Abstract
The growing use of tubular structures in nuclear reactor facilities such as pipes, conduits and ducts that are buried underground, requires more detailed stress analysis to demonstrate structural integrity as required by Section III of the Boiler Pressure Vessel Code and other applicable industry codes.
Thermal behavior of the pipe and soil interference can be conservatively evaluated by implementing the thermal characteristics and properties of the pipe into the expressions, as deduced by previous studies, which are made for the seismic analysis of buried piping. This paper presents procedures to evaluate the different pipe/soil parameters to be applied in those expressions, and explains these equations from designers perspectives and, finally, suggests an approach to combine various pipe stresses to check against ASME Boiler and Pressure Vessel Code Section III. The analysis assumes that the soil is linearly elastic and homogenous and the structure is a straight slender solid or hollow beam with a uniform, symmetrical cross section that satisfies the conditions of the elementary theory of beams on elastic foundations.
