Findings of a recent ORNL review of dosimery for the Japanese atomic-bomb survivors
More detail than previously available on the leakage spectra of neutrons from the Nagasaki and Hiroshima weapons was provided by calculations made at the Los Alamos National Laboratory in 1976. Several neutron-transport calculations using these data predicted significantly less neutron exposure in Hiroshima than the current radiation-exposure estimates for survivors designated as T65D (or Tentative 1965 Doses). The difference was extremely important since recent studies using the T65D estimates have predicted a very large leukemia risk for neutrons at low exposure levels in Hiroshima. Some findings are that the neutron exposures in Hiroshima were probably less than the T65D estimates by factors varying from about four at a ground distance of 1000 m to eight at 2000 m, and the gamma-ray exposures were greater than the T65D estimates starting at about 1000 m and were probably larger by a factor of about three at 2000 m. In Nagasaki, the situation was reversed with respect to gamma rays, and the T65D estimates were higher, but the differences were small (i.e., about 20% at 1000 m and 30% at 2000 m). As a result, it now appears that leukemia and other late effects at lower exposure levels in Hiroshima were due largely to gamma rays rather than neutrons. This may not be true at higher exposure levels in Hiroshima, however. Any reanalysis of data on late effects among the atomic-bomb survivors should be regarded as highly speculative until some other important issues have been investigated in more detail. These issues include the anisotropy in neutron leakage from the Hiroshima weapon, the energy yield of the Hiroshima weapon, the shielding factors for houses, and the organ-dose factors for the atomic-bomb survivors.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5296078
- Report Number(s):
- ORNL/TM-8078; CONF-810928-1; ON: DE82010404; TRN: 82-014138
- Resource Relation:
- Conference: Symposium on neutron dosimetry, Germantown, MD, USA, 15 Sep 1981; Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
A-BOMB SURVIVORS
PERSONNEL DOSIMETRY
RADIATION DOSES
DELAYED RADIATION EFFECTS
FAST NEUTRONS
GAMMA RADIATION
HIROSHIMA
NAGASAKI
NUCLEAR EXPLOSIONS
NUCLEAR WEAPONS
ASIA
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DOSES
DOSIMETRY
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EXPLOSIONS
FERMIONS
HADRONS
HUMAN POPULATIONS
IONIZING RADIATIONS
JAPAN
NEUTRONS
NUCLEONS
POPULATIONS
RADIATION EFFECTS
RADIATIONS
WEAPONS
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