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42291001371600Volume 16 / Number 2 / August 201600Volume 16 / Number 2 / August 20166858001143000Sponsored by the U.S. Nuclear Regulatory Commission00Sponsored by the U.S. Nuclear Regulatory CommissionSpring 2016 CAMP MeetingThe Spring 2016 CAMP Meeting was hosted by FANR on April 26th through the 28th at Khalifa University, Abu Dhabi. It was another successful CAMP meeting and a gracious “Thank You” is extended to the host members from FANR and Khalifa University.The CAMP members were welcomed to the meeting by Mr. Al Khadouri, meeting host and Manager for International Cooperation. Representatives from over 15 of the 25 Countries in CAMP were in attendance, and the meeting was broadcast over the internet via GoToMeeting. She wished everyone a very pleasure stay in Abu Dhabi.The CAMP members were then welcomed to the meeting by Mr. Christer Viktorsson, Director General (FANR). He reviewed FANR’s commitment to high standards for safety and security, and a basis of operation based on transparency and openness. He (Continued on page 2) 541020243840EMAIL FOR TRACE BUGS:Any TRACE bugs can be reported to the following email address: TRACE.Bugs@00EMAIL FOR TRACE BUGS:Any TRACE bugs can be reported to the following email address: TRACE.Bugs@TRACE Usage WarningChristopher Murray, USNRC419101918335Thermal-HydraulicCode News Committed to the support of the T/H Codes User Community00Thermal-HydraulicCode News Committed to the support of the T/H Codes User Community38055556981190Contents:Spring 2016 CAMP MeetingTRACE User ProblemsRecent RELAP5 User ProblemsRELAP5/Mod3.3Patch05Basic TRACE/SNAP WorkshopNew CAMP Program ManagerUpcoming Fall CAMP MeetingStatus of NUREG/IAsOther Items of Interest00Contents:Spring 2016 CAMP MeetingTRACE User ProblemsRecent RELAP5 User ProblemsRELAP5/Mod3.3Patch05Basic TRACE/SNAP WorkshopNew CAMP Program ManagerUpcoming Fall CAMP MeetingStatus of NUREG/IAsOther Items of InterestAs part of our normal operating procedure, NRC typically shares developmental code versions of TRACE with users that request them. These versions always come with a qualification of “Use at your own risk” since they do not have assessment pedigree of the patch releases. We recently shared V5.1051 with several users to use its new features and address issues they were having. However, a severe issue was uncovered in all code versions after V5.861 that causes CCFL-defined edges to not work correctly (in general, counter-current flow can still be predicted). We want users of these more recent code versions to be aware of this issue because CCFL is such an important phenomenon in many classes of accidents. As such, users should not be using versions after V5.861 for making important decisions unless they have checked to ensure any CCFL phenomena are being simulated correctly. We are diligently working on a fix and should have something ready soon. We apologize for any inconvenience this may cause you in your code applications. Spring 2016 CAMP Meeting …continued from page 1mentioned the number of international agreements established by the government of the UAE, extensive collaboration with the International Atomic Energy Agency (IAEA) and with other nuclear regulatory authorities in other countries which help ensure that they are consistent with international best practices. They also may consider effort to engage stakeholders to ensure their understanding of FANR regulatory programs. He mentioned UAE’s intent to ensure that UAE citizens are developed in nuclear technical and regulatory competencies, and that their selection of Khalifa University helps to fulfil that purpose. He then reviewed construction of the Barakah Nuclear Power Plant facility underway by the Emirates Nuclear Energy Corporation (ENEC) which commenced in 2012, with the four reactor units being scheduled for completion in 2020. He indicated that the project at Barakah was progressing steadily with Unit 1 now more than 85 percent complete, Unit 2 more than 60 percent complete, and that Unit 3 and Unit 4 are sequentially behind in succession.Dr. Philip Beeley, Nuclear Engineering Director of Kalifa University, gave a brief overview of the University’s Nuclear Engineering program and the ongoing research, equipment, international collaborations, and facilities in support of FANR and ENEC.Carl Thurston then welcomed the CAMP members and thanked the hosts country representatives for their efforts in providing and preparing the meeting facilities. He also stated that the general and TPC meeting minutes from the Fall 2015 CAMP meeting were completed and uploaded to . He motioned to accept the meeting minutes as uploaded and Dr. Pavel Kral, UJV, seconded the motion, and the minutes were accepted.Mr. Thurston then gave the first technical presentation of the meeting, presenting slides for Dr. Chris Hoxie in his absence. Mr. Thurston gave a presentation on the Status of NRC Code Development. CAMP related contacts at the NRC were provided as follows:?CAMP Program: Carl.Thurston@ After 6/5/16: Joseph.Kelly@ ?NUREG/IA: Kirk.Tien@ ?TRACE: Christopher.Murray@ ?SNAP: Chester.Gingrich@ ?PARCS: Nathanael.Hudson@ ?RELAP5: Joseph.Staudenmeier@ Mr. Thurston described the major elements of the “Reactor Core and System Analysis Code Suite”, and provided a summary of improvements. The codes included in this suite include SNAP (platform/graphical user interface), Triton/Polaris/Helios/CASMO/Serpent and GenPMAXS (cross section library generation), PARCS & PATHS (core physics and steady state thermal hydraulics) and TRACE (reactor system thermal hydraulic analysis).Mr. Thurston provided an overview of NRC/ISL presentations at this meeting. He then presented a high-level look at some of the recent improvements in TRACE, PARCS/PATHS/GenPMAXS, and SNAP, and announced the release of RELAP5/Mod3.3Patch05. Lastly, Mr. Thurston reported on the use of TRACE for a variety of licensing and design certification activities, including: APR-1400, SMR, ESBWR, US-EPR, US-APWR, AP1000, ABWR, power & research/test reactor licensing actions, and Generic Safety Issue (GSI) and Rulemaking support. He reminded CAMP members that TRACE is the future of NRC safety systems thermal hydraulic analysis. To assist the NRC, he would like to see member assessments on five key areas: (1) fuel rod models, (2) spacer grid models, (3) Droplet field void fraction predictions, (4) testing of new features, e.g., higher order numeric, and (5) additional integral tests.On behalf of Mr. Christopher Murray, Dr. Matthew Bernard gave a presentation on the TRACE Code Development Status, and announced that V5.0 Patch 5 is anticipated to be released this Fall. He showed a summary of trouble reports being tracked, and indicated that the current developmental version is 5.1013. He then reviewed major changes implemented since the last CAMP meeting, i.e., since