title: Skull counting in late stages after internal contamination by actinides.
abstract: Monitoring preparation for internal contamination with actinides (e.g. Pu and Am) is required to assess internal doses at nuclear fuel cycle-related facilities. In this paper, the authors focus on skull counting in case of single-incident inhalation of (241)Am and propose an effective procedure for skull counting with an existing system, taking into account the biokinetic behaviour of (241)Am in the human body. The predicted response of the system to skull counting under a certain counting geometry was found to be only ∼1.0 × 10(-5) cps Bq(-1) 1y after intake. However, this disadvantage could be remedied by repeated measurements of the skull during the late stage of the intake due to the predicted response reaching a plateau at about the 1000th day after exposure and exceeding that in the lung counting. Further studies are needed for the development of a new detection system with higher sensitivity to perform reliable internal dose estimations based on direct measurements.
authors.affiliation: Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan tani@kk.t.u-tokyo.ac.jp.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Tani
authors.affiliation: Internal Dosimetry Group, Toxicology Department, Public Health England, Chilton, Didcot, Oxon OX11 ORQ, UK.
authors.forename: Arron
authors.initials: A
authors.lastname: Shutt
authors.affiliation: Research Center for Radiation Emergency Medicine, Research Program for Radiation Emergency Medicine, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kurihara
authors.affiliation: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-Shirane, Tokai-mura, Naka-gun, Tokyo 319-1188, Japan.
authors.forename: Toshiso
authors.initials: T
authors.lastname: Kosako
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000396:Air Pollutants, Radioactive; D000576:Americium / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D001681:Biological Assay / Q000295:instrumentation / Q000379:methods; D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008297:Male; D008954:Models, Biological; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012886:Skull / Q000502:physiology*
chemical_list: D000396:Air Pollutants, Radioactive; D000576:Americium