ML20097H596

Responds to NRC Re Violation Noted in Insp Repts 50-445/95-28 & 50-446/95-28 on 951022-1125.Corrective Actions:Engineering Will Periodically Review Temp Data for Plant Upper FW Bypass Penetrations for Period of One Yr

ML20097H596
Person / Time
Site:	Comanche Peak
Issue date:	01/25/1996
From:	Terry C TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TXX-96013, NUDOCS 9601300044
Download: ML20097H596 (4)

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Log # TXX 96013 EM File # 10130

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7 ~" IR 95 28 Ref. # 10CFR2.201 i r r tilELECTRIC 7

' January 25, 1996 l Grmp Yke Presided U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET N05. 50 445 AND 50 446 NRC INSPECTION REPORT NOS. 50 445/95 28: 50 446/95 28 RESPONSE TO NOTICE OF VIOLATION Gentlemen:

TV Electric has reviewed the NRC's letter dated December 29, 1995, concerning the inspection conducted b.e A.T. Gody and other inspectors during the period of October 22 through Novenber 25, 1995. Attached to the  !

December 29, 1995 letter was a Notice of Violation.

TU Electric hereby responds to the Nctice of Violation in the attachment to this letter.

Sincere y, 1

C. L. Terr GLM/glm Attachment cc: Mr. L. J. Callan Region IV Mr. W. D. Johnson, Region IV Resident Inspectors. CPSES 9601300044 960125 PDR ADOCK 05000445 G PDR , f 300007 '

P.O. Box 1002 Glen Rose. Texas 76043 ll

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J At'tachment'to TXX 96013 l Page 1.of 3 )

i l NOTICE OF VIOLATION l (445(6)/9528 01) ~j l

Criterion XVI of Appendix B to 10 CFR Part 50 requires, in part, that L measures be established to assure that conditions adverse to quality, such l as failures, malfunctions, deficiencies, deviations, defective material, and equipment and nonconformances are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.

Contrary to the above, corrective actions which were developed for the 1992 Unit I upper feedwater preheater bypass penetration overheating events were not sufficiently comprehensive to preclude repetition. The inspectors i discovered on April >19, 1995, that Unit 2 upper feedwater preheater bypass Penetration MV 19 and MV 20 temperatures were above their steady state l design temperature. Archived upper feedwater preheater bypass penetration  ;

temperature data showed that all four of the Unit 2 upper feedwater <

preheater bypass penetration temperatures were frequently above their design '

limits since 1993.

RESPONSE TO THE NOTICE OF VIOLATION l

TV Electric ~ accepts the violation and the requested information follows:

1. Reason for Violation '

TV Electric believes that the corrective actions which were developed for.the 1992 Unit I upper feedwater bypass penetration overheating events did not preclude repetition on Unit 2 because the June 1992 events on Unit I were incorrectly assumed to be limited to valve leakage on an operating (Unit 1) piping system and therefore an i evaluation of the condition on the other unit (Unit 2) was not initiated. At the time of the overheating events on Unit 1 (June 1992). Unit 2 was in the design / construction process and the valve leakage which contributed to the concrete overheating was not yet evident.

2. Corrective Steos Taken and Results Achieved A separate deficiency document was issued to ev.luate the concrete overheating events on Unit 2. Operations entered Abnormal Operating Procedure (ABN) 305, " Auxiliary Feedwater System Malfunction" and the piping insulation on the Unit 2 upper feedwater bypass lines for all four loops was removed from the temperature elements outside containment to the first feedwater check valves inside containment.

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Attachment to TXX-96013 Page 2 of 3 After removing the insulation, the upper feedwater bypass penetration l temperatures remained below 200 degrees. l l

Operations revised procedure IP0 003B, " Power Operations", to more closely monitor the upper feedwater bypass lines by initiating a temporary equipment log to monitor the lines once per shift to' assure temperatures remained below 200 degrees. Changes were made to plant computer alarms including changing the "HI" temperature alarm from 295 degrees to 190 degrees and changing the "HI HI" temperature alarm from 305 degrees to 295 degrees. . Engineering reviewed existing temperature data and generated a new calculation, which enveloped the previous analysis, for the upper feedwater bypass penetrations. This calculation demonstrated that the concrete satisfies the American Concrete Institute (ACI) 359 code requirements and that the. safety of plant operations was not affected. - A new design basis maximum temperature'of 320 degrees was established for the concrete following section CC-3430'of the ACI 359 code.

Changes similar to those outlined above were also made for Unit 1.

Operations procedure IP0 003A, " Power Operations", was revised, computer alarm changes were made to the "HI" and "HI HI" alarms, and a new engineering calculation was generated after reviewing the Unit'l data establishing a new design basis of 320 degrees consistent with the ACI 359 code requirements.

Based upon the new calc.lation completed for both units, the "HI" temperature alarm for both units was subsequently changed from 190 degrees to 245 degrees. Operations procedures were also changed to allow for the higher temperature.

Field inspections were completed for all four penetrations in both units. Two of the penetrations were found to have some spalling of the grout, however, this grouting has no structural impact and documentation has been issued to repair the grouting.

3. Corrective Steos That Will be Taken to Preclude Recurrence Prior to Unit 2 licensing, all Unit 1 deficiency documents were reviewed for applicability to Unit 2. However, as noted above, this Unit 1 deficient condition was incorrectly assumed to be limited to valve leakage on an operating' piping system. TU Electric believes that this was an isolated occurrence.

Engineering will periodically review the temperature data for the Unit 1 and Unit 2 upper feedwater bypass penetrations for a period of one year to assure that the temoeratures remain below specified values bounded by calculations consistent with the ACI-359 code requirements.

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, 1 Attachment to TXX-96013  !

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4. Date of' Full Comoliance  !

TU Electric is in full compliance. l i

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