Effects of Nodalization on Containment Analysis in a Loss of Coolant Accident Using GOTHIC

• Main Author: McNeil, Wilfred J. IV
• Other Authors: Mechanical Engineering
• Format: Others
• Published: Virginia Tech 2014
• Subjects: GOTHIC; Nodalization; Loss of Coolant Accident; Containment Model
• Online Access: http://hdl.handle.net/10919/50845

Existing containment models for a loss of coolant accident at many nuclear power plants<br />were created in the 1970s using older computer technology and thermal hydraulic models<br />which were available at that time. While conservative, these models may not present the<br />detail necessary to identify conditions which may be used to produce additional design<br />margin for the plant.<br />After exploring containment and critical flow modeling, the basis for the use of GOTHIC<br />in this analysis was established. A GOTHIC model was then created to simulate the loss<br />of coolant accident results shown in an Updated Final Safety Analysis Report analysis for<br />the North Anna Power Station. This model was used to examine the effects of increased<br />nodalization in a subcompartment on the existing containment model.<br />It is shown that adding multidimensional sub-nodes to areas of interest can provide<br />valuable detail which was absent in the UFSAR model. Simulations are able to show the<br />localized pressure spike around a LOCA pipe break that quickly dissipates, leaving<br />significantly lower pressures in what was once an averaged, single, lumped-parameter<br />node. This suggests that additional design margin may exist depending on where the pipe<br />break is assumed to occur. === Master of Science