ML093490876

Meeting Slides from December 15, 2009 - Mellla+ LAR

ML093490876
Person / Time
Site:	Monticello
Issue date:	12/15/2009
From:	Gunderson L Xcel Energy
To:	Office of Nuclear Reactor Regulation
Tam P S
Shared Package
ML093451640	List: ML093490876
References
TAC ME2449
Download: ML093490876 (23)

Text

MELLLA+ LAR I I Maximum Extended Load Line Limit Analysis Plus Monticello Nuclear Generating Plant December 15, 2009 1 Attendees AI Williams Steve Hammer Lynne Gunderson Doug Blair Ralph Hayes Juswald Vedovi Mike Lalor Project Manager -EPU & MELLLA+ Project Manager Projects Licensing Manager Licensing Support Licensing Support GE-Hitachi Nuclear Energy GE-Hitachi Nuclear Energy 2 Agenda

• Meeting Purpose

• Background

• Overview of MELLLA+

• Regulatory Discussion

• LAR Overview

• TS Changes

• Schedule

• Discussion 3

Meeting Purpose Common understanding of the proposed scope of the MELLLA+ LAR Discuss Schedule Concurrent review with EPU 4 Background BWR Operation

• Maintain reactivity balance to accommodate fuel burn-up

• Control Rod Movements

• Core Flow Adjustments

-preferred method

• EPU decreases available core flow window at rated power

• Without M+ >99% core flow required to operate at uprated power

• M+ justifies

>800/0 core flow to operate at uprated power 5 120 110 i 100 90 oo:fI 0 0 80 10 60 50 P-t 40 0 30 20 10 ------_C-----_C_---:::_ _* : : ::::: T:-:_J::::::::r::::::::

L:::::-:-:::: T:--::::::::

-----------f ______ o A B C D E F G H I J K L M N . NaturalCirculation

' ...... .:

B: : ..: *ff" ;. j (.. * :::: . 0* I 10 Power 'l.n lO.n; '5'.l1I>

100.0" 100.0" 100.0" 10.1." 20 Flow

10'.0" 111.+" 10'.0" ".n ".+" Core Flow (% of Rated} 1) 40 50 60 70 80 90 100 110 120 1 00% CLTP = 2004 M\IIJI ..... .." " .,.  ;, '..... .. -" .. 100% CLTP = 1670 MWI MEI.l.LA+

Openting Domain BoundaIy 2004 MWt 100% Core Flow= 57.6 Mlbm/hr .... ..*..*......; .K...*..}*.....i i q 2000 : :L * ................

_ .... .. _ ..........

-_:.. -or"" __ .. __; ...... Cumnt Licensed Boundazy MEU.l.A Operating 1500 ., .. -:---:-":-.. .. *" N'  : : Q ******* ********.J ****1****

\ i **.*.*. P-t*, .*, . Cil': Increased Core : .-.;-----.--.

--.--------Flow Region .:.:..:..::.

.......*.... . -...Minimum Pump St:>eed :  :..; 'G' : ':""'" J :: J:*. . ..+ + -+

.**-_ [ 500 o 5 10 15 20 25 30 35 40 45 50 55 60 65 Rated Care Flow CMlbmlhr) 6 Background (cont'd) Benefits of Adopting MELLLA+

• Improved Operational Flexibility

• Increased Core Flow Range at Rated Power

• Decrease in Rod Pattern Changes to Compensate for Fuel Burnup

• Safer Operation with Fewer Control Rod Manipulations

• Minimizes likelihood of fuel failures

• Reduces the likelihood of accidents initiated by reactor maneuvers 7

Overview of MELLLA+ Expands Operating Domain

• Allows operation at 2004 MWt with >80% core flow

• Changes stability solution Current stability

-Option Proposed stability solution -Detect and Suppress Solution -Confirmation Density (DSS-CD) 8 Regulatory Discussion L TR Compliance to Support Request

• primary topical for MELLLA+ DSS-CD: topical for change in stability solution required for MELLLA+

