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{{#Wiki_filter:ArnerGeno, An Exelon Company TMI Mark-B-HTP Implementation License Amendment Request Meeting April 30, 2007 ENCLOSURE2 Ames Gen..An Exelon Company Purpose of Meeting* Review License Amendment Request (LAR) Technical Specification (TS) changes supporting implementation of Mark-B-HTP Fuel Design in Cycle 17 reload (Fall 2007) -LAR # 335 submitted March 22, 2007* Discuss LAR scope and content, and clarify any initial questions to minimize need for NRC requests for additional information
{{#Wiki_filter:ArnerGeno, An Exelon Company TMI Mark-B-HTP Implementation License Amendment Request Meeting April 30, 2007 ENCLOSURE2
* Identify any additional information needed for LAR 1 A m=irner en rO 0 An Exelon Company Agenda TMI Unit 1 Presentation
 
-Mark-B-HTP Implementation
Ames Gen..
-Benefits of Mark-B-HTP Fuel Design-Methods Review-Scope of License Amendment Request-Proposed Technical Specification Changes-VLPT Setpoint-Questions  
An Exelon Company Purpose of Meeting
& Feedback AmerGen,.An Exelon Company TMI-1 Mark-B-HTP Implementation First reload batch of Mark-B-HTP will be loaded in Fall 2007-Original plans to introduce the HTP design in 2009 were accelerated due to TMI fuel defect in Fall 2006-TMI will be the 4 th B&W reactor to introduce HTP design" CR-3, Davis-Besse, and ANO-1 are currently operating mixed Mark-B-HTP/Mark-B cores" TMI transition is similar to other B&W transitions previously analyzed by AREVA* NRC has reviewed similar submittals for B&W plant applications
* Review License Amendment Request (LAR) Technical Specification (TS) changes supporting implementation of Mark-B-HTP Fuel Design in Cycle 17 reload (Fall 2007) - LAR # 335 submitted March 22, 2007
-HTP design uses the same M5 material and same fuel rod as current Mark-B 12 design An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)o Mixed core transition requires change to TMI- 1 Technical Specifications
* Discuss LAR scope and content, and clarify any initial questions to minimize need for NRC requests for additional information
-Mark-B-HTP grid design has higher pressure drop than resident Mark-B 12 fuel resulting in mixed core T-H penalties-Core safety limits and Variable Low Pressure Trip setpoint revised based on mixed core DNB analysis-TS Amendment requested by October 15, 2007 to support TMI, 1 Cycle 17 startup date A An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)* Introduction of the Mark-B-HTP fuel design at TMI-1 is being processed as a design change via the Exelon configuration control process-Areas not requiring changes to Technical Specifications and not requiring NRC review will be addressed under the 10 CFR 50.59 process-Mixed-core LOCA analyses have been performed for TMI-1 Cycle 17 Cycle 17 analysis justified the same LOCA kW/ft limits used for the resident Mk-B 12 fuel. Peak clad temperatures (PCT) previously calculated for the resident Mk-B 12 fuel bound Mk-B-HTP fuel PCT results calculated using NRC-approved hot pin methodology contained in BAW-10164P-A
* Identify any additional information needed for LAR 1
* Mixed-core and full core Mark-B-HTP LOCA analyses will be performed that specifically consider EOTSG replacement for Cycle 18-Non-LOCA safety analyses are being addressed in the design change package* The Mark-B-HTP fuel design has been shown to have a negligible effect on the overall system response* The present TMI- 1 UFSAR DNB evaluation for the control rod ejection accident will be shown to bound the TMI- 1 core with the implementation of the Mark-B-HTP fuel design* Cycle-specific evaluation of the loss of flow transients will be performed as described in BAW-10179P-A (Section 6.5) using the BHTP CHF correlation Ana Mere 1ýAn Exelon Company Major Benefits of Mark-B-HTP Design Mark-B-HTP design will significantly increase margin to grid-to-rod fretting failures-TMI- 1 experienced what appears to be a grid-fretting failure in Fall 2006-Extensive in-reactor experience has demonstrated superior HTP fretting resistance
 
