CPSES-200400542, Response to Notice of Violation (EA-04-009)
| ML040650516 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 02/27/2004 |
| From: | Blevins M, Madden F TXU Electric, TXU Generation Co, LP |
| To: | Document Control Desk, NRC Region 4 |
| References | |
| CPSES-200400542, EA-04-009, IR-02-009, TXX-04046 | |
| Download: ML040650516 (7) | |
Text
, TXU TXU Energy Mike Blevins Comanche PeakSteam Senior Vice President & Principal Nuclear Officer Ref: 10 CFR 2.201 Electric Station P.O. Box 1002 EO1)
Glen Rose.TX 76043 Tel: 254 897 5209 Fax: 254 897 6652 mike.blevins@txu.com CPSES-200400542 Log # TXX-04046 February 27, 2004 U. S. Nuclear Regulatory Commission ATMN: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NO. 50-445; NRC SPECIAL TEAM INSPECTION REPORT 50-445/02 RESPONSE TO NOTICE OF VIOLATION (EA 009)
REF: 1. NRC's letter from Bruce S. Mallet to M. R. Blevins, dated February 13, 2004; Special Team Inspection Report 50-445/02-09 Final Significance Determination For A White Finding And Notice Of Violation
- 2. NRC's letter from Dwight D. Chamberlain to M. R. Blevins, dated January 27, 2004; Special Team Inspection Report 50-445/02-09 Preliminary White Finding
- 3. NRC Special Team Inspection Report 50-445/02-09, dated January 9, 2003.
- 4. TXU Energy letter logged TXX-02181 from C. L. Terry to the NRC dated November 5, 2002; Licensee Event Report 445/02-002-00
- 5. TXU Energy letter logged TXX-03024 from C. L. Terry to the NRC dated March 5, 2003; Additional Information for Inspection Report 50-445/02-09
- 6. TXU Energy letter logged TXX-03072 from C. L. Terry to the NRC dated April 9, 2003; Additional Information Concerning CPSES Ninth Refueling Outage (I RF09) Steam Generator Tube Conditions
- 7. TXU Energy letter logged TXX-03059 from C. L. Terry to the NRC dated April 25, 2003; Supplemental Licensee Event Report 445/02-002-01 A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- South Texas Project
- Wolf Creek
TXX-04046 Page 2 of 3 Gentlemen:
TXU Generation Company LP (TXU Energy) has reviewed the NRC letter (Reference 1) concerning the final results of the NRC's significance determination for a White Finding under the Cornerstone of Barrier Integrity. This finding was identified in both the NRC's letter of January 27, 2004 (Reference 2) and the Special Team Inspection Report (Reference 3). The issue cited identified one instance where TXU Energy failed to promptly identify a tube flaw in Comanche Peak, Unit 1, Steam Generator No.2, and correct the flaw by removing the tube from service.
TXU Energy has previously submitted additional information concerning the Steam Generator condition cited in this finding and Notice of Violation (NOV) via References 4, 5, 6, and 7. of this letter provides TXU Energy's response to the NOV pursuant to the requirements of 10 CFR 2.201.
Should you have any comments or require additional information, please contact Bob Kidwell at (254) 897-5310 for assistance.
This communication contains no new licensing basis commitments.
Sincerely, TXU Generation Company LP By: TXU Generation Management Company LLC, Its General Partner Mike Blevins By: 6 2Q zFred W. Madden Nuclear Licensing Manager RJK/rk - Response to Notice of Violation
TXX-04046 Page 3 of 3 c- B. S. Mallett, Region IV W. D. Johnson, Region IV M. C. Thadani, NRR Resident Inspectors, CPSES
Attachment I to TXX-04046 Page 1 of 4 NOTICE OF VIOLATION RESTATEMENT OF VIOLATION TXU Energy Docket No. 50-445 Comanche Peak Steam Electric Station License No. NPF-87 EA-04-009 During an NRC inspection conducted from October 7 through November 1, 2002, a violation of NRC requirements was identified. In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1 600, the violation is listed below:
10 CFR Part 50, Appendix B, Criterion XVI requires, in part, that licensees shall establish measures to assure that conditions adverse to quality are promptly identified and corrected.
