Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Gamma Dose Calculations in the Target Service Cell of the SNS

Conference ·
OSTI ID:11021

Calculations of the gamma dose rates inside and outside of the Target Service Cell (TSC) of the Spallation Neutron Source (SNS) are complicated by the large size of the structure, large volume of air (internal void), optical thickness of the enclosing walls, and multiplicity of radiation sources. Furthermore, a reasonably detailed distribution of the dose rate over the volume of the TSC, and on the outside of its walls is necessary in order to optimize electronic instrument locations, and plan access control. For all these reasons a deterministic transport method was preferred over Monte Carlo, The three- dimensional neutral particle transport code TORT was employed for this purpose with support from other peripheral codes in the Discrete Ordinates of Oak Ridge System (DOORS). The computational model for the TSC is described and the features of TORT and its companion codes that enable such a difficult calculation are discussed. Most prominent is the presence of severe ray effects in the air cavity of the TSC that persists in the transport through the concrete walls and is pronounced throughout the problem volume. Initial attempts at eliminating ray effects from the computed results using the newly developed three-dimensional uncollided flux and first collided source code GRTUNCL3D are described.

Research Organization:
Oak Ridge National Lab., TN (US)
Sponsoring Organization:
USDOE Office of Science (US)
DOE Contract Number:
AC05-96OR22464
OSTI ID:
11021
Report Number(s):
ORNL/CP-104078
Country of Publication:
United States
Language:
English