-Supports TMI-1 drive towards goal of Zero Fuel Defects* Welded cage expected to reduce fuel assembly twist/bow-Lateral stiffness more than twice that of Mk-B 12 floating grid design-Lower drag forces on control rod insertion and increased margin to Incomplete Rod Insertion-Straighter assembly expected to decrease risk of grid damage during core loading/off-loading Am,.e Gern , An Exelon Company Methods Review 0 AREVA's NRC-approved Reload Topical BAW-10179P-A, Rev. 6 will be used to develop revised TS safety limits and setpoints-BAW-10179 Rev. 6 includes: " BAW-10187P-A, Statistical Core Design methodology (same methodology used for current TMI Mark-B DNBR design limits)" BAW-10156-A, LYNXT (same core T-H methodology used for current TMI core safety limits)" BAW-10241P-A, Rev. 0 and Rev. 1, BHTP DNB correlation applied with LYNXT (required for use with Mark-B-HTP fuel design)" BAW-10192P-A, BWNT LOCA EM and BAW-10164P-A, RELAP5/MOD2-B&W (same methodologies used for current TMI-1 LOCA analyses, with BHTP correlation added)-Core safety limits and VLPT setpoint are developed using the same methodology as the current TMI- 1 limits/setpoint that were last revised in 2003 (Amendment  
A m=irner enrO 0 An Exelon Company Agenda TMI Unit 1 Presentation
#247)-7 ArnwrGen.R An Exelon Company LAR Scope and Technical Content* Proposed TS changes* DNB analysis description and mixed core penalty derivation
- Mark-B-HTP Implementation
* LOCA and non-LOCA accident summaries (Analyses not required to support TS change)" VLPT LSSS derivation" VLPT setpoint methodology
- Benefits of Mark-B-HTP Fuel Design
* Precedents Amer6,ren..
- Methods Review
An Exelon Company DNB Transition Core Penalty A Thermal Design Limit (TDL) has been determined, which provides sufficient margin for TMI- 1 mixed core transition period-A Statistical Design Limit (SDL) has been determined for TMI-1 using the SCD methodology assuming a full core of Mark-B-HTP fuel-Mixed core penalties have been determined for varying number of Mark-B-HTP fuel assemblies co-resident with Mark-B fuel-The first transition cycle, which requires the largest mixed core penalty, is fully accommodated by the margin between the SDL and TDL AmerGe~n,,.
- Scope of License Amendment Request
An Exelon Company DNB Transition Core Penalty (cont.)Cycle 16 Design Basis Limit Cycle 17 Design Basis Limit A Thermal Design Limit (TDL)DNB margin between the TDL and SDL will offset the Transition Core Penalty and other cycle-specific needs Thermal Design Limit (TDL)Statistical Design Limit (SDL)BWC CHIF Design Limit Cycle 17 Transition Core Penalty Statistical Design Limit (SDL)BHTP CHF Design Limit.4 ^~
- Proposed Technical Specification Changes
An Exelon Company Proposed Technical Specification Changes" Core Protection Safety Limits specified in TS Figure 2.1-1 and Bases Figure 2.1-3* TS Table 2.3-1, Reactor Protection System Trip Setting Limits, and Figure 2.3-1, Protection System Maximum Allowable Setpoints, are modified to revise the variable low pressure trip setpoint* TS Section 2.1 and 2.3 Bases are revised to incorporate reference to Topical Report BAW- 10241P-A o TS Section 2.3 Bases are modified to reflect the revised variable low reactor coolant system pressure trip setpoint* TS Table 4.1-1 and Section 4.1 Bases modified to add VLPT as-found/as-left requirements
- VLPT Setpoint
.4 4 Amerv -en.An Exelon Company VLPT Setpoint Change The revised VLPT setpoint will not pose a challenge to Operators-Cycle 17 setpoint will be less limiting than previous settings Projected VLPT Setpoint for TMI Cyl7 2500 ---- -I 2300 1_= I 02100o ,O PsIg .Cy16 VLPT.Cy17 VLPT 0 " 1942 psig Q01900 1500"-540 560 580 600 620 640 Reactor Outlet Temperature (F)4 n  
- Questions & Feedback
.AmerGen,.
 
AmerGen,.
An Exelon Company TMI-1 Mark-B-HTP Implementation First reload batch of Mark-B-HTP will be loaded in Fall 2007
  - Original plans to introduce the HTP design in 2009 were accelerated due to TMI fuel defect in Fall 2006
  - TMI will be the 4 th B&W reactor to introduce HTP design
      " CR-3, Davis-Besse, and ANO-1 are currently operating mixed Mark-B-HTP/Mark-B cores
      " TMI transition is similar to other B&W transitions previously analyzed by AREVA
* NRC has reviewed similar submittals for B&W plant applications
  - HTP design uses the same M5 material and same fuel rod as current Mark-B 12 design
 
An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)
o Mixed core transition requires change to TMI- 1 Technical Specifications
  - Mark-B-HTP grid design has higher pressure drop than resident Mark-B 12 fuel resulting in mixed core T-H penalties
  - Core safety limits and Variable Low Pressure Trip setpoint revised based on mixed core DNB analysis
  - TS Amendment requested by October 15, 2007 to support TMI, 1 Cycle 17 startup date A
 
