ML022520025
| ML022520025 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/05/2002 |
| From: | Rinaldi F NRC/NRR/DLPM/LPD2 |
| To: | |
| References | |
| Download: ML022520025 (44) | |
Text
NRC FORM 658 U.S. NUCLEAR REGULATORY COMMISSION (9-1999)
TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR IMMEDIATE PLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed)by the person who announcedthe meeting (i.e., the person who issued the meeting notice). The completed form, and the attachedcopy of meeting handout materials,will be sent to the Document ControlDesk on the same day of the meeting; under no circumstanceswill this be done later than the working day after the meeting.
Do not include proprietarymaterials.
DATE OF MEETING The attached document(s), which was/were handed out in this meeting, is/are to be placed 09/05/2002 in the public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:
Docket Number(s) 50424 AND 50425 Plant/Facility Name VOGTLE, UNITS 1 AND 2 TAC Number(s) (ifavailable) IJ Reference Meeting Notice AUGUST 19, 2002 Purpose of Meeting (copy from meeting notice) DISCUSS UPGRADE OF EXISTING SEQUENCERS NAME OF PERSON WHO ISSUED MEETING NOTICE TITLE F. RINALDI PROJECT MANAGER OFFICE NRR DIVISION DLPM BRANCH PD 1I1 Distribution of this form and attachments:
Docket File/Central File PUBLIC NRC FORM 658 (9-1999) PRINTED ON RECYCLED PAPER "T'hisform1was designed using InForms
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. 4~~r - LNZ Overview of Vogtle Electric Generating Plant (VEGP) Safety Features Sequencer (SFS) Upgrade September 5, 2002 11OT0R ASid
$OUTHERNY COMAPANY Slide 1 I
J1 Introduction of Team Members Southern Nuclear Westinghouse
- Lewis Ward e Glenn Lang
- Ron Bush o Carl Vitalbo
- Jack Stringfellow o Denny Popp
- Steve Swanson Jim Andrachek m
IM4 Slide 2
l ° Meeting Agenda
"*Introductory Remarks
"*Design Modification Implementation Schedule
"*Scope of Design Modification
"*Licensing Evaluation
"*Summary
"*Questions and Answers Slide 3
Purpose of Meeting
- Inform NRC ofVEGP SFS digital upgrade project
-Scope, schedule and status of upgrade
-Licensing approach
- 10 CFR 50.59
- Diversity & Defense-in-Depth analysis
- Deterministic/probabilistic approach used for addressing FSAR Chapter 15 initiating events Slide 4 I
SOUTHERN K....
COMPANY Slide 4
Design Modification Implementation Schedule e Unit 1, Train B- Fall refueling outage, September 2003 9 Unit 2, Train A -Spri ng refueling outage, April 2004 9 Unit 1, Train A-Spri ng refueling outage, March 2005 9 Unit 27 Train B - Fall refueling outage, October 2005 Slide 5 I
SOUTHERN COMPANY Slide 5 I
Scope of Design Modification Description of Existing VEGP SFS
. 2-Train System
-Single Channel in Each Train
. Two SFSs per Unit (one per train)
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SOUTHERN COMPANY Slide 6 gWe ouse
Scope of Design Modification Description of Existing VEGP SFS
- Actuated on Loss of Vital Bus Voltage or Safety Injection Signal o Generates Three Seq uence Signals
-SI Only
-SI and LOSP
-LOSP Only SOUTHERN . Slide 7 COMPANY
Scope of Design Modification Description of Existing VEGP SFS
- Load Sequence
-Four Groups - Basic, A, B and C
-Nine Steps per Group - 0 to 30 seconds in 5 second intervals o Dedicated Maintenance and Test Panel Slide 8 ISOUTHERN -
COMPANY Slide 8 'West ngr
View of Existing SFS Cabinets ISOUTHERNAE~w COMPANY Slide 9 G. IRý
Scope of Design Modification Description of VEGP SFS Upgreide o 2-Train System
-Three Channels in Each Train
- 3 Stand Alone PLCs Per Train - no inter-PLC communication links
- 2-out-of-3 PLC Redundancy in each Train
- Single PLC failure will not result in spurious actuation
- Single PLC failure will not preclude automatic or manual actuation
- Voting Performed in Non Software Based Circuits
. Two SFSs per Unit (one per train)
A I % I I
.5UI-MlAL.1 tCOMPANY15 Slide 10 rem M-
Scope of Design Modification Description of VEGP SFS Upgrade 9 Actuated on Loss of Vital Bus Voltage or Safety Injection Signal 9 Generates Three Sequence Signals SI Only, SI and LOSP, or LOSP Only
-Functional Replacement
-Inputs the same
-Outputs the same
-Similar Sighalization
[OUTHERN R~k COMPANY Slide 11 G.