developmental version 5.960. He concluded by discussing some of the future plans for TRACE.Mr. Doug Barber reported on the RELAP5/MOD3.3 status. The latest full release is RELAP5/MOD3.3Patch04, which is Version 3.3iy, October 2010. The most recent developmental version is 3.3km, which fixes a bug and includes a new feature: Card 1 Option 35 for ramping between the jetmixer and branch momentum equations between void fractions of 0.3 and 0.4.One user problem that was resolved and one that is in-work were discussed. A complete list of user problems from 1998 to date is posted on the NRCCodes Sharepoint site (). In addition, 2 new code versions have been created since the Fall 2015 CAMP Meeting, and these were described. Lastly, the release of Mod3.3Patch05 was announced for May/June of 2016 (see article on Page 11).Dr. Nathanael Hudson gave a presentation on the status of PARCS. He first discussed the recent PARCS/PATHS progress, and then provided some detail on PARCS development. He then discussed some SCALE/GenPMAXS development, followed by a discussion of PARCS assessment activities. He concluded with a summary of the on-going and future development activities.Mr. Chester Gingrich reported to the group on the SNAP development status and updates. He began by reporting on SNAP “Core” updates and status. This was followed by a discussion of the Microsoft Word format for the Model Notebook, along with advances in the Job Stream functionality and Uncertainty Quantity tool. Additional details were provided on TRACE plug-in updates, TRACE/PARCS mapping updates, PARCS plug-in updates, and SCALE plug-in updates. He concluded by discussing ongoing development work.Additional presentations included:Dr. Pavel Kral, UJV, “Member country status report on CAMP activities in the Czech Republic”Dr. Andriy Kovtonyuk, Tractebel, “CAMP-related Activities in Belgium”Mr. Aleksandar Delja, Canadian Nuclear Safety Commission, “Status of CAMP Activities in Canada”Mr. Hsiung-Chih Chen, National Tsing Hua University, “Status of CAMP Activities in Taiwan”Mr. Joaquin Basualdo, Karlsruhe Institute of Technology, “PARCS/Subchanflow/Transuranus Internal Coupling”Dr. Viktor Sánchez, Karlsruhe Institute of Technology, “Internal Coupling of TRACE with DYN3D-MG (TRADYN): Current Status”Dr. Sang Yong Lee, KINGS, “On the Development of Multi-Dimensional RELAP5 with Conservative Convective Terms”Dr. Guido Mazzini, CVRez, “Activity of LVR15 Research Reactor using NRC codes”Dr. Andriy Kovtonyuk, Tractebel, “Natural Circulation Benchmark”Dr. Andrej Pro?ek, Jo?ef Stefan Institute, “Comparison between TRACE and RELAP5 calculation of SB LOCA in PWR”Dr. Cesar Queral, Technical University of Madrid, “New AP1000 studies with TRACE5 patch2 and ATLAS test A5.1 SBLOCA benchmark”Mr. Julio Rivas Lewicky, Technical University of Madrid, “Validation and application of Almaraz NPP model. Power uprate and TRACE5 Patch1 to Patch4 transition”Dr. Konstantin Nikitin, BKW Engineering AG, “BWR-4 ATWS modeling with RELAP-S3K coupled code”Jan Frélich, TES, s.r.o, “Validation of Bubble Condenser Model in RELAP5/MELCOR”Mr. Petr Heraleck?, TES, s.r.o, “Preliminary Post-Test Analysis of Cold Leg Small Break 4.1 %at PSB VVER Facility Using TRACE V5.0”Dr. Oleg Orlov, Amec Foster Wheeler, “Coupling of RELAP5 and Darlington NGS controllers in MOOSE”Dr. Ivor Clifford, Paul Scherrer Institut, “TRACE Analysis Activities at STARS”Dr. Masahiro Furuya, Central Research Institute of Electric Power Industry, “Code Validation against Boiling Two-Phase Flow Experiments in Rod Bundle”Dr. Matthew Bernard, US NRC, “Presentation of Advanced Code Development Activities in TRACE”TRACE User ProblemsThis is a report on TRACE user problems and resolutions. Open trouble reports identified in the previous newsletters with no new progress are not discussed, but can be found in the TRACE trouble report system (TRACEZilla) on the NRC Codes website (). For the time period between January 1, 2016 and June 30, 2016, 18 new trouble reports were submitted to TRACEzilla. 35 trouble reports were either resolved or closed during this same time period. As of June 30, 2016, there were 757 trouble reports in the TRACE bug reporting system. Five of those are for the PARCS code, two are bugs for the AVScript, 14 are bugs entered to test the system, and one bug number (452) was skipped. There were 735 TRACE-specific bugs in the system at the end of the reporting period; 36 of those were open, with the remainder resolved, closed, or duplicates. This implies that ~95% of the TRACE trouble reports have been resolved or closed or duplicates.A resolved trouble report indicates that it has been addressed with an update or documentation change that is pending. A closed trouble report indicates that it has either been addressed by successfully re-running the test problem(s) of interest with a current version of TRACE or it has been closed by incorporating a pending update into the NRC developmental version of TRACE. A pending update implies that it has been tested, documented, reviewed, and submitted to the NRC, but has not been included in the developmental version of TRACE. Inclusion of a pending update into TRACE typically requires additional review and testing by the NRC staff.The most current developmental version of TRACE is Version 5.1062 as of June 30, 2016. Updates included in Version 5.1062 are listed on the TRACE user support web site ().New Trouble Reports Still OpenTrouble Report 742 – Problems running PARCS-coupled calculations with debug executable.Developer reported that for a coupled PARCS/TRACE calculation with a debug executable it failed with a runtime fatal error associated with a variable used before it has been defined. Sometimes optimized compiles will run through coding that uses undefined variables. Developer reported that run time error occurred with versions 5.910 through 5.973 and also with the cleanTH update included. This trouble report is still open.Trouble Report 743 – Incorrect HTSTR surface heat flux/power reported for HTC boundary condition..User reported that when HTSTR boundary condition (BC) is user specified heat transfer coefficient and sink temperature, then the calculated heat flux is not consistent with the calculated surface temperature. It was determined that for this HTSTR BC option the sink temperature is loaded into array tlnr, but the routine that updates the surface heat flux uses the tlr array. The tlr array for this HTSTR BC is zero. Problem and fix has been identified, but update has not be developed. This trouble report is still open.Trouble Report 745 – Heat structure documentation is duplicated in Users Guide Component Models in HTSTR and CHAN chapters.Developer indicated that heat structure documentation was duplicated in the HTSTR and CHAN chapters of the Component Models User Guide. The specific example identified was documentation of