Accession Number : ADA192288

Title :   Calculation of the BREN Japanese House Shielding Experiments.

Descriptive Note : Technical rept. 1 Oct 82-1 May 83,

Corporate Author : SCIENCE APPLICATIONS INTERNATIONAL CORP SAN DIEGO CA

Personal Author(s) : Woolson, William A ; Gritzner, Michael L

PDF Url : ADA192288

Report Date : 22 Aug 1983

Pagination or Media Count : 66

Abstract : The techniques used to calculate the house shielding as part of the dosimetry reassessment for the survivors of the Hiroshima and Nagasaki A-bombs are validated by modeling the Operation BREN Japanese house shielding experiments and comparing calculated radiation transmission factors to the measured values. Single and two-story houses were modeled, as well as multiple house configurations. In all cases, the agreement for the 60Co transmission and the reactor neutron transmission was excellent with most cases better than 10 percent. The agreement for the reactor gamma-ray transmission was poor; analysis indicates the discrepancy is probably due to problems in the measurements. The calculational procedure consists of performing a surface integral of the incident energy-angular fluence in air-over-ground geometries from the source with the energy-angular importance of the detector response in the three-dimensional house configuration. The air-over-ground fluence is computed by discrete ordinates; the importance function is computed by Monte Carlo in the adjoint mode. The excellent agreement obtained between the calculations and measurements for the 60Co source and reactor neutrons demonstrates that the calculational procedure can provide accurate house transmission factors required in the dosimetry estimates for over half of the A-bomb survivor used in radiobiological effects studies. Keywords: Nuclear radiation, Protection factor, Neutrons, Gamma ray.

Descriptors :   *RADIOBIOLOGY, *RADIATION SHIELDING, *RADIATION PROTECTION, *HOUSING(DWELLINGS), AIR, DETECTORS, DOSIMETRY, ESTIMATES, GAMMA RAYS, GRAPHS, LAND AREAS, MODELS, MONTE CARLO METHOD, NEUTRONS, NUCLEAR RADIATION, RESPONSE, SURFACES, SURVIVAL(PERSONNEL), TRANSMITTANCE, VALIDATION, WALLS, NEUTRON IRRADIATION

Subject Categories : Nuclear Radiation Shield, Protection & Safety
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE