TABLE IV 
MAXIMUM CONCENTRATION C_, AT DISTANCES X FROM 
SUSTAINED GROSS SOURCE WITH RATE OF SUPPLY 100 
CURIES PER YEAR 
x (Km) C, (we /ml) 
1 2 x 10°7 
2 1.6 x 10°7 
4 151072, - 
10 Tix 10:8 
20 5x 10°8 
40 3 x 108 
100 2 x 10°8 
It has been estimated that because of the assumptions under which 
equation 1 was developed, the concentrations listed in Table IV are 
certainly high by at least a factor of 10, and probably by a factor of 100. 
Instantaneous Source. This case is analogous to the sudden rup- 
turing of a cubical canister on the bottom under the assumption that all 
of the contaminant is then free. Assuming no current to aid in dispersal, 
the reduction in concentration at the canister due to diffusion processes 
is given by: 
C V 
Ce Qa _ 
4 (nKt) 3/2 
where, C = the concentration at time t 
ce = initial concentration 
V = volume of canister 
K = diffusivity coefficient 
The ratio of the interim concentration to initial concentration as 
a function of time for the specific case of K= 1 cm2/sec, V = 190 liters 
(volume approx. 50 gallons) is given in figure 3. It is seen that 0.01 
curies contained initially in approximately 50 gallons, C, = 54 uc/kg, 
would be reduced to approximately 2 uc/kg in 1 hour and to 0.06 uc/kg 
in 10 hours. 
21 
