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CTF, jointly developed with NCSU, is a subchannel thermal-hydraulics tool built from the legacy code COBRA-TF. CTF has been adopted for use in the CASL VERA toolset. This project has led to numerous improvements to CTF, including:

  • Implementation of new closure models and user features in support of CASL challenge problems, including departure from nucleate boiling (DNB), crud-induced power shift (CIPS), and reactivity insertion accident (RIA)
  • Extensive verification and validation testing of the code
  • Coupling to the neutron transport code, MPACT, the crud-chemistry code, MAMBA, and the fuel performance code BISON
  • Code performance improvements, including a domain decomposition parallelization of the code using the message-passing interface (MPI)
  • Integration into the VERA environment, allowing for CTF models to be developed from the VERA common input file and for CTF results to be visualized in the VERAView visualization tool
  • Expansion of the code documentation suite to include a software assessment manual, software requirements, a lifecycle process, and a training and change control plan
  • Integration of an automated code build and testing system

ORNL jointly maintains CTF with NCSU and participates in the CTF User Group, which is responsible for distributing the code to users outside of CASL, providing user support, and providing a forum where users can share code-related research and improvements.

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