Red Wolf Associates offers containment analysis consultation and services, particularly with use of the GOTHIC code. Red Wolf personnel have extensive experience modeling Mark I, II, and III BWR containment types as well as PWR containments, including sub-atmospheric containments, with GOTHIC. Our staff believes that containment analysis consists of more than simply running a code and accepting the generated results. It is critical to understand the physics of the phenomena being modeled and important to understand how the code operates to model those phenomena. Our personnel have performed in depth research to assist in the development of underlying constitutive models in GOTHIC with regard to the condensation heat transfer and turbulence modeling. We also have experience in designing, developing, and implementing various code modifications to the GOTHIC preprocessor and solver.

Red Wolf personnel have extensive experience modeling various BWR and PWR containment types with GOTHIC including events such as: 

Loss of Coolant Accident Main Steam Line Break Feedwater Line Break Small/Intermediate Breaks

Station Blackout Anticipated Transient Without Scram (ATWS) Suppression Pool Bypass

Red Wolf Associates staff can benchmark GOTHIC models against other containment codes such as CONTEMPT, CONTRANS, COPATTA, and LOCTIC to support transition to GOTHIC as the plant licensing basis.

Our staff also has the capability and experience to utilize GOTHIC to develop long-term mass and energy releases for PWRs and BWRs to be used with the containment analysis. The detailed long-term mass and energy release model components may be coupled with the containment portion of the GOTHIC model to obtain a more accurate response.

In addition to typical containment pressure and temperature response, Red Wolf personnel have experience employing GOTHIC to model containment equipment and other containment phenomena of interest. Examples of these unique applications of GOTHIC include:

• Detailed modeling of containment fan coolers and associated ventilation systems
• Predicting temperature and pressure response inside compartments (e.g., steam generator compartment temperature response, annulus pressurization loads, etc.)
• Non-accident containment heat up scenarios
• Detailed modeling of system piping within containment
• Determining effect of transient sump level and temperature variations on ECCS pump NPSH
• Assessing feasibility of early drain down of upper containment pools

A GOTHIC model of containment or associated systems can be created or utilized for any number of purposes in addition to the standard post-accident response.  Several examples of the benefit gained from advanced modeling include:

• Evaluating past, current, and future operability of systems
• Assessing proposed modifications to reduce outage duration
• Determining effect of proposed operator actions (for reasons such as Appendix R response, procedure development, etc.)
• Support of equipment qualification program
• Developing piping fluid temperature response and pipe wall temperature profiles for thermal stress analysis input

With our depth of knowledge with GOTHIC containment modeling and breadth of experience in GOTHIC applications, Red Wolf Associates is uniquely positioned to provide solutions for your containment analysis thermal-hydraulic needs.

Red Wolf Associates, PLLC © 2012