An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)
* Introduction of the Mark-B-HTP fuel design at TMI-1 is being processed as a design change via the Exelon configuration control process
  -   Areas not requiring changes to Technical Specifications and not requiring NRC review will be addressed under the 10 CFR 50.59 process
  -   Mixed-core LOCA analyses have been performed for TMI-1 Cycle 17 Cycle 17 analysis justified the same LOCA kW/ft limits used for the resident Mk-B 12 fuel. Peak clad temperatures (PCT) previously calculated for the resident Mk-B 12 fuel bound Mk-B-HTP fuel PCT results calculated using NRC-approved hot pin methodology contained in BAW-10164P-A
* Mixed-core and full core Mark-B-HTP LOCA analyses will be performed that specifically consider EOTSG replacement for Cycle 18
  -   Non-LOCA safety analyses are being addressed in the design change package
* The Mark-B-HTP fuel design has been shown to have a negligible effect on the overall system response
* The present TMI- 1 UFSAR DNB evaluation for the control rod ejection accident will be shown to bound the TMI- 1 core with the implementation of the Mark-B-HTP fuel design
* Cycle-specific evaluation of the loss of flow transients will be performed as described in BAW-10179P-A (Section 6.5) using the BHTP CHF correlation
 
Ana Mere       1ý An Exelon Company Major Benefits of Mark-B-HTP Design Mark-B-HTP design will significantly increase margin to grid-to-rod fretting failures
  - TMI- 1 experienced what appears to be a grid-fretting failure in Fall 2006
  - Extensive in-reactor experience has demonstrated superior HTP fretting resistance
  - Supports TMI-1 drive towards goal of Zero Fuel Defects
* Welded cage expected to reduce fuel assembly twist/bow
  - Lateral stiffness more than twice that of Mk-B 12 floating grid design
  - Lower drag forces on control rod insertion and increased margin to Incomplete Rod Insertion
  - Straighter assembly expected to decrease risk of grid damage during core loading/off-loading
 
Am,.e Gern, An Exelon Company Methods Review 0 AREVA's NRC-approved Reload Topical BAW-10179P-A, Rev. 6 will be used to develop revised TS safety limits and setpoints
  - BAW-10179 Rev. 6 includes:
        " BAW-10187P-A, Statistical Core Design methodology (same methodology used for current TMI Mark-B DNBR design limits)
        " BAW-10156-A, LYNXT (same core T-H methodology used for current TMI core safety limits)
        " BAW-10241P-A, Rev. 0 and Rev. 1, BHTP DNB correlation applied with LYNXT (required for use with Mark-B-HTP fuel design)
        " BAW-10192P-A, BWNT LOCA EM and BAW-10164P-A, RELAP5/MOD2-B&W (same methodologies used for current TMI-1 LOCA analyses, with BHTP correlation added)
  - Core safety limits and VLPT setpoint are developed using the same methodology as the current TMI- 1 limits/setpoint that were last revised in 2003 (Amendment #247)
                                                                                -7
 
ArnwrGen.R An Exelon Company LAR Scope and Technical Content
* Proposed TS changes
* DNB analysis description and mixed core penalty derivation
* LOCA and non-LOCA accident summaries (Analyses not required to support TS change)
" VLPT LSSS derivation
" VLPT setpoint methodology
* Precedents
 
Amer6,ren..
An Exelon Company DNB Transition Core Penalty A Thermal Design Limit (TDL) has been determined, which provides sufficient margin for TMI- 1 mixed core transition period
  - A Statistical Design Limit (SDL) has been determined for TMI-1 using the SCD methodology assuming a full core of Mark-B-HTP fuel
  - Mixed core penalties have been determined for varying number of Mark-B-HTP fuel assemblies co-resident with Mark-B fuel
  - The first transition cycle, which requires the largest mixed core penalty, is fully accommodated by the margin between the SDL and TDL
 
AmerGe~n,,.
An Exelon Company DNB Transition Core Penalty (cont.)
Cycle 16                                         Cycle 17 Design Basis                                     Design Basis Limit                                            Limit A
Thermal Design Limit (TDL)
DNB margin between the TDL and SDL will offset the Transition Core Penalty and other cycle-specific needs                                             Cycle 17 Transition Core Penalty Thermal Design Limit (TDL)
Statistical Design Limit (SDL)
Statistical Design Limit (SDL)
BWC CHIF Design Limit BHTP CHF Design Limit
                                                                                                                                .4 ^~
 
An Exelon Company Proposed Technical Specification Changes
" Core Protection Safety Limits specified in TS Figure 2.1-1 and Bases Figure 2.1-3
* TS Table 2.3-1, Reactor Protection System Trip Setting Limits, and Figure 2.3-1, Protection System Maximum Allowable Setpoints, are modified to revise the variable low pressure trip setpoint
* TS Section 2.1 and 2.3 Bases are revised to incorporate reference to Topical Report BAW- 10241P-A o TS Section 2.3 Bases are modified to reflect the revised variable low reactor coolant system pressure trip setpoint
* TS Table 4.1-1 and Section 4.1 Bases modified to add VLPT as-found/as-left requirements
                                                                              .4 4
 
