ML17332A702
| ML17332A702 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/29/1995 |
| From: | Fitzpatrick E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AEP:NRC:0692DD, AEP:NRC:692DD, GL-92-08, GL-92-8, NUDOCS 9504040139 | |
| Download: ML17332A702 (10) | |
Text
P R.IC)R.I"EY' (ACCELERATED RIDS PROCESSING~
~
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9504040139
$ DOC.DATE: 95/03/29 NOTARIZED: YES DOCKET FACIL:50-315 Donald C.
Cook Nuclear Power Plant, Unit 1, Indiana M
05000315 50-316 Donald C.
Cook Nuclear Power Plant, Unit 2, Indiana M
05000316 AUTH.NAME AUTHOR AFFILIATION P
FITZPATRICK,E.
Indiana Michigan Power Co. (formerly Indiana
& Michigan Ele RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
R
SUBJECT:
Forwards to follow-up 941229 ltr request for addi info re GL 92-08, "Thermo-Lag '330-1 Fire Barriers."
DISTRIBUTION CODE:
A029D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: Generic Letter 92-008 Thermal-Lag 330 Fare Barrier NOTES:
0 RECIPIENT ID CODE/NAME PD3-1 LA HICKMAN,J INTERNALMKL'E CENTER 0
NRR/DRPW/PD3-1 RGN3
..;.FILE EXTERNAL: NOAC COPIES LTTR ENCL 1
0 1
1 1
1 1
1 1
1 1
1 RECIPIENT ID CODE/NAME PD3-1 PD NRR/DE/EELB NRR/DSSA/SPLB NRC PDR COPIES LTTR ENCL 1
1 l.
1 2
2 1
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NOTE TO ALL"RIDS'ECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACTTHE DOCUMENTCONTROL DESK, ROOM Pl-37 (EXT. 504-2083 ) TO ELIMINATEYOUR NAME'FROM DISTRIBUTIONLISTS I:OR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 11 ENCL 10
Indiana Michigan Power Company P.O. Box 16631 Columbus, OH 43216 March 29, 1995 AEP:NRC:0692DD Docket Nos.:
50-315 50-316 U.
S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.
C.
20555 Gentlemen:
Donald C.
Cook Nuclear Plant Units 1 and 2
RESPONSE
TO FOLLOW-UP TO THE REQUEST FOR ADDITIONALINFORMATION REGARDING GENERIC LETTER (GL) 92-08, "THERMO-LAG 330-1 FIRE BARRIERS" The purpose of this letter is to respond to a December 29,
- 1994, NRC letter that requested supplemental information associated with
- tests, analyses, and inspections required to determine the material properties and attributes of Thermo-Lag installed at Donald C.
Cook Nuclear Plant.
Our response is provided in the attachment to this letter.
The December 29,
- 1994, NRC letter requested that our response be made under oath or affirmation according to the provisions of Section 182a of the Atomic Energy Act of 1954, as
- amended, and 10 CFR 50.54(f).
Sincerely, C'e~
Vice President SWORN TO AND SUBSCRIBED BEFORE ME THI 2~
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AEP:NRC:0692DD Attachment CC:
A. A. Blind G. Charnoff J.
B. Martin NFEM Section Chief NRC Resident Inspector
- Bridgman J.
R. Padgett
ATTACHMENT TO AEP:0692DD
Response
to NRC Follow-up Letter dated December 29,
- 1994, Request for Additional Information Regarding Generic Letter (GL) 92-08, "Thermo-Lag 330-1 Fire Barriers"
Attachment to AEP:NRC:0692DD Page 1
Thermo-Lag Materials a.
Describe the specific tests and analyses that will be performed to verify that the Thermo-Lag fire barrier materials that are currently installed at Cook Nuclear
- Plant, or that will be installed in the future, are representative of the materials that were used to address the technical issues associated with Thermo-Lag barriers and to construct the fire endurance and ampacity derating test specimens.
The tests and analyses shall address the material properties and attributes that were determined or controlled by TSI during the manufacturing process and the quality assurance program.
The tests and analyses shall also address the material properties and attributes that contribute to conclusions that the Thermo-Lag materials and barriers conform to NRC regulations.
These include:
1.
2 ~
3.
4, 5.
6.
7.
8.
9.
chemical composition; material thickness; material weight and density; the presence of
- voids, cracks, and delaminations; fire endurance capabilities; combustibility; flame spread rating; ampacity derating, and mechanical properties such as tensile strength, compressive
- strength, shear
- strength, and flexural strength.
b.
Describe the methodology that willbe used to determine the sample size, and demonstrate that the sample size willbe large enough to ensure that the information and data obtained will be sufficient to assess the total population of in-plant Thermo-Lag barriers, and the materials that will be installed in the future.
In determining the sample
- size, consider the time of installation and manufacture of the various in-plant materials and barrier installations.
Give the number and types (e.g.,
- panels, conduit preshapes, trowel-grade materials, stress skin) of samples that will be tested or analyzed.
Attachment to AEP:NRC:0692DD Page 2
c ~
Submit the schedule for verifying the Thermo-Lag materials.
RESPONSE
a.
The extent of additional Thermo-Lag tests and analyses performed for Cook Nuclear Plant will be influenced by the outcome of our effort to reduce the need for Thermo-Lag fire barriers.
Through revalidation of our Appendix R safe shutdown analysis, we believe we can reduce the number of 10 CFR 50 Appendix R fire barriers by approximately seventy percent.
We are also evaluating the use of alternate fire barrier materials for replacement of the remaining Thermo-Lag fire barriers.
If an alternate material is used for replacement, only a few Thermo-Lag fire barriers would remain.
