convention was adopted frequently that the exposure rate from material deposited at a given location varies with time according to the relationship R(t) SN R(1) tv? [1] Ff ~~” where, A(t) Exposure rate at time t in hr, and fo: 2 “RQ) = Exposure rate at 1 hr. é f- — aie This has beceimeknown as the t"“1.2 "law," but the relationship was originally derivedas an approximation (Wa48) of the rate of decay of fission-product pete actiy ty. It is instructive to note that Way and Wigner (Wa48) actually| taldulated two quantities: the rate of betaparticle emission as a functionof time, 8(t), and the rate of total energy emission as a function-oFtime, 3B(t) +1P(t); where B(t) is the rate of total beta-energy emission, ane-T(t) is the rate of total gamma-energy emission. Neither of-these quantities is an appropriate analog of the external gamma-exposure rate for the resulting fallout field, but presumably the rate of total energy emission would be the better analog. The results of Way and Wigner's calculations for t.< 1 sec are 6(t) zy ©” (0.38 - 2.6t) /sec _ —- and 38(t) +T(t) =~ (3.8 - 0.61t) MeV/sec * — 205 [2] [3]