Amerv -en.
An Exelon Company VLPT Setpoint Change The revised VLPT setpoint will not pose a challenge to Operators
  - Cycle 17 setpoint will be less limiting than previous settings Projected VLPT Setpoint for TMI Cyl7 2500                     -         ---     -I 2300     1
_=                     I 02100o
                                                              ,O       PsIg     . Cy16 VLPT
                                                                                  . Cy17 VLPT 0                                                 "     1942 psig Q01900 1500"-
540 560         580               600         620         640 Reactor Outlet Temperature (F) 4 n
 
                                                .AmerGen,.
An Exelon Company Variable Low Pressure Safety Limit Derivation Variable Low Pressure Safety Limit derived following NRC approved methodology in BAW- 10179 (Section 7.6) using BHTP CHF correlation
An Exelon Company Variable Low Pressure Safety Limit Derivation Variable Low Pressure Safety Limit derived following NRC approved methodology in BAW- 10179 (Section 7.6) using BHTP CHF correlation
-Variable low pressure safety limit is determined from DNB analyses for 2-, 3-, and 4-pump operation and provides 95/95 steady-state protection for DNBR using the TDL and 4-pump limits were derived using BHTP CHF correlation approved in BAW-10241P-A, Rev. 0-2-pump limits were derived using the BHTP CHF correlation approved in BAW-10241P-A, Rev. 1, which expanded the range of the correlation
  - Variable low pressure safety limit is determined from DNB analyses for 2-, 3-, and 4-pump operation and provides 95/95 steady-state protection for DNBR using the TDL and 4-pump limits were derived using BHTP CHF correlation approved in BAW-10241P-A, Rev. 0 pump limits were derived using the BHTP CHF correlation approved in BAW-10241P-A, Rev. 1, which expanded the range of the correlation
-1 AnmerGenK An Exelon Company VLPT Setpoint Derivation VLPT Setpoint (LSSS) derived following NRC approved methodology in BAW-10179 (Section 7.6)-Variable low pressure safety limit from DNB analysis is conservatively adjusted to account for the pressure drop from the core exit to the pressure instrument tap-The adjusted safety limit is conservatively bounded by a straight line-Instrument uncertainties for the pressure and temperature components of the VLPT trip hardware are combined and translated into a pressure uncertainty that is conservatively applied to the adjusted safety limit line If necessary, the slope of the error-adjusted safety limit line is conservatively rotated to ensure the final setpoint is within the capability of the instrumentation Amer~en'An Exelon Company VLPT Setpoint Methodology Methodology for establishing limiting setpoint and limiting acceptable values for As-Found and As-Left setpoints measured in Surveillance Tests-Safety Limit Related Determination
                                                                        -1
 
AnmerGenK An Exelon Company VLPT Setpoint Derivation VLPT Setpoint (LSSS) derived following NRC approved methodology in BAW-10179 (Section 7.6)
  - Variable low pressure safety limit from DNB analysis is conservatively adjusted to account for the pressure drop from the core exit to the pressure instrument tap
  - The adjusted safety limit is conservatively bounded by a straight line
  - Instrument uncertainties for the pressure and temperature components of the VLPT trip hardware are combined and translated into a pressure uncertainty that is conservatively applied to the adjusted safety limit line If necessary, the slope of the error-adjusted safety limit line is conservatively rotated to ensure the final setpoint is within the capability of the instrumentation
 
Amer~en' An Exelon Company VLPT Setpoint Methodology Methodology for establishing limiting setpoint and limiting acceptable values for As-Found and As-Left setpoints measured in Surveillance Tests
  - Safety Limit Related Determination
* Calculate the VLPT LSP, NSP, Total Loop Uncertainty (TLU) and Margin using methodology provided by ANSI/ISA-67.04
* Calculate the VLPT LSP, NSP, Total Loop Uncertainty (TLU) and Margin using methodology provided by ANSI/ISA-67.04
-Calculate predefined limits for the as-found TSP based on the NSP* The predefined limits will be determined in accordance with the NRC accepted methodology described in NRC RIS 2006-17.-The setting tolerance band is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, and readability uncertainties
  - Calculate predefined limits for the as-found TSP based on the NSP
-The setting tolerance is included in the total loop uncertainty
* The predefined limits will be determined in accordance with the NRC accepted methodology described in NRC RIS 2006-17.
-The pre-defined test acceptance criteria band for the as-found value is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, readability uncertainties and drift AmerGenl An Exelon Company VLPT Setpoint Methodology Safety Limit Related Determination
            - The setting tolerance band is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, and readability uncertainties
-The VLPT Setpoint is a Limiting Safety System Setting (LSSS) as defined in TMI Unit 1 TS 2.3" The VLPT initiates an automatic reactor trip" The VLPT provides reactor protection for the core safety limits contained in TMI Unit 1 TS Figure 2.1-1, which ensure margin to core DNBR limits ArnerGea, An Exelon Company VLPT Setpoint Methodology
            - The setting tolerance is included in the total loop uncertainty
* Compliance with 10 CFR 50.36 ensured by compliance with RIS 2006-17* As-Found Setpoint Evaluation
            - The pre-defined test acceptance criteria band for the as-found value is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, readability uncertainties and drift
-If the as-found Trip Setpoint exceeds the Limiting Setpoint, declare VLPT channel inoperable
 
