ML021140225
ML021140225 | |
Person / Time | |
---|---|
Site: | Summer ![]() |
Issue date: | 04/08/2002 |
From: | South Carolina Electric & Gas Co |
To: | Office of Nuclear Reactor Regulation |
Shared Package | |
ML021140207 | List: |
References | |
Download: ML021140225 (48) | |
Text
REFUEL 13 April 8, 2002 Pre-Outage Presentation
Agenda
- General Introduction and Plant Status (Greg Halnon)
- Outage Overview (Alan Torres)
- Major Modifications
- Major Maintenance
- Shutdown Safety
- Major Efforts (Gary Moffatt)
- Hot Leg Follow-up
- MSIP
- I&C Modernization (Steven Fipps)
- Main Feedwater Pump Controls
- Alterrex Voltage Regulator
- Closing Comments (Steve Byrne)
Refuel 13 Overview A D Torres, Manager of Outage & Work Controls
Refuel 13
- Duration
- Approximately 33 Days
- Cost
- Budgetary Goal Is $12.3 Million
Refuel 13
- Number 1 Outage Goal
- Safety
- Nuclear
- Industrial
- Radiological
Refuel 13
- Whats in Our Outage (7000 Items)
- Modifications
- Non-conformance Notices /Condition Evaluation Reports
- Maintenance Work Requests
- Preventive Maintenance
- Surveillance Tests
- Support Activities
Refuel 13
- Critical Path
- Shutdown
- RV Disassembly
- Core Off-Load
- CCW Exchanger Repair
- Core Reload
- Startup
Refuel 13
- Modifications
- FWP Digital Controls
- Excitation Upgrade
- MSIP Process
- Reroute of Condenser Transmitter Lines
- RHR Miniflow Switch Relocation
- D/G Day Tank Level Instruments
- D/G Air Start Receiver Relief Valve
Refuel 13
- Modifications
- D/G Fuel Oil Strainer Sensing Lines Redesign
- Replacement of RB Component Cooling Isolation Valve (XVC-9689CC)
- FWP Drain Isolation Valve
- Dynamic Brake for Refueling Bridge
- S/G Cover Modification
- FW Heater Instrumentation Manifold Rework
Refuel 13
- License Amendments
- Amendment 154 - Pressure Isolation Valve Leakage Allowance
- Amendment 155 - Corrects Reactor Trip Settings for Main Steam Safety Valve Testing
- Amendment 156 - Provisions for Performing RTD Cross-calibration With MSIVs Closed
- Amendment 157 - Requires High Flux Reactor Trips Be Operable for Rod Withdrawal in Source Range (NSAL 01-016)
- Amendment 158 - Extends Elimination of Response Time Testing for Additional 7300 Process Cards
Refuel 13
- PRA Review of Modifications
- None of These Projects will Increase the Long Term Risk at VCS
- The DG fuel oil instrumentation and the RHR sensing modifications will have an elevated risk due to major component out of service, but manageable under 10CFR50.65a(4)
Refuel 13
- Major Maintenance Work
- Major FWP Work: 3 Pumps/1turbine
- CCW Heat Exchanger Repair
- 2 Reactor Coolant Pump Seal Jobs
- Repair of Steam Generator Sludge Covers
- Flow Accelerated Corrosion Inspection and Pipe Replacement
- Condenser and Heat Exchanger Cleaning
- Reactor Vessel Head Inspections
Refuel 13
- Potential Issues
- RCS Hot Leg Nozzle Inspection
- FWP Digital Modification
- Scope of CCW Heat Exchanger Repair
- RBCU Testing
- Startup Testing
Refuel 13
- Why Are They Potential Issues
- Schedule Impact High
- Potential Startup Delays
- Repair Scope Unknown
- Personnel Hazard
Refuel 13
- Dealing with Risks
- Contingency Planning
- Potential Repair Plans Developed
- Employing HIT Team Project Mentality
- Evaluating Additional Options
Refuel 13 Relative Risk Profile 9" below flange 6
230 kV 9" below 115 kV Outage flange Outage 5
1 DB Outage flange level 4 230 kV Back in Service, Core "B" Train Offloaded "A" Outage 3
RCS 2 Flooded Up, Intact Depresurrize "A" Train RCS Outage 1 "A" Train "B" Train in 1DB In service Upper Internal In service 115 kV In Installed Core re-loaded service 0 4/20/2002 4/24 4/25 4/28 5/5 5/6 5/7 5/11 5/12 5/14 5/16 5/20 5/18
Reactor Coolant Hot Legs &
Reactor Vessel Head Gary Moffatt, Manager of Design Engineering
B & C Hot Leg Plan:
Mechanical Stress Improvement Process (MSIP)
VC Summer RF 12 Relevant Indications A Loop Hot Leg - New Weld with Alloy 690 Material A,B, &C Cold Legs - WCAP 15615 > 25 years (Low Temperature = Low Stress)
HOT LEG LOOP LOCATION LENGTH ORIENTATION (EDDY CURRENT)
C 309/CIRC 0.5 B 35/CIRC 0.6 B 200.8/AXIAL 0.25 B 348/AXIAL 0.25
B & C Hot Leg NDE Plan
- ET Indications From RF-12 will Be Scrutinized by Axial and Circumferential ET.
- Screening Criteria will Be Applied to ET Indications.
- Flaws will Be Characterized by UT.
