EPRI Plenary Session Circuit Breaker Users Group Briefing

Transcription

1 EPRI Plenary Session Circuit Breaker Users Group Briefing Jim Sharkey Senior Project Manager Circuit Breaker Users Group Meeting June 16, 2010 Columbia, SC

2 Operating Experience: Bus Events Columbia; August 2009; Failed catastrophically in the location of a flexible link. Al Sperling to discuss Palo Verde; March 2010; Fault and unit trip; Robinson; November 2009; Administrative control of grounding devices. Generator Breaker Failures VC Summer; October, 2009; B-phase did not open properly and was damaged. Millstone; December 2009; Extensive damage to C- phase. Cause attributed to manufacturing defect. 2

3 Operating Experience: April 2009; Smoldering fire in MCC; Cause attributed to failure to generate preventative maintenance plans for the replacement of the main contactors due to age related degradation July 2009; Lesson Learned for the Industry: Classification of MCUs and MCCBs should be performed based on the protective function of the breaker for the upstream bus, and not on load. Breakers inappropriately reclassified as Run-To-Failure (RTF) based on review of respective loads they feed. Failure of these breakers results in a trip of the upstream feeder breaker and a loss of all (safety related) loads supplied by the respective upstream Motor Control Center (MCC). 3

4 Working Groups Report Working Groups Report Bus maintenance; Jim Sharkey MCC maintenance; Jim Sharkey New Breaker specialist training; Chris Kowal ABB working group; Pete Pawlak 4

5 Action Items Completed Website update: Completed All meeting materials and minutes are listed by year, then by meeting (Breaker type). ABB K-Line PM Working Group meeting held in May to revise the K-Line PM guide; Progress made Prior issues and resolutions documented by Pete Pawlak s ABB Working Group CBUG Issues Brief; Posted on the website Breaker-specific conference calls held in April 5

6 Action Items Completed Updating industry list of circuit breaker primary plant contacts Process developed for storing procedures for benchmarking purposes on EPRI Collaboration Website Located on the main tabs at top of EPRI s home page Primary benefit: Ability to upload and download documents. Please forward your plant procedures to me or upload them yourself. Added day of working group meetings to meeting format 6

7 Action Items No Progress Made Rescinding specific-sections of NP-7410 documents Magne-Blast overhaul video Training None developed Proposed topics: Electrical Testing; Time Current Curves and Set-points; Bus Maintenance/Inspection; Other? 7

8 Circuit Breaker Users Group Briefing EPRI Focus areas: Bus maintenance MCC maintenance and replacements Breaker working groups; EPRI document review Distribution System - Unchanged Status of industry survey Breaker Populations, PM/Overhaul intervals, etc. Updated in 2008 and 09, but not in

9 Circuit Breaker Users Group Briefing Questions to the group: Verbal Generator circuit breaker survey Any recent NRC or INPO attention? Format of future meetings Future meetings: Dates and potential locations 9

10 Working Group Meeting Held Today Working Groups June 14, 2010 Morning Sessions ABB HK and K-Line; Pawlak; Palmetto I MCC-MCCB maintenance; Sharkey; Palmetto II Afternoon Sessions Bus maintenance; Sharkey; Palmetto I New Breaker specialist training; Kowal; Palmetto II 10

11 MCC-MCCB Maintenance Considerable industry interest and questions over the years on MCC maintenance and replacements. No EPRI guidance exists on maintenance or replacements. The need appears to exist due to the level of interest and questions. Significant issues/needs (based on input) are : MCC maintenance best practices need to be documented Replacement information repository is needed. Working Group tasks? Verify, modify and document industry issues and needs. 11

12 Electrical Bus; NRC Information Notices IN ; Brunswick Bolts were over-torqued. Re-torque of bolts may not be adequate to ensure continued service; replacement may be necessary. IN ; Point Beach Bus fault due to lack of maintenance and inspection, insulation degradation, condensation. IN ; Diablo Canyon Catastrophic failure. Center bus bar overheated at splice joint IN ; ANO Bus fault and fire. Inadequate design of aluminum bus bars and questionable engagement of stabs into bus. 12