the crud model. Recommendation was to only have the crud model documented in the HTSTR component documentation and have the CHAN component references the HTSTR documentation. Better references also need to be identified for the crud model documentation. This trouble report is still open.Trouble Report 747 – Two-phase interfacial heat transfer model gives unphysical results for subcooled filling/emptying of vertical pipes.User reported that unphysical pressure spikes were observed when running a test problem that involve filling and emptying of a vertical pipe with subcooled water. User indicated that a fix to plug flow model that went into version 5.182 was causing the problem. In earlier versions of TRACE the plug flow model was incorrectly applied to vertical tubes. The plug flow model for vertical tubes reduced the interfacial heat transfer so that pressure spikes were not observed. Applying the plug flow condensation model to vertical tubes, is not consistent with the assumptions used for the basis of this model. Investigation of this problem indicated that turning on level tracking would eliminate the pressure spikes. Level tracking only comes on for vertical PIPEs and the determination of whether a PIPE is vertical or not is based on the user input for the GRAV array. When IELV = 1 or 2, then GRAV array is not loaded until after initialization. Determination of whether or not a PIPE is vertical is completed before the GRAV array has been loaded when IELV = 1 or 2. The FxInitLtrk update has been developed to address this issue and is currently in testing. This trouble report is still open.Trouble Report 748 – CPU time showing up in eciTest_2pipe_b.msg.Developer reported that cpu time is in ECI test problem outputs, even when –nouniqueout TRACE command line option is used. When running the Regression test problem set, developers typically run with –nouniqueout, so that edits such as cpu time, date and time, version number, etc. do not show up in the TRACE ASCII output file. This allows diffs to identify test problems with differences in the results and not flag test problems that have slightly different cpu times. When ECI test problems are run, the test problem is spread over more than one processor and it appears that the –nouniqueout command is not duplicated on the other processors. This trouble report is still open.Trouble Report 751 – 5.1003 with test problem mslb_trace_htrd_ss debug version of TRACE/PARCS dies with FORTRAN error.Developer reported that debug version 5.1003 of TRAC/PARCS compiled with Intel compiler 13.1, running on Windows 7 OS with 64 bit dies with test problem mslb_trace_htrd_ss FORTRAN run time error indicating read past the end of the a PARCS input file. Test problems pbtt_trace_tr and pbtt_trace_ws also fail with a divide by zero for version 5.1003 coupled TRACE/PARCS calculation. This trouble report has been marked as a duplicate of trouble report 742. This trouble report is still open.Trouble Report 756 – Problems with Film Condensation Model for PIPE ComponentsUser reported that there exists differences between the CONTAN film condensation model and the TRACE PIPETYPE = 8 condensation model. There is currently no expectations that these two models would give the same results. Film thickness in the CONTAN model is based on condensation rates and film draining rates at the heat structure surface. There is no droplet interaction with the film in the CONTAN film model. The TRACE film model estimates film thickness from the local void fraction with estimated droplet volume fraction removed and assuming a vertical wall geometry. There is currently no expectations that these two models will yield the same results. This trouble report is still open.Trouble Report 757 – Potentail problem with calls to error in SensCoefficients module.Developer reported that is no USE ErrorInterface, ONLY: error in the SensCoefficients module. The error routine interface is only needed when optional arguments are used in calls to error. To avoid optional arguments, the developer passed a zero as the component index in the call to error. If 0 is used in genTab(0)%num to determine the component number, then the user will see a programming error message and will be requested to help the NRC debug this unexpected error. Zero should not be used as the component index, if USE ErrorInterface, ONLY: error is used at the top of this module, then calls to error can use optional arguments such as details and calledBy and the component index can be skipped in the call to error. This trouble report is still open.Trouble Reports ClosedDuring the time period from January 1, 2016 to June 30, 2016, the following trouble reports have been closed. A trouble report is closed by: 1) rerunning the test problem of interest successfully with the latest version of TRACE, 2) updating documentation to address the trouble report, 3) incorporating an update into the NRC development version of TRACE. In some cases a combination of these three fixes may be used.Trouble Report 692 – Regression test problem BWRMassErrTest has a mass error of ~9% after 1100 time steps.Running Regression test problem BWRMassErrTest with an earlier version of TRACE indicated a significant mass error. When this test problem was run with verison 5.910 the mass error was not significant, 5.5x10-8%. This trouble report has been closed.Trouble Report 697 – Solubility limit added as a graphics variable.User requested that the solubility limit be added as a graphics variable. The solubility limit is a function of the liquid phase temperature. The solubility limit function can be one of two default curves or defined by user input. Update FxFillCOntan included the changes to add solubility limit as graphics variable. Update FxFillContan was included in version 5.1011, closing this trouble report. Trouble Report 698 – Problem with Moderator Density Feedback Reactivity.User reported that RELAP5 reactivity feedback input model input into TRACE and the moderator density reactivity feedback appeared to be in error. In general the RELAP5 reactivity feedback tables are in terms of absolute change in reactivity from a given initial critical state. TRACE reactivity feedback tables are in terms of derivatives of the change in reactivity given a change in the core average parameter of interest. Therefore, conversion of RELAP5 reactivity tables to TRACE input requires that a derivative of the RELAP5 table be estimated and used to develop the TRACE reactivity feedback table. As part of the FxFBModDen update guidelines on converting RELAP5 reactivity into TRACE reactivity tables was developed. Update FxFBModDen went into version 5.972, closing this trouble report.Trouble Report 721 – FILL mass flow rates in error under some conditions for IFTY = 10.User reported for an APR1400 model, the feed water FILL velocities were calculated correctly, but the FILL