Road blocks were establicied on Ficghways 93 and 91 following shots
numbers eeven and nine ef Upshot-Enothole,
‘The hifhest reading on a private
muitomobile was 100 mr/hr (gamma) inside and 110 mr/hr outside at H plus 3$
hours,
About 75 oars were washed (rovghly 1/8 of the total monitored).
All of the ears that were washed except the one mentioned stove, had ovtaice
Gose rate readings less than half of the hig-est.
‘The ratio of dose rate
readings on the outside of the oar to inside varied from unity to about h/l,
Probably one of the important factors here is the difference betwee; driving
with windows and/or ventilators opened or closed,
One bus read 250 ar/hr
outaide and average ef 100 mr/nr inaide with a high inside reading ever the
rear seat of 110 mr/hr at © plus & 3/1], hours.
Considering the amount of time one normally spends i: an autono ile,
these dose rates do uot necessarily represent a health hagard in terns of
gavza doses,
What is provably @ more limiting factor is the direct contan-
ination one mignt acquire by rubbing against the outside of the car, especially
When changing a tire, —
Tt is assumed that monitoring will be accomplished outside a general
radiation field.
Theoretical ealowlations (Appendix D) indicate that garzma
dose rate readings taken at four inoces from a surface will te 51%, hot, and
27% of those by a meter at three feet acove an equally contaminated infinite
fleld wien the redii of contamination are respectively 3 feet, 2 feet, ant
1 foot.
these data gucrest that wien t.e gamma dose rate readi-:g at four
inctes fron @ geverally contaminated car is atout ons half t.at for an
infinite pla-e taken at three feet, t.e degree of co:taninstio.: per unit
°-2°50>
pee pio
cuenta
ae
7