Experimental Radiation Measurements in Conventional Structures, Part 2: Comparison of Measurements in Above-Ground and Below-Ground Structures From Simulated and Actual Fallout Radiation.

摘要

An experimental study designed to provide a basis for estimating protection against fallout radiation was made on two types of structures at the Nevada Test Site. This study was sponsored by the Civil Effects Test Operations, Division of Biology and Medicine, U. S. Atomic Energy Commission. The two buildings studied were a lightly constructed building with a basement, and an underground group shelter. An idealized fallout radiation field was simulated by the use of the Mobile Radiological Measuring Unit (MRMU). The unit employed a sealed radioactive Co(60) source that was pumped at a uniform speed through a long length of flexible tubing evenly distributed over the area of interest. Radiation levels at selected points inside the structures were measured with sensitive ionization-chamber detectors. These measurements were compared with measurements taken under actual fallout conditions at an earlier time and were also compared with the theoretical calculations. Protection factors from fallout data and MRMU data at the basement structure compared roughly within a factor of 2. This was good, considering the limitations of the two sets of data and other factors affecting the differences. Comparisons between protection factors from fallout data and MRMU data at the underground group shelter were excellent. MRMU data and theoretical calculations also compared satisfactorily.