid.
For.
continuous consumption of milk from cows grazing an pasture’
until x21 activity essentially Zero ————y O2e44e rad dose. "©
‘His calculation was for a wartime situation, but an atmospheric
“nuclear explosion creates and deposits radioactive fallout
irrespective of the use to which it is put.