A Comparison of Direct Gamma Dose Rates from a Stationary Gaussian Plume Using Different Models

Journal Article · Wed May 15 04:00:00 EDT 2002 · Nuclear Technology

OSTI ID:20826758

Raza, S Shoaib; Avila, Ruben R

The direct gamma dose rates due to a stationary Gaussian plume of radionuclides in the atmosphere have been calculated using different models [Lagrangian dose model (LDM), Gaussian plume model (GPM), and uniform cloud model (UCM)], and the results are compared.The atmospheric parameters (used in the Lagrangian model) like mean and fluctuating wind components, etc., were obtained from the published field data on a neutral atmosphere. In the LDM, a continuous release of radionuclides into the atmosphere was simulated by liberating a large number of Lagrangian particles, whose trajectories were tracked for various hours in a three-dimensional computational domain. A point isotropic source formula was used for calculating the direct gamma dose contribution from all Lagrangian particles constituting the plume. Each particle represented a point source of radioactivity, whose strength was calculated from the known release rate and was subsequently allowed to decay as a function of time.The comparison of the LDM results with the GPM indicated that both models predict comparable results in a homogeneous atmosphere. The LDM is, however, more versatile, as it can incorporate variation in meteorological data in space and time (of course when available). The UCM also compared well for ground releases; however, it cannot be used for elevated releases and short downwind distances. The purpose of this work was to test the LDM for simulating the transport, dispersion, and decay of a radionuclide plume. The LDM shall later be used for complex topographic and meteorological conditions, where the GPM is not suitable.

• OSTI ID: 20826758
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 2 Vol. 138; ISSN 0029-5450; ISSN NUTYBB
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATMOSPHERES
COMPARATIVE EVALUATIONS
DOSE RATES
GAUSS FUNCTION
GROUND RELEASE
LAGRANGIAN FUNCTION
LETHAL DOSES
POINT SOURCES
RADIOACTIVITY
RADIOISOTOPES
THREE-DIMENSIONAL CALCULATIONS
TIME DEPENDENCE