A short-term study was made to investigate the removal of radioiodine vapor from air-steam mixtures as could occur immediately following a nuclear incident in a pressurized water reactor. Activated charcoal traps, designed to simulate a small section of a commercial charcoal canister, were tested at gas velocities of 23.9 to 74.9 ft/min over the temperature range of 75 to 118°C. The iodine removal efficiency was found to range from 99.80 to 99.4% with an average of 99.9%. One test performed at a temperature of 105°C and with gas velocity of 290 ft/min indicated that the iodine removal efficiency was reduced to 99.54%. Activated charcoal exhibits a high efficiency for iodine vapor removal under these test conditions and appears suitable for application in the decontamination of air-steam mixtures.

Some results have been obtained which may be of use in studying the escape of fission fragments from slurry particles which contain fissioning material. Assuming that the fission fragments are of fixed range H, that they are generated uniformly and isotopically in a sphere of diameter D, the escape probability , mean path length, and path length distribution function have been derived.

A development program is being carried out in the pilot plant to improve the equipment involved in monitoring, metering and pumping process streams. The equipment under development includes an alpha monitor, a gamma monitor, a waste water monitor, a liquid flow rate meter, a canned rotor pump, a diaphragm pump, air lifts and a pressure tank pump. This report presents the present status of the testing program.