ML20099B951
| ML20099B951 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 07/27/1992 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-92-001, IEB-92-1, NUDOCS 9208030186 | |
| Download: ML20099B951 (6) | |
Text
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Duke 1%iar Company T C M wnm McGwe Purlear Generation thportmen ike IWsident 1:100 Ilus,rs l'rtry Road (MGDI A)
(M t)375400
. Iluntersolle. NC280iM985 (704)MTS b09 fu DUKEPOWER July 27, 1992 U.
S. Nuclear Regulatory Conunission Attention: Document control Desk washington, D.
C.
20555
Subject:
McGuire Nuclear Station, Unite 1 and 2 b
Docket Nos. 50-369 and 50-370 NRC Bulletin No. 92-01 Failure of Thermo-Lag 330 Fire Barrier System to Maintain Cabling in Wide Cable Trays and Small a
Conduits Free From Fire Damaga Dear Sir; By letter dated June 24, 1992, NRC Bulletin 92-01 was
' issued.
Attached, please find the response for McGuire Nuclear Station.
There is limited use of the Thermo-Lag 330 fire barrier system protecting safe shutdown equipment at McGuire.
The attached response discusses the actione that we have taken as a result of this bulletin.
Please contact Paul Guill at (704) 875-4002, if you have any questions regarding this issue.
I declare under penalties of perjury that the statements set forth herein are true and correct to the best of my knowledga.
Very truly yours,
)
Y4 c
Ted C. McMeekin f
Q i'. n.
9208030186 920727 7
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~ U.:Se Nuclear-Regulatory Commission
- J.uly 27, 1992
- page 2
-- xc S.'D.
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-Regicn91' Administrator, Region II P.
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Van Doorn
' Senior-Resident Inspector, McGuiro
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A.__ R e e d, Project-Manager
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ATTACHLMENT i
DUKE POWER COMPANY MCGUIRE NUCLEAR STA; ION l
RESPONSE TO NRC BULLETIN 92-01 NRC REQUESTED ACTION 1.
For those plants that use either 1-or 3-hour pre-formed Thermo-1 --
Lag 330 panels and conduit shapes, identify the areas of the plant
'which have Thermo-Lag 330 fire barrier material installed and determine the plant areas which use this material for protecting L
oither small diameter conduit or wide trays (widths greater tha(n) 14 inches) that provide safe shutdown cap.ibility.
DUKE'S, RESPONSE TO REQUESTED ACTION 1.
Thermo-Lag 330 panels are utilized in three areas ut AcGuire Nuclear-Station.
They are the Auxiliary Building Unit 1 Pipe Chase, Unit-1 B Train Switchgear Room (elevation 733+0) and the Unit 2 ' Motor DLiven Auxiliary Feedwater Fump Room (elevation 716+0).
All. applications are 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rated and serve to protect cables / components that provide safe shutdown capability.
There~are nc applications on wide cable trays
(>
14 inches) or l-small conduli.s (< 4 inches).
NRC hEOUESTED ACTION'2.
In those plant areas in which Thermo-Lag fire barriers are used to orotect wide cable trays, small - conduits, or both, the licensee
=should implement, in accordant:e with plant procedures, the
- appropriate compensatory measures, such as fire watches, consis tent with those which would be implemented by either the plant Technical Specifications or the operating license for an inoperable fire-barrier.
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DUKE?S RESPONSE TO NRC: REQUESTED ACTION 2.
On June 25, 1992 NRC Bulletin.92-01 was received and an initial cassessment was. performed.
Based on information contained within
?the bulletin and the configuration, as well as the installation of the. barriers at McGuire, the. initial-engineering assessment was that the fire.barriors with Thermo-Lag 330 were - operable and capable of: fulfilling their safety. function.
Accordingly no compensatory measures were implemented at that time.
A mere detailed evaluation of the barriers in question was initiated, to verify the appropriateness of the initial engineering evaluation.
Further, the 3 fire barriers in question were inspected to evaluate material condition and installation procedure conformance.
The barriers were found in good condition and.in conformance with-
- installation procedures.-
TM following paragraphs document the results of the more detailed. evaluation of the barriers.