mass flow rates were not consistent with the FILL velocities. The FILL mass flow rates were used in the feed water control system and the error in the FILL mass flow rates resulted in steam generator dry out during steady-state calculation. Update FxFBModDen included fixes to the FILL IFTY = 10 mass flow rate calculations and update FxFBModDen went into version 5.972. This trouble report was marked closed.Trouble Report 703 – TRACE error check for gas gap material ID does not work.User reported a 3x3 channel model using a PIPE and HTSTR failed because the fuel was melting. This was unexpected behavior for this simulation. It was determined that the fuel rod model included two gas gaps. The TRACE code assumes only one gas gap in a typical fuel rod model with the dynamic gas gap model turned on. If the gas gap HTC is a fixed user input constant, then multiple gas gaps are allowed. Input checking should have caught the input error that cause the fuel rod to melt. Even when multiple gas gaps are present, with constant gas gap HTC, the gas gaps cannot be adjacent to each other. Update FxMultGap resolved this input checking logic failures and changed the logic so this user input would result in a user input error. Two adjacent radial nodes are not allowed to be gas gap material types. A gas gap is expected to occupy only one radial node. Multiple gas gap are allowed if there are no adjacent radial nodes with gas gap material type and if NFCI = 0. NFCI = 0 implies constant gas gap HTC. Update FxMultGap went into version 5.1006 and closed this trouble report.Trouble Report 708 – Error conc – solute concentration input description concerning units.User indicated that on page 41 of the Users Guide Volume 2 Component Models Chapter the description of the fluid component solute concentration input variable was in error. The input description indicated that conc user input units depended upon the user input for ISOLUT. The coding is TRACE expects the same units for conc input independent of the input for ISOLUT. User user input units for conc are always kg-solute / kg-water. Fixes to this documentation were included with update FxFillContan that went into version 5.1011. This closes this trouble report.Trouble Report 709 – LBLOCA simulation using side junctions in error.Using side junctions at the break locations for a LBLOCA is not consistent with the guidelines. Resolution of this trouble report did not require coding or documentation changes and was closed..Trouble Report 710 – For heat transfer regime inverted annular film boiling, radiation heat transfer may be accounted for twice.The criteria for inverted annual film boiling requires that the local void fraction be less than 60%. When inverted annular film boiling comes on, than the film boiling heat transfer includes radiation heat transfer from the hot walls to the liquid phase. The radiation heat transfer enclosure model comes on based on the maximum temperature difference for the heat structure surfaces within an enclosure and when at least one heat structure surface is more than 100K above the saturation temperature. The criteria for radiation heat transfer enclosure model no longer depends upon the local void fraction. Radiation heat transfer with the liquid and gas phases is included in the model. Therefore, it was possible for inverted annual film boiling and the radiation heat transfer enclosure model to double account for radiation heat transfer. Update ZrEmiss modified the logic so that radiation heat transfer would not be double accounted. Update ZrEmiss went into version 5.970.Trouble Report 711 – Differences in TRACE Predictions for Two Similar Inputs.User reported that adding dead end side junctions to an existing SBLOCA input model resulted in a change in the calculated results. Adding dead end side junctions should not impact the results, since there was no flow or heat transfer in these dead end side junctions. Investigation of this problem indicated that adding a side junction to the top of a pressurizer component changed the flow regime calculated for that cell. This logic was corrected with update FxPzrAcc. Final differences were determined to be due to changes in the cell average hydraulic diameter at the top of the pressurizer. The dead end side junction at the top of the pressurizer had a hydraulic diameter significantly different than the hydraulic diameter in the pressurizer. The cell edge hydraulic diameters are used to estimate the cell center hydraulic diameter. Adding the dead end pipes to the pressurizer effectively change the geometry of the pressurizer. When the hydraulic diameters were consistent and with the FxPrzAcc update, the results were the same for these two input models. This trouble report was closed when update FxPrzAcc went into version 5.973.Trouble Report 712 – Error in format for error message..Developer reported that call to CheckAscending could result in a run time FORTRAN error is error message is attempted. Update HydrogenClad included fixes for this format error. Update HydrogenClad went into version 5.980 and closed this trouble report.Trouble Report 714 – Spacer grid model implementation for CHAN component does not appear to be complete.Developer identified logic errors in the TRACE grid spacer model indicated that implementation of grid spacers for 1D fluid components had not been completed. Update FxGridSpacers completed the implementation of the grid spacer model for 1D fluid components (i.e., CHANs and PIPEs with pipetype 7). Update FxGridSpacers went into version 5.1061 and closed this trouble report.Trouble Report 715 – Stratified flow in pressurizer and acumulators.Developer indicated that specific blocks of coding in PRIZER and PIPE accumulator components for flow regime modifications for these components had not be include for PIPE components with PIPETYPE = 9. Logic to address this trouble report was included into update FxPzrAcc. Update FxPzrAcc went into version 5.973 and closed this trouble report.Trouble Report 719 – No fluid in cellDuring a PKL simulation a FORTRAN error associated with a divide by zero occurred. The divide zero occurred when the calculated mass and energy conservation equations residuals were normalized by dividing by the fluid cell mass and energy. The fluid cell mass and energy was zero and it never should be zero. The zeros for mass and energy occurred because the arrays used to normalized the residuals were not included in the stateData data structure and were not backed up when the solution backed up. Three approaches were proposed: 1) Add the arrays to state data, 2) add call to SetSysMacros after the backup of stateData has been loaded, 3) use macroscopic densities stored in the blocks data structure. The fix used in update FxSMass was to call SetSysMacros after the backup of stateData has been loaded. This update went into verison 5. 