Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Jie Li Applicant's institution: ANL Applicant's division: NE Project Name: storage_cask Project title: Thermal Analyses of Vertical Spent Fuel Storage Cask by Using Parallel CFD Approach Associated funding: DOE EM and NE office Other Systems: We have a dedicated “ANSYS” server with 12 cores in total (8 of them are used for MPI parallel calculation via one pack ANSYS-Fluent license). Recently we have purchased a license for additional two HPC packs, which enables us to use the total computer cores to 128 if we can use LCRC's facility. Science: Spent nuclear fuel needs to be stored safely in a vertical storage cask for a period that may be longer than 40 years. The host containers for spent fuel must be robust enough to perform their confinement functions during the extended period. Simulation of temperature fields of the spent fuel and its storage cask is critical to determine the cladding temperature, canister surface temperature, concrete overpack temperature, as well as their peak locations (or regions of interest such as the weld heat affected zones) because most materials degradation mechanisms are temperature-dependent with rates generally increasing with temperature. Elucidating heat transfer mechanisms is also important in aiding the design of an advanced storage cask. The proposed project is to study thermal hydraulics in a commercial scale spent fuel storage cask by using the ANSYS/Fluent CFD code. The thermal performances of the vertical cask will be simulated for various events such as vent blockage, filled gas leakage, and ambient temperature variations. Our work will contribute to the understandings of the role of natural convection in the passive cooling of spent fuel in the vertical storage cask, and what is the key parameter(s) that controls heat dissipation. This study will generate useful knowledge that can guide and enable novel designs of a vertical fuel storage cask. Moreover, this study will also aid in aging management by providing guidance on inspection and monitoring. Project description: This project is to conduct thermal analyses for a commercial-scale vertical spent fuel storage cask to obtain the information important to safety storage of spent fuel including peak cladding temperatures, canister surface temperatures, as well as the corresponding temperatures under abnormal operating conditions (e.g. gas inlet blockage). Particularly, we aim to identify the key parameter(s) that dominates heat dissipation out of the cask, thereby guiding the optimized design of a storage cask. The CFD code of ANSYS/Fluent will be employed, which can conduct a large scale parallel simulations using up to 12, 000 cores. In this work, the maximum cores of 128 will be employed which is licensed via SimuTech Inc. (starting from March 15, 2015). As compared to our existing server (12 cores, 8 of them are being used), Blues can boost the computational rate approximately ten times (per our scaling analysis), suggesting that using blues can save a significant amount of time. For this problem, mutual interactions between fluid flow and heat transfer exist (per natural convection). As such, it takes a relatively longer time to get it converged. Additionally, it is further complicated by 1) thermal radiation at an elevated temperature environment, and 2) a large cask dimension (~5 million cells), both being extremely time consuming. As a result, it will need a long time for a CFD code to run and converge. Based on our computational rate analysis, it takes about 23 hours to complete a single run for such a case when 128 cores are used. In FY 15, we plan to conduct 75 runs. Including time for development and debugging, this project will need about 450,000 core-hours in total. Industry partnership: We have a close connections with Holtec. International Inc., the vendor who designs this storage cask. Project URL: Requested allocation: 450000 Q1: 100000 Q2: 100000 Q3: 150000 Q4: 100000 Justification: Storage requirements: 1 TB will be enough. The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System