Scope of Design Modification Description of VEGP SFS Upgrade
- Load Sequence
-Four Groups - Basic, A, B and C
-Nine Steps per Group - 0 to 30 seconds in 5 second intervals
- FPDS Maintenance and Test Panel ISOUTHERN ~~w I COMPANY Slide 12 I(g*ýl
Scope of Design Modification Description of VEGP SFS Upgrade
. Protection Signals Not Impacted
-All Reactor Trip System (RTS) signals
-Dedicated MCB component controls
-ESF system-level actuation signals from SSPS
-LOSP signals
-Sequencing of SI actuated loads (e.g., rotating machinery) jSOUTHERNAM-A Slide 13 I COMPANY
VEGP SFS Upgrade Architecture Vogtle Diesel Generator Safety Features Sequencer Block Diagram SOUTHERN -k COMPANY Slide 14 I (g*o I
Unique Common Q Circuits associated with SFS Upgrade
- 2-out-of-3 voting logic performed in non software based circuits
- Termination unit special circuits (pulse, interlock circuit)
LOUTHERN K...L COMPANY Slide 15 I.
VEGP SFS Upgrade Licensing Evaluation
- Key Regulatory/Industry Guidelines
-NEI 01-01 (EPRI TR-1 02348, Revision 1)
-NEl 96-07, Revision 1
-BTP HICB 19
-NUREG/CR-6303 9 Applicability of Common QSER Diversity & Defense-in-Depth Analysis (D3)
. Evaluation of FSAR Chapter 1 5 AQOs and DBEs
- j.Q p W-'-
- ZýIR94 4 oiý41 SOUTHERN A COMPANY Slide 16 Westin ouse
VEGP SFS Upgrade Licensing Evaluation 9 License Amendment Request vs. 10 CFR 50.59
-Design modification "screens in"consistent with NEI 96-07
-Example 4-8 of NEI 01-01 supports VEGP sequencer upgrade concludes prior approval not required ISOUTHERN Slide 17 I COMPANY
VEGP SFS Upgrade Licensing Evaluation o Key 10 CFR50.59 Questions
-Does the proposed activity result in more than a minimal increase in the frequency of occurrence of an accident previously evaluated in the FSAR?
-Does the proposed activity result in more than a minimal increase in the likelihood of occurrence of a malfunction of an SSC important to safety previously evaluated in the FSAR?
-Does the proposed activity create the possibility for a malfunction of an SSC important to safety with a different result I
than any previously evaluated in the FSAR?
Slide 18
[ OUTHERN ....
COMPANY Slide 18 J@iýwuse
VEGP SFS Upgrade Licensing Evaluation 10 CFR 50.59 Evaluation 1
-D&D-in-D analysis performed prior to 10 CFR 50.59 evaluation
- Analysis performed as part of design phase
- Postulated software common mode failure beyond design basis of plant
- SER Issued by NRC on Common Q System SOUTHERN AM*
COMPANY Slide 19 1(9ýwýfl
VEGP SFS Upgrade Licensing Evaluation
- 10 CFR 50.59 Evaluation(continued)
-D-G Sequencer I&C Upgrade Features Simple Architecture
- Three stand alone PLCs per Train With 2-out-of-3 Voting in Non Software Based Circuits
- No inter-PLC communication links for actuation path Slide 20 I
SOUTHERNYK....
COMPANY SOUTHERN Slide 20 0.
VEGP SFS Upgrade Licensing Evaluation
- Applicability of Common Q SER
-Update on Status of Generic SER Open Items (GOls)
-Response to Plant Specific Action Items (PSAIs)
Slide 21 I
SOUTHERN E COMPANY Slide 21 1@. 1
Status of Generic SER Open Items
- Following Open Items Closed by Revision 1 of SER
-7.4 Section 4.2.1.2
-7.7 Section 4.3.1.j
-7.9 Section 4.4.4.3.4
-7.10 Section 4.4.4.3.5 Slide 22 I
$OUTHERNYH SOUTHERN ICOMPANY Slide 22 J@i
Status of Generic SER Open Items e Following SER Open Items Related to Completion of the Common Q Equipment Qualification Program. All EQ Testing Has Been Completed and Additional Information Has Been Filed in August 2002 to Close Out These items.