-If the as-found Trip Setpoint exceeds the predefined limits, determine if the instrument is functioning as required prior to returning the VLPT channel to service. If it cannot be determined that the instrument is functioning as required, declare VLPT channel inoperable.
AmerGenl An Exelon Company VLPT Setpoint Methodology Safety Limit Related Determination
-If the as-found Trip Setpoint exceeds the predefined limits, the condition must be entered into the Corrective Action program* As-Left Setpoint Control-Instrument will be left within the setting tolerance band 17 AMerGenci)
  - The VLPT Setpoint is a Limiting Safety System Setting (LSSS) as defined in TMI Unit 1 TS 2.3
      " The VLPT initiates an automatic reactor trip
      " The VLPT provides reactor protection for the core safety limits contained in TMI Unit 1 TS Figure 2.1-1, which ensure margin to core DNBR limits
 
ArnerGea, An Exelon Company VLPT Setpoint Methodology
* Compliance with 10 CFR 50.36 ensured by compliance with RIS 2006-17
* As-Found Setpoint Evaluation
  - If the as-found Trip Setpoint exceeds the Limiting Setpoint, declare VLPT   channel inoperable
  - If the as-found Trip Setpoint exceeds the predefined limits, determine if the instrument is functioning as required prior to returning the VLPT channel to service. If it cannot be determined that the instrument is functioning as required, declare VLPT channel inoperable.
  - If the as-found Trip Setpoint exceeds the predefined limits, the condition must be entered into the Corrective Action program
* As-Left Setpoint Control
  - Instrument will be left within the setting tolerance band 17
 
AMerGenci)
An Exelon Company VLPT Setpoint Methodology Proposed TS and TS Bases Changes to address setpoint methodology
An Exelon Company VLPT Setpoint Methodology Proposed TS and TS Bases Changes to address setpoint methodology
-Table 4.1-1 specifies required actions regarding response to as-found/as-left criteria* Actions similar to those proposed in TSTF-493.-TS Section 4.1 Bases specifies that the UFSAR incorporates by reference the document that contains the following: " Limiting Trip Setpoint* Methodology used to determine the Limiting Trip Setpoint, pre-defined as-found acceptance criteria band, and as-left setpoint tolerance band-TS Section 4.1 Bases specifies the definition of the pre-defined as-found acceptance criteria band for the VLPT 4 AmurGen, .An Exelon Company VLPT Setpoint Methodology Sample of Variable Low Pressure Trip (VLPT) Setpoints and Calibration Criteria 1990 ---, 4 , 1970 VLPT Pre-defined As-found Tolerance Band -'1970.VLPT As-left Tolerance Band 0.1950 -00, , "S High Temp Trip CL VLPT Nominal Setpoint (NSP)cr1930--djusted TS VLPT 1910-- --4~- S VLPTr LSSS Setpoint 1910. -TSLow'S Trp Tri.1890 -" '612 613 614 615 616 617 618 619 Thot.4r %
  - Table 4.1-1 specifies required actions regarding response to as-found/as-left criteria
An Exelon Company Summary* Mark-B-HTP design provides improved fuel reliability" NRC approved Reload Topical Report and methodologies used for Cycle 17 core reload design* Revised VLPT provides required safety margin and does not challenge plant operation* NRC approved methodology used to determine VLPT safety limit* VLPT parameters established based on ANSI/ISA-67.04
* Actions similar to those proposed in TSTF-493.
* VLPT predefined limits determined based on NRC RIS 2006-17* TS & TS Bases changes similar to recent NRC approved VLPT amendment for B&W plant design* TMI Amendment requested to support Cycle 17 startup An Exelon Company Questions  
  - TS Section 4.1 Bases specifies that the UFSAR incorporates by reference the document that contains the following:
/ Feedback 011}}
      " Limiting Trip Setpoint
* Methodology used to determine the Limiting Trip Setpoint, pre-defined as-found acceptance criteria band, and as-left setpoint tolerance band
  - TS Section 4.1 Bases specifies the definition of the pre-defined as-found acceptance criteria band for the VLPT 4 n*
 