• topical supporting use for DSS-CD Methods L TR: topical for application of GEH methods for expanded operating domains (EPU & MELLLA+) 9 Regulatory Discussion (cont'd) M+ LAR Use of Safety Evaluations for Topicals

• Compliance with applicable limitations

• Taking no exceptions to L TR requirements 10 Regulatory Discussion (cont'd)

• MELLLA+ SAR Core, Fuel Performance and Thermal Limits evaluation in SAR and with core reload evaluations supporting COLR consistent with SER for L TR No significant effect on: Reactor Coolant System Engineered Safety Features Electrical Power and Auxiliary Systems Power Conversion Systems Radwaste Systems and Radiation Sources Design Basis Accidents and Events 11 Regulatory Discussion (cont'd)

• MELLLA+ SAR ATWS Event Evaluated with Significant Margin to acceptance criteria

• Response to Core Instability Event acceptable

• Monticello EOP actions effectively mitigate Stability

• DSS-CD would replace Option III as stability solution

• Automated Backup Stability Protection (SSP) would provide backup solution 12 Regulatory Discussion (cont'd)

• Probabilistic Risk Assessment

• Core Damage Frequency increase of 7.36E-08/yr

• Large Early Release Frequency increase of 1.62E-08/yr

• Both within Region III range of Regulatory Guide 1.174

• TSTF-493 13 LAR Overview License Amendment Request Outline

• Enclosure 1

• Standard Content

• Attachments to Enclosure 1 1. Technical Specification Markup 2. Technical Specification Bases Mark-up for information

3. Re-typed TS pages 4. MELLLA+ Safety Analysis Report (M+SAR) Proprietary

5. Affidavit supporting proprietary M+SAR 6. MELLLA+ Safety Analysis Report (M+SAR) Non-Proprietary

7. Monticello MELLLA+ Risk Assessment 14 Proposed TS Changes

• TS 3.3.1.1, "RPS Instrumentation ACTIONS"

• ACTION I Addresses OPRM Inoperability:

• Backup Stability Protection (BSP) -Implement Manual BSP Regions AND -Implement Automated SSP -Implement Reporting Requirements

• ACTION J Addresses inability to Implement ACTION I: -Implement Manual SSP Regions AND -Reduce Operation to below the BSP Boundary 15 Proposed TS Changes (cont'd) TS SR 3.3.1.1.16 OPRM not bypassed -Delete unnecessary surveillance requirement TS Table 3.3.1.1-1 APRM STP-High -Change APRM STP Function 2.b Allowable Value -Add note (d) for OPRM Function 2.f inoperable TS Table 3.3.1.1-1 OPRM Upscale -Add note (h) for OPRM Function 2.f implementation 16 Proposed TS Changes (cont'd) TS LCO 3.4.1, "Recirculation Loops Operating" -Prohibit SLO in M+ Domain TS LCO 3.4.3, "Safety/Relief Valves (S/RVs)" -Restrict number of inoperable S/RV in M+ Domain Update associated TS Bases 17 Proposed TS Changes (cont'd) TS 5.6.3, "Core Operating Limits Report (COLR)" -Add DSS-CD requirements for the -Update analytical methods TS 5.6.5, "Reporting Requirements" -Add OPRM oas reporting requirements 18

..J ..J ..J W o o N CO ::::J C CO J 0) +-II CO -"'C CO..c ::::J CJ) "'C 0) CJ) O s.... 0)0) s.... ..c +-II C I N +-II CJ) 0) ::::J 0) 2009 2011 2008 2010 2012 , EPU Evaluatiqn

& LAR PreparatIon " I* I.. MELLLA+/ DSS-CD Stability Solution NRC Review LAR Preparation Refueling C25 Outage EPU Phase I oalTlcatlons C24 EPU Escalation 2004 MW Refueling Outage EPU Phase II oalTlcatlons Key: "Y'= Submittal

=NRC Approval A= Implementation C26 20 Conclusion

• LAR complies with applicable limitations

• LAR takes no exceptions to L TR requirements

• Proposed submittal date of January 2010

• 12-month review requested 21

-I -I -I W CI)