-7.1 Section 4.1.1.1.2
-7.2 Section 4.1.4
-7.3 Section 4.1.5
-7.5 Section 4.2.2.1.3
-7.6 Section 4.2.2.2 gSOUTHERN Skde2 I COMPANY I
Status of Generic SER Open Items
- This Open Item Will Be Addressed in a Future Submittal to the NRC.
-7.8 Section 4.4.4.3.2 - biversity of loop controllers- Not Applicable to VEGP Slide 24 m A
MUHMI tAEA Slide 24 I
Status of Plant Specific Action Items e The Plant Specific Action items are addressed as follows:
-6.1 SNC ensUres hardware meets environmental and performance requirements via purchase specifications.
-6.2 SNC will use the Westinghouse FPDS.
-6.3 This item closed in SER, revision 1. The Westinghouse FtDS is used only for alarm, indication, and test. It is not required to function as part of the sequencer safety function.
-6.4 See the response to item 6.1 above.
ISOUTHERNA MA Slide 25 ICOMPANY
Status of Plant Specific Action Items (Cont'd)
-6.5 SNC will rely on the Westinghouse software life-cycle process.
-6.6 SNC and Westinghouse have performed a timing sensitivity study, and we have determined that the response time of the digital system is adequate.
-6.7 The OM panel is not being used for the VEGP SFS upgrade. SNC and Westinghouse will develop the MTP to duplicate existing test panel function. Westinghouse and SNC will ensure the MTP incorporates human factors considerations.
LOUTHERN N....
COMPANY Slide 26 @
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. .I --- - I
Status of PlantdSpecific Action Items (Cont'd)
-6.8 The digital sequencer is designed to provide the same functionality as the existing sequencer.
-6.9 Not Applicable. No Technical Specification changes will r
result from this modification
-6.10 A FMEA is being prepared as part of the standard SNC design process.
-6.11 A Diversity and Defense-in-Depth analysis being p
performed as part of the design process.
SOUTHERN ,K.A. Slide 27 COMPANY I
Status of Plant Specific Action Items (Cont'd)
-6.12 The sequencer upgrade will be subjected to rigorous factory acceptance testing and routine periodic surveillance testing thereafter.
-6.13 This item is not applicable to this modification.
-6.14 TMI actions are not impacted by this modification.
ISOUTHERN AL COMPANY Slide 28 Igow4l
S ummary of Licensing Evaluation
"*Adopted 10 CFR 50.59 licensing approach
"*D3 analysis performed as part of design process
"*Modification to Design to Resolve Potential Software CMF Susceptibility IU UATAk m
Slide 29
Diversity and Defense-in-Depth (D3)
Analysis e Followed Guidelines presented in HICB-i 9, NUREG/CR-6303 and Reg Guide 1.i74
- Developed simplified functional model of SFS
- Identified common software blocks e Single failure assumed to be CMF in a common software block ISOUTHERN I
I COMPANY Slide 30 ous,,e
- I
Diversity and Defense-in-Depth (D3)
Analysis 9 All common software blocks assumed to fail to same mode (fail high, fail-as-is, or fail low)
- No other single failures assumed
- Only one initiating event assumed concurrent with postulated software CMF (LOSP is an ANS Condition ii event)
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SOUTHERN COMPANY Slide 31 W " ou..s.e
Evaluation of FSAR Chapter 15 AOOs and DBEs
- Best estimate initial conditions and assumption assumed
-Nominal operating conditions
-ANS best estimate decay heat model
-Best estimate break flow model (Henry-Fauske)
-NSSS control systems function normally
-Relaxed acceptance criteria specified in NUREG/CR-6303 adopted Slide 32 k
OUTHERNY COMPANY OUTHERN Slide32 lgýoýl
Evaluation of FSAR Chapter 15 AOOs and DBEs
- Best estimate operator action times assumed
-Diverse process indications available
-Diverse system/component controls available i
- Use of "Risk-lnformed" Insights
-Low probability of occurrence initiating events not required to be analyzed
-Only analyzed initiating events identified as significant contributors (at least 1 to plant CDF and/or LERF using NRC qualified codes
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- SOUTHERN A Slide 33 u.se.