Because of these
- factors, additional Thermo-Lag testing and analysis, including sample size, willbe tailored to these specific remaining Thermo-Lag fire barriers.
AEP is participating in the NEI-sponsored industry effort to evaluate chemical composition of Thermo-Lag samples as a means of addressing product consistency and thereby meeting the intent of the request for additional information (RAI).
NEI will provide information on product consistency, based on the chemical composition testing, to NRC and licensees as described in NEI's February 21, 1995, letter to NRC.
By using the chemical composition test data, AEP will have a basis to independently confirm applicability of generic industry test data to Cook Nuclear Plant installations with respect to chemical composition, fire endurance capability, combustibility, flame
- spread, and ampacity.
For each Thermo-Lag barrier for which credit is taken to satisfy fire protection requirements, at least one destructive examination willbe performed to determine material thickness and to check for the presence of voids, cracks, and delaminations.
AEP does.not believe ampacity is an issue of concern for Cook Nuclear Plant.
AEP's position on ampacity was explained in our two previous responses to NRC RAIs, AEP:NRC:0692CV and AEP:NRC:0692DA.
Attachment to AEP:NRC:0692DD Page 3
Mechanical properties such as tensile
- strength, compressive
- strength, shear
- strength, and flexural strength relate to the ability of a fire barrier to maintain its structural integrity.
Surveillances conducted at least every eighteen months in accordance with plant Technical Specifications indicate that the Thermo-Lag fire barriers at Cook Nuclear Plant have remained structurally intact.
While it is unlikely that any slight variation in expected material properties would cause gross failure of the barriers during a
seismic
- event, each installed Thermo-Lag barrier will be evaluated to determine if degradation of the barrier during a seismic event could reasonably endanger seismic category 1
equipment installed underneath the barrier.
Upon completion of the evaluations, for any Thermo-Lag barriers which pose a
seismic concern, actions willbe taken as necessary to address the concern.
These actions include but are not limited to removal or modification of the barriers.
b.
AEP will provide NEI with a total of seven Thermo-Lag samples for chemical testing.
Five of these samples will be taken from installed barriers and will represent each of the Thermo-Lag product forms installed in each unit with the exception of preformed one-hour conduit sections.
Two samples of preformed one-hour conduit sections were previously taken from stock material and chemically tested using the same test methodology and laboratory that NEI is using.
The one-hour conduit sections were tested as a part of the fire endurance testing performed at Omega Point Laboratories for the Hot Shutdown Panel enclosures.
The results of these tests will also be forwarded to NEI for inclusion in the NEI chemical test program.
It is anticipated that any future ins tallation of Thermo-Lag materials would only be associated with the upgrading or repair of existing Thermo-Lag fire barriers.
Thermo-Lag materials installed in the future will be analyzed for chemical composition.
Prefabricated conduit sections and panels will be inspected for proper thickness prior to installation.
Prefabricated conduit sections and panels willalso be inspected for the presence of voids,
- cracks, and delaminations when such pieces are required to be cut during the installation process.
Attachment to AEP:NRC:0692DD Page 4
An integrated schedule of activities necessary for the resolution of the Thermo-Lag issue for Cook Nuclear Plant was provided in our December 21, 1994, letter to NRC (AEP:NRC:0692DA).
This schedule showed a final resolution date of December 30, 1996, and includes the above tests and analyses.
2.
Important Barrier Parameters a.
Describe the examinations and inspections that willbe performed to obtain the important barrier parameters given in Section II of the RAI of December 1993, for the Thermo-Lag fire barrier configurations installed at Cook Nuclear Plant.
b.
Describe the methodology that will be applied to determine the number and type of representative in-plant fire barrier configurations that will be examined in detail and demonstrate that the sample size is adequate to ensure that the information and data that will be obtained are adequate to assess the total population of in-plant Thermo-Lag barriers.
A large enough sample of the total population of configurations should be examined to provide reasonable assurance that the materials and important barrier parameters used to construct the in-plant barriers and any future barrier installations or modifications, are representative of the parameters used to construct the fire endurance test specimens.
c ~
Submit the schedule for obtaining and verifying all of the important barrier parameters.
RESPONSE
a,b.
Examinations and inspections that have been performed to obtain the important barrier parameters given in Section II of the RAI of December
- 1993, for the Thermo-Lag fire barrier configurations installed at Cook Nuclear Plant were previously described in our letter to NRC dated December 21, 1994.
That letter stated that the majority of the Thermo-Lag barrier parameters were known based upon visual inspections.
Parameters such as panel rib orientation, which may not be verifiable by visual examination, would be assumed to be in the worst case orientation when using the NEI Application guide to evaluate the barrier.
Attachment to AEP:NRC:0692DD Page 5
Material thickness was previously identified as a
parameter which was not verified through physical examination.
Therefore, additional destructive examinations of each required Thermo-Lag barrier will be conducted to determine material thickness as described in our response to item l.a above.
For the relatively small number of Thermo-Lag barriers that will still be required for the protection of raceways following our Appendix R revalidation effort, the majority of the eight important cable parameters identified in Section II of the RAI of December
- 1993, have been obtained.
Identification of cable operating temperatures and temperatures at which the cables can no longer perform their intended function when energized at rated voltage and current are not considered necessary at this time.
Per the acceptance criteria stated in GL 86-10, Supplement 1,
these two parameters are not of importance if the fire endurance test results are satisfactory on the basis of internal temperature of the fire barrier
- system, visual inspection of the protected
- cables, and hose stream tests.
.c.
An integrated schedule of activities ne'cessary for the resolution of the Thermo-Lag issue for Cook Nuclear Plant was provided in our December 21, 1994, letter to NRC.
This schedule showed a final resolution date of December 30, 1996, and includes the above examinations and inspections.