DISTRIBUTION OF VOLCANIC FALLOUT IN AND ABOUT A ONE-STORY RESIDENCE
Abstract
The sand-like debris from Volcano Irazu in Costa Rica closely resembles the type of fallout produced by a nearsurface or underground nuclear detonation. The activity of the volcano during April and May 1964 presented an opportunity to use this phenomenon in a field-scale study of some relationships between urban reclamation and nuclear fallout contamination. The investigation was divided into two phases: (I) distribution of debris inside a one-story residence; and (II) distribution outside the residence. In Phase I, it was observed that particle size distributions inside the house did not differ greatly from those deposited outside. Mass loadings inside were a factor of 50 less than those outside. It was concluded that, if this were a case of radioactive fallout, the ratio of outside dose to inside dose would be reduced significantly in the vicinity of the window through which air is moving. In Phase II, it was observed that in the absence of rain, the particle size distribution and mass deposited was uniform from one sample location to another, only minor variations having been observed from day to day. On this basis, it was concluded that reclamation tests using uniformly distributed synthetic fallout are realistic even when the surface configurations are quite complex. When rain accompanied the debris deposition, however, different results were observed. Particle size distributions and mass loadings were a function of redistribution and varied with sample location. Deposits on roof surfaces will be significantly reduced but will accumulate in the gutters. In the case of radioactive fallout, a concentrated radiation source would result.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 11, 1965
- Accession Number
- AD0629527
Entities
People
- F. K. Kawahara
- Robert J. Crew
Organizations
- Naval Radiological Defense Laboratory