A gamma scintillation spectrometer was assembled. and calibrated in a low background radiation area to analyze air samples. Air samples were taken from different locations in the physics building during reactor operation to determine the concentrations of A⁴¹ released to the surroundings of the building during reactor operation. The samples were collected in a one gallon polyethylene bottle with a 3 ¾” x 3 ¾” cylindrical well sealed in the bottom. The air samples were taken to the counting area and the sampling bottle placed on the detector, a 3” x 3" cylindrical NaI(TI) crystal which fitted into the well. The pulses from the detector were fed te a multi-channel analyzer. From the number of pulses per unit time under the photo-peak, the concentration of A⁴¹ for each location was determined. Samples were analyzed for 4, 7, and 10 kw from which a linear extrapolation was made to estimate the concentrations of A⁴¹ in these locations if higher power operation is authorized. / Master of Science