I
.From' earlier reports, the primary emphasis was on problems with installation of tho material.
NRC Bulletin 92-01 continues this L
.lineLofLthoughtJby describing failure with' an assembly on wide ie trays due to-material sagging.
This resulted in separation of
-joints; in the material and an inability of the material to
.successtully meet testing acceptance standards.
In ' the Pipe ' Chase - a, Fcedwater Pump Room, motor operators are
- wrapped ' wJ th Thermo Lag 330.
Stainless steel wire on 6 inch spacing:is used to secure the panels.
The spacing is assured on both initial installations and reinsta11ations by a
station H
procedure, ~which specifies. a 6 inch conter. spacing for the wire banding.
From information provided and discussed in tne above paragraph, it-was. concluded that the panels are adequately secured
.and: failure would not occur as described in the tests ncted in the Bulletin.
. 'Further, additional testing performed by Thermal
-Science,- Inc.
and
. witnessed by -Office of Nuclear Reactor Regulationc(ONRR),'on a-36 inch cable' tray configuration with the
~
wire banding -on 8: inch centers successfully passed the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> l
exposure test.
Therefore, for this application, these barriers
- wore considered operable.
l-l In the Auxiliary Building Pipe C ase, Unit 1 the combustible fire cloading is minimal.
A fire of proportions to the ASTM E119-test fire t woul6 not be. expected in ' this area due - to the lack of
-combustible-materials.
- Also, using the NRC approved Five-methodology, a fire loading evaluation was performed fn this. area
.using S gallons of-hoptano~as a combustible material.
Heptane war chosen for its combustible intensity since other materials did not exist Lin the area in question.
Results of the evaluation indicated -
- the~ fire would not threaten the safo shutdown related componenta located above the floor.
L I'
x In the Unitt 2 Auxiliary Feedwater Pump Room, valves are also
, enclosed with 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rated Thermo-Lag 330 panels.
These 3
- hour panels were substituted for a required 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire rated material.
The panels were inst alled in accordance with station
- procedures, - which require a 6 inch wire band spacing.
The NRC has suggested ' measures-to compensate for material deficiency which includes automatic sprinklers.
Automatic sprinklers exist in this area and, tharoforo, this installation is not considered to be threatened by a fire.
In the remainina area, Train B Switchgear Room for Unit 1,
the cable trays are-less than 14 inches wide.
Testing to date has shown this configuration to be acceptable.
-In summary, the limited areas at McGuire Nuclear Station in which the Thermo-Lag 330 material is used as a
fire barrier are considered operable.
In addition, procedures restrict introducing combustible loading _to a level where the equipment being protected by Thermo-lag 330 would not be impacted should a fire occur.
I NRC REQUESTED ACTION 3.
.Each.Uconsee, within 30 days of receiving this bulletin, is required to provide a written notification stating whether it has or.does not have.Thermo-Lag 330 fire barrier systems installed in its facilities.
Each licensee who has installed Thermo-Lag 330 fire barriers is required to inform the NRC, in writing, whether it l
'has taken the above actions and is required to describe the L
messures being taken to ensure or restore fire barrier operabiJity.
D'EE'S RESPONSE TO NRC REQUESTED ACTION 3.
As discussed in response to NRC requested Action 1, McGuire Nuclear Static,n has limited application of the Thermo-Lag 330 fire barrier systems protecting safe shutdown equipment.
The response to NRC requested Action 2 describes the actions that have been taken as a l'
result of this bulletin.
Briefly, the information and the concern l-
. associated with -the bulletia were reviewed.
Based on tne
- eng] toering evaluation' performed, the fire barriers in question are considered to.be operable.
As such, no additionc1 actions would need to be taken to ensure or restore fire barrier operability
-since the_ barriers are considered to be operable.
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2 Notwithstanding the
- above, additional actions to ensure the l
continued operability of the Thermo-Lag 330 fire barriers are being developed through an industry program being coordinated through NUMARC.
This program will include establishment of a
test database, development of generic guidance for applicability of
- tests, development of generic installation guidance and consideration and coordination of additional testing as appropriate.
The results of those ef forts when completed, will be applied to the Thermo-Lag installations at McGuire Nuclear Station.
N
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