| -17=- 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.