Pi scussion of t.e Attemation and NeatieringFactor, From the tine of fallout until tie time of evacuation it is expeoted that personnel will be kept indoors. (See Policy ) KBajor losses due to weat uring can net ce relied upon during this period, so tiat the estiuated factor is 1/2. Fron tue tine evacuation @ould have been accomplisied until tie time of ealimated retura it is assumed t.at persomel will te indoors aout half of eac’ 2), ‘oura and tiat major losses due to weather! £ ean not be relied upon. Te over-all factor is tous 3/4. The wane reasoning applies to tie t ird period of tins, i.e., from assuned time of return to 15 das after fallovt, : . | From 15 days after fallout until one yoar later it is estinated that the attenuation due to :vildings and tie effects of weat-erisg will yeild an over- all factor of 1/2, Tose rate readings have [een take: wit: survey meters outside and inaide N of houses around tie Nevada Proving Grousds after fallout occurred, ‘the ratio of readings varied wit? te type of construction of tie neuse and wit: tie location wit:in tue tullding, Generally, tre ratio ef readings outside to inside a frame house wes about 2/1 wit: a somew at greater differewe for magoury Gonstruction, A lisited numer of film ‘acges were placed ovtside aod i-cside of s.se houses duriog Tom ler~Snapper and also Ups:ot~not’ole, In the first exae, the difference in tetal doses was aga:: 2 to 1 or greater but during Ups-ot-Knowele only about 2 20% difference was wisd, In fact, fa one case during lps otfnotiele t.e file hadve inside read hig:er tian outside, ‘ne differences etween t.cse experime:1al data will “eve to :¢ duvestifpated during feture operations, POLSPLO Lys (7