ML15142A448
| ML15142A448 | |
| Person / Time | |
|---|---|
| Site: | Robinson, Harris  |
| Issue date: | 06/11/2015 |
| From: | Duke Energy Progress |
| To: | Plant Licensing Branch II |
| Galvin D, DORL/LPL2-2, 301-415-6256 | |
| References | |
| Download: ML15142A448 (42) | |
Text
H.B. Robinson / Shearon Harris Thermal-Hydraulic Transient Analysis Methodology June 2015 NRC Offices Duke Energy - PWR Methods
Presentation Outline
- Update on Proposed Submittals
- Licensing Approach
- Background on DPC-NE-3000-PA
- RETRAN-3D Code and Application
- Overview of RETRAN-3D Plant Models
- RETRAN-3D Input Model Validation
- Expanded VIPRE-01 Model
- Conclusion Duke / NRC Meeting 2 Duke Energy - PWR Methods
Methods Reports MNS/CNS ONS Proposed RNP/HNP Target Submittal Date Physics Codes / Models DPC-NE-1005 CASMO-4/SIMULATE-3 DPC-NE-1006 CASMO-4/SIMULATE-3 DPC-NE-1008 CASMO-5/SIMULATE-3 July 2015 Physics Applications Power Distribution Monitoring DPC-NE-2011 NFS-1001 DPC-NE-1002 DPC-NE-2011 revision December 2015 Physics Applications Reload Design DPC-NF-2010 NFS-1001 DPC-NE-1002 DPC-NF-2010 revision December 2015 NSSS Codes / Models DPC-NE-3000 RETRAN-02 DPC-NE-3000 RETRAN-3D DPC-NE-3008 RETRAN-3D August 2015 Subchannel T/H Methods DPC-NE-3000 DPC-NE-2004 VIPRE-01 DPC-NE-3000 DPC-NE-2003 VIPRE-01 DPC-NE-3008 DPC-NE-2005 (Appendix)
VIPRE-01 August 2015 SCD Methodology DPC-NE-2005 DPC-NE-2005 DPC-NE-2005 revision March 5, 2015 Transient Analysis DPC-NE-3001 DPC-NE-3002 SIMULATE-3K (REA)
DPC-NE-3005 SIMULATE-3K (REA)
DPC-NE-3009 SIMULATE-3K (REA)
December 2015 Fuel Performance DPC-NE-2008 (TACO-3)
DPC-NE-2009 (PAD 4.0)
DPC-NE-2008 (TACO-3 and GDTACO)
N/A - TS changes only COPERNIC-2 December 2015 Duke / NRC Meeting 3 Duke Energy - PWR Methods
Licensing Approach
- DPC-NE-3008-P describes the RETRAN and VIPRE base analysis models (similar to DPC-NE-3000-PA)
- Extends the Duke methodology to the Harris and Robinson Nuclear Plants
- System response uses the RETRAN-3D computer code in RETRAN-02 Mode
- Minor modeling enhancements implemented
- DNBR analysis will use the VIPRE models described in DPC-NE-2005-P (submitted to the NRC 3/15)
- Extended VIPRE models described in the report Duke / NRC Meeting 4 Duke Energy - PWR Methods
Licensing Approach (cont.)
