Internal Thermal Gradients Research Articles

Optimization of Elastic, Multilayer, Cylindrical Vessels Loaded by Pressure and Radial Thermal Gradient

Radius and interference design parameters of elastic, multilayer, thick-walled cylindrical vessels are optimized on the basis of the Mises distortion energy yield criterion. Loadings are assumed uniform along cylinder length and may be independently applied or combined internal pressure and steady-state axiallysymmetric thermal gradients, as well as specified initial stresses to simulate autofrettage or other residual stresses. The optimization is effected by an accelerated, steepest-ascent, gradient projection method, subjected to constraints on loaded stress intensity, shrink stress intensity, end loading, tangential stress (e.g., for a brittle liner), and monotonic-decreasing interface pressures. Independent elastic and thermal properties are allowed for each layer; however, time-dependent phenomena are not considered. The general procedure developed is compared with several published optimization solutions for various special cases.

Civil Engineering for CVNPA Nuclear Power Plant

Selection of the plant location was made by applying a point system to a list of desirable attributes for a nuclear plant site. The concrete external shell wall of the cylindrical vapor container is designed to resist internal pressure and thermal gradients and to serve as a biological shield. A metal liner is provided for gaseous containment instead of a steel container and a separate concrete biological shield wall. A steel plate dome acts to resist the internal pressure, provides gaseous containment and serves as the interior form for the biological concrete shielding. The service building contains special purpose areas not required for fossil fuel steam plants. Throughout the plant, special protective finishes are required in areas subjected to high level activity where liquids are in contact with the surface and in areas subjected to spillage of liquids containing radioactive products. Finishes used include metal liners, plastic coatings, vinyl sheets and special paints, some of which require special surface preparation and application procedures.