teken.
a
Thus, by necesaity, the most practical eriteria upon which to base a
decision are gamma dose rate readings whiict are in turn related to the
amount of fallout,
DoseSein
The most immediate solution might be to establish lower permittod
dose rate levels at later times efter destination
However, if a series of
Gose rates are established for Increasing timee after detonation so that
their relationship follows t7/-*, then tre doses delivered in X hours
(before the material 1s washed off) wil! be greater for earlier tines
after detonation.
‘f one vere sue of tre tine that the fallout eaterial
was to remain in place, then a scale of ¢ose rates versus tine after detonation could be wade te yiel¢ the same total dose over the X hours,
Since
there is obviously no set time period for duration of contact that would
be valid for al! eases, one might assure the worst case where the saterial
i—™
remains in place unt{i its activity har ¢eoayed to an insignificant level,
Dose rates ooul] then be ap:roximate¢, %
Dem Sit
were:
yield a given infinity dose, byt
GF infinity dose
A @ dose rate at time "t*,
If the above discussion js acce;ted, then the rezaining question is to
set the infinity dose
Here, we sist be clear that whereas the measurezents
taken by the monitors, and the date upon which action will be decided will
be gamma dose rate readings, the point o% principal concern is the beta dose
delivered to the besal layer of the epidermis (assured as 7 milligrazs per
aquare centimeter .
Gti
The retic of es «i'r of beta to gamma is a function of