ML20156A281
| ML20156A281 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/08/2020 |
| From: | Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML20156A281 (24) | |
Text
Browns Ferry ATRIUM11 Fuel Transition License Amendment Request: PreApplication Meeting June 8, 2020
Background
- TVA intends to transition to ATRIUM11 fuel at Browns Ferry
- First reload targeted for unit 2 reload 22 in February 2023
- TVA has experience with ATRIUM11 fuel
- Eight LUAs were inserted into unit 2 in 2015
- Have completed nearly three two year cycles of irradiation
- No adverse operating experience
- Framatome advanced methods are needed to support ATRIUM11
- TVA will docket a Licensing Amendment Request (LAR) to request approval to add the methods to the Technical Specifications
- Implementation addressed under 10 CFR 50.59 Browns Ferry ATRIUM11 Fuel Transition 2 License Amendment Request: PreApplication Meeting
Licensing Approach
- LAR will demonstrate application of new methods using an equilibrium Browns Ferry ATRIUM11 core
- Select cycle specific reports will be provided for information post LAR for the implementation cycle
- LAR will also address RAIs received during Brunswick and Susquehanna LAR reviews, as applicable Browns Ferry ATRIUM11 Fuel Transition 3 License Amendment Request: PreApplication Meeting
LAR Content Overview
- Fuel cycle design report
- Document BFN equilibrium ATRIUM11 core design
- Nuclear fuel design report
- Document bundle design details of equilibrium cycle assemblies
- Assembly mechanical design report
- Compliance with SRP and Framatome mechanical design criteria
- Compatibility of ATRIUM11 with BFN coresident fuel and reactor internals
- Fuel rod thermal mechanical design report
- Demonstrate application of RODEX4 to ATRIUM11 using equilibrium cycle design Browns Ferry ATRIUM11 Fuel Transition 4 License Amendment Request: PreApplication Meeting
LAR Content Overview (cont)
- Thermal hydraulic report
- Demonstration of thermal hydraulic compatibility of ATRIUM10 XM and ATRIUM11 at BFN
- Methods applicability supplement
- Address topics related to ATRIUM11 and new methods
- Similar in content to Brunswick report ANP3705P
- LOCA report
- Analysis of BFN break spectrum with NRC approved AURORAB LOCA method
- Derivation of exposure dependent MAPLHGR limits
- Stability report
- BEOIII with CDA demonstration analysis Browns Ferry ATRIUM11 Fuel Transition 5 License Amendment Request: PreApplication Meeting
LAR Content Overview (cont)
- ATWSI report
- Demonstrate application of RAMONA5FA method using equilibrium ATRIUM11 core
- Control rod drop accident report
- Demonstrate application of AURORAB CRDA using BFN equilibrium ATRIUM11 core
- Transient demonstration report
- Demonstrate application of AURORAB AOO using BFN equilibrium ATRIUM11 core
- Limitations and Conditions (L&C) Report
- Brunswick and Susquehanna LARs did not address L&Cs up front
- Resulted in RAIs
- Address L&Cs of the new Framatome methods SERs Some L&Cs will need to be addressed as part of implementation cycle reports Browns Ferry ATRIUM11 Fuel Transition 6 License Amendment Request: PreApplication Meeting
ATWSI
- LAR will request changing the licensing basis method from GEH TRACG04 to the Framatome RAMONA5FA method
- Framatome method now NRC approved
- ANP-10346P-A Revision 0, ATWS-I Analysis Methodology for BWRs Using RAMONA5-FA
- Key plant inputs will be unchanged from the analysis in the MELLLA+
- Feedwater temperature reduction rate
- Operator response times
- Does NRC plan on performing confirmatory TRACE analyses?
- ATRIUM11 core and thermal hydraulic information only
- NRC need date?
