ML20095D378
| ML20095D378 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/08/1995 |
| From: | J. J. Barton GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| C321-95-2350, GL-92-08, GL-92-8, NUDOCS 9512130057 | |
| Download: ML20095D378 (13) | |
Text
_ _ _ _ _ _ _ _ _.
t GPU Nuclear Corporation
. Nuclear
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Forked River, New Jersey 08731-0388 609 971-4000 Writer's Direct Dial Number:
December 8, 1995 C321-95-2350 U. S. Nuclear Regulatory Commission Att: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Oyster Creek Nuclear Generating Station (OCNGS)
Docket No. 50-219 Facility Operating License No. DPR-16 Response to the Followup to the Request for Additional Information Regarding Generic Letter (GL) 92-08 NRC letter dated September 27,1995 requested additional information regarding ampacity derating evaluations for Thermo-Lag fire barriers installed at OCNGS. The Attachment to this letter provides an itemized response for the specific areas of the NRC request for additional information.
Sincerely,.
(
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- Barton gic President and Director, Oyster Creek Attachment DJD/ pip c
Administrator, Region i OCNGS NRC Resident inspector OCNGS NRC Project Manager
- CPO
.1 o u ;.4 n.1 J 9512130057 951208 DR ADOCK 05000219 l
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GPU Nuclear Corporation is a subsidiary of General Public Utilities Corporation
Attachment Followup Request for Additional Information Regarding Generic Letter (GL) 92-08 "Thermo-Lag 330-1 Fire Barriers" Pursuant to 10 CFR 50.54(f) 1.0 Reauest for Additional Information (RAD of February 10.1994 a.
NRC Reauest The licensee is requested to submit its ampacity derating evaluations, including any applicable test reports, in order to provide an adequate response to Generic Letter 92-08 Reporting Requirement 2(c).
Response
GPU Nuclear letter dated December 27,1994 provided the results of OCNGS ampacity derating calculations performed in 1987 to support the initial installation of Thermo-Lag fire barriers at OCNGS. This calculation is documented in Burns and Roe (B&R), Inc. Calculation No. 3731-29-E007, Revision 0, " Adequacy of Fire Wrapped Cables for Appendix R Modifications." This calculation indicates that the maximum available derating margins for these circuits exceeded the 8% for 1-hour fire rated barriers and 11% for 3-hour fire rated barriers as specified by TSI.
GPU Nuclear Calculation No. C-1302-814-5350-002 has been performed to determine the calculated ampere derating for Thermo-Lag protected power circuits. Instrumentation and control circuits typically carry low current in relation to cable size and cable derating is not a concern. Therefore, these circuits have not been included in this calculation. The Thermo-lag barrier derating factor, based on TSI design values and values derived from Texas Utilities (TU)/ Tennessee Valley Authority (TVA) testing, is applied after all other applicable derating factors have been calculated. This calculation utilizes circuit information including derating factors for ambient temperature and the number of conductors in a raceway. The following conservatisms are also incorporated in the above calculation:
(1) 125% of full load current is used for circuits which feed motors or circuits which are energized continuously.
(2) 100% of full load current is used for circuits which are not energized continuously.
l 1
- Attachment - Page 2 q
l (3)
All circuit currents are based on the rating of the equipment. Actual loads are normally lower.
Table 1 provides the results of this conservative calculation. This Table indicates that the OCNGS Thermo-Lag protected power circuits can be adequately derated to account for ambient temperatures, multiple conductors in a raceway, and Thermo-Lag fire barrier wrap based on TU/TVA testing, while i
fully satisfying the calculated actual circuit current requirements.
i GPU Nuclear has not incorporated the results of any ampacity test reports other than the referenced TU/TVA testing, which we understand NRC has
]
previously reviewed.
j 2.0 Reauest for Additional Information (RAI) of December 29.1994 a.
NRC Reauest The staff recognizes that most licensees may have excess ampacity margin using valid test data. However, those licensees who utilize industry test data must evaluate whether installed configurations are representative of the tested configurations. The subject evaluations should also analyze any deviations of the installed configuration with respect to the test configuration. The licensee did not indicate that CPSES Unit 2 Thermo-Lag fire barrier configurations were representative of OCNGS configurations.
]
f
Response
i i
The following discussion provides a comparison of installed Thermo-Lag configurations at OCNGS with those tested by TU for Comanche Peak and those tested by TVA to determine Thermo-Lag ampacity derating factors.
The TU CPSES Test Report, " Electrical Test to Determine the Ampacity Derating of a Protective Envelope for Class IE Electrical Circuits, Project No.