AmurGen,         An Exelon Company
                                                                                                                                                          .
VLPT Setpoint Methodology Sample of Variable Low Pressure Trip (VLPT) Setpoints and Calibration Criteria 1990 ---
                                                                                                  ,                             4, 1970                             1970.              VLPT Pre-defined As-found Tolerance Band                                   -'
VLPT As-left Tolerance Band 0.
1950 -                                                                             00,                       ,     "S High Temp Trip CL VLPT Nominal Setpoint (NSP) cr1930-
                                                                  -                     djusted TS VLPT 1910--                                                               - -     4 ~-   S VLPTr LSSS Setpoint 1910.                                       -
Trp TSLow'S Tri.
1890         -"       '
612             613                 614                 615                   616             617             618               619 Thot
                                                                                                                                                      .4r %
 
An Exelon Company Summary
* Mark-B-HTP design provides improved fuel reliability
" NRC approved Reload Topical Report and methodologies used for Cycle 17 core reload design
* Revised VLPT provides required safety margin and does not challenge plant operation
* NRC approved methodology used to determine VLPT safety limit
* VLPT parameters established based on ANSI/ISA-67.04
* VLPT predefined limits determined based on NRC RIS 2006-17
* TS & TS Bases changes similar to recent NRC approved VLPT amendment for B&W plant design
* TMI Amendment requested to support Cycle 17 startup
 
An Exelon Company Questions / Feedback 011}}

Revision as of 06:06, 23 November 2019

Enclosure 2 (Slides) - 04/30/2007 Summary of Meeting with Amergen Energy Co., LLC, Regarding License Amendment Request Relating to the Insertion of New Area High Thermal Performance Fuel in the TMI-1 Reactor
ML071370167
Person / Time
Site: Three Mile Island Constellation icon.png
Issue date: 04/30/2007
From:
AmerGen Energy Co, Exelon Corp
To:
Office of Nuclear Reactor Regulation
Bamford, Peter J., NRR/DORL 415-2833
Shared Package
ML071290417 List:
References
Download: ML071370167 (22)
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Text

ArnerGeno, An Exelon Company TMI Mark-B-HTP Implementation License Amendment Request Meeting April 30, 2007 ENCLOSURE2

Ames Gen..

An Exelon Company Purpose of Meeting

  • Review License Amendment Request (LAR) Technical Specification (TS) changes supporting implementation of Mark-B-HTP Fuel Design in Cycle 17 reload (Fall 2007) - LAR # 335 submitted March 22, 2007
  • Discuss LAR scope and content, and clarify any initial questions to minimize need for NRC requests for additional information
  • Identify any additional information needed for LAR 1

A m=irner enrO 0 An Exelon Company Agenda TMI Unit 1 Presentation

- Mark-B-HTP Implementation

- Benefits of Mark-B-HTP Fuel Design

- Methods Review

- Scope of License Amendment Request

- Proposed Technical Specification Changes

- VLPT Setpoint

- Questions & Feedback

AmerGen,.

An Exelon Company TMI-1 Mark-B-HTP Implementation First reload batch of Mark-B-HTP will be loaded in Fall 2007

- Original plans to introduce the HTP design in 2009 were accelerated due to TMI fuel defect in Fall 2006

- TMI will be the 4 th B&W reactor to introduce HTP design

" CR-3, Davis-Besse, and ANO-1 are currently operating mixed Mark-B-HTP/Mark-B cores

" TMI transition is similar to other B&W transitions previously analyzed by AREVA

  • NRC has reviewed similar submittals for B&W plant applications

- HTP design uses the same M5 material and same fuel rod as current Mark-B 12 design

An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)

o Mixed core transition requires change to TMI- 1 Technical Specifications

- Mark-B-HTP grid design has higher pressure drop than resident Mark-B 12 fuel resulting in mixed core T-H penalties

- Core safety limits and Variable Low Pressure Trip setpoint revised based on mixed core DNB analysis

- TS Amendment requested by October 15, 2007 to support TMI, 1 Cycle 17 startup date A

An Exelon Company TMI-1 Mark-B-HTP Implementation (cont.)

  • Introduction of the Mark-B-HTP fuel design at TMI-1 is being processed as a design change via the Exelon configuration control process

- Areas not requiring changes to Technical Specifications and not requiring NRC review will be addressed under the 10 CFR 50.59 process

- Mixed-core LOCA analyses have been performed for TMI-1 Cycle 17 Cycle 17 analysis justified the same LOCA kW/ft limits used for the resident Mk-B 12 fuel. Peak clad temperatures (PCT) previously calculated for the resident Mk-B 12 fuel bound Mk-B-HTP fuel PCT results calculated using NRC-approved hot pin methodology contained in BAW-10164P-A

  • Mixed-core and full core Mark-B-HTP LOCA analyses will be performed that specifically consider EOTSG replacement for Cycle 18

