Simplified Method for Calculating Nitrogen-Capture and Fission-Product Gamma-Ray Doses inside Underground Concrete Structures

摘要

A simplified method has been developed to calculate the gamma dose at a detector position on the centerline of underground cylindrical structures that results from the fission-product and nitrogen-capture gamma rays produced by a nuclear weapon detonation. Application of the method requires knowledge only of the structure geometry and the fission-product and capture gamma-ray doses incident on the concrete cover shield of the underground structure. To provide the dose transmission data used in the calculational method, a series of S sub n problems were run for isotropic and anisotropic fission-product and nitrogen-capture gamma rays incident on concrete slabs for thicknesses up to 60 inches. The gamma-ray dose at a detector on the centerline of the structure is calculated from the product of the outside dose, the transmission factor, and the fraction of the transmitted dose which reaches the detector. Functions defining the fraction of the transmitted dose reaching a detector positioned on the centerline of an underground cylindrical structure were derived for both the isotropic and anisotropic fission-product and nitrogen-capture gamma-ray source terms. (Author)