User Group Meeting | 2016 | Boise, Idaho, USA 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 Pacific Northwest National Laboratory Richland, WA November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

User Group Meeting | 2016 | Boise, Idaho, USA Summary Current code versions Summary of Changes FRAPCON-4.0 FRAPTRAN-2.0 Upcoming Changes Changes beyond these versions Next Code Release November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

User Group Meeting | 2016 | Boise, Idaho, USA Current Code Versions FRAPCON-4.0 FRAPCON-4.0 patch 1 FRAPTRAN-2.0 November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPCON-4.0 Extensive work has been done to modernize the FORTRAN language used for FRAPCON Commons have been eliminated and variables are stored in modules for use in other subroutines Code changed from fixed format to free format More modern syntax has been employed for logic tests. Eg <, <=, ==, >=, > rather than lt, le, eq, ge, gt All subroutines have been grouped into modules according to their function Go to statements and if, then, else constructs have been replaced with CASE statements wherever possible Need for compiler options has been eliminated Double precision explicitly stated on all variables All variables explicitly declared Variables are dynamically dimensioned to the size of the current problem No restriction on # of axial (na) or radial (nr, ngasr) nodes, no limit to the # of timesteps (im) or axial power profiles (up to im) Code will be distributed with makefile for compiling on LINUX and OSX November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPCON-4.0 (cont.) Code predictions from FRAPCON-4.0 are nearly identical to FRAPCON-3.5 Several bugs have been removed and models have been improved Update to plenum temperature model Update to gas properties Several new capabilities have been added Added the ANS-5.4 (2011) Standard Fission Product Release Model “EM” options have been removed Ability to model spent fuel storage using the DATING creep models added Ability to use the ANS-5.1 decay heat model to calculate heating after shutdown added Ability to specify axial coolant conditions (Temp, Press) was added Various “Developer” options have been added to allow the user to change various model parameters for sensitivity study These options have the potential to change the FRAPCON results such that the outputs are no longer validated November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPCON-4.0 Patch 1 Fix error in terminating oxidation calculation (calcoxide) Intel 2015 Compliance Fix error with specified cladding temperatures Compiles with GNU FORTRAN Replaced error function to use FORTRAN error function Removed Scratch file Added ability to output B10 concentration Added ability to input ZrB2 thickness in SI units Fix error in spring unit conversion Corrected error in ANS-5.4 2011 model November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPTRAN-2.0 Extensive work has been done to modernize the FORTRAN language used for FRAPTRAN Commons have been eliminated and variables are stored in modules for use in other subroutines Code changed from fixed format to free format More modern syntax has been employed for logic tests. Eg <, <=, ==, >=, > rather than lt, le, eq, ge, gt All subroutines have been grouped into modules according to their function Go to statements and if, then, else constructs have been replaced with CASE statements wherever possible Need for compiler options has been eliminated Double precision explicitly stated on all variables All variables explicitly declared Variables are dynamically dimensioned to the size of the current problem No restriction on # of axial (na) or radial (nr, ngasr) nodes, no limit to the # of timesteps (im) or axial power profiles (up to im) Code will be distributed with makefile for compiling on LINUX and OSX November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPTRAN-2.0 (cont.) Code predictions from FRAPTRAN-2.0 are nearly identical to FRAPTRAN 1.5 Several bugs have been removed and models have been improved Update to void volume calculations Changes to transient thermal solution proposed by Lars Jernkvist from Quantum Technologies was implements Several new capabilities have been added Water properties file not necessary Option to select relocation model was added Improved ability to link to TH codes November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPCON-4.0 and FRAPTRAN-2.0 Updates have been made to the Excel Auto Input Generator All input variables are available to the user through this file Tabs with required input are shown in red Tabs with optional input for exercising various code options are shown in blue Standard dimensions from various assembly designs are available to pre-populate input Generator has been made dynamic (can continue as needed for axial variations, power history, coolant conditions, etc.) Updates have been made to the Excel Plot File Ability to plot an axial plot at a various time steps has been added to “1D data” tab Surface plots in “2D data” tab improved Ability added to plot axial and radial gas information added (nplot=2) e.g. gas in grains, grain boundary gas, produced gas Ability to switch between British/SI units November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Summary of Changes: FRAPCON-4.0 and FRAPTRAN-2.0 (cont.) Updates have been made to the QA procedures GitHub used for version control of source code V&V cases established Unit test cases. Separate driver program run subroutines to verify their performance relative to hand calculations Verification test cases. Database of test cases is being established to test all code functionality Validation test cases. Integral Assessment cases used to validate code predictions Code change tracking tool implemented to assign, track, and document new code developments FRAPVALID auto validation tool from IRSN implemented to assess the impact of new code modifications Dakota scripts written for FRAPCON and FRAPTRAN uncertainty analyses Modernization of assessment cases November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Upcoming Changes (underway) 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 Investigate and fix problems with code crashes and eliminate unnecessary error messages Investigate and fix as appropriate the following potential issues in the code: 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 Add fuel swelling due to fission gas swelling in FRAPTRAN Fix problem with calculating DT on OD and ID of cladding in FRAPTRAN Add ability to input CRUD thickness and calculate DT in FRAPTRAN Develop hydride reorientation model Modernization of assessment input cases to match current code capability November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

Changes Beyond These Versions NRC and PNNL are developing a 5 year plan for FRAPCON and FRAPTRAN. Some items for this plan include: Better integration with SNAP 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 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 and PARCS 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 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA

User Group Meeting | 2016 | Boise, Idaho, USA Next Code Release Plan to release FRAPCON-4.1 and FRAPTRAN-2.1 by September 2018 November 13, 2018 User Group Meeting | 2016 | Boise, Idaho, USA