title: Cloud immersion building shielding factors for US residential structures.
abstract: This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units.
authors.affiliation: United States Nuclear Regulatory Commission, Rockville, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Dickson
authors.forename: D M
authors.initials: DM
authors.lastname: Hamby
mesh_terms: D016902:Air Pollution, Indoor / Q000517:prevention & control / Q000706:statistics & numerical data*; D000398:Air Pollution, Radioactive / Q000706:statistics & numerical data*; D003198:Computer Simulation; D003252:Construction Materials / Q000032:analysis* / Q000706:statistics & numerical data; D005160:Facility Design and Construction / Q000379:methods; D006798:Housing; D015233:Models, Statistical; D009010:Monte Carlo Method; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D011847:Radioactive Fallout / Q000706:statistics & numerical data; D018570:Risk Assessment; D012542:Scattering, Radiation; D014481:United States; D014887:Weather
chemical_list: D011847:Radioactive Fallout