ML13133A241
| ML13133A241 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/12/2013 |
| From: | John Lamb Plant Licensing Branch 1 |
| To: | NextEra Energy Seabrook |
| Lamb J | |
| Shared Package | |
| ML13133A158 | List: |
| References | |
| TAC MF1491 | |
| Download: ML13133A241 (29) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 12, 2013 LICENSEE: NEXTERA ENERGY SEABROOK, LLC FACILITY: SEABROOK STATION, UNIT 1
SUBJECT:
SUMMARY
OF MAY 9, 2013, MEETING WITH NEXTERA ENERGY SEABROOK, LLC 01\1 PRE-SUBMITTAL OF A FIXED INCORE DETECTOR LICENSE AMENDMENT REQUEST (TAC NO. MF1491)
On May 9, 2013, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of NextEra Energy Seabrook, LLC (NextEra) at the NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss a pre-submittal of a fixed incore detector license amendment request (LAR). The meeting notice and agenda, dated April 18, 2013, is available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML13099A215. A list of attendees is provided as Enclosure 1.
NextEra presented information during the meeting (see Enclosure 2, ADAMS Accession No. ML13133A249). NextEra provided a brief overview of the Seabrook fixed incore detector system design, provided a summary of the initial licensing through the current status of the fixed incore detector system, and an overview of the fixed incore detector LAR that it plans to submit to the NRC in July 2013.
The NRC staff queried NextEra about uncertainties in the analysis. NextEra explained the manufacturing differences, gamma correction factor, and platinum depletion factor.
The NRC staff made no decisions during this meeting.
Members of the public were not in attendance. Public Meeting Feedback forms were not received.
-2 Please direct any inquiries to me at 301-415-3100, or John.Lamb@nrc.gov.
Docket No. 50-443
Enclosures:
- 1. List of Attendees
- 2. Licensee Handout cc w/encls: Distribution via Listserv
LIST OF ATTENDEES MAY 9.2013. MEETING WITH NEXTERA ENERGY SEABROOK. LLC ON PRE-SUBMITTAL OF A FIXED INCORE DETECTOR LICENSE AMENDMENT REQUEST Organization Mike O'Keefe NextEra Paul Gurney NextEra Carl O'Farrili NextEra Glen Seeburger Areva John G. Lamb NRC Meena Khanna NRC Norbert Carte NRC Kevin Heller NRC Mathew Panicker NRC Enclosure 1
Enclosure 2 NextEra Presentation to Nuclear Regulatory Commission on Fixed Incore Detector Methodology Supplement May 9,2013
Fixed Incore Detector Methodology Supplement Presentation to Nuclear Regulatory Commission May 9, 2013
FPL/NextEra Representatives
- Paul Gurney
- Reactor Engineering Supervisor, Seabrook Station
- Michael OKeefe
- Licensing Manager, Seabrook Station
- Carl OFarrill
- Core Design Manager, FPL Juno Beach
- Glen Seeburger
- Advisory Engineer, AREVA Lynchburg 2
Fixed Incore Detector Methodology Supplement
- Overview
- Seabrook Fixed Incore Detector System (FIDS)
Overview of fixed incore detectors
- License Amendment Basis Initial licensing through current status
- License Amendment Overview Topical report to supplement initial licensing Addresses changes to detector processing Implementation 3
Seabrook Fixed Incore Detector System
- Seabrook Station
- 4 loop Westinghouse NSSS
- Rated for 3648 MWt
- Combination fixed and moveable incore detector system for measuring core power distribution
- Use of a fixed incore detector system is unique for operating Westinghouse designed reactors 4
Seabrook Fixed Incore Detector System
- 58 combination fixed and moveable incore detector assemblies
- Mechanical and electrical connections for each assembly are located at the seal table
- Each original assembly contains a moveable incore detector path
- Replacement assemblies do not have a moveable incore detector path 5
Seabrook Fixed Incore Detector System
- The fixed incore detectors use a platinum emitter
- For fixed incore detector applications platinum is unique Most fixed detector applications use a rhodium emitter
- Platinum is largely gamma sensitive Some sensitivity to neutrons
- Platinum is a long life emitter 6
Seabrook Fixed Incore Detector System 7
License Amendment Basis
- Initial FIDS Licensing Background
- License Amendment Request (LAR) to utilize FIDS for core power distribution monitoring submitted November 1992
- Technical basis for methodology documented in topical report YAEC-1855P Seabrook Station Unit 1 Fixed Incore Detector System Analysis
- Validation of FIDS methodology was good agreement between fixed and moveable flux maps obtained in cycles 1 & 2 8
License Amendment Basis
- NRC Issued License Amendment 27 in December 1993