- Our Expectation: We will See the Same Indications
- NDE Inspection Before & After Mitigation Application
MSIP Principle MATERIALS ENVIRONMENT MATERIALS ENVIRONMENT CONDITIONS FOR STRESS TENSILE STRESS RELATED CRACKING EXIST Sr Sy (a) AS WELDED TENSILE STRESS Sr << Sy (b) AFTER MSIP Removal of Tension Provides Permanent Protection of Weldments Against Stress Related Cracking
Mechanical Stress Improvement Process - MSIP
- Invented, Developed, and First Used in 1986
- Mitigates Stress Related Cracking in Nuclear Reactor Plant Piping Weldments
- Permanently Removes Weld Residual Tensile Stresses and Generates Compressive Residual Stresses
- Displacement Controlled - Verifiable by Measuring Pipe Hoop Contraction
Basic Concept Of MSIP
- a. Application of Pressure to Contract Pipe
- b. Schematic of Permanent Deformation after MSIP
- c. Mechanism of Compression
- Generation in Axial and Hoop Directions
- Deformation in pictures are exaggerated for viewing purposes
V. C. Summer Hot Leg Nozzle Weld Region V. C. Summer Hot Leg Nozzle As-welded Residual Stress (Axial)
V. C. Summer Hot Leg Nozzle Weld Post-MSIP Residual Stress (Axial)
MSIP Experience
- Used Since 1986 on Over 1300 Welds Including more than 500 Nozzle and Safe-End Welds in Over 30 BWR Units Worldwide
- Applied to Welds Without and With Stress Corrosion Cracks
- No Indications Found in Treated Welds
- Pre-existing Cracks Arrested; No Crack Growth after MSIP During Subsequent Fuel Cycles
- Verified by Argonne National Laboratory and EPRI for Pipe Specimens and Nozzle Specimens Without and With Cracks
MSIP Acceptance Criteria And Repair Contingency
- Nureg 0313 Acceptance Criteria
- < 10% of the Circumference
- < 30% of the Wall Thickness
- Code Repairs for Flaws > MSIP Acceptance Criteria
- Localized Repair
- Weld Replacement
- Spool Piece Replacement
- MSIP After Code Repair
MSIP Qualification Mock-up For VC Summer Rigging Upper Clamp Into Position MSIP Clamp In Place In VC Summer Mock-up Hot Leg Surface After Qualification Test Hot Leg Plan Conclusions
- Inspection Plan Is Sound / Effective
- MSIP - Effective Aging Management Preventive / Mitigative / Repair Process for the B & C Hot Legs
NRC Bulletin 2002-01 Reactor Vessel Head Degradation
- Vessel Head Inspection & Maintenance Programs -
Defense in Depth
- Corner Stone: Prevent / Manage Leaks Above the Head
- Programs Have Been Effective & Meet the Regulatory Requirements
- Very Low Susceptibility to CRDM Penetration Cracking
- 2 Very Minor Conoseal Leaks W/ Minor Boric Acid
- No Boric Acid on the Insulation or Head
- Best Effort Remote Visual Inspection Under the Insulation in RF 13
Refuel 13 I&C Modernization Steven F. Fipps, Design Engineering Supervisor &
I&C Modernization Committee Chairman
Driving Issues
- Reliability and Availability
- Operating Costs
- Obsolescence
- Improved Operational Performance
- Staff Utilization
Modernization History Phase I
- Start With BOP NNS Systems
- Choose a Standard Platform
- Identified Training Needs
- Establish Implementation Schedule
- Apply Lessons Learned
Implemented Digital Control Modifications
- Turbine Building Closed Cycle Cooling
- Moisture Separator Reheater Controls
- Feedwater Heater Vents and Drains
DCS Modifications Lessons Learned
- No Problems With Digital
- Improved Problem Identification and Resolution
- Improved Control & Mitigation of Transients/events
- Fewer Initiating Events
- Improved System Redundancy
- Operator Simulator Training - High Priority
Refuel 13 I&C Modernization
- Main Feedwater Pump Digital Speed Control
- Main Electrical Generator Alterrex Digital Voltage Regulator
Main Feedwater Pump Digital Speed Control Why
- Obsolescence of Existing Controls
- Maintenance Cost Increasing
- System Reliability What
- Replace Analog Controller With Bailey (ABB)
INFI-90 Digital Control System
- Replace Mechanical Controller With Hydraulic Servo Actuator
- Upgraded Turbine Supervisory Instrumentation
- Upgrade FWP Re-circulation Valve Control
Main Feedwater Pump Digital Speed Control (Benefits)
- Improved Operator Controls and Indication
- Reduced Maintenance Cost
- Improved Reliability & Availability
- Improved Operational Performance
- Improved Human Factors
- Improved Problem Identification
- Improved Mitigation of Events
Main Electrical Generator Alterrex Digital Voltage Regulator Why
- Obsolescence of Existing Controls
- Maintenance Cost Increasing
- System Reliability
- Operational Performance What
Main Electrical Generator Alterrex Digital Voltage Regulator (Benefits)
- Improved Problem Identification
- Reduced Maintenance Cost
- Improved Reliability & Availability
- Improved Operational Performance
- Improved Human Factor
Feedwater Heater Vents And Drains Instrumentation Manifold (Follow-up)
Why
- System Reliability
- Operational Performance What
- Re-pipe the Instrumentation Manifolds
- Replace Globe Valves With Ball Valves
Feedwater Heater Vents And Drains Instrumentation Manifold (Benefits)
- Reduced Maintenance Cost
- Improved Reliability & Availability
- Improved Operational Performance
- Improved Mitigation of Events
I&C Modernization Phase II
- Control Room Review
- Main Turbine EHC Control
- Radiation Monitoring
- Moduflash Control Room Display Unit
- Plant Process Computer
- DA/hotwell Level Control
- ESF D/G Digital Controls
- Digital Rod Position
- 7300 Process Racks (ASICS)
Closing Remarks Steve Byrne, Senior Vice President of Nuclear Operations