Browns Ferry ATRIUM11 Fuel Transition 7 License Amendment Request: PreApplication Meeting
BEOIII with CDA
- TVA intends to follow the Brunswick precedent for stability
- Stability analysis will utilize the RAMONA5FA methodology to analyze events and generate time dependent LPRM responses for each trial case
- LPRM responses will be fed into a separate code for evaluation with the confirmation density algorithm (CDA)
- Time of trip will be determined by this code
- Framatome will use time of trip values to determine CPR response for each trial and margin to SLMCPR Browns Ferry ATRIUM11 Fuel Transition 8 License Amendment Request: PreApplication Meeting
BEOIII with CDA (cont)
- Implementation will differ from Brunswick in one regard
- Brunswick used a screening process to reduce the number of cases analyzed with CDA
- CDA utilized for all aspects of the evaluation
- Every stability trial case evaluated by RAMONA5FA will have a CDA evaluation
- No screening out of cases
- No issues of PBDA tripping before CDA Time of trip always based on CDA Browns Ferry ATRIUM11 Fuel Transition 9 License Amendment Request: PreApplication Meeting
BEOIII with CDA (cont)
- Current backup capabilities will be retained
- Manual BSP regions retained
- ABSP retained and functional
- Validity of BSP regions and ABSP setpoints confirmed each reload
- No changes to the Tech Spec actions for an inoperable OPRM required Browns Ferry ATRIUM11 Fuel Transition 10 License Amendment Request: PreApplication Meeting
Preferred Stability Approach for LAR
- Generic BEOIII topical still under NRC review
- TVA desires to reference the generic in the Browns Ferry LAR
- Use of CDA will require a plant specific report
- Plant specific report
- Would reference the generic report for the overall BEOIII methodology
- Describe the incorporation of CDA within the calculation framework
- Describe how the CDA code used by Framatome complies with the approved CDA and Browns Ferry implementation
- Describe how the CDA is validated on the Framatome computational platforms Browns Ferry ATRIUM11 Fuel Transition 11 License Amendment Request: PreApplication Meeting
Backup Stability Approach for LAR
- Two options if generic BEOIII topical not approved prior to LAR
- Options differ in terms of how the generic topical ultimately gets referenced
- CDA aspects still included as discussed on the prior slide
- Option 1 generic report approval imminent at LAR submittal
- Plant specific report duplicates the methodology description in the generic report
- Plant specific report will address draft Limitations and Conditions from generic report
- Once generic approved the LAR would be amended to reference the approved report
- Avoids having identical generic and plant specific topical reports
- Option 2 generic report review extends well beyond LAR submittal
- Plant specific report duplicates the methodology description in the generic report
- Use RAI process to address any Limitations and Conditions if not available at the time of LAR submittal
- Plant specific methodology topical would remain as Browns Ferry licensing basis Browns Ferry ATRIUM11 Fuel Transition 12 License Amendment Request: PreApplication Meeting
Control Rod Drop Accident
- Application of NRC approved AURORAB CRDA method
- ANP10333PA Revision 0, AURORAB: An Evaluation Model for Boiling Water Reactors; Application to Control Rod Drop Accident Scenarios
- Methodology applied on a cycle specific basis Demonstration analysis based upon ATRIUM11 equilibrium core.
- Will address RIA criteria in Reg Guide 1.236
- By end of October 2020 TVA will use available RG1.236 (draft or final)
- Show current dose analysis for event remains bounding
- Dose aspects will consider steady state and transient release criteria Transient release fraction from DG1327 Rev 1 (July 2019)
A part of this material did not remain in RG 1.236 Steady state release fractions based on Reg Guide 1.183, July 2000 Browns Ferry ATRIUM11 Fuel Transition 13 License Amendment Request: PreApplication Meeting
Transient Demonstration Analysis
- A demonstration analysis using the ATRIUM11 equilibrium core will be performed using NRC approved AURORAB AOO method
- ANP10300PA Revision 1, AURORAB: An Evaluation Model for Boiling Water Reactors; Application to Transient and Accident Scenarios
- Case matrix similar to Brunswick
- Base case analyses for turbine trip, load rejection, and feedwater controller failure
- Rated power and select off rated powers including below Pbypass
- Event disposition for UFSAR Chapter 14 events
- Brunswick RAI on equipment out of service will be addressed Table of rated power case results for each currently licensed equipment out of service domain (alone and in combination) will be presented
- Report will discuss specifics on scram times, cycle exposure points, and full range of power flow points that will be analyzed for the full reload report Browns Ferry ATRIUM11 Fuel Transition 14 License Amendment Request: PreApplication Meeting
Transient Demonstration Analysis (cont)
- Additional cases
- TVA is considering extending the ARTS thermal limits administration used below Pbypass to the power range above Pbypass
- Below Pbypass MCPRp limits depend on both power and core flow
- MCPRp limits at a specified power below Pbypass depend on whether core flow is above or below a specified value (50% flow for BFN)
This is referred to as a flow flag
- Above Pbypass a single MCPRp limit at a given power is set by the transient results at the limiting core flow Typically ICF sets the limit
- If a similar flow flag concept is applied above Pbypass, you would have two MCPRp limits for a given power One limit for flows above the flag value, and another limit for flows below the flag value Browns Ferry ATRIUM11 Fuel Transition 15 License Amendment Request: PreApplication Meeting
Transient Demonstration Analysis (cont)
- Additional cases (cont)