- Conditional acceptance of FIDS for power distribution monitoring
- Additional flux maps required in cycles 3 & 4
- Required a follow-up report documenting continued consistency of results
- Follow-up report YAEC-1931 submitted in March of 1996
- Demonstrated continued acceptability of the FIDS methodology
- FIDS used for flux mapping since cycle 5, December 1995 9
License Amendment Basis
- Replacement FIDS
- Project to replace FIDS initiated in 2006
- Platinum emitters still providing a good signal
- Mechanical and electrical connections at the seal table were degrading 10
License Amendment Basis
- YAEC-1855P does not specifically address replacement detectors
- Design of a replacement FID was a like-for-like detector which met the concept of the standard detector
- Standard detector defined in YAEC-1855P
- Detectors corrected for individual detector differences
- Detector material and manufacturing differences
- Original detectors - surface area ratio 11
License Amendment Basis
- Additional factors were necessary for replacement detectors to meet the standard detector
- Manufacturing differences
- Platinum purity differences
- Pt-195 depletion 12
License Amendment Basis
- Gamma Correction Factor - GCF
- Manufacturing and purity differences
- Determined by direct measurement
- Platinum Depletion Factor - PDF
- Accounts for aging differences between original and replacement detectors 13
License Amendment Basis
- Detector Replacements
- Extensive post-modification testing
- Validate performance of replacement FIDS
- Post modification testing completed before using the replacement detectors for power distribution monitoring 14
License Amendment Basis
- NRC Modification Inspection (Spring 2012)
- Questioned the 10CFR50.59 Evaluation for the flux mapping software changes implemented for replacement detectors
- A previous change (2002) to the flux mapping software was self-identified as part of this review
- Change involved the neutron sensitive component of the detector signal Pt-195 15
License Amendment Basis
- YAEC 1855P
- Neutron component of signal Assumed to be 25% of total signal
- Weighted by thermal flux
- Increasing measured-to-predicted signal differences observed starting in cycle 6 16
License Amendment Basis
- Improved prediction of the neutron component of signal
- Neutron Conversion Factor (NCF)
- Based on Predicted gamma signal and neutron reaction rate Measured signal
- Provides better estimate of neutron component of the detector signal
- Implemented in Cycle 9 (2002) 17
License Amendment Basis
- Changes were considered input changes
- GCF & PDF (for replacement detectors)
- NCF (for neutron signal component)
- Did not affect the power distribution processing methodology 18
License Amendment Basis
- Actions Taken Following Inspection
- Contracted AREVA to prepare a topical report to address the changes made to the flux mapping software Initial system development by YAEC, now part of AREVA Extensive FIDS operational performance data (15 cycles) used for validation Technically robust, complete and comprehensive validation Detailed data analysis results available to facilitate NRC review 19
License Amendment Overview
- New COLR reference to be added to Technical Specifications
- Topical Report
- Supplement YAEC-1855P
- Replacement Detectors
- Neutron conversion factor
- Uncertainty Analysis 20
License Amendment Overview
- Replacement Detectors
- Describe the methodology used to incorporate replacement detectors into flux mapping software Gamma Correction Factor Platinum Depletion Factor
- Standard Detector Relationship to initial licensing basis 21
License Amendment Overview
- Neutron Conversion Factor
- Basis for NCF
- Relationship to initial licensing input assumption 25% of detector signal 22
License Amendment Overview
- Uncertainty Analysis
- 2 components of the current licensed uncertainty analysis potentially affected Reproducibility for replacement detectors Detector processing uncertainty
- Total and integral detector processing
- Failed detector analysis to support minimum requirements 23
License Amendment Overview
- Draft Schedule
- Submit amendment - July 2013
- Request approval - May 1, 2014
- Supplemental topical report to be added as a COLR reference in Technical Specification section 6.8 24
Pkg ML13133A158.
Meeting Notice ML13099A215 Meeting Summary ML13133A241 Handouts ML13133A249 OFFICE NRR/DORULPL 1-2/PM NRRlDORULPL 1-2/LA NRR/DORULPL 1-2/BC(A} NRRlDORULP~ 1-2/PM NAME JLamb ABaxter VRodriguez JLamb DATE 06/12/13 06/04/13 06/12113 06112113