QUALITY ASSURANCE FOR RADIATION PROCESSING

The growth of the Radiation Processing Industry has presented a new set of parameters for QA programs. The large massive doses of radiation required for commercial applications of sterilization, curing, cross linking, etc., needs measurement methods outside the scope of familiar radiation survey instruments. Among the problems that need to be considered by a QA engineer in establishing the validity of a radiation source are; 1) detector response to dose and dose rate, 2) variations due to source spectrum and quality, 3) perturbations due to physical environment, and 4) ease of handling, read-out, and interpretation. In addition, special problems have been encountered in developing proper calibration procedures and selecting transfer instrumentation that supply tracability to primary radiation standards. Thin plastic and dyed plastic films have been used extensively in radiation measurement due to their low cost, ruggedness, ease of handling and read-out, and compatibility to many geometrical configurations. Radiachromic detectors have been developed that minimize problems associated with QA procedures, and may be standardly checked with calibration services available to industry by the National Bureau of Standards. Radiachromic films are now available which provide selected sensitivity over dose ranges of interest to Radiation Processing. Instrumentation is available for single point checks and for one and two dimensional scans which may be used to support QA programs. A variety of instruments may be selected to read-out in 1) transmission, 2) optical density, or 3) directly in absorbed dose. © 1979.