ML12249A454
| ML12249A454 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 08/31/2012 |
| From: | Office of Nuclear Reactor Regulation |
| To: | Division of License Renewal |
| References | |
| Download: ML12249A454 (21) | |
Text
1 LimerickNPEm Resource From:
Milano, Patrick Sent:
Friday, August 31, 2012 2:06 PM To:
Christopher.Wilson2@exeloncorp.com Cc:
LimerickHearingFile Resource
Subject:
Limerick ACRS SC Slides - Revised Draft Attachments:
Limerick ACRS SC Mtg 09-05-12 R5.pdf This is the latest version of the draft presentation.
Hearing Identifier:
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Limerick ACRS SC Slides - Revised Draft Sent Date:
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8/31/2012 2:06:20 PM From:
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Safety Evaluation Report (SER) with Open Items Limerick Generating Station, Units 1 and 2 Issued: July 31, 2012 Advisory Committee on Reactor Safeguards License Renewal Subcommittee 1
September 5, 2012 Patrick Milano, Sr. Project Manager Office of Nuclear Reactor Regulation Safety Evaluation Report (SER) with Open Items Limerick Generating Station, Units 1 and 2 2
Presentation Outline
Overview of Limerick license renewal review
SER Section 2, Scoping and Screening review
Region I License Renewal Onsite Inspection
SER Section 3, Aging Management Programs and Aging Management Review Results
SER Section 4, Time-Limited Aging Analyses 3
Facility Facts
License Renewal Application (LRA) submitted June 22, 2011
Applicant: Exelon Generation Company, LLC (Exelon)
Facility Operating License Nos. NPF-39 and NPF-85
Docket Nos. 50-352 and 50-353
Current License Expiration Dates: October 26, 2024, and June 22, 2029
Requested renewal period of 20 years beyond the current license dates
Approximately 21 miles northwest of Philadelphia, PA
BWRs (GE 4) with Mark II containment design 4
Audits and Inspections
Scoping and Screening Methodology Audit
- September 19-23, 2011(report December 9, 2011)
Aging Management Program (AMP) Audit
- October 3-14, 2011 (report February 28, 2012)
Region I Inspection (Scoping and Screening & AMPs)
- June 4-21, 2012 (report July 30, 2012)
Environmental Review Audit
- November 7-10, 2011 5
Overview (SER)
Safety Evaluation Report (SER) with Open Items issued July 31, 2012
SER contains 2 Open Items (OIs):
- Suppression Pool Liner and Downcomer Corrosion
- Operating Experience
Final SER is tentatively expected to be completed in January 2013 6
SER Section 2 Summary Structures and Components Subject to Aging Management Review
Section 2.1, Scoping and Screening Methodology
Section 2.2, Plant-Level Scoping Results
Sections 2.3, 2.4, 2.5 Scoping and Screening Results 7
Six inspectors over three weeks
10 CFR 54.4(a)(2) inspection
32 of 45 Aging Management Programs Reviewed Overview Regional Inspections 8
Systems in the Units 1 and 2 Reactor Enclosures
Systems in the Units 1 and 2 Turbine Enclosures
Essential Service Water pipe tunnel
2A Emergency Diesel Generator Room
Battery Rooms
Refueling Floor
Control Room
Unit 1 and 2 Spray Pond Structure
Compressed Air System
Turbine Building, Containment Building, Diesel Generator Building, and Intake Structures
Metal Enclosed Buses Walk-downs Regional Inspections 9
Scoping of non-safety SSCs and application of the AMPs to those SSCs were acceptable.
Inspection results support a conclusion that reasonable assurance exists that aging effects will be managed and intended functions maintained Inspection Conclusions Regional Inspections 10
Calvert Cliffs June 1998
Peach Bottom May 2002
Ginna June 2003
Millstone July 2004
Nine Mile February 2005
Oyster Creek March 2006
Pilgrim September 2006
Vermont Yankee February 2007
Fitzpatrick April 2007
Indian Point January 2008
Beaver Valley June 2008
Susquehanna August 2008
Three Mile Island December 2008
Salem Hope Creek June 2010
Seabrook April 2011
Limerick June 2012 All Region I Plants Inspected for Renewal Regional Inspections 11
Section 3: Aging Management Review
Section 3.0 - Use of the GALL Report
Section 3.1 - Reactor Vessel & Internals
Section 3.2 - Engineered Safety Features
Section 3.3 - Auxiliary Systems
Section 3.4 - Steam and Power Conversion System
Section 3.5 - Containments, Structures and Component Supports
Section 3.6 - Electrical and Instrumentation and Controls System 12
SER Section 3
3.0.3 - Aging Management Programs
- 45 Aging Management Programs (AMPs) presented by applicant and evaluated in the SER
-No plant-specific AMPs 13
Open Item 3.0.3.2.13-1 ASME Section XI, Subsection IWE
Corrosion in suppression pool carbon steel liner
- General corrosion of liner up to 35 mils in depth, and affecting up to 72% of surface area in some liner panels
- Pitting up to 122 mils deep
- Method for augmented inspection to measure loss of liner material
Degradation of liner coating
- Existing coating is inorganic zinc material, 6-8 mils thick
- Adequacy of criteria for selecting locations for recoating
- Effective identification of degradation in liner plates underwater
Identification of acceptance criterion for downcomer corrosion SER Section 3 Open Items 14
Proposed Enhancement to IWE AMP Concerning Suppression Pool Liner Plate Degradation
Remove any accumulated sludge in suppression pool every refueling outage
Examine submerged portion of suppression pool every ISI period
Use results of examination to implement coating maintenance plan
- Perform local recoating of areas with general corrosion that exhibit greater than 25 mils loss in plate thickness
- Perform spot recoating of pitting greater than 50 mils deep
- Recoat plates with greater than 25 percent coating depletion
Coating Maintenance Plan will be implemented for the selected areas in a phased approach starting in 2012 Open Item 3.0.3.2.13-1 15
Corrosion of liner Pitting corrosion rates are much higher than general corrosion, are unpredictable, and could result in a leak in liner over time Use of depth gage under water to measure pitting with extensive general corrosion present Effective technique to measure remaining thickness of liner plates
Coating Degradation Managing aging effects due to corrosion and pitting by phased approach of selective recoating of corroded liner areas Underwater liner plate coating beyond its service life Basis for using 25% loss of coated area to classify affected area requiring augmented inspection Open Item 3.0.3.2.13-1 16
SER Section 3.0.5 Operating Experience for Aging Management Programs (OI 3.0.5-1)
Applicant identified several areas where enhancements to operating experience review activities are necessary
Applicant plans to implement these enhancements within two years of receipt of the renewed operating licenses
Given this schedule, it is not clear whether operating experience related to aging management and age-related degradation will be adequately considered in the period between issuance of the renewed licenses and implementation of the enhancements SER Section 3 Open Items 17
4.1 Introduction
4.2 Reactor Vessel Neutron Embrittlement
4.3 Metal Fatigue Analysis
4.4 Environmental Qualification of Electrical Equipment
4.5 Concrete Containment Tendon Prestress Analysis
4.6 Containment Liner Plate, Metal Containments, and Penetrations Fatigue Analysis
4.7 Other Plant-Specific TLAAs SER Section 4: TLAA 18
On the basis of its review and pending satisfactory resolution of the open items, the staff will be able to determine that the requirements of 10 CFR 54.29(a) have been met for the license renewal of Limerick Generating Station Conclusion 19