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This paper summarizes the effects of the pressure sensor shape on the dynamic oscillating pressure measurements when the pressure wave modulating along the steam/air flow path is to be characterized. In the study presented in the paper, a three-dimensional CFD model of the external flow around the protruding, dome-shaped sensor was developed to evaluate the effects of the sensor shape on the external flow pattern, and the detailed flow patterns were studied with this protruding, dome-shaped sensors and compared with the flow patterns for the flush mounted sensors. Then, a one-dimensional analysis was done to predict that the dynamic pressures measured with the protruding sensor do not require significant correction, and this was later supported by wind tunnel tests. The amplitude of the dynamic pressure measured on the protruding sensor was determined to be ranging from 0 to 8% higher than measured by a flush mounted pressure sensor. The frequency of the pressure wave is not affected by the presence of the protrusion.Copyright © 2006 by ASME

The paper presents a three-dimensional (3-D) finite element (FE) model of a nuclear pressure vessel and the analyses results under typical loadings using ANSYS finite element code. Structural analyses of the vessel with internal pressure loading and thermal transient loading are described. The main focus of the analysis is on the bottom head shell with the Control Rod Drive (CRD) penetration holes. The vessel support skirt and selected CRD housing/welds that attached to the bottom head shell are included in the model. The objective of this study is to assess the bottom head stress distributions of a nuclear pressure vessel, especially the stress concentrations due to the CRD penetration openings. The calculated stresses around uphill oblique holes in the vessel are compared with those around the normal facing center penetration hole. The preliminary results and conclusions drawn from the study are presented in the paper.