Glass dosimeter developed by Piesch for measuring the absorbed dose in critical organs, in which only one FD-P8-1 glass was encased in asuitable badge case, was examined for the case of FD-3 glass, FGD-6 type Fluorimeter, standard Japanese man phantom, and a badge case manufactured by us. This experiment confirmed the same validity for this case as well as the case of FD-1 glass, FGD-3B type Fluorimeter and Alderson man phantom which were used used by Piesch. The merits of this glass dosimeter against other dosimeters are discussed from the view point of the personnel dosimetry for radiation protection.
Two types of cartridges to be attached to full face Gass masks, which are commercially available and have been in use for the purpose of preventing inhalation hazard due to airborne radioactive materials for a few years at JAERI, were examined for the performance of removing airborne radioiodine in order to obtain data necessary for establishing a guide of the radiation protection in wearing them. The airborne radioiodine-131 discharged ieto the exhaust system during the processing of iodine-131 at the radioisotope production plant was used for the tests, the concentrations of which ranged from 10-5 μCi/cc to 10-8 μCi/cc. The tests were carried out at the flow rate of 20 1/min (moderate work) and 40 1/min (medium hard work), respectively, in conditions of ralative humidities being over the range from 50% to 70%. This paper describes the experimental results on the penetration of airborne radioiodine two types of cartridges as a function of the period of air flow and discusses the relationship between the concentration and the service time, considering the leakage at seal between the mask and face.
A multichannal air monitoring system with centralized sampling method is reqired with development of atomic energy. This monitoring system is commonly sampled through conduits from sampling points. The disadvantage with this monitoring system will be the aerosol loss due to deposition in the sampling conduits. This report is exlained to the factors of aerosol loss in sampling conduits. Aerosol loss is caused by diffusion, impaction, gravity settling, electrical force and other mechanism. It must be considered for design to minimize aerosol loss in sampling conduits.
Samples of Taiwan the product were collected and investigated for 90Sr and 137Cs contents by radiochemical analysis in 1968. The average concentration obtained was 397 pCi/kg or 89.8 pCi/gCa for 90Sr and 116.2 pCi/kg or 7.09 pCi/gCa for 137Cs. The ratio 137Cs/90Sr was found to be 0.29. A compariso nwith previous reports by different authors is given, and an intercomparison run of 90Sr and 137Cs concentration in diet sample is also included.