- The purpose of applying the flow flag concept above Pbypass is for operating thermal margin gain Very beneficial during startup and maneuvering when xenon transients can erode margins
- Using increased core flow based MCPRp limits in the MELLLA+ region is restrictive
- Using a MCPRp limit set by analysis at the intermediate flow flag value provides a less restrictive MCPR limit than the increased core flow based limit Improves operating margin while at reduced flow in the MELLLA+ region especially for non steady state conditions
- Core monitoring system will be modified to enforce the flow dependence of the MCPRp limits above Pbypass just as it does today below Pbypass
- Concept illustrated on the next slide Browns Ferry ATRIUM11 Fuel Transition 16 License Amendment Request: PreApplication Meeting
Flow Flag Above Pbypass Concept MCPRp below Pbypass For illustrative purposes Flow 50%
only - 95% flow flag MCPRp below Pbypass assumed above Pbypass Flow < 50%
MCPRp above Pbypass MCPRp Flow 95%
MCPRp Flow < 95%
Above Pbypass power range Browns Ferry ATRIUM11 Fuel Transition 17 License Amendment Request: PreApplication Meeting
Transient Demonstration Analysis (cont)
- Overpressure analysis
- The report will include both ASME and ATWS overpressure cases
- ASME analysis based on MSIV closure with flux scram 102% EPU power at increased core flow and MELLLA+ min flow
- ATWS analysis will evaluate MSIV closure and pressure regulator failure open transients 100% EPU power at increased core flow and MELLLA+ min flow Browns Ferry ATRIUM11 Fuel Transition 18 License Amendment Request: PreApplication Meeting
Technical Specification Changes
- The following approved methods topicals will be added to TS 5.6.5.b
- BAW10247PA, Supplement 1PA, Revision 0, Realistic ThermalMechanical Fuel Rod Methodology for Boiling Water Reactors Supplement 1: Qualification of RODEX4 for Recrystallized Zircaloy2 Cladding - Approved April 2017
- BAW10247PA, Supplement 2PA, Revision 0, Realistic ThermalMechanical Fuel Rod Methodology for Boiling Water Reactors Supplement 2: Mechanical Methods - Approved August 2018
- ANP10340PA Revision 0, Incorporation of ChromiumDoped Fuel in AREVA Approved Methods - Approved May 2018
- ANP10335PA Revision 0, ACE/ATRIUM 11 Critical Power Correlation - Approved May 2018
- ANP10300PA Revision 1, AURORAB: An Evaluation Model for Boiling Water Reactors; Application to Transient and Accident Scenarios - Approved January 2018
- ANP10332PA Revision 0, AURORAB: An Evaluation Model for Boiling Water Reactors; Application to Loss of Coolant Accident Scenarios - Approved March 2019
- ANP10333PA Revision 0, AURORAB: An Evaluation Model for Boiling Water Reactors; Application to Control Rod Drop Accident Scenarios - Approved March 2018
- The plant specific stability topical report will also be added
- Description of the overall stability methodology will depend on timing of NRC review and approval of ANP10344P Revision 0, Framatome BestEstimate Enhanced Option III Methodology, Browns Ferry ATRIUM11 Fuel Transition 19 License Amendment Request: PreApplication Meeting
Technical Specification Changes (cont)
- TVA desires to include TSTF564 related changes to the Tech Specs
- Framatome has established MCPR95/95 values for the ATRIUM10XM and the ATRIUM11 fuel types
- A report documenting the derivation of the MCPR95/95 values will be included in the LAR
- Method used to derive the values is in accordance with the NRC approved process in the TSTF
- Two associated Tech Spec changes will be made:
- TS 2.1.1.2 will be modified to reflect the MCPR95/95 value, applicable to both two loop and single loop operation
- TS 5.6.3 will be modified to require that the MCPR99.9% values for two loop and single loop operation be included in the COLR Modified language of TS 5.6.3 will be consistent with that shown in the TSTF Browns Ferry ATRIUM11 Fuel Transition 20 License Amendment Request: PreApplication Meeting
Implementation Cycle Reports
- TVA will provide cycle specific reports for information for the implementation cycle
- Reports will be provided on a schedule specified in the LAR
- Reports include:
- Fuel Cycle Design Report
- Nuclear Fuel Bundle Design Report
- Safety Limit MCPR Report May include cycle exposure dependent values
- Fuel Rod Design Report
- Reload Safety Analysis Report Include disposition of events summary Address remaining Framatome methodology Limitations and Conditions Browns Ferry ATRIUM11 Fuel Transition 21 License Amendment Request: PreApplication Meeting
Criticality Report LAR
- EPU safety evaluation noted the criticality analysis reviewed for fuel types up to and including ATRIUM10 XM
- TVA believes adding ATRIUM11 to the spent fuel pool requires additional NRC review
- Approval needed earlier than the transition LAR to support receipt of first ATRIUM11 reload batch in early fall of 2022
- Approval of this LAR only grants the ability to receive and store ATRIUM11 fuel in the fuel pool racks
- LAR will not change the existing Technical Specification kinfinity limit
- TVA does not view this LAR as having linkage with the transition LAR Browns Ferry ATRIUM11 Fuel Transition 22 License Amendment Request: PreApplication Meeting
Schedule
- Proposed date for criticality report LAR submittal - 5/28/2021
- Proposed date for transition LAR submittal 6/9/2021
- Safety evaluation need date for criticality report LAR - 5/30/2022
- 12 month review
- Safety evaluation need date for transition LAR - 12/9/2022
- 18 month review
- Outage start date 2/25/2023
- All but one of the new methods is NRC approved
- LAR review can focus on application of the approved methods to BFN
- Critical NRC action is approval of BEOIII topical report by March 2021
- Allows avoidance of supplementing the LAR or having a permanent plant specific methodology topical report Browns Ferry ATRIUM11 Fuel Transition 23 License Amendment Request: PreApplication Meeting