RADIOACTIVE FALLOUT FROM THE CHERNOBYL NUCLEAR REACTOR ACCIDENT data in CA

Tncrc arc several possible explanations for the concentration-time profile
measured in the Livermore area. Since the radioactivity release from the
Chernobyl-reactor site lasted for many days it is possible that part of the variation is
due to the release pattern, however, the radioactivity was detected for several weeks
after the last radioactive release so this is probably only a partia? explanation.
Another explanation is that the air mass containing the radioactive plume passed over
the western United States several times before the level of activity was below our
detection limits. Each time the air mass passed over our area more activity woufd be
detected, at successively lower concentrations due to continuous deposition and
radioactive decay. This would result in the pattern seen in Fig. 5. This explanation
has been proposed by others to explain similiar concentration patterns. It has also
been suggested that such an oscillatory pattern is normal for surface deposition from
a wide ranging plume. The variety of factors which affect the plume transport rate
can produce a striated concentration pattern within the plume. Then as the plume
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passes over a given area the concentration-time profile of the deposited material will
have nn oscillatory pattern which will mimic the plume striations .