- Non-LOCA safety analyses are being addressed in the design change package

  • The Mark-B-HTP fuel design has been shown to have a negligible effect on the overall system response
  • The present TMI- 1 UFSAR DNB evaluation for the control rod ejection accident will be shown to bound the TMI- 1 core with the implementation of the Mark-B-HTP fuel design
  • Cycle-specific evaluation of the loss of flow transients will be performed as described in BAW-10179P-A (Section 6.5) using the BHTP CHF correlation

Ana Mere 1ý An Exelon Company Major Benefits of Mark-B-HTP Design Mark-B-HTP design will significantly increase margin to grid-to-rod fretting failures

- TMI- 1 experienced what appears to be a grid-fretting failure in Fall 2006

- Extensive in-reactor experience has demonstrated superior HTP fretting resistance

- Supports TMI-1 drive towards goal of Zero Fuel Defects

  • Welded cage expected to reduce fuel assembly twist/bow

- Lateral stiffness more than twice that of Mk-B 12 floating grid design

- Lower drag forces on control rod insertion and increased margin to Incomplete Rod Insertion

- Straighter assembly expected to decrease risk of grid damage during core loading/off-loading

Am,.e Gern, An Exelon Company Methods Review 0 AREVA's NRC-approved Reload Topical BAW-10179P-A, Rev. 6 will be used to develop revised TS safety limits and setpoints

- BAW-10179 Rev. 6 includes:

" BAW-10187P-A, Statistical Core Design methodology (same methodology used for current TMI Mark-B DNBR design limits)

" BAW-10156-A, LYNXT (same core T-H methodology used for current TMI core safety limits)

" BAW-10241P-A, Rev. 0 and Rev. 1, BHTP DNB correlation applied with LYNXT (required for use with Mark-B-HTP fuel design)

" BAW-10192P-A, BWNT LOCA EM and BAW-10164P-A, RELAP5/MOD2-B&W (same methodologies used for current TMI-1 LOCA analyses, with BHTP correlation added)

- Core safety limits and VLPT setpoint are developed using the same methodology as the current TMI- 1 limits/setpoint that were last revised in 2003 (Amendment #247)

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ArnwrGen.R An Exelon Company LAR Scope and Technical Content

  • Proposed TS changes
  • DNB analysis description and mixed core penalty derivation
  • LOCA and non-LOCA accident summaries (Analyses not required to support TS change)

" VLPT LSSS derivation

" VLPT setpoint methodology

  • Precedents

Amer6,ren..

An Exelon Company DNB Transition Core Penalty A Thermal Design Limit (TDL) has been determined, which provides sufficient margin for TMI- 1 mixed core transition period

- A Statistical Design Limit (SDL) has been determined for TMI-1 using the SCD methodology assuming a full core of Mark-B-HTP fuel

- Mixed core penalties have been determined for varying number of Mark-B-HTP fuel assemblies co-resident with Mark-B fuel

- The first transition cycle, which requires the largest mixed core penalty, is fully accommodated by the margin between the SDL and TDL

AmerGe~n,,.

An Exelon Company DNB Transition Core Penalty (cont.)

Cycle 16 Cycle 17 Design Basis Design Basis Limit Limit A

Thermal Design Limit (TDL)

DNB margin between the TDL and SDL will offset the Transition Core Penalty and other cycle-specific needs Cycle 17 Transition Core Penalty Thermal Design Limit (TDL)

Statistical Design Limit (SDL)

Statistical Design Limit (SDL)

BWC CHIF Design Limit BHTP CHF Design Limit

.4 ^~

An Exelon Company Proposed Technical Specification Changes

" Core Protection Safety Limits specified in TS Figure 2.1-1 and Bases Figure 2.1-3

  • TS Table 2.3-1, Reactor Protection System Trip Setting Limits, and Figure 2.3-1, Protection System Maximum Allowable Setpoints, are modified to revise the variable low pressure trip setpoint
  • TS Table 4.1-1 and Section 4.1 Bases modified to add VLPT as-found/as-left requirements

.4 4

Amerv -en.

An Exelon Company VLPT Setpoint Change The revised VLPT setpoint will not pose a challenge to Operators

- Cycle 17 setpoint will be less limiting than previous settings Projected VLPT Setpoint for TMI Cyl7 2500 - --- -I 2300 1

_= I 02100o

,O PsIg . Cy16 VLPT

. Cy17 VLPT 0 " 1942 psig Q01900 1500"-

540 560 580 600 620 640 Reactor Outlet Temperature (F) 4 n

.AmerGen,.

