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
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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

MELLLA+

Attendees AI Williams Project Manager - EPU & MELLLA+

Steve Hammer Project Manager Lynne Gunderson Projects Licensing Manager Doug Blair Licensing Support Ralph Hayes Licensing Support Juswald Vedovi GE-Hitachi Nuclear Energy Mike Lalor GE-Hitachi Nuclear Energy 2

MELLLA+

Agenda

• Meeting Purpose

• Background

• Overview of MELLLA+

• Regulatory Discussion

• LAR Overview

• TS Changes

• Schedule

• Discussion 3

MELLLA+

Meeting Purpose

• Common understanding of the proposed scope of the MELLLA+ LAR

• Discuss Schedule

• Concurrent review with EPU 4

MELLLA+

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

MELLLA+

BackfJround Core Flow (% of Rated}

0 10 20 1) 40 50 60 70 80 90 100 110 120 120 Power Flow 110 A 'l.n ~+.l1I>

100% CLTP = 2004 M\IIJI ..... ~ . " " .,. ~  ; , '..... . -" ..

i 100% CLTP = 1670 MWI B lO.n; ~5'.5'~ MEI.l.LA+ Openting Domain BoundaIy 2004 MWt 100% Core Flow= 57.6 Mlbm/hr C '5' .l1I> +~.~~ i i q

.... ~ ..*~.~ ..*...... ; .K.. .*..}*..... 2000 100  : ~ :L

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• I o 5 10 15 20 25 30 35 40 45 50 55 60 65 Rated Care Flow CMlbmlhr) 6

MELLLA+

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

MELLLA+

Overview of MELLLA+

Expands Operating Domain

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

• Changes stability solution

• Current stability solution

- Option III

• Proposed stability solution

- Detect and Suppress Solution - Confirmation Density (DSS-CD) 8

MELLLA+

Regulatory Discussion LTR Compliance to Support Request

• MELLLA+: primary topical for MELLLA+

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

• TRACG: topical supporting use for DSS-CD

• Methods LTR: topical for application of GEH methods for expanded operating domains (EPU & MELLLA+)

9

MELLLA+

Regulatory Discussion (cont'd)

M+ LAR Use of Safety Evaluations for Topicals

• Compliance with applicable limitations

• Taking no exceptions to LTR requirements 10

MELLLA+

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 LTR

• 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

MELLLA+

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

MELLLA+

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

MELLLA+

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

MELLLA+

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

MELLLA+

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

MELLlA+

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

MELLLA+

Proposed TS Changes (cont'd)

• TS 5.6.3, "Core Operating Limits Report (COLR)"

-Add DSS-CD requirements for the COLR

-Update analytical methods references

• TS 5.6.5, "Reporting Requirements"

-Add OPRM oas reporting requirements 18

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MELLLA+

2008 2009 2010 2011 2012 Key:

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=NRC Approval A = Implementation

, EPU Evaluatiqn &

LAR PreparatIon

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MELLLA+/ DSS-CD Stability Solution NRC Review LAR Preparation EPU Escalation ~o 2004 MW C24 Refueling C25 Refueling C26 Outage Outage EPU Phase I EPU Phase II oalTlcatlons oalTlcatlons 20

MELLLA+

Conclusion

• LAR complies with applicable limitations

• LAR takes no exceptions to LTR requirements

• Proposed submittal date of January 2010

• 12-month review requested 21

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