Operation TEAPOT Nevada Test Site, February - May 1955. Project 38.3. Evaluation of Civil Defense Radiological Defense Instruments. Report to the Test Director,
ATOMIC ENERGY COMMISSION WASHINGTON DC
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Experiments were performed during Operation Teapot 1 to investigate the beta-gamma exposure-rate ratio from fall-out to establish design criteria for high-range survey instruments, 2 to evaluate commercial radiological defense instruments, and 3 to investigate the feasibility of the use of commercial and amateur roll film and dental X-ray film as indicators of prompt gamma radiation. The results of the beta-gamma exposure-rate ratio measurements indicate that, for an instrument having a beta window of the order of 50 mgsq cm thickness, the quantity of hazardous radiation not indicated by the instrument will not exceed a factor of 2. An analysis of the absorption data of fission-product radiation indicates the presence of high-energy beta radiation, low-energy gamma radiation, and secondary X-radiation in large quantities immediately postshot. The soft component tends to diminish rapidly, and the high-energy gamma radiation of the longer-lived fission products becomes predominant after approximately 2 days. The evaluation of commercial radiological defense instruments indicated that 1 satisfactory calibration facilities must be developed, 2 ionization-chamber survey meters must have sealed chambers to avoid change in sensitivity with altitude, 3 an operational check rather than a simple battery check must be provided for all survey meters, and 4 dosimeters intended for monitoring applications must not demonstrate leakage resulting from high initial exposure and must be relatively insensitive to beta contamination.
- Nuclear Instrumentation