- LAR submittals
- Methodology report
- Tech Spec 5.6.5 and 6.9.1.6 changes
- COLR/Tech Spec changes as required
- UFSAR changes
- Implemented via 10 CFR 50.59 following methodology report approval with first in-house reload analysis Duke / NRC Meeting 5 Duke Energy - PWR Methods
Schedule
- Support the reload licensing analysis for Harris Cycle 22 and Robinson Cycle 32
- H1EOC21 (4/18)
- R2EOC31 (9/18)
- Reload Analyses Start:
- HNP (December 2016)
- RNP (Spring 2017)
- Review requested by end of 2016 Duke / NRC Meeting 6 Duke Energy - PWR Methods
Background on DPC-NE-3000-PA Revision SER Date Relevant Portions 0 1991 Describes the transient analysis simulation models and validation analyses for McGuire and Catawba using RETRAN-02 and VIPRE-01 0a 1994 Adds Oconee transient analysis simulation models and validation analyses using RETRAN-02 and VIPRE-01 1 1995 Replacement SGs for McGuire and Catawba; incorporates improvements such as non-equilibrium bubble rise model 2 1998 3 2003 Oconee SG replacement; received approval to use RETRAN-3D in a mode that essentially defaults to RETRAN-02 4a 2008 Includes an expanded Oconee VIPRE-01 methodology (Appendix E) 5a 2012 SER for implementation of Gadolinia as an integral burnable absorber Duke / NRC Meeting 7 Duke Energy - PWR Methods
DPC-NE-3008-P
- W 3-Loop design (models are similar to McGuire/Catawba)
- Use RETRAN-3D in a mode that essentially defaults to RETRAN-02 (similar to Oconee)
- Describes each RETRAN plant model and validates the RETRAN models against selected events from Chapter 15 of each plants FSAR
- Describes an expanded VIPRE-01 methodology Duke / NRC Meeting 8 Duke Energy - PWR Methods
Why Upgrade to RETRAN-3D for HNP/RNP?
- RETRAN-3D has many new and enhanced capabilities relative to RETRAN-02
- e.g., 3-D kinetics, implicit numerical scheme, improved heat transfer correlation package
- Most of the RETRAN-02 features are retained as options
- Approved by the NRC in 2001 with 45 limitations and conditions of use
- Previously approved for Oconee
- Subsequent updates to RETRAN-3D add new features and correct errors Duke / NRC Meeting 9 Duke Energy - PWR Methods
DPC-NE-3008-P: RETRAN-3D Approach
- Like Oconee, use RETRAN-3D in a mode that essentially defaults to RETRAN-02
- For example, use the algebraic slip equation based on the drift flux model of Chexal-Lellouche in the SG tube bundle region
- Other model improvements related to, for example,
- Enthalpy transport
- Accumulator modeling Duke / NRC Meeting 10 Duke Energy - PWR Methods
Overview of RETRAN-3D Plant Models
- Following slides show layout of RETRAN-3D volumes and junctions for primary and secondary systems
- Level of modeling detail similar to that used for McGuire and Catawba Nuclear Stations
- See DPC-NE-3000-PA Figures 3.2-1 to 3.2-3
- Plant-specific models reflect design features, modeling improvements, etc.
- Two improvements selected for discussion today
- Final modeling to be described in DPC-NE-3008-P Duke / NRC Meeting 11 Duke Energy - PWR Methods
Primary System (HNP)
Duke / NRC Meeting 12 Duke Energy - PWR Methods
Secondary System (HNP)
Duke / NRC Meeting 13 Duke Energy - PWR Methods
Loop Modeling
- Single RETRAN-3D model developed for each plant
- Each model has three reactor coolant loops, steam generators and steam lines (to common header)
- Simplifies maintenance of plant models Duke / NRC Meeting 14 Duke Energy - PWR Methods
Steam Generator Boiler Region Duke / NRC Meeting 15 Duke Energy - PWR Methods
Model Validation
- Goal:
- Demonstrate the ability to appropriately model key phenomena for a range of transient responses
- Method:
- Conduct code-to-code benchmarks using selected transients from HNP and RNP Chapter 15 AOR
- McGuire/Catawba and Oconee used plant transient data
- Philosophy:
- Match key analysis inputs and modeling assumptions
