ML20099H339
| ML20099H339 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/13/1992 |
| From: | William Cahill, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-92389, NUDOCS 9208180255 | |
| Download: ML20099H339 (2) | |
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- TXX-92389 File # 10010 TUELECTRIC August 13, 1992 William J. Cahlfl. Jr.
Gwup he tro sident U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 5UBJECT:
CDMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REF:
NRC letter dated August 3, 1992 from A. Bill Beach to W. J. Cahill, Jr.
Gentlemen:
This is in response to a request for addition i informat. ion submitted by Reference 1.
We have reviewed your questit.as and the requested information follows.
Question a)
"What acceptance criteria are being used for correr gap widtn of Thermo-Lag fire barrier envelopes.
Response
The CPSES criteria for Thermo-Lag fire barrier material does not explicitly provide fcr or allow "aaps".
gecifically, prefabricated panel and conduit section mating surfaces are required to be cut flush and square to achieve the tightest fit physically permitted by the configuration and the material. All seams and joints are precaulked (i.e., " buttered") with 1/4" to 1/2" of Thermo-Lag 330-1 trowel grade material.
CPSES application procedures provide for the application of trowel grade material at joints and seams (i.e., " corners") which adequately fills minor gap areas that may exist on mating surfaces. The test assemblies prepared and tested to date at Omega Point Laboratories utilized this criteria (as well as configurations installed in Unit 1 and Unit 2) and exhibited no failures attrisuted to such gaps.
Question b) is this criteria different from the acceptance criteria used for Unit 1 instellations? If yes, please expiain.
Response
No.
920818025S 920813 PDR ALOCK 05000445 p
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400 N.Ouve Street LB. 81 Dallas, Texas 75201
J 1XY-92389 Page of 2 Question c)
What was the corner gap width acceptance criteria used to fabricate the test assemblies used at Omega Point Labs? Is this criteria different from that used in the Unit 1 and 2 insta llations?
If yes, please explain.
Response
The criteria was the same as described above in response to questiona),no.
Questiond) 00 you have QA/QC data relative to the actual installed corner gap width in the tested assemblies, and as installed in Unit 1 and Unit 2?
Response
Yes, ConstrJCtion/ Quality Procedure CQP-CV-107 requires in-process QC surveillance to ensure that mating surfaces at seams, joints, etc. are adequately precaulked with trowel grade material (no gap). Accordingly, QC monitors in-process Thermo-Lag installations to verify this requirement is implemented and documents this surveillance via inspection reports. This same level of verification has been utilized for Thermo-Lag installations in Unit 1, Unit 2 and at Omega Point Laboratories for test assemblies.
Questior,e)
What type filler material is used for filling the gaps during installation? Was the same type filler material used in Unit 1 and in the assemblies tested at Omegn Point Labs?
Response
Thermo-Lag 330 trowel grade material was used in both applications (Unit 1 and the test at Omegd PointLabs).
Should you have any question or need additional information, contact Obaid Bhatty at (817) 897-5839.
Sincerely, Y
nh William J. Cahill, Jr.
By:
W1 h-Roge?D. Walker 1
Manager of Regulatory Affairs for NLO OB/tg c-Mr. J. L. Milhoan, Region IV Mr. A. 8. Beach, Region IV Mr. B. E. Holian, NRR Resident Inspectors CPSES (2)
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