This report details measurements of fission product ratios which were made an various samples of the Purex canyon exhaust filter to determine the manner and time interval in which the filter became plugged vith foreign material. Results for samples from different levels within the filter bed were compared to investigate accumulation as a function of depth. Strontium-89/strontium-90, Zr-95/Ca-137, Ru-103/Ru-106, and Ce-141/Ce. Pr-144, ratios were determined. These were compared to a constant rate model for accumulation of fission products on the filter. Observed Sr-89/Sr-90 and Zr-95/Cs-137 ratios fall within a range of values typical of normal plant operation, Specifically long-term accumulation of Hanford material irradiated at 10 MW/T to between 600 and 900 MWD/T total exposure and cooled between 120 and 200 days. Low Ru-103/Ru-106 and Ce-141/Ce, Pr-144 ratios definitely rule out rapid accumulation of short-cooled material as the build-up mechanism but are not sensitive indicators in the case of long-cooled material. Ratios did not vary significantly with sample location, indicating that accumulation age does not differ with depth within the filter.
An analytical chemistry program was conducted to determine total U-233 and U-232/U-233 ratio in the irradiated thorium oxide. This report summaries the results for samples exposed for one month and briefly describes the analytical procedures.
Date: September 17, 1963
Creator: Matsumato, W. Y.; Weiler, M. R. & Schneider, R. A.