The setting up, calibration operation, characteristics, and problems of the precision long counter for neutron intensity measurements are discussed. (WHK)

Studies of atmospheric aerosols have demonstrated that much of the /sup 55/Fe associated with the aerosol input to the oceans is present as either an amorphous or hydrous iron oxide or as very small particulate species attached to the surfaces of the large aerosol particles. By comparison, nearly all of the stable iron is bound in the mineral phase of aerosol particles. This difference in the chemical and physical forms of the radioactive and stable iron isotopes results in the /sup 55/Fe being more biologically available than is the stable iron. This difference in availability is responsible for the transfer of a much higher specific activity /sup 55/Fe to certain ocean organisms and man relative to the specific activity of the total aerosol or of sea water. This differential biological uptake of the radioactive element and its stable element counterpart points out that natural levels of stable elements in the marine environment may not effectively dilute radioelements or other stable elements of anthropogenic sources. The effectiveness of dilution by natural sources depends on the chemical and physical forms of the materials in both the source terms and the receiving environments. The large difference in specific activities of /sup 55/Fe in …

Laboratory equipment is being assembled for the investigation of unusual particulate and gaseous radioactive material in the incinerator offgas when commercial wastes are incinerated. This equipment will constitute a bench-scale incinerator system with monitoring equipment to effect the investigation. A literature search was made to determine the current technology used in removing the expected effluents from gas streams. A series of controlled-feed incinerator runs was performed to determine the mass balance of chloride in the Cyclone incinerator system. Approximately 74% of the chloride present in the feed material was found to be in the scrubber solution, 8% in the flue gas, and the remaining chloride was distributed in the ash and retained in the system. A conceptual design was prepared and modifications were begun on a glove box which is to be used for the demonstration phase of incinerator ash immobilization. Concrete and cold-pressed pellets are being studied and compared for ash immobilization.