ML20132C787
| ML20132C787 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/13/1996 |
| From: | Terry C, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-95-03, GL-95-3, TAC-M92233, TAC-M92234, TXX-96527, NUDOCS 9612180459 | |
| Download: ML20132C787 (4) | |
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905.4 1U LECT C*
- c. Lana Terry December 13, 1996 Gmup Mce President U. S. Nuclear Regulatory Commission Attn..
Document Control Desk Washington. DC 20555-0001
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)-UNITS 1 AND 2 l
DOCKET NOS. 50-445 AND 50-446 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON CPSES RESPONSE TO GENERIC LETTER 95-03, "CIRCUMFERENTIAL CRACKING OF STEAM GENERATOR TUBES" (TAC NOS. M92233 AND M92234)
REF:
- 1) Generic Letter 95-03. "Circumferential Cracking of Steam Generator Tubes ' <1ated April 28, 1995
Terry to the NRC. dated June 27, 1995
- 3) NRC Letter from Timothy J. Polich to C. Lance Terry, dated December 15. 1995
- 4) TV Electric letter logged TXX-96020. from C. L. Terry to the NRC, dated January 18, 1996
- 5) NRC Letter from Timothy J. Polich to C. Lance Terry, dated November 13. 1996 On April 28, 1995, the NRC issued Generic Letter 95-03 "Circumferential cracking of Steam Generator Tubes" (Reference 1).
TV Electric submitted a response to the Generic Letter via Reference 2.
The NRC issued a Request for Additional Information (Reference 3) regarding TV Electric's response (Reference 2).
The response to Reference 3 was provided via Reference 4.
The NRC subsequently issued a Request for Additional Information (Reference 5) regarding TU Electric's response (Reference 4). Attachment 2 to this letter provides TV Electric's response to the NRC's Request for Additional Information.
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Pursuant to Section 182a of the Atomic Energy Act of 1954. as amended, and 4/
10 CFR 50.54(f). TV Electric is submitting this response to a Request for Additional Information under affirmation (Attachment 1) to the requested information as stated in Reference 1 (Requirement for Affidavit) and Reference 5 (Request for Additional Information).
The response is provided in Attachment 2.
9612190459 961213 PDR ADOCK 05000445 P
PDR 170095 P. O. Box 1002 Glen Rose Texas 76043 i
TXX-96527 Page 2 of 2 If you have any questions, please contact Obaid Bhatty at (817) 897-5839.
Sincerely, j
6.3. Q C. L. Terry By:
O RogerM. Walker Regulatory Affairs Manager OB/ob Attachments cc:
Mr. L. J. Callan, Region IV Mr. T. J. Polich, NRR Mr. J. I. Tapia, Region IV Resident Inspectors, CPSES
i Attachment I to TXX-96527 l
Page 1 of 1 l
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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Texas Utilities Electric Company
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Docket Nos. 50-445 i
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and 50-446 l
(Comanche Peak Steam Electric
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Station Units 1 & 2)
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AFFIDAVIT Roger D. Walker being duly sworn, hereby deposes and says that he is the Regulatory Affairs Manager, Nuclear Production of TU Electric, the licensee herein: that he is dul.y authorized to sign and file with the 1
Nuclear Regulatory Commission this Response to Request for Additional Information on TV Electric's Response to Generic Letter 95-03, "Circumferential Cracking of Steam Generator Tubes"; that he is familiar l
with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.
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Roger D. Walker Regulatory Affairs Manager, Nuclear Production STATE OF TEXAS
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COUNTY OF O[lnaC7t)
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v Subscribed and sworn to before me, on this _.13_ day of December. 1996.
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Notary Pahiic
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, to TXX-96527 Page 1 of 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON CPSES RESPONSE TO GENERIC LETTER 95-03, "CIRCUMFERENTIAL CRACKING OF STEAM GENERATOR TUBES" (TAC NOS. 92233 AND M92234)
NRC RAI:
Several plants with preheater model steam generators expanded tubes into the tube support plate in the preheater region to minimize the potential for vibration induced wear.
Since these expansions contain similarities to other expanded regions which have experienced circumferential cracking, discuss whether or not this area is susceptible to circumferential cracking.
If this area is susceptible to circumferential cracking, please submit the information requested in GL 95-03 per the guidance contained in the GL.
l TU Electric Response:
To Electric concurs that the expanded tubes into the tube support plate in i
the preheater region may be susceptible to circumferential cracking.
As j
stated in Reference 2. "[T]he standard industry practice has been to repair (plug or sleeve) upon detection of a circumferential crack.
This is based in part on the threshold of detection and uncertainties as to crack growth rates.
This practice of repair on detection will be implemented at CPSES until such time as the industry reliably defines the uncertainties related to detection sizing and growth rates.
If any circumferential degradation is detected. 100% of the tubes in each of the steam generators will be examined in the area along the tube length where the crack was detected.
Expansion criteria for defects which are not circumferentially oriented will be consistent with Technical Specification 4.0.6."
During the recent refueling outage for Unit 1 a twenty percent l
sample of the B&D baffle plates in the preheater regions were inspected j
using the rotating pancake (RPC) technique.
No circumferential cracks were identified during the Unit 1 fifth refueling outage.
For the I
upcoming Unit 2 outage. a sample of the B&D baffle plate expanded intersections will be inspected using RPC technique, following the same sample inspection philosophy as discussed above.
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