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Title: Evaluation of Near Field Atmospheric Dispersion Around Nuclear Facilities Using a Lorentzian Distribution Methodology

Atmospheric dispersion modeling within the near field of a nuclear facility typically applies a building wake correction to the Gaussian plume model, whereby a point source is modeled as a plane source. The plane source results in greater near field dilution and reduces the far field effluent concentration. However, the correction does not account for the concentration profile within the near field. Receptors of interest, such as the maximally exposed individual, may exist within the near field and thus the realm of building wake effects. Furthermore, release parameters and displacement characteristics may be unknown, particularly during upset conditions. Therefore, emphasis is placed upon the need to analyze and estimate an enveloping concentration profile within the near field of a release. This investigation included the analysis of 64 air samples collected over 128 wk. Variables of importance were then derived from the measurement data, and a methodology was developed that allowed for the estimation of Lorentzian-based dispersion coefficients along the lateral axis of the near field recirculation cavity; the development of recirculation cavity boundaries; and conservative evaluation of the associated concentration profile. The results evaluated the effectiveness of the Lorentzian distribution methodology for estimating near field releases and emphasized the needmore » to place air-monitoring stations appropriately for complete concentration characterization. Additionally, the importance of the sampling period and operational conditions were discussed to balance operational feedback and the reporting of public dose.« less
  1. Idaho State Univ., Pocatello, ID (United States). Dept. of Nuclear Engineering and Health Physics
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0017-9078; TRN: US1500090
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Health Physics; Journal Volume: 107; Journal Issue: 6
Health Physics Society
Research Org:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org:
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; Fission Product Release; Gaseous Effluents; Radioactive Effluents; Radiation Doses; Radioecological Concentration; CONCENTRATION RATIO; AIR; ABUNDANCE; NUCLEAR FACILITIES; EVALUATION; POINT SOURCES; Source Terms; Spatial Distribution; DILUTION; PLUMES; SAMPLING; Air Pollution Monitoring; Radiation Monitoring; SIMULATION; Atmospheric dispersion modeling