1001 and closed this trouble report. Trouble Report 728 – Programming error in SolverUser reported a Programming Error when a zero was detected on matrix diagonal, for version 5.0 Patch 4. We were never able to duplicate the problem with version of TRACE on any of our available platforms. Some input changes were proposed for the test problem of interest concerning heat structure properties and noding as well as replacing a FILL with a BREAK so that the control system for adjusting flow losses worked correctly. With these changes the user no longer saw the programming error. This trouble report was marked closed, since we could not reproduce this programming error.Trouble Report 729 – Error in Adjusted Flow Losses Feature in TRACE.User reported that for the input model provided the Adjusted Flow Losses (AAFL) feature in TRACE was not working. The user indicated that: 1) the AAFL feature does not work during a transient, 2) user anticipated the he needed to run TRACE first to get the adjusted flow losses and then manually input them into another TRACE input model and rerun the steady-state and then restart the transient, 3) there is an index error in the AdjustAddLoss routine for 3D cell edges, 4) there is confusing in terms of documentation and output concerning FRIC based adjusted flow loss factors and K-factor based adjusted flow loss factors. The AAFL feature is designed to only work during a steady-state. During a steady-state the flow loss factors are adjusted to satisfy either a mass flow rate or a pressure drop boundary condition and the final adjusted flow loss factors are written to the restart/dump file, so that the transient restart if rested from the final restart dump will use the adjusted flow loss factors. The fix to the index error in routine AdjustAddLoss went into version 5.960. Update FxAddLoss made the adjusted additive flow loss factors consistent with the IKFAC namelist input. If IKFAC = 0, then the adjusted 1D and 3D flow loss factors were edited as FRIC. A FRIC is defined as:?p = (FRIC * L / D) * ? * |V|*VWhere,?p = pressure drop due to FRICL = flow path lengthD = hydraulic diameter? = densityV = velocityIf IKFAC = 1, then the adjusted 1D and 3D flow loss factors are edited as K factors. A K factor is defined as:?p = K * ? * |V| * V / 2The 1D and 3D internal flow loss factor models were made to be consistent with this update. The FxAddLoss update went into version 5.1003. The FxAddLoss update also addresses the documentation issues identified by this trouble trouble. During development of this update it was determined that the radial additive flow loss was included twice the 3D radial momentum equation. Update FxXrLoss went into version 5.1004 and closed this trouble report.Trouble Report 731 – Vent Valve Input Description in Error.The vent valve input description indicated that user input for FROVN and FRCVN were unitless K-factors. However, the vent valve coding used that as 3D CFZ factors. A 3D CFZ factor has units of 1/m has a form of FRIC / D. It should be noted that no units conversion was performed on these vent valve inputs, which implies then even the TRACE input was input in English units, then user input for FROVN and FRCVN will have units of 1/m. Update FxXRLoss update resolved this trouble report by making the vent valve input flow loss factors consistent with the name list input for IKFAC. Input documentation was update to be consistent with the vent valve coding. This trouble report was closed when update FxXRLoss went into version 5.1004.Trouble Report 733 – Heat Structure Input Processing for oxLayerAr and burn2D is in error when fine mesh turned on.User reported a problem with the initial oxide layer thickness for the fine mesh nodes at the top and bottom of heat structure that had fine mesh turned on. When fine mesh is turned on an extra coarse mesh axial level is added to the top and the bottom of the heat structure. These extra axial levels split the user input top and bottom heat structure axial levels. Logic in TRACE duplicates the user input for the original top and bottom axial levels for the new extra axial levels. Investigation of top down and bottom up reflood data indicates that the first coarse mesh axial level must be relatively small to allow for the correct timing of the start of a quench. For the cladding initial oxide layer and the 2D burnup data input processing this duplication of user input for the two extra nodes happened twice. Once in the heat structure input module and once in the heat structure utility module. The FxFMOL update removes this extra adjustment in the heat structure input module. This fine mesh extra node adjustment needs to be accomplished in HtStrUtil module, since both the CHAN and HTSTR components use this logic and it has to be used consistently for spawned for heat structures as well as HTSTR components. The FxFMOL update went into version 5.1002 and closed this trouble report.Trouble Report 735 – User Reported Simple Trip does not include non-zero delay times.User reported that simple trip appears to ignore non-zero delay times. The simple trip |ITST| = 4 capability was added to the TRACE trip options to support RELAP4 to TRACE conversions. Therefore delay times for the trip are not available for this simple trip, but are available with other TRACE trip types. Update TR735 adds input checking so that a warning is written if a simple trip is input with a non-zero delay time. Documentation was updated so it would be clear to the user that delay times are not available for simple trips. Update TR735 went into version 5.1007.Trouble Report 737 – Built-in D2O property error.User reported that the built-in D2O properties resulted in a run time error indicating that the pressure was above the maximum pressure available for these property fits. The TRACE built-in D2O properties fits were developed for application to heavy water reactors operating at atmospheric pressure. The built-in D2O properties fits have an upper pressure limit of 10 MPa. TRACE has available D2O steam tables with a significant higher upper pressure limit. Update D2O fit removes built-in D2O properties fits makes the D2O steam tables the default thermodynamic properties for D2O applications. This update went into version 5.1040 and closed this trouble report.Trouble Report 740 – Hot rod signal variable plot incorrect for POWER component spawned by TRAC-P ROD component.Developer reported that Regression test problems loftl26_ss and loftl26_tr have been failing because grid spacer input had not be updated to be consistent with the most current versions of TRACE, When the input was updated, then it was determined that hot rod PCT plots for ROD components in this input were in error. ROD components are fuel rod heat structure input used by TRAC-P input models. TRACE has the capability to process this input, but it is not documented in the input or component