Let a(t) = Activity yl, d/m per 10,000 fissions. a ce Na” fF q a = Total activity of fission preducts, d/m per 10,000 fissions. S ~~ ct Nw A(t) Total activity of fission products in the area, po/ft- Activity P31 an the area, uofft” 2 s Arca, in ft /day, grazed by sheep p@ Fraction pl caten which goes to thyroid. If th. fission products in thc area are not disproportionated, u(t) uy(t) a A(t) Akt) andi thus the amount of I" per day going to the thyroid of the sheep is Q(t) = pquzlt). 2s weer ee cccvce (1) Then the change in the thyroid activity per day is given by a = pau(t) (t)-w aay @ecweecevee (2) Where A, = total biclogical and radioactive deaay constant for pu a = amount of DP (5) in thyroid at any time t (days) Also, from H. M Parker, ref (5) D = 55Ga cecccceccccocce (3) Where D = dose rate, rep/day, to organs the dot denoting the time derivative of D. Let: m= mass of organ, gn E = average energy of beta radiation, Mev (all raddatdon assumed absorbed in the tissue). NO’ ARCHIVES