Operation report on the low temperature fissiochemical loop (LTFL), 7

From December 1976 to March 1977, LTFL was operated four times, irradiating 19 capsules which contained a total of 57 samples. Of these, 45 samples were of carbon dioxide added with propane, including 33 with fission fragment sources, or U-Pd foil pieces. Other 12 were of ethylene for dosimetry. Operations were without trouble. A capsule was irradiated 12 hours, which was the longest irradiation time with the loop. Maintenance works during the one year period ending March 1977, included modification of the cooling water piping for descaling and calibration check of the instrumentation system. Analysis of the irradiation carbon dioxide samples revealed that water and other oxygen containing products were formed besides carbon monoxide. E.g., by addition of 1% propane and irradiation to 10 - 15 Mrad, G(CO)=5.4, G(H2O)=3.5, G(i-PrOH)=0.2, and G(Acetone)=0.1. For future dismounting of the LTFL, which has been in service since 1965, an estimation was made of weight distribution of the nuclides constituting the in-pile portion of the loop. The estimation is important in connection with radiation protection at the time of the dismounting. (auth.)