- Compare important trends and behaviors Duke / NRC Meeting 16 Duke Energy - PWR Methods
Scope of Model Validation Cases Scope of Validation Cases Plant/Event Evaluated Harris Robinson 15.1 Increase in Heat Removal by the Secondary System Increase in Feedwater Flow 15.2 Decrease in Heat Removal by the Secondary System Turbine Trip Loss of Feedwater Feedwater Line Break 15.3 Decrease in RCS Flow Rate Loss of Flow Locked Rotor 15.4 Reactivity and Power Distribution Anomalies Uncontrolled Bank Withdrawal at Power Duke / NRC Meeting 17 Duke Energy - PWR Methods
15.2 Turbine Trip (HNP)
Transient Overview and Summary
- Classified as ANS Condition II event (fault of moderate frequency)
- Analyzed for two main purposes
- Verify primary/secondary relief capability
- Protect Specified Acceptable Fuel Design Limits (SAFDLs)
- Assumptions designed for conservative prediction
- Example: No credit for direct reactor trip on turbine trip Duke / NRC Meeting 18 Duke Energy - PWR Methods
15.2 Turbine Trip (HNP)
Transient Overview and Summary
- Benchmark calculations completed for two cases from FSAR §15.2.3
- Primary and secondary over-pressurization
- Used to evaluate model performance for decrease in secondary heat removal
- Match key analysis inputs and modeling assumptions
- Following slides compare sequence of events and transient response for each case Duke / NRC Meeting 19 Duke Energy - PWR Methods
Event Event Time, s AOR RETRAN-3D Turbine Trip 0.0 0.01 Reactor Trip Signal - High Pressure 5.03 4.74 Scram Initiation 7.04 6.74 Peak Primary Side Pressure 7.8 7.7 (2742.7 psia)
SG 1st bank MSSVs open 8.4 8.7 SG 2nd bank MSSVs open 9.3 10.4 SG 3rd bank MSSVs open 10.8 11.7 SG 4th bank MSSVs open SG 5th bank MSSVs open 15.2 Turbine Trip (HNP)
Primary Over-Pressurization Sequence of Events Duke / NRC Meeting 20 Duke Energy - PWR Methods
HNP Turbine Trip - Primary Over-Pressurization Reactor Power Duke / NRC Meeting 21 Duke Energy - PWR Methods
HNP Turbine Trip - Primary Over-Pressurization Average Temperature Duke / NRC Meeting 22 Duke Energy - PWR Methods
HNP Turbine Trip - Primary Over-Pressurization Pressure at Bottom of Core Lower Plenum Duke / NRC Meeting 23 Duke Energy - PWR Methods
HNP Turbine Trip - Primary Over-Pressurization Pressurizer Level Duke / NRC Meeting 24 Duke Energy - PWR Methods
15.2 Turbine Trip (HNP)
Secondary Over-Pressurization Sequence of Events Event Event Time, s AOR RETRAN-3D Turbine Trip 0.0 0.01 Pressurizer spray on 1.0 0.9 Pressurizer compensated PORV open 1.2 1.2 Pressurizer uncompensated PORV open 4.3 4.0 SG 1st bank MSSVs open 5.4 5.3 SG 2nd bank MSSVs open 6.5 5.9 SG 3rd bank MSSVs open 7.9 7.0 SG 4th bank MSSVs open 10.1 9.7 OTT trip signal 11.16 12.06 Reactor scram 12.41 13.32 SG 5th bank MSSVs open 13.2 13.8 Peak pressurizer level 16.2 17.7 (98.7%)
Peak secondary side pressure 18.9 19.3 (1296.5 psia)
Duke / NRC Meeting 25 Duke Energy - PWR Methods
HNP Turbine Trip - Secondary Over-Pressurization Reactor Power Duke / NRC Meeting 26 Duke Energy - PWR Methods
HNP Turbine Trip - Secondary Over-Pressurization Average Temperature Duke / NRC Meeting 27 Duke Energy - PWR Methods
HNP Turbine Trip - Secondary Over-Pressurization Pressurizer Level Duke / NRC Meeting 28 Duke Energy - PWR Methods
HNP Turbine Trip - Secondary Over-Pressurization Pressure at Bottom of SG Downcomer Duke / NRC Meeting 29 Duke Energy - PWR Methods
15.3 Locked Rotor (RNP)
Transient Overview and Summary
- Classified as ANS Condition IV event (limiting fault)
- Analyzed for two main purposes
- Verify primary/secondary relief capability
- Protect Specified Acceptable Fuel Design Limits (SAFDLs)
- DNB event
- Assumptions designed for conservative prediction
- Heaters disabled Duke / NRC Meeting 30 Duke Energy - PWR Methods
15.3 Locked Rotor (RNP)