An Exelon Company Variable Low Pressure Safety Limit Derivation Variable Low Pressure Safety Limit derived following NRC approved methodology in BAW- 10179 (Section 7.6) using BHTP CHF correlation

- Variable low pressure safety limit is determined from DNB analyses for 2-, 3-, and 4-pump operation and provides 95/95 steady-state protection for DNBR using the TDL and 4-pump limits were derived using BHTP CHF correlation approved in BAW-10241P-A, Rev. 0 pump limits were derived using the BHTP CHF correlation approved in BAW-10241P-A, Rev. 1, which expanded the range of the correlation

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AnmerGenK An Exelon Company VLPT Setpoint Derivation VLPT Setpoint (LSSS) derived following NRC approved methodology in BAW-10179 (Section 7.6)

- Variable low pressure safety limit from DNB analysis is conservatively adjusted to account for the pressure drop from the core exit to the pressure instrument tap

- The adjusted safety limit is conservatively bounded by a straight line

- Instrument uncertainties for the pressure and temperature components of the VLPT trip hardware are combined and translated into a pressure uncertainty that is conservatively applied to the adjusted safety limit line If necessary, the slope of the error-adjusted safety limit line is conservatively rotated to ensure the final setpoint is within the capability of the instrumentation

Amer~en' An Exelon Company VLPT Setpoint Methodology Methodology for establishing limiting setpoint and limiting acceptable values for As-Found and As-Left setpoints measured in Surveillance Tests

- Safety Limit Related Determination

  • Calculate the VLPT LSP, NSP, Total Loop Uncertainty (TLU) and Margin using methodology provided by ANSI/ISA-67.04

- Calculate predefined limits for the as-found TSP based on the NSP

  • The predefined limits will be determined in accordance with the NRC accepted methodology described in NRC RIS 2006-17.

- The setting tolerance band is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, and readability uncertainties

- The setting tolerance is included in the total loop uncertainty

- The pre-defined test acceptance criteria band for the as-found value is less than or equal to the square root of the sum of the squares of reference accuracy, M&TE accuracy, readability uncertainties and drift

AmerGenl An Exelon Company VLPT Setpoint Methodology Safety Limit Related Determination

- The VLPT Setpoint is a Limiting Safety System Setting (LSSS) as defined in TMI Unit 1 TS 2.3

" The VLPT initiates an automatic reactor trip

" The VLPT provides reactor protection for the core safety limits contained in TMI Unit 1 TS Figure 2.1-1, which ensure margin to core DNBR limits

ArnerGea, An Exelon Company VLPT Setpoint Methodology

  • As-Found Setpoint Evaluation

- If the as-found Trip Setpoint exceeds the Limiting Setpoint, declare VLPT channel inoperable

- If the as-found Trip Setpoint exceeds the predefined limits, determine if the instrument is functioning as required prior to returning the VLPT channel to service. If it cannot be determined that the instrument is functioning as required, declare VLPT channel inoperable.

- If the as-found Trip Setpoint exceeds the predefined limits, the condition must be entered into the Corrective Action program

  • As-Left Setpoint Control

- Instrument will be left within the setting tolerance band 17

AMerGenci)

An Exelon Company VLPT Setpoint Methodology Proposed TS and TS Bases Changes to address setpoint methodology

- Table 4.1-1 specifies required actions regarding response to as-found/as-left criteria

  • Actions similar to those proposed in TSTF-493.

- TS Section 4.1 Bases specifies that the UFSAR incorporates by reference the document that contains the following:

" Limiting Trip Setpoint

  • Methodology used to determine the Limiting Trip Setpoint, pre-defined as-found acceptance criteria band, and as-left setpoint tolerance band

- TS Section 4.1 Bases specifies the definition of the pre-defined as-found acceptance criteria band for the VLPT 4 n*

AmurGen, An Exelon Company

.

VLPT Setpoint Methodology Sample of Variable Low Pressure Trip (VLPT) Setpoints and Calibration Criteria 1990 ---

, 4, 1970 1970. VLPT Pre-defined As-found Tolerance Band -'

VLPT As-left Tolerance Band 0.

1950 - 00, , "S High Temp Trip CL VLPT Nominal Setpoint (NSP) cr1930-

- djusted TS VLPT 1910-- - - 4 ~- S VLPTr LSSS Setpoint 1910. -

Trp TSLow'S Tri.

1890 -" '

612 613 614 615 616 617 618 619 Thot

.4r %

An Exelon Company Summary

  • Mark-B-HTP design provides improved fuel reliability

" NRC approved Reload Topical Report and methodologies used for Cycle 17 core reload design

  • Revised VLPT provides required safety margin and does not challenge plant operation
  • NRC approved methodology used to determine VLPT safety limit
  • VLPT parameters established based on ANSI/ISA-67.04
  • VLPT predefined limits determined based on NRC RIS 2006-17
  • TS & TS Bases changes similar to recent NRC approved VLPT amendment for B&W plant design
  • TMI Amendment requested to support Cycle 17 startup

An Exelon Company Questions / Feedback 011

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