descriptions. Logic error for hot rod PCT calculation for hot rods was fixed with update FxHotRodPlot, which went into version 5.1052 and closed this trouble report.Trouble Report 741 – Correction factor tube CHF is in error.User reported that TRACE predictions were significantly different than the Bennett test 5394 results. Reviewing the 1995 look-up table for critical heat flux in tubes by Groeneveld, the correction factor coded in TRACE was in error. Update TR741 fixed this correction factor and then update went into version 5.1013 and closed this trouble report.Trouble Report 744 – When fine mesh is on and NZHTSTR = 1, then error message is programming error.When fine mesh is on and NZHTSTR = 1 (one axial coarse mesh), a fatal input error should be declared. Due to a logic error in the heat structure input processing this resulted in a programming error. The FxGadC update fixes this logic error and also fixes a logic error that was not allowing INSIDEOXAPPK = false logic to work correctly. When name list input INSIDEOXAPPK = false, then fine mesh axial nodes smaller than 3 inches are allowed for heat structures with cladding rupture. When INSIDEOXAPPK = true, then axial node heights at cladding rupture cannot be smaller than 3 inches, which implies inside surface metal water reaction only over the inside surface 3 inches. This update went into version 5.1012 and closed this trouble report.Trouble Report 746 – DetailedFRM = true has logic missing to set ecrplimit < 0.The name list input DETAILEDFRM = true had logic to force ECRPLIMIT to -1.0. That was not the NRC expectation. The ECRPLIMIT should not be part of the DETAILEDFRM = true logic. Update CleanUpFuel removes the ECRPLIMIT logic from the DETAILEDFRM = true logic. Udpate CleanUpFuel went into version 5.1053 and closed this trouble report. Trouble Report 749 – Pitch to diameter ratio (pdrat) not recognized by code.For Regression test problem Req7.1chan it appeared that TRACE was using a pitch to diameter ratio of 1.0, rather than the user input of 1.33. The confusion is the user input for pitch to diameter ratio is for the outside surface of a heat structure. For a tube the inside surface pitch to diameter ratio is defaulted to 1.0. There was no coding, documentation, or input error and this trouble report was closed.Trouble Report 750 – XML header error for restarts for test problems added to MasterList with version 5.1003.When a given Regression test problem restarts from another test problem the test problem that it restarts from must appear in the XML header as:* <Restart>AdjFlowLossTest1</Restart>In this case this test problem would restart from test problem AdjFlowLossTest1, which would have a TRACE ASCII input file named AdjFlowLossTest1.inp. The test problems included with the update that went into version 5.1003 had restart file names that included .inp. This was unexpected and resulted in failures for the restarts. These XML headers were fixed with version 5.1004 and this closed this trouble report.Trouble Report 753 – Version 5.1004 failes to compile with Intel Fortran Compiler 13.1.In version 5.1004 iKFac in routine FricCoefS3D was referenced in modules GlobalDat and GlobalPnt. iKFac is in module GlobalDat, but not in GlobalPnt. Intel Fortran compiler 13.1 declared this a fortran error, while earlier versions of Intel compiler may not have declared it a Fortran error. This was fixed in version 5.1007 and closed this trouble report. Trouble Report 755 – Choked flow problems with oconee.31mmbrk.Regression test problem oconee.31mmbrk restarts from oconee.ss. oconee.31mmbrk is a small break simulation. For a short period time at the beginning of the transient as pressure waves travel around inside of the broken loop, pressures upstream of the break are approaching the critical pressure. The IAPWS property fits are known to be in error at or near to the critical pressure and the LocateSaturationPlane routine calculated two-phase conditions at the choking plane that had enthalpy larger than the upstream stagnation enthalpy. This resulted in an attempt to take the square root of a negative number which resulted in a Fortran run time error. If the small break modeling was changed to be consistent with the recommendations for small break modeling with TRACE, then the problem sent away. Update FxNewChoke also addresses this issue by returning from LocateSaturationPlane without a converged solution if the convergence logic did not appear to be converging on a reasonable solution. Update FxNewChoke went into version 5.1051 and closed this trouble report.Trouble Reports Resolved with Updates PendingDuring the time period from January 1, 2016 to June 30, 2016 the following Trouble Reports have been resolved with updates or documentation modifications pending. These Trouble Reports are awaiting NRC review and a decision to implement or not to implement the associated code updates or document modifications into TRACE. Please note that at the time of publication, these trouble reports may have already been closed.Trouble Report 48 – Time step diagnostic problems.User name list input for TSDLS, TSDUS, TSDLT, and TSDUT was ignored in terms of detailed time step diagnostic. Earlier versions of TRAC-P had the capability to provide detailed diagnostic information on what was controlling the time step size in a TRAC-P calculation. However, that capability did not make it over in TRACE. The logic to be able to generate these detailed diagnostic edtis was included in the FxHGAM update, but this update was not included into TRACE. Another update replaced the FxHGAM update. The time step diagnostic edits were moved from the FxHGAM update to the FxDebugEdit update, that only fixed the debug edits. The debug edits were modified to provide clear user edits on where and what was controlling the time step size. This FxDebugEdit update was moved up to version 5.1051 and resubmitted to the TRACE Holding Bin and resolves this trouble report. This update is pending NRC review.Trouble Report 680 – Center line fuel rod temperatures do not look reasonable.User noted that a steady-state fuel rod center line axial temperature profile had jumps in the temperature that did not appear to be consistent with any changes in sink temperature, heat transfer coefficient or gap conductance. Changed the number of heat structure axial levels or turning off or on axial conduction did not appear to have any significant on these steady-state axial center line temperature profiles. The root cause of this center line axial temperature profile was traced to the axial power profile which was not input consistent with the fuel rod axial noding. Integration of the axial power profile for each coarse mesh heat structure axial level resulted in some heat structure axial levels getting more power than expected. Recommendation is make fuel rod heat structure noding consistent