Ken Geelhood Walter Luscher FRAPCON/FRAPTRAN Users Group Meeting: Recent Code Release and Future Plans Photo Title Slide Design #11 with PLATINUM Background To best incorporate the contents of this title slide into your presentation(s), be sure to use the Select All command (Ctrl+A) before choosing to Copy (Ctrl+C) the content and then Pasting (Ctrl+V) it onto the title slide location within your new or existing PowerPoint file. Ken Geelhood Walter Luscher Pacific Northwest National Laboratory Richland, WA November 20, 2018

Summary Current code versions Summary of Changes Upcoming Changes FRAPCON-3.5 FRAPTRAN-1.5 Upcoming Changes Changes beyond these versions Next Code Release November 20, 2018

Summary of Changes: FRAPCON-3.5 See Handout November 20, 2018

Summary of Changes: FRAPTRAN-1.5 See Handout November 20, 2018

Upcoming Changes Code Modernization Removal of unused code Migration to FORTRAN 95 Logic Improvements Switch from explicit dimensions to dynamic dimensions FRAPCON General Improvements and Reliability Automate time step size reduction in creep subroutine to avoid crashes Retune FRAPFGR model to make this model the primary FGR model and add output of grain boundary gas and high burnup rim structure. FRAPTRAN General Improvements and Reliability Move sth2xt files into the code Investigate and fix problems with code crashes and eliminate unnecessary error messages Confirm validity of transient temperature solution November 20, 2018

Upcoming Changes Peer-Review Items Adapt the IRSN tool to automate the FRAPCON assessment cases and compare the results to the appropriate data or to a previous FRAPCON version. Add benchmark cases to the assessment database Investigate and fix as appropriate the following potential issues in the code: Investigate radial thermal expansion of the central hole and the coupling of FRAPCON and FRAPTRAN for annular pellets Adjust fast neutron flux and burnup for gadolinia rods Investigate potential inconsistencies between thermal and mechanical gaps Investigate passage of rod internal pressure from FRAPCON to FRAPTRAN Change FRAPCON power history input format Add fuel swelling due to fission gas swelling in FRAPTRAN Add outputs from plot file in printed output November 20, 2018

Upcoming Changes Permanently import FRAPCON-DATING in to the latest version of FRAPCON Updates to input generators and post-processors Updates to ARM-FRAPCON, and development of ARM-FRAPTRAN Investigate reflood rate predictions and heat transfer coefficients in the FLECHT model Add the ANS-5.4 Standard Fission Product Release Model to FRAPCON Review the decay heat models currently in the FRAPCON and FRAPTRAN codes,assess their validity and adequacy, and make necessary changes to both codes as necessary November 20, 2018

Changes Beyond These Versions Better integration with SNAP TUBRNP update Auto-validation tool, including long and short assessment, as well as development of standard problem cases to increase code coverage in the validation, and updates to the QA program based on use of GIT and auto-validation tool Modernization of assessment input cases to match current code capability Expansion of the integral assessment case inventory including most or all Halden tests Improvements in ballooning models in axial direction, to support eventual predictions of fuel dispersal, as well as axial stack relocation, and inclusion of grid spacers Look into vendor developments and ensure that NRC codes are following the trends, such as pellet additives, new cladding types November 20, 2018

Changes Beyond These Versions Ensure that the NRC codes are providing reasonable predictions for SMR fuel designs and make necessary changes Perform a targeted literature review to keep track of domestic and international developments in licensed fuel performance codes, to stay at the state-of-the-art Integration or coupling with TRACE FRAPTRAN dynamic time stepping based on back-stepping and normalized change metric, as well as output to the console to inform the user on status of calculation November 20, 2018

Next Code Release Plan to release FRAPCON-3.5a and FRAPTRAN-1.5a (same predictions with modern FORTRAN) in 2015 Plan to release FRAPCON-3.6 and FRAPTRAN-1.6 by December 2016 Open to discussion of more frequent beta releases November 20, 2018