ML021140225

From kanterella
Jump to navigation Jump to search
Refuel 13, April 8, 2002 Pre-Outage Presentation
ML021140225
Person / Time
Site: Summer South Carolina Electric & Gas Company icon.png
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)
v • d • e


Text

REFUEL 13 REFUEL 13 April 8, 2002 April 8, 2002 Pre-Outage Presentation 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

- NRC Bulletin 2002-01

  • 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

0 1

2 3

4 5

6 Refuel 13 Relative Risk Profile Depresurrize RCS 9" below flange flange level Flooded Up, "A" Train Outage Core Offloaded "A" "A" Train In 230 kV Outage 230 kV Back in Service, "B" Train Outage "B" Train in service Core re-loaded 1 DB Outage 1DB In service Upper Internal Installed 9" below flange RCS Intact 115 kV Outage 115 kV In service 4/20/2002 5/20 5/5 4/28 4/25 4/24 5/12 5/11 5/7 5/6 5/14 5/18 5/16

Reactor Coolant Hot Legs &

Reactor Vessel Head Gary Moffatt, Manager of Design Engineering

B & C Hot Leg Plan:

Mechanical Stress Improvement Process (MSIP)

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 VC Summer RF 12 Relevant Indications

B & C Hot Leg NDE Plan

  • UT Examination Complemented by ET Examination.
  • ET Indications From RF-12 will Be Scrutinized by Axial and Circumferential ET.
  • Whole Weld will Be Examined by Circumferential UT and 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

TENSILE STRESS Sr Sy MATERIALS ENVIRONMENT TENSILE STRESS Sr << Sy ENVIRONMENT (a) AS WELDED (b) AFTER MSIP MATERIALS Removal of Tension Provides Permanent Protection of Weldments Against Stress Related Cracking MSIP Principle CONDITIONS FOR STRESS RELATED CRACKING EXIST

- 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 Mechanical Stress Improvement Process - 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 Basic Concept Of MSIP

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)

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 Experience

MSIP Acceptance Criteria And Repair Contingency

- < 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
  • Arrangements With NRR for Rapid Inspection Results Communication and SER Turn Around

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
  • 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

DCS Modifications Lessons Learned

  • No Problems With Digital
  • Improved Problem Identification and Resolution
  • Improved Control & Mitigation of Transients/events
  • Improved System Redundancy
  • Operator Simulator Training - High Priority

Refuel 13 I&C Modernization

  • 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
  • Replace GE Analog Alterrex Voltage Regulator With a GE Digital Alterrex Voltage Regulator

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

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
  • 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

Retrieved from "https://kanterella.com/w/index.php?title=ML021140225&oldid=5439937"