with POWER profile axial power profile noding. Documentation was included with update TR685, which resolves this trouble report.Trouble Report 685 – Reset of signal variable ISVN = 51 and 115.There are a number parameters that are calculated for edit only or graphics only purposes which are not part of the solution scheme that are typically updated at the end of time step and not included on restart file. Signal variable 115 – volume weighted core average fuel temperature is an edit only parameter and is not used in the reactive feedback model. In general, signal variables are loaded at the beginning of the time step so signal variable 115 is not valid until the second time step. First graphics point for this signal variable can be ignored and removed from the plot of interest.Signal variable 51 is the power weighted coarse average fuel temperature and is used by the reactivity feedback model and is included on the restart file. Therefore, when the signal variables are loaded at the beginning of the time step, then signal variable 51 should be the same for the first time step as it was for the restart dump that it was read from. For a steady-state calculation, both signal variables 51 and 115 will start out at zero, since they are loaded at the beginning of the time step and reactivity feedback parameters are not updated until the end of the time step. However, the POWER component has a graphics variable tFuelAvg that is the power weighted core average fuel temperature and will have been calculated before the first call to the graphics dump. Unless the user plans to use signal variables to control some component action, graphics variables for all of the core average parameters are available in the POWER component graphics package. In general signal variables tend to be off one time step since they are loaded at the beginning of the time step. Update TR685 added the xa array to the dump restart file. The xa array is used by signal variable type 115. With this update both signal variable types 51 and 115 do not reset to zero. This update is pending NRC review and resolves this trouble report.Trouble Report 713 – HEMSound can fail when pressure > pCrit if liquid density = gas density.Developer report that conditions above the critical point could result in a failure when the liquid and gas phases are the same. Above the critical point the liquid and gas phase properties are the same and division by zero and negative square roots, etc. must be avoid as the liquid phase density approaches the gas phase density. The NewChoke update which makes a significant rewrite of the TRACE choking model is believed to have addressed this issue. Although no test problem is available to address this issue with TRACE. This trouble report is marked as resolved.Trouble Report 720 – Helical coil model.User misunderstand the TRACE helical coil input model and assumed that it was necessary to have two separate VESSEL components: 1) for the core and 2) for the helical steam generator. The fluid component on the inside of the helical steam generator tubes must be a PIPE component, but the outside surface fluid component can be a PIPE or VESSEL. In either case the location of the helical tubes is identified by the user input for number helical tubes in the fluid cell. If there are no helical tubes in the fluid cell then this input is zero. If there are helical tubes in the fluid cell, then this input is non-zero and is used to determine the cross-flow flow loss and heat transfer. Therefore since the core and helical steam generator tubes are in the different regions in the pressure vessel, then only on VESSEL component is needed to simulate a Small Modular Reactor. Documentation changes to make this input description clear was added to the FxPowerWt update. The FxPowerWt update is pending NRC review and resolves this trouble report.Trouble Report 734 – Divide by zero error in PowerTask resulting from logic error in BWR power modeling.A developer attempted to include a POWER component that powers HTSTR components (i.e., PWR application) with a POWER component that powers CHAN components (i.e., BWR application). The resulting input file resulted in a divide by zero. There was never any intent for TRACE to be able to handle this situation. Update TF734 adds input checking to throw an input error, if this situation occurs in an input model. This update resolves this trouble report and is pending NRC review.. Trouble Report 752 – Reactor power dropping after transient restart and before scam.User indicated that transient restart from steady-state resulted in a significant drop in reactor power before reactor scram. For this input user provided zero for all of the decay heat groups and provided the delayed neutron concentrations. For a steady-state calculation the fluid and heat structure properties are updated to be consistent with the steady-state calculation, but when the user provides the decay heat and delayed neutron concentrations, these are not updated to be consistent with steady-state. At the beginning of the transient the delayed neutron concentrations were approximately two orders of magnitude lower than what we be required for a steady-state power level. Delayed neutron groups have relatively small decay time constants, with the longest on the order of 100 seconds. So to go from hot standby to full power operation typically takes on the order of hours, and we would expect even for a clean reactor core with no significant burnup that the delayed neutron concentrations would be close to steady-state values, when the reactor reached full power. TRACE simulations with operating history to go from zero power to full power in one hour did not result in the expected initial decay heat power levels. The operating period equations were found to be in error when the reactor power was varying between two points in the operating history. For constant reactor power, the equations were correct. The reactor operating period equations for decay heat and delayed neutron group initialization were modified to be consistent with the integrations of the original differential equations. Update FxDH resolves this trouble report and the update is pending.Recent RELAP5 User ProblemsRELAP5 user problems reported or resolved are summarized in each issue of the newsletter. If you encounter a problem with RELAP5, please report it to Joseph.Staudenmeier@.The complete list of RELAP5 user problems, including a description of the problem, status (resolved, in work, on hold or unresolvable) and, if resolved, the manner of resolution, is available on the web site.Since the last TH newsletter was published one new user problem was submitted. A description of this user problem is provided below.No. 2016-01 (1/26/2016), In Work Code Versions Affected: RELAP5/Mod3.3kcThe user reported property errors when testing the RELAP5/MOD3.3/kc code version