13 Electrical Bus; Other Notices OE 26979, Salem (May 2008) Fault and load reduction due to water intrusion. OE 28305; Browns Ferry (August 2008) Buswork fault and load reduction on all three units OE 29557; Columbia (August 2009) Non Segregated bus failed catastrophically in the location of a flexible link. OE 30775; Palo Verde (March 2010) Fault of 13.8 kv Non-Class Calvert Bus Results in Reactor Trip OE?????; Robinson (March 2010) Catastrophic failure 13

14 Electrical Bus; Other Notices OE 28740; Limerick Fault and load reduction due to mis-positioning of conductor. Root cause: Diagonal entry of conductor into the receiving saddle of the MCCB. Others? INPO O&MR

15 Electrical Bus Maintenance / Monitoring EPRI existing guidance EPRI , Bus Maintenance Guide EPRI , Iso-Phase Bus Maintenance Guide What additional guidance is needed? What are life-cycle management considerations? What bus monitoring technologies are available? 15

16 Electrical Bus Maintenance / Monitoring EPRI Proposed Project for later half of 2010/2011: Investigate bus maintenance techniques and determine if the current recommended and/or accepted maintenance programs are sufficient for the world s existing fleet of nuclear plants, assuming long term operation in excess of 40 years? 16

17 Circuit Breaker Specialist Training Guideline Due to the high turnover rate in the industry, a Circuit Breaker Specialist Training Guideline was drafted in 2009 (Based on LEMUG Motor Specialist Training). This document was presented to CBUG in 2009 for comments and a working group was formed to provide input into the document. To finish the document; Working group time needed to provide input into the document and review references, wording and specifications along with timeline development. 17

18 Model-Specific Working Group Objectives Review Guidance Review existing EPRI documents to verify technical accuracy and completeness. Help resolve any issues and improve existing guidance. If necessary, work with EPRI to update existing guidance. Suggest New Guidance Suggest any new EPRI guidance or initiatives needed that would benefit utility personnel. Review OE Reports Review new or existing industry operating experience reports to identify significant lessons learned and communicate these lessons via revisions to industry guidance, meetings, workshops, etc. 18

19 Model-Specific Working Group Objectives Identify Topics Work with EPRI and the OEM and/or service providers to develop a model-specific circuit breaker agenda and discussion topics for their respective user s group meeting. Training Identify any training that may be needed by utility personnel and help EPRI or the OEM and/or service providers fill this need. PM Basis Verification Review applicable EPRI PM Basis Templates to determine appropriateness and accuracy. Suggest any new PM Basis templates that need to be developed 19

20 ABB Working Group ABB Working Group formed in 2009 Pete Pawlak, Southern Nuclear, Plant Vogtle Gene Black, Duke Power Kevin Shea, NextEra, Seabrook Irmari Rios, Entergy Scott Quernemoen, TVA Objective(s): Gather and review older meeting materials and better document prior issues and their resolution. 20

21 ABB K-Line Working Group EPRI TR , K-Line PM Guidance (Issued in 2000) EPRI and the Industry Owners groups share the ownership and responsibility to keep this document updated. Revision of this document is a high priority for EPRI s CBUG due to the high number of breakers (5000+) Working group meeting held on May 5-6, 2010 at EPRI offices. Gene Langlois participated. Half of the maintenance tasks were revised. Revisions must be reviewed and approved by utility working group members Additional work is needed. 21

22 ABB Working Group K-Line PM procedures needed Please forward to ( request went out to all contacts regarding procedures) Review and input of knowledgeable breaker specialists is needed Recommended future actions: Hold additional working groups to complete the revision Forward to everyone for review and approval. 22

23 ABB Working Group To complete the revision: Conduct working Group meeting on June 14 Conduct additional working group meetings later at EPRI offices in Charlotte, ABB in Florence, SC Plant site (plant needs to volunteer) When? Gene Langlois booked through December, 2010 EPRI available after August Schedule August-November? Schedule with Gene in January? 23

24 2010 CBUG Meeting Session Facilitators AK / AKR Magne-Blast ABB (Combined) DS DB DHP Eaton Wyle-Siemens MCC-MCCB Paul West Mike Baldwin Ron Ferrie Henry Johnson Mike Baldwin Paul West Ron Gadagno Robert Francis Nick Pournas / Mike Baldwin 24

25 Together Shaping the Future of Electricity 25