RBG-43067, Provides Supplemental Response to Request for Addl Info Re Ampacity Derating,Per GL 92-08, Thermo-Lag 330-1 Fire Barriers. Calculation Encl

Provides Supplemental Response to Request for Addl Info Re Ampacity Derating,Per GL 92-08, Thermo-Lag 330-1 Fire Barriers. Calculation Encl

ML20113F220
Person / Time
Site:	River Bend
Issue date:	06/28/1996
From:	King R ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20113F222	List: ML20113F227 RBG-43067, Provides Supplemental Response to Request for Addl Info Re Ampacity Derating,Per GL 92-08, Thermo-Lag 330-1 Fire Barriers. Calculation Encl
References
GL-92-08, GL-92-8, RBF1-96-0227, RBF1-96-227, RBG-43067, TAC-M85596, NUDOCS 9607080463
Download: ML20113F220 (5)

Text

Ent rgy operations,Inc.

, River Bend Station S485 U S Highway 61 i e PO Box 220 l

f O

St. Francisvde. LA 70775 l Tel 504 33G 6225 Fax 504 635 5068 Rick J. King Director f4scl ear Safety & Regulatory t. hairs

! I l

l June 28,1996 l

l U.S. Nuclear Regulatory Commission Document Control Desk l Mail Stop Pl-37 Washington, D.C. 20555

Subject:

River Bend Station - Unit 1 Supplemental Response to Request for AdditionalInformation (re: Ampacity Derating), Generic Letter 92-08, "Thermo-Lag 330-1  ;

Fire Barriers," (TAC No. M85596) l Docket No. 50-458 l File No.: G9.5, G9.33.4 I

RBG-43067 RBF1-96-0227 Gentlemen:

The purpose of this letter is: (1) to provide supplemental information on our ampacity derating methodology as it applies to Thermo-Lag fire barriers, (2) to docket information provided during a recent telephone conversation with our NRC project manager on two other Thermo-Lag related issues and (3) to provide a brief status of our Thermo-Lag Resolution project.

As committed in our Reporting Requirement 2(c) from & Calculations Which Will Be Used to Detemine Ampacity Derating Parameters|letter dated November 9,1995]] (RBG-42159) to NRC's Request for Additional Information dated September 25,1995, transmitted herewith as Enclosure 1 is the River Bend Station Project Instruction (PI) which houses our analytical methodology for evaluating ampacity derating due to application of Thermo-Lag fire barriers. Sample calculations based on the methodology in the P1 are provided for your information as Enclosure 2.

Specifically, Appendix A of the P1 (Enclosure 1) provides the analytical methodology that will j be used to establish cable ampacities for electrical raceways enclosed with Thermo-Lag 330-1 ,

material and determine their adequacy based on load requirements. Appendix B of the PI l specifies the computer software requirements that will enable the automatic computation of l derated ampacities per the methodology in Appendix A.

9607080463 960628 6 QQC[ I

' PDR ADOCK 05000458 I i (

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1 Supplemental Response to Request for Additional Information (re: Ampacity Derating),

Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers," (TAC No. M85596)

June 28,1996 -

RBG-43067 RBF1-96-0227 Page 2 of 4 Enclosure 2 includes various computer-generated ampacity derating calculation reports which represent typical derating calculations. The calculations in these reports will be computed via software using the River Bend Station Plant Data Management System (PDMS), per the methodology and specifications of the Pl. Please note that the software is at a trial use and comment status. Portions of the data required to accurately evaluate the derating of some cables have not been verified and validated. Accumulation of the remaining data and performing subsequent runs of the computer report will be accomplished until all of the pertinent cables are analyzed. As cables are identified which do not possess the adequate ampacities, thcy will be evaluated and corrective actions will be implemented as appropriate.

The ampacity derating evaluation will be completed by the first quarter of 1997.

Implementation of any corrective action will be completed by the end of Refueling Outage Number 7.

With regard to the second purpose of this letter, the use of Thermo-Lag as a Radiant Energy Shield and the results of the chemical analysis performed for NEI on the Thermo-Lag used at River Bend Station were discussed with our NRC Project Manager during a May 16,1996 telephone conversation.

While previous River Bend correspondence had referenced the existence of a radiant energy shield in the plant, River Bend is not crediting this shield for fire protection purposes. With regard to the chemical composition of River Bend's Thermo-Lag, during the spring of 1995, RBS submitted several samples of Thermo-Lag 330-1 for pyrolysis gas chromatography using the same test protocol and laboratory as that used by other nuclear utilities under the guidance of NEl. The independent laboratory's test report concluded that the results of the RBS samples were consistent in terms of chemical composition to other Thermo-Lag samples tested as part of the NEI generic testing program.

The final item being addressed by this letter is a project status summary. By s|letter dated February 9,1994]] (RBG-40047), Entergy Operations Inc. outlined an action plan in response to a 10CFR50.54(f), Request For Additional Information. As part of the resolution, River Bend Station elected to reevaluate the post-fire safe shutdown analysis to determine if safe shutdown could be achieved utilizing less reliance on Thermo-Lag as a fire barrier material. River Bend Station is on schedule with the timetable presented in our December 21,1994 (RBG-41123) letter submitted in response to the NRC's Follow-Up Request for Additional Information.

J

Supplemental Response to Request for Additional Information (re: Ampacity Derating),

Generic Letter 92-08,"Thermo-Lag 330-1 Fire Barriers,"(TAC No. M85596)

June 28,1996 RBG-43067 RBF1-96-0227 Page 3 of 4 The Fire Area Compliance Assessments, which evaluate all post-fire safe shutdown components (cables, pumps, valves , etc.) located or routed within a specific fire area, will be completed by the end of July,1996. Presently there are nine proposed modifications to River Bend Station which will be implemented to reduce our reliance on Thermo-Lag. The modifications are being designed at this time. Completion of the design phase of these nine modifications is scheduled to occur during the fourth quarter of 1996. The scope of these modifications include:

One (1) extension of an existing sprinkler system Two (2) installation of new switch and or fuse Five (5) cable re-routes One (1) rework existing Thermo-Lag barriers in accordance with NEl Guidance Criteria.

Installation of these nine modifications will occur during 1997, with an expected completion before the end of Refueling Outage 7, (October 1997).

Should you have any questions concerning this response or require additional information, please contact me at (504) 336-6225 or M. K. Brandon at (504) 381-4506.

Sincerely,

) .

RJK/MK.B enclosures i

l '

4 l

t 1

} Supplemental Response to Request for Additional Information (re: Ampacity Derating),

Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers," (TAC No. M85596)

June 28,1996 j RBG-43067 j RBF1-96-0227 j Page 4 of 4 l

i i

i

! cc: U.S. Nuclear Regulatory Commission i Region IV j 611 Ryan Plaza Drive, Suite 400 j_ Arlington, TX 76011 i

l NRC Resident Inspector

! P.O. Box 1050 St. Francisville, LA 70775 i

Mr. David Wigginton

, NRR Project Manager

! U.S. Nuclear Regulatory Commission j M/S OWFN 13-H-15 l Washington, DC 20555 i

i E._

Supplemental Response to Request for Additional Information (re: Ampacity Derating),

Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers," (TAC No. M85596)

June 28,1996 RBG-43067 RBF1-96-0227 ENCLOSUREI RIVER BEND PROJECT INSTRUCTION ON AMPACITY DERATING EVALUATION J