TXX-9222, Submits Results of Evaluation of Thermo-Lag 330-1 Fire Barrier Sys,Per NRC Concerns Raised at 920212 Meeting. Confirmatory Test Rescheduled for 920615-19

Submits Results of Evaluation of Thermo-Lag 330-1 Fire Barrier Sys,Per NRC Concerns Raised at 920212 Meeting. Confirmatory Test Rescheduled for 920615-19

ML20113G853
Person / Time
Site:	Comanche Peak
Issue date:	05/06/1992
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TXX-92228, NUDOCS 9205130005
Download: ML20113G853 (3)

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1. 909.5 TilELECTRIC William J. Cahill, Jr.

Group Mce Perswtent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 SUBJEC : COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NO. 50-445 AND 50-446 EVALUATION OF THERMO-LAG 330-1 FIRE BARRIER SYSTEM REF: 1) TU Electric letter from W. J. Cahill, Jr. to the NRC logged TXX-92219 dated May !, 1992.

Gentlemen:

! At-a meeting in Rockville, Mar .nd on February 12, 1992, the Nuclear Regulatory Commi.sion (NRC) expressed co sens regarding Thermo-Lag 330-1 materials. Our understanding of the current NRC staff concerns relative to Thermo-Lag 330-1 fire barrier systems at e summarized as follows:

1. Adequacy of fire endurance testing and applicability td test results j to as-installed configurations.

2. Adequacy of ampacity derating design bases.

3. _Less than adequate installation and inspection processes and procedures as recommended by Thern. Science Inc. (TSI).

Subsequent to the Rockville presentation and other recent NRC concerns. ~U Electric conducted an assessment of test results and documentation, empacity derating design basis, and installation / inspection specifications and procedures applicable to Thermo-Lag configurations at CPSES. This review concluded that Thermo-Lag fire barrier systems at CPSES are adequately designed and installed.

Accordingly, we are pruceeding with application of Thermo-Lag in Unit 2 as contemplated by _our completion plan and schedule. This review has been documented via an Engineering Report and includes a Design Matrix of the Thermo-Lag configurations at CPSES with associated supporting test documentation. The aforementioned Engineering Report is available at the site for your review, Specific results of TU Elottric's review -and related actions to the above concerns are as follows.

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9205'150005 920506 PDR ADOCK 05000445 g h F PDR P. O. Box 10tX2 Glen Rose. Tetas 76043-10L'2 S

i . TXX 92228 Page 2 of 3

1. Nine fire endurance tests were reviewed to support the one-hour fire rating qualification basis for Thermo-Lag conf igurations installed.

Tnese tests demonstrate that the vast majority of configurat ions are adequately substantiated by test and the commodities tested are representat ive of as-installed conditions. Specifit instances (small diameter conduits and large cable trays) where available test documentation could be improved or detail enhanced have been identified and further evaluatior is in process. Nevertheless, to provide further assurance f the overall adequacy of the Thermo-Lag program, TU Electric has initiated a comprehensive confirmatory test program to envelope the f ull range of protected conduit and cable tray configurations used. TU Electric has contracted directly with Omeg6 Point Laboratories in San Antonio, Texas to conduct this program. To fabricate the test assembly, CPSES stock Thermo-Lag products will be installed by site craft personnel in accordance with our installation procedures and inspected by CPSES Quality Control (QC) inspectors. Per ref erence 1, TU Electric has submitted an invitation to your staff representatives to witness these confirmatory tests.

2. The TU Electric review of the CPSES design basis for applying ampacity derating f actors has concluded that c^qservative values have been incorporated into cable sizing c r 'teria for raceways protected with Thermo-Lag. No change to the current CPSES program is required.

3. Tho TU Electric review has concluded that the installation and ins' oction controls as implemented by tne Thermo-Lag specifications and urplicable procedures satisf actorily address concerns identified during the February 12, 1992, meeting. The installation drawings are significantly more detailed than corresponding TSI installation guidance. In some instances, the CPSES rc uirements are more conservative than TSl's recommended pract; s. Tne Thermo-Lag products are installeo by CP5ES site crat t personnel in accordance with our installation procedures and inspected by CPSES QC inspectors. No change to the current CPSES program is required.

Upon completion of confirmatory testing activities as described above, the Thermo-Lag Engineering Peport and Design Matrix will be revised to include applicable test results. The test report to be issued by Omega Point Laboratories will also be made available for review by NRC Staff personnel.

As discussed above in item 1 and reference 1 TU Electric had submitted an invitation to your staff representatives to witness these confirnatory tests during the second week of June 1992. Subseuuent discussions with your staff regarding the cure time of the trowelable grade Thermo-lag, TU electric has rescheduled the conf irmatory test for June 15 through June 19, 1992. However, tnis is a tentative schedule. We will verbally inform your representatives in ample time if there is a change in this schedule.

. TXX-92228 I

Page 3 of 3 Should you require additional information regarding this issue or details related to the testing activities, please contact Obaid Bhatty at (817) 897-5839.

Sincerely,

, o h

'I, -

William J. .ab Jr DB/cs Enclosures c - Mr R. D. Martin, Region IV Mr. B. E. Holian, NRR Mr. T. A. Bergman, t4RR Resident inspectors, CPSES (2)

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