I COMPANY
Evaluation of FSAR Chapter 15 AQOs and DBEs 9 Use of VEGP PRA Results
-Total CDF of~--1.6 E-05
-All initiating events with contribution to CDF less than 1.6 E-07 not evaluated - less than 1%
- LOSP initiating events contribute -11% total CDF and 1% total LERF
- LOCA initiating events contribute -7% total CDF and 2% LERF
- SGTR initiating events contribute -0.5% total CDF and -10% LERF ISOUTHERN W-A Slide 34 ICOMPANY
Evaluation of FSAR Chapter 15 AOOs and DBEs (Cont'd)
- Contributions to CDF From Component Cutsets
-SFS failure --2%of total CDF (excluding sensors and switchgear)
-RTS & ESF failure -1 %total CDF (excluding sensors, slave relays and switchgear)
[OUTHERN K...
COMPANY Slide 35
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Evaluation of FSAR Chapter 15 AOOs and DBEs 9 ANS Condition ii Events
-ATWS Mitigation System diverse from SFS
- Turbine trip on low-low SG level
-Generic ATWS analyses part of VEGP licensing basis
-Only initiating event that is a significant contributor to CDF or LERF is LOSP
- Turbine driven auxiliary feedwater pump actuated independent of SFS
-inadvertent Safety Injection event precluded by SI signal interlock directly from SSPS OUTHIERN - Side36 COMPANY
Evaluation of FSAR Chapter 15 AQOs and DBEs
. ANS Condition III Events
-Only event that is a significant contributor to CDF or LERF is LOCA
-Small Break (SBLOCA)
-Medium Break (MBLOCA)
-VEGP Leak-before-Break licensing basis
-RCS hot leg - 6 inch
-RCS cold leg -4 inch
-Pressurizer steam space - 6 inch I
SOUTHERN A Slide37 Mýl COMPANY
Evaluation of FSAR Chapter 15 AOOs and DBEs
- ANS Condition III Events (Cont'd)
-Sensitivity studies conducted on NRC approved code (NOTRUMP)
- 2 inch LOCA - passive accumulator injection not required
+Operator has >10 minutes to manually actuate ECCS
- 6 inch break- RCS pressure decreases below passive accumulator setpoint
+ Operator has >10 minutes to manually actuate ECCS OUTHERN A COMPANY Slide 38 E* t , . e .. r "rJ,
Evaluation of FSAR Chapter 15 AOOs and DBEs
- 4 inch break - RCS pressure remains sufficiently high such that ECCS injection flow decreased -tradeoff of loss of RCS break flow versus ECCS reduced injection flow
+ Operator has >1i0 minutes to manually actdate ECCS OUTHERN*Afl COMPANY Slide 39 1@444ý41
Evaluation of FSAR Chapter 15 AOOs and DBEs
- ANS Condition IV Events
-LBLOCA not required to be anaiyzed due to VEGP Leak before-Break licensing basis
-Only event that is significant contributor to CDF or LERF is SGTR
- IfSFS outputs fail high, actuation precluded by design feature of upgrade and also interlock directly from SSPS signal, event bounded by FSAR analysis
'a ;A 4A CWTHT-IRN ALWk COMPANY 40 Slide 40 1.99) 1
J*
AOO and DBE Evaluation Summary 9 All FSAR Chapter 15 Events Evaluated
-Low probability events not required to be evaluated (Condition IV) - LBLOCA
-Used risk-informed insights to0justify only evaluating events that are significant contributors to VEGP CDF and/or LERF (Condition IlI and IV)
- SBLOCA, MBLOCA, SGTR
- Analyzed bounding events using NRC qualified code
'.1WSlid 4l~
AOO and DBE Evaluation Summary
-Referenced existind bou nding plant or generic analysis to greatest extent possible (Condition iI)
- Applied ATWS analysis to all Condition Ii events Slide 42 I
SOUTHERNYE.A&
SOUTHERN H.
COMPANY Slide 42 I(g iie'
Summary
"*Adopted 10 CFR 50.59 licensing approach
"*D3 analysis performed as part of design process
"*Modification to design to resolve potential software CMF susceptibility
"*All VEGP Chapter 15 events evaluated concurrent with software common mode failure using risk insights- BTP HICB-19, NUREG/CR-6303, and Reg Guide 1.174.
6 Zk Slide 43 .3 COAPU