Contrary to the above, in April 2001, despite the existence of eddy current data that indicated the existence of a flaw in a steam generator tube, the licensee failed to promptly identify a flaw in Comanche Peak, Unit 1, Steam GeneratorNo. 2 Tube R41C71, a condition adverse to quality, and correct it by removing it from service. As a result, in September 2002, the flaw developed into a leak that caused operators to shut the plant down. The tube subsequently failed in situ testing.
This violation is associated with a White Significance Determination Process finding.
Attachment I to TXX-04046 Page 2 of 4 RESPONSE TO NOTICE OF VIOLATION LICENSEE RESPONSE TO VIOLATION TXU Energy has performed a thorough review of the issue and accepts the violation. The reasons for the violation, as well as corrective actions taken to address the issue and prevent its recurrence, have been captured by the Comanche Peak Corrective Action Program under SmartForm 2002-003142.
Detailed information concerning the NRC-identified reasons for the violation and the immediate corrective actions taken by TXU Energy during the 2002 Unit 1 Refueling Outage (IRF09) have been previously captured in the Special Team Inspection Report 50-445/02-09 (Reference 3 of the cover letter).
A summary of the NRC-identified information, as well as further information developed by TXU Energy through its root cause analysis of this issue, are provided below.
- 1. Reason for Violation
- The inherent probe wobble and possible material wall thickness variation in the U-bend region limited detection of a precursor ding less than about 2.5 volts. The 1RF08 eddy current analysis guidelines were written to analyze freespan indications in two manners: one without the presence of a ding and a smaller threshold in the presence of a ding. The indication in tube R41 C71 did not meet the guideline reporting criteria partly because the ding was masked by the probe wobble signal and the non-conservative criteria for non-ding locations was applied by both the primary and secondary analysts.
- The computerized primary analysis process was rule-based and had been limited due to previously identifying many false indications of very low voltage data.
- The secondary analyst did not recognize the presence of a tube ding due to probe wobble and strictly applied the non-ding reporting criteria of the eddy current analysis guideline.
- Root cause analysis has also identified that the work process was less than adequate in that it relied on a single individual to perform a very detailed task with no peer, independent, nor supervisory review of data not identified as possible flaw indications.
- Contributing factors included human performance in performing repetitive tasks and poor workplace layout.
to TXX-04046 Page 3 of 4
- 2. Corrective Steps Taken and Results Achieved Short term actions taken to assure immediate compliance:
- Expanded the scope of Steam Generator tube inspections during 1RF09.
- Human (versus computer-based) eddy current analysts were used for both primary and secondary analysis positions.
- The eddy current analysis guidelines were revised to refine the freespan bobbin evaluation flowchart to preclude a probe wobble signal from masking a ding signal.
- Training was provided to all analysts prior to the start of IRF09 tube inspections, topics included:
- tube R41 C71 conditions,
- analysis guideline changes, and
- the importance of defect identification.
A tertiary 100% review was performed on all bobbin coil data which included training, independent qualified data analyst reviews, and use of a "Judas Tube."
A history review back to the first in-service inspection was performed on 100% of the free span differential calls, inclusive of training and peer reviews.
Steam Generator tube R41 C71 was plugged during 1RF09 after completion of in-depth analysis.
Long term actions taken to prevent recurrence:
- NRC Information Notice IN 2003-005; "Failure to Detect Freespan Cracks in PWR Steam Generator Tubes" has been included in the analysis guidelines for analyst review and training.
- TXU Energy and the vendor Overall Lead Analysts are assigned to review the performance of the primary and secondary analysts daily by comparing the primary/secondary analysts calls to the results of the Resolution Analyst.
- Additional controls have been incorporated into the Automated Data Screening software to ensure the correct sorts are used.
- Resolution Analysts have been separated into an A-Team / B-Team concept, and resolution of data is performed independently in separate rooms with the most conservative call taking precedence.
- A Lead Analyst has been assigned on each shift to provide a greater level of team oversight and guidance.
- A previous history lookup requirement has been changed to require lookup back to the first in-service inspection versus only the last in-service inspection.
- Training and testing has been added on data lookups for change in signal.
- A new requirement has been added to zoom strip charts and scroll freespans at a span of 5.
to TXX-04046 Page 4 of 4
- 3. Corrective Steps That Will Be Taken to Preclude Recurrence No additional steps are required to preclude recurrence. All necessary preventative actions have been completed as discussed in the previous section.
- 4. Date of Full Compliance TXU Energy is currently in full compliance.