Transient Overview and Summary
- Benchmark calculations completed for a case from FSAR §15.3.2
- DNB
- Instantaneous seizure of one RCP (speed to zero)
- Reactor Protection System:
- Low RCS flow reactor trip
- Used to evaluate model performance for decrease in RCS flow rate
- Match key analysis inputs and modeling assumptions Duke / NRC Meeting 31 Duke Energy - PWR Methods
15.3 Locked Rotor (RNP)
Sequence of Events Event Event Time, s AOR RETRAN-3D Single Primary Pump Seizes 0
0 Low RCS Flow Trip Signal 0.075 0.038 Scram 1.075 1.04 Turbine Trip 1.10 1.04 Trip of Unaffected Pumps 1.10 1.04 Affected-loop Flow Reversed 1.50 1.7 Minimum DNBR Occurred 2.25 2.55 Duke / NRC Meeting 32 Duke Energy - PWR Methods
RNP - Locked Rotor Normalized Reactor Power Duke / NRC Meeting 33 Duke Energy - PWR Methods
RNP - Locked Rotor Core Inlet Temperature Duke / NRC Meeting 34 Duke Energy - PWR Methods
RNP - Locked Rotor RCS Loop Mass Flow Rate Duke / NRC Meeting 35 Duke Energy - PWR Methods
RNP - Locked Rotor Primary Pressure Duke / NRC Meeting 36 Duke Energy - PWR Methods
Expanded VIPRE-01 Model
Background
The RNP and HNP expanded VIPRE-01 models are based on their respective 14-channel VIPRE-01 models The RNP and HNP 14-channel VIPRE-01 models have been developed and submitted to the NRC for review and approval in DPC-NE-2005-P
- Applicable to the AREVA Advanced W HTP fuel type
- Based on the NRC-approved ONS 14-channel VIPRE-01 model documented in DPC-NE-3000-PA The 14-channel model will primarily be used for the following applications:
- Determination of steady-state and transient MDNBR for UFSAR Chapter 15 events
- Maximum Allowable Radial Peaking (MARP) calculations
- Statistical Core Design (SCD) analyses Duke / NRC Meeting 37 Duke Energy - PWR Methods
Expanded VIPRE-01 Model Background (cont.)
- Key characteristics of the 14-channel VIPRE-01 model:
- Simulates limited fuel pin detail in the interior of the hot fuel assembly
- Uses a conservative center-peaked and flat radial pin power distribution
- Computationally efficient
- Conservative MDNBR results
- Limitations of VIPRE-01 14-channel model:
- Limited to specific applications where the pin peaking is located in the interior of the hot fuel assembly
- Not suitable for mixed-core applications Duke / NRC Meeting 38 Duke Energy - PWR Methods
Expanded VIPRE-01 Model Model Description
- To address the limitations of the 14-channel models, the following expanded VIPRE-01 models are developed:
- [ ] model for RNP, and
- [ ] model for HNP
- Key Characteristics of the expanded models:
- [
]
- [ ]
- Surrounding the above pin-wise detail are lumped fuel assemblies of assemblies adjacent to the hot assembly and a lumped core representing the rest of the fuel assemblies
- VIPRE-01 code options (e.g., flow, heat transfer and CHF correlations, turbulent mixing parameters, code solution scheme and convergence criteria, ) selected are identical to the 14-channel model Duke / NRC Meeting 39 Duke Energy - PWR Methods
Expanded VIPRE-01 Model Applications of the Expanded Model
- Supplement the existing smaller VIPRE-01 models
- Quantify mixed-core effects
- Quantify the effects of fuel assembly gap changes (specifically if the pin peaking is occurring at or near the fuel assembly gap)
- Recover DNB margin by implementing actual pin-wise power distribution from CASMO/SIMULATE core design codes Duke / NRC Meeting 40 Duke Energy - PWR Methods
41
Conclusion
- RETRAN Base Models developed for Harris and Robinson
- Benchmark analysis against current FSAR analysis demonstrates the ability to model key phenomena
- Computer codes and analysis approach build upon previous Duke Energy experience
- With minor enhancements
- Extended VIPRE-01 model provides capability to address a wider range of conditions Duke / NRC Meeting 42 Duke Energy - PWR Methods