Also known as: RA#, RA...
RA stands for various terms. Discover the full forms, meanings, and possible interpretations of RA across different fields and industries.
Any part of an installation accessible to employees in which there exists a radiation level of 7.5 millirem in any one hour over 150 millirem in any seven consecutive days. Any area with radiation levels greater than 5 millirems (0.05 millisievert) in one hour at 30 centimeters from the source or from any surface through which the radiation penetrates.
CautionScienceTechnologyThe spontaneous decay of an unstable atomic nucleus, giving rise to the emission of radiation.
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