Experimental Evaluation of the Radiation Protection Provided by an Earth-covered Shelter
Experimental Evaluation of the Radiation Protection Provided by an Earth-covered Shelter

Author: Zolin G. Burson

Publisher:

Published: 1962

Total Pages: 48

ISBN-13:

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A study was undertaken to determine the protection against fallout radiation provided by an earth-covered shelter. The study indicated that the shelter offered excellent protection from fallout radiation deposited on and around the shelter. This study also added additional data to the research in radiation shielding provided by various structures which is being conducted by the Civil Effects Test Operations, Division of Biology and Medicine, U.S. Atomic Energy Commission. A fallout radiation field was simulated by pumping, at constant speed, a sealed Co60 source through a long length of tubing which was evenly distributed over an area. Radiation measurements were made Inside the shelter by dose-integrating ionization chambers. In general, the results indicated that the protection factor (ratio of the open-field exposure dose rate to the exposure dose rate in the structure) was approximately 5000 in the center of the shelter, increasing to 10,000 to 15,000 along the sides, and decreasing to about 3000 near the ends. Directly below vents the protection factor was found to be approximately 2500 at the 3-ft level. The shelter was a half-round corrugated-steel structure covered by a minimum of approximately 2 ft of earth on the top and 5 to 7 ft of earth on the sides.

Experimental Evaluation of the Fallout-radiation Protection Afforded by a Southwestern Residence
Experimental Evaluation of the Fallout-radiation Protection Afforded by a Southwestern Residence

Author: Z. Burson

Publisher:

Published: 1962

Total Pages: 28

ISBN-13:

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An experimental study was conducted to determine the fallout-radiation protection afforded by a residence representative of a type of construction much in favor in the Southwest: a single-story stucco and frame house with a heavy shake roof and no basement. This study was one of many such studies sponsored by Civil Effects Test Operations, Division of Biology and Medicine, U. S. Atomic Energy Commission, for the purpose of evaluating the protection presently afforded by ordinary homes and structures against the dangers of fallout radiation. The protection afforded by the home was determined by simulating a fallout-radiation field above and immediately surrounding the house and measuring the radiation level within. The radiation field was simulated by pumping a sealed Co(60) source through a long length of tubing evenly distributed over the test area. Highly sensitive dose-integrating ionization chambers were used to measure the radiation level inside the structure. The test was performed rapidly, easily, and safely. Valid statistical data were obtained even though the radiation level was of such low magnitude that it was unnecessary to evacuate any of the neighboring homes. The protection factors within the house (ratio of exposure dose rate in the open field to exposure dose rate in the structure) ranged from 2.8 to 4.4, depending on the location. The results compare favorably with those found in previous exercises under similar conditions.

Technical Concept
Technical Concept

Author: F. F. Haywood

Publisher:

Published: 1965

Total Pages: 28

ISBN-13:

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A small but intense source of 14 Mev neutrons is to be mounted in the hoisting mechanism of the 1500-ft BREN tower at the Nevada Test Site. The experimental program, designated Operation HENRE, will be conducted during the spring and summer of 1965 and will be sufficiently comprehensive to characterize the radiation fields. In addition, a series of applied shielding experiments will include configurations of interest to both military and civilian laboratories. It is important that data be accumulated which will assist in understanding the apparent uncertainties in existing transport calculations, especially data which will give approximate values for effective neutron cross sections for air-over-ground transport. The neutron source will be operated at heights from about 25 ft to 1500 ft above the air-ground interface. The average neutron yield during operational periods of about 4 hours is expected to be equal to or greater than 10 13 n/sec.

Barrier Attenuation of Air-scattered Gamma Radiation
Barrier Attenuation of Air-scattered Gamma Radiation

Author: Zolin G. Burson

Publisher:

Published: 1965

Total Pages: 96

ISBN-13:

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Additional measurements at this same location were made to determine: (1) the skyshine dose rate as a function of distance from a cobalt-60 source placed on an air-ground interface: (2) the geometry factor describing a detector response to scattered gamma rays at the air-ground interface from a point isotropic cobalt-60 source on the ground 100 ft away; and (3) lip scatter and wall backscatter corrections for a detector in an open hole exposed to skyshine radiation from cobalt-60. The results apply to a variation of shielding problems. One practical application is the shielding provided by basement roofs and exposed basement walls from skyshine radiation originating from fallout.