12340-94583, 95165-95168, 95246," dated March 19, 1993, yielded ampacity derating values for one hour fire rated conduit, cable tray and air drop fire barriers. OCNGS uses Thermo-Lag on conduit and air drops, not cable tray.
OCNGS uses one hour and three hour rated fire barrier configurations. For three hour rated conduit configurations, comparison is made with testing performed by TVA as documented in TVA Report, " Fire Endurance and Ampacity Testing of One and Three-hour Rated Thermo-Lag Electrical Raceway Fire Barrier Systems."
4 t-w-
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3.
Attachment - Page 3 of NRC letter to NEl dated October 16,1995 asserts that barrier construction is the most important variable in the applicability of test results.
Attributes of construction which are important are as follows:
I Size of any air gap (s)
Barrier Thickness Barrier Geometry l
Raceway Emissivity Intervening thermal resistance (i.e. Flexi-Blanket used m CPSES tests) j i
The TU tests for conduits'were conducted on 3/4 inch,2 inch, and 5 inch conduits. At OCNGS, the size of protected conduits ranges from 1 to 4 inches. The following is a comparison of OCNGS and TU construction attributes-l A. 1-Hour Barriers-Conduit OCNGS TU Size 1,1.25,1.5,2" dia.
Size:
.75-2" dia.
Raceway Material Galvanized Steel Raceway Material Galvanized Steel TSI Thickness
.5 "
TSI Thickness
.75" Preformed Coixluit Yes Preformed Conduit Yes Topcoat No Topcoat-TSI 350 Yes Air gaps No Air Gaps No Steel Bands Yes Max.12" Spacing Steel Baruls Yes 12 " Spacing Size 2.5.3.3.5,4" dia.
Size 5" dia.
Raceway Material Galvanized Steel Raceway Material Galvanized Steel i
TSI Thickness
.5 "
TSI Thickness
.5 "
Preformed Conduit Yes Preformed Conduit Ye, Topcoat No Topcoat-TSI 350 Yes Air Gaps No Air Gaps No Steel Bands Yes Max.12" Spacing Steel Baixis Yes 12" Spacing In comparing OCNGS with TU tested configurations, the lack of an air gap is assumed for both configurations since preformed TSI conduit sections are designed to fit directly around conduit. Note that TU did not test the derating effect around j
j
Attachment - Page 4 l
The differences between OCNGS and TU configurations are in the thickness of the TSI for conduits up to 2" diameter. Because the TU configurations used.75" of TSI vs. 5" at OCNGS, the additional insulating effect of the TU configurations results in the TU test bounding the OCNGS configurations. The results of testing on the 5" diameter conduit should be comparable with OCNGS configurations ranging from 2.5 to 4" as they are the same with the following exception. The presence of the topcoat on the TU configurations is the one common difference between TU and OCNGS configurations. However, the presence of the topcoat tends to result in higher derating values. It is therefore reasonable and conservative to apply derating values obtained in the TU tests for conduit configurations at Oyster Creek.
B.1-Hour Barriers-Air Drops (TU)
In comparing OCNGS and TU configurations, a specific evaluation is not necessary as in the case of the 1-Hour Barriers for conduit. The nature of the difference in the two configurations should be overriding in establishing that the TU tests bound OCNGS configurations. TU's configurations use 3 layers of TSI flexi-blanket material while OCNGS configurations use 2 layers of TSI flexi-blanket material.
Based upon this inherent conservatism, it is reasonable to conclude that the TU test data on air drops bounds the OCNGS configurations.
l l
C. 3-liour Barriers-Conduit (TVA)
4" dia.
Size:
I"-4" dia.
Raceway Material:
Galvanized Steel Raceway Material:
Galvanized Steel TSI Thickness:
1-1.25" TSI Thickness:
1.25" Preformed Conduit: Yes Preforned Conduit: Yes Upgrade:
No Upgrade:
Yes' Air gaps:
No Air Gaps:
No Steel Bands:
Yes-Max.12" Spacing Steel Bands:
Yes-12" Spacing
'The TVA configurations were reinforced with external stainless steel stress skin'and Thermo-Lag 770-1 trowel grade material. Then at least two layers of 3/8" thick Thermo-lag 770-1 Mats buttered with Thermo-Lag 770-1 trowel grade material were installed over the reinforced base Thermo-Lag 330-1 assembly.
Attachment - Page 5 i
The differences between the OCNGS and TVA configurations are in the upgrade
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employed by TVA. Because the TVA configurations used additional mats and trowel-grade material, the additional insulating effect of the TVA configurations should result in the TVA test bounding