for simulation of a vertically heated tube at super-critical conditions. The model was initialized at zero power then ramped to full power to achieve the new steady-state at the correct test conditions. Shortly after reaching steady-state, the code crashed, and indicated a two-phase condition. Runs with Card 1 options 21 and 26 were not successful. They "survived' the trouble point but with unacceptable high mass error at minimal time steps.Evaluation (02-25-16): The code is failing when the void fraction changes from 0.0 to 1.0 while in the supercritical region. Changing the void fraction messed up the solution of the 5x5 matrix because all the heat from heat structures was instantaneously switched from the liquid energy equation to the vapor energy equation. Since the void fraction is undefined in the supercritical region the code could be modified to not change the void fraction. However, this change was originally put into the code by Glen Mortensen to address the issue of what to do when crossing the supercritical temperature above the supercritical pressure. Further investigation is needed before removing this logic.RELAP5/Mod3.3Patch05RELAP5/Mod3.3Patch05 was released in July. This version was based on developmental version 3.3km and contains numerous improvements and bug fixes over Mod3.3Patch04, which was released in October 2010. Distributions have gone out and most CAMP members and domestic user group members should have already received a copy. If you have not received a copy and would like to request one, please contact Christopher Murray at NRC (Christopher.Murray@) or Doug Barber at ISL (dbarber@). Basic TRACE/SNAP WorkshopA Basic TRACE/SNAP Workshop is being offered in Idaho Falls, Idaho the week prior to the Fall CAMP Meeting. The workshop will be held October 24th – 27th, 2016 at the Residence Inn Marriott.This workshop is directed toward beginning users with some T/H system code experience, and will focus on model development, modeling guidelines and plant modeling. The workshop will be held in the hotel conference room, which will be furnished with laptops suitable for running TRACE/SNAP. Attendance will be limited to one participant per computer. Attendees may bring their own laptop computer, but will need to install the software themselves.The deadline for registering is October 10th, 2016. This deadline is firm. We must know the precise number of attendees by that date in order to prepare the laptops and materials for the training. Any registration received after that date will not be accepted. Please note that registering for the meeting does not include hotel reservation. Lodging reservations should be made separately by the workshop attendee.The meeting registration fee is $2,500. This fee will be waived for all attendees from the NRC staff and CAMP member organizations. In addition, the registration fee will be waived for the first attendee from a T/H Codes Domestic User Group organization. A Domestic User Group organization is one that has paid the annual $5,000 user group fee and is current at the start of the training workshop. Each additional attendee from a Domestic User Group organization will be charged the registration fee. University users who have received the code for free, or domestic users that have only paid the one-time code fee but are not part of the user group, will be charged the full registration fee of $2,500.Additional information regarding room reservations, travel, etc., along with the registration form can be requested from Doug Barber (dbarber@). New CAMP Program ManagerBeginning on June 6th, 2016, Dr. Joseph Kelly (Joseph.Kelly@) took over as the new CAMP Program Manager for the NRC. He has replaced Carl Thurston who has moved to a new position in the Office of New Reactors at NRC. Please welcome Dr. Kelly to this new role, and direct any CAMP-related issues to him going forward.Upcoming Fall CAMP MeetingThe Fall 2016 CAMP Meeting is scheduled for November 2nd – 4th, and will be hosted at the NRC’s Three White Flint Facility in Bethesda, MD. The TPC meeting will be held the morning of November 4th. Details and registration information are available on the NRCCodes Sharepoint site (). Please contact Joseph Kelly (Joseph.Kelly@) or Doug Barber (dbarber@), if you have any questions regarding the meeting.Status of NUREG/IAsSince the Fall 2016 CAMP meeting, there have been several NUREG/IAs completed or published. The list of recently completed NUREG/IAs include:NUREG/IA-0458, RELAP5/MOD3.3 Analysis of Event with Actuation of Safety Injection System at the Lost of External Power (Slovenia)NUREG/IA-0460, Model 3D Cores for PWR Using Vessel Components in TRACEv5.0p3 (Spain)NUREG/IA-0461, TRAC-BF1 to TRACE Semi-Automatic Model Conversion, PBTT Example (Spain)NUREG/IA-0459, EPR Medium Break LOCA Benchmarking Exercise Using RELAP5 and CATHARE (Poland)NUREG/IA-0464, RELAP5/MOD3.3 Model Assessment and Hypothetical Accident Analysis of Kuosheng NPP with SNAP Interface (Rep of China)NUREG/IA-0465, Fuel Rod Performance Uncertainty Analysis during Overpressurization Transient for Kuosheng Nuclear Power Plant with TRACE/FRAPTRAN/DAKOTA codes in SNAP interface (Rep of China)The list of pending NUREG/IAs include:NUREG/IA-0457, Assessment of Critical Subcooled Flow through Cracks in Large and Small Pipes using TRACE and RELAP5 (Canada)NUREG/IA-0462, Uncertainty and Sensitivity Investigations with TRACE-SUSA and TRACE-DAKOTA by Means of Post-test Calculations of NUPEC-BFBT Experiments (Germany)NUREG/IA-0466, Analysis of the OSU-MASLWR 001 and 002 tests by using the TRACE code (Italy)NUREG/IA-0467, RELAP5 Analysis of Mitigation Strategy for Extended Blackout Power Condition in PWR (Slovenia)NUREG/IA-0468, Validation of RELAP5 Model of Ringhals 4 Against a Load Step Test at Uprated Power (Sweden)NUREG/IA-04xx, Fuel Rod Behaviour and Uncertainty Analysis by FRAPTRAN/TRACE/DAKOTA Code in Maanshan LBLOCA (Taiwan-ROC)NUREG/IA-04xx, Relap5/MOD3.3 Model Assessment of Maanshan Nuclear Power with SNAP Interface (Taiwan-ROC)Other Items of InterestCode users are encouraged to visit the SharePoint site, . You can join in discussions, download relevant documents, access TRACE (Bugzilla) and RELAP5 User Problem descriptions and, for CAMP members, access information on the CAMP program including status of proposed and active in-kind contributions, announcements and a calendar of upcoming events. The discussions area supports asking questions and sharing experiences. As a reminder, TRACE bugs may now be reported to the following email: TRACE.Bugs@.Christopher Murray is the contact point for the SharePoint site. If you have any problems accessing the site, or if you have any questions or would like additional information on the NRC TH codes, please contact Christopher Murray at Christopher.Murray@. ................
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