ML17297B789
| ML17297B789 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 10/26/2017 |
| From: | Duke Energy Progress |
| To: | Andrew Hon Plant Licensing Branch II |
| Hon A, NRR/DORL/LPL2-2, 415-8480 | |
| References | |
| Download: ML17297B789 (20) | |
Text
Brunswick Advanced AREVA Methods LAR NRC Pre-Submittal Meeting Follow-up 10/26/17
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Background===
On 8/22/17, Duke Energy and the NRC discussed the high-level overview of the content and timeframe for the LAR to support using Advanced AREVA Methods at Brunswick Nuclear Plant (BNP)
Pre-submittal meeting highlights Submittal in September 2018 after approval of MELLLA+ LAR Approval needed by February 2020 to support the first reload of ATRIUM 11 LAR will request the use of many advanced AREVA methodologies that are currently under NRC review Prior to LAR submittal, key NRC actions are approval of MELLLA+ and the Draft SE for AURORA-B LOCA Risk/Challenges identified and addressed along with review prioritization Proposed schedule/plan is challenging but achievable 2
Background (cont.)
During the pre-submittal meeting the NRC requested further information and schedule details on the following topics ATWS with core instability (ATWSi)
Long Term Stability Solution (LTSS) for MELLLA+
ATRIUM 11 Seismic Analysis 3
ATWSi During the 8/22 meeting, the NRC indicated that reviewing the generic ATWSi LTR in parallel with the plant specific methodology could strain resources AREVA intends to submit the generic ATWSi LTR in November 2017 with BNP A10XM as the sample problem AREVA and the NRC held preliminary discussions on the possibility of allowing a LIC-109 exception to allow Duke to reference the generic LTR under review Allows the NRC 27 months of exposure to the methodology prior to BNP approval No resource conflict with a generic and plant specific methodology Ability to respond to NRC concerns in the plant specific application of the generic methodology Potential ACRS review of the generic can be performed while LAR review is proceeding Duke supports this approach since it mitigates the risk of delayed approval for the overall Advanced AREVA Methods LAR and alleviates the previous resource and schedule concerns If the NRC agrees, the documentation of this exception is recommended in the acceptance review documentation of the generic LTR 4
LTSS for MELLLA+
Upon approval of MELLLA+, BNP will utilize GEHs DSS-CD LTSS for ATRIUM 10XM ATRIUM 11 introduction will not change the licensing basis Confirmation Density Algorithm (CDA) and Automatic Backup Stability Protection (ABSP) SCRAM implemented for MELLLA+
No changes to plant NUMAC hardware or related TS's CDA and ABSP safety margin and operating flexibility will be retained LAR will include plant specific AREVA RAMONA5-FA based methodology to replace TRACG based DSS-CD methodology AREVA Best-estimate Enhanced Option III (BEO-III) to determine MCPR versus time (including uncertainty)
Supplemental Duke report for ABSP and determination of OLMCPR to protect SLMCPR at time of CDA scram ATRIUM 11 equilibrium cycle sample problem for LAR; analysis will be cycle specific 5
LTSS for MELLLA+ - BEO-III The plant specific BEO-III methodology will be consistent with what AREVA has previously presented to the NRC in preparation for a generic LTR Pre-Submittal Meeting 11/4/2016 (ADAMS #ML16342A994)
Methodology Update 6/6/2017 (AREVA/NRC Fuel Performance Meeting)
BEO-III utilizes a best-estimate plus uncertainty analysis approach over the entire event to ensure margin to the SLMCPR at the time of SCRAM Demonstration that fuel assemblies that may become hydraulically unstable do not result in decoupled oscillations and a local MCPR response that challenges the SLMCPR Will allow for SLO and FWHOOS operation (not concurrently) outside of the MELLLA+ region AREVA will not submit the generic BEO-III LTR prior to the Brunswick LAR 6
LTSS for MELLLA+ - BEO-III The RAMONA5-FA model is expected to be nearly identical to the NRC review and approved model (EMF-3028P-A)
The limiting event for the BEO-III methodology is the Two-Pump Trip (2PT) from rated reactor power and minimum core flow Draft PIRT presented by AREVA in the Pre-Submittal Meeting on 11/4/2016 Defines the key stability parameters that will be varied using non-parametric order statistics in the uncertainty analysis to ensure margin to the SLMCPR with 95% probability and 95% confidence For a particular initial condition and selection of uncertainty parameters, RAMONA5-FA will:
Simulate the 2PT transient with full 3D kinetics and MCPR response up to the time of oscillation suppression based on the PBDA (defense in depth)
Assess the hydraulic stability of all fuel channels at the terminal condition 7
LTSS for MELLLA+ - Use of the CDA The analysis performed by AREVA will use the PBDA for the time of oscillation suppression Due to the ability of the CDA to detect the onset of instability, it is expected to trip prior to the PBDA The CDA from the plant hardware will be used to process the RAMONA5-FA output to determine the CPR (final over initial) at the time the CDA trip suppresses the oscillation Limiting CPR from the best-estimate and uncertainty analysis cases will be used to define the OLMCPR With the CDA tripping the plant prior to the PBDA, the decoupled channel oscillation confirmation remains applicable BEO-III method description and sample problem report will provide demonstration Relying on the analysis methodology of BEO-III with the use of the plant hardware CDA trip precludes any methodology incompatibility between DSS-CD/TRACG and BEO-III/RAMONA5-FA 8
LTSS for MELLLA+ - BSP Current plant hardware contains the ability to activate ABSP in the event the OPRM system is not operable An automatic SCRAM region is implemented by the APRM flow-biased SCRAM setpoint Region is defined to bound the manual BSP SCRAM region determined using decay ratio calculations similar to the BWROG Option III BSP In the event the ABSP is not operable, manual exclusion regions on the power/flow map will be utilized by the operators similar to Option III MELLLA+ operation is prohibited (MELLLA line is the BSP Boundary)
Continued operation limited to Tech Specs specified 120 days upon MELLLA+ LAR approval No required changes to Tech Spec actions that will be in place for MELLLA+ implementation 9
LTSS for MELLLA+ - Summary Duke believes the approach and schedule are achievable BEO-III is as an evolutionary change from Enhanced Option III (EO-III) previously approved for MELLLA+ operation Only minor modifications are made to the approved RAMONA5-FA code for DIVOM and EO-III No changes to the physics module Main additions are the implementation of trip algorithm and statistical sampling Non-parametric order statistics methodology and approved MICROBURN-B2 uncertainties from AURORA-B AOO will be directly applied in BEO-III AURORA-B AOO SE has been reviewed by the ACRS and is anticipated to be issued shortly Cycle specific analysis approach is consistent with other industry LTSS 10
ATRIUM 11 Seismic Analysis ATRIUM 11 seismic analysis will be documented in the Mechanical Design Report for Brunswick equivalent to that presented for ATRIUM 10XM (ANP-2948P, Section 3.4.4, ML103260322)
Application of AREVA topical report faulted methodology is unchanged
ANF-89-98, Revision 1 and Supplement 1, Generic Mechanical Design Criteria for BWR Fuel Designs (§3.2.7, 3.4.4)
EMF-93-177(P)(A), Revision 1, Mechanical Design for BWR Fuel Channels. (§3.3.1)
Loads are based on plant seismic response
ATRIUM 11 applicability will be addressed in the Methods Applicability Supplement Document submitted with the LAR 11
LAR Methodologies: AREVA Generic 12 Current Advanced AREVA Methods Generic Methodology approval status
LAR Schedule Milestones Prerequisites AREVA submits Generic ATWSi LTR (November 2017)
Proposed LIC-109 exception documented in acceptance review (February 2018)
Draft SE for remaining AREVA LTRs
Final expected to be AURORA-B LOCA by 6/30/2018 MELLLA+ LAR Approval (September 2018)
LAR submittal (September 2018)
Audit for Understanding (January 2019)
Implementation cycle reports submitted as available for information (March 2019 to October 2019)
LAR approval (February 2020)
Implementation cycle startup (April 2020) 13
Conclusion ATWS with Core Instability AREVA will submit the generic LTR with BNP A10XM as the sample problem in November 2017
Acceptance review documentation requested to contain LIC-109 exception to reference the generic LTR prior to Draft SE ATRIUM 11 ATWSi analysis will be submitted with the LAR Allows for increased review time with no parallel review issues impacting NRC resource allocation Long Term Stability Solution Plant specific BEO-III methodology with the CDA as the licensing basis RAMONA5-FA previously approved MELLLA+ with minor modification No interface issues between GEH and AREVA methodologies Proposed schedule/plan for 17 month LAR review is challenging but achievable 14
Nomenclature A10XM - ATRIUM 10XM ACRS - Advisory Committee on Reactor Safeguards APRM - Average Power Range Monitor DSS-CD - Detect and Suppress Solution - Confirmation Density FWHOOS - Feedwater Heater Out-of-Service LIC-109 - Acceptance Review Procedures MCPR - Minimum Critical Power Ratio OLMCPR - Operating Limit MCPR PIRT - Phenomena Identification and Ranking Table PBDA - Period Based Detection Algorithm SE - Safety Evaluation SLMCPR - Safety Limit MCPR SLO - Single Loop Operation 15
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Other Follow-up Actions ANF-89-98(P)(A) compliance document for ATRIUM 11 References topical reports, some of which are still under review Will be provided for information as soon as practical after all topical reports have been approved Includes ATRIUM 11 PIE data 17
LAR Methodologies: AREVA Generic 18
LAR Content Reports submitted with LAR based upon BNP equilibrium ATRIUM 11 Design:
Assembly Mechanical Design reports Methods Applicability Supplement Document Thermal Hydraulic Design Report LOCA/MAPLHGR Report BWR Licensing Methodology Compendium
Updated for new methods (AURORA-B [LOCA / Transients and Accidents / CRDA], ACE / ATRIUM 11, and Cr-Doped fuel)
ATRIUM 11 ATWSi Analysis Report Fuel Cycle Design Report Nuclear Fuel Bundle Design Report Fuel Rod Design Report AURORA-B Limiting Transient Analysis Uncertainty Demonstration ATRIUM 11 Long-term Stability Solution 19
LAR Content (cont.)
Implementation cycle reports will be submitted post LAR for information:
Fuel Cycle Design Report - March 2019 Nuclear Fuel Bundle Design Report - March 2019 Safety Limit MCPR Report - May 2019 Fuel Rod Design Report - October 2019 Reload Safety Analysis Report - October 2019 (dates represent a 3 month acceleration compared to a normal reload schedule)
Submittal strategy and timeline based upon successful BNP LAR submittals used to implement AREVA methods in 2007 and 2010.
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