Evaluation of the environmental significance of the projected 41Ar release from the Lowell Technological Institute Reactor

Because of the nearness of buildings to the 100 ft reactor stack of the Lowell Technological Institute research reactor, standard diffusion equations are not directly applicable to the calculation of ground concentrations from the projected 41Ar release of 400 μCi sec−1. Because of this and the proximity of the City of Lowell, there is some reluctance to use any atmospheric dilution in the evaluation of exposure concentrations. Since the stack concentration of 5.7 × 10−5 μCi cm 3 is considerably above the MPC of 4 × 10−8μCi cm3, other physical and mathematical models had to be used in the evaluation of the environmental significance of the projected 41Ar release. These models and an evaluation of the basis for the 41Ar MPC indicate the general inapplicability of infinite cloud submersion dose MPC values and show that these values may be unrealistic and unduly restrictive especially in the case of exposure to finite volumes of short lived, inert, beta-gamma emitting, radioactive gases.