Accession Number : AD0645661

Title :   AN EXPERIMENTAL EVALUATION OF ROOF REDUCTION FACTORS.

Descriptive Note : Final rept.,

Corporate Author : CONESCO INC CAMBRIDGE MASS

Personal Author(s) : McDonnell,C. ; Velletri,J.

Report Date : 01 MAY 1966

Pagination or Media Count : 80

Abstract : A major portion of the radiation dose received within a structure is due to the fallout deposited on the roof. The report describes experiments conducted to measure the attenuation introduced by the roof to this radiation as a function of the mass thickness and the solid angle fraction subtended by the roof source to a detector in the structure. The first series of experiments conducted on a roof of an inhomogeneous mass distribution, determined the attenuation introduced by mass thicknesses of 0, 48.6, 97.2, and 145.8 psf. Qualitative agreement between data from these experiments and calculated values made in an infinite homogeneous media is good. Measured dose rates from a rectangular source array of eccentricity 1.5 agreed within 10 per cent with a circular source array subtending the same solid angle fractions. A second series of experiments designed to closely simulate the analytical model used in the theoretical calculations was conducted for mass thicknesses of 0, 48.6, 97.2, and 145.8 psf. A maximum discrepancy of 15% is shown between theory and experiment for all mass thicknesses investigated. (Author)

Descriptors :   (*ROOFS, *SHIELDING), (*FALLOUT, SHIELDING), BUILDINGS, ATTENUATION, THICKNESS, REDUCTION, GAMMA RAYS, CONCRETE, COBALT

Subject Categories : Structural Engineering and Building Technology
      Nuclear Radiation Shield, Protection & Safety

Distribution Statement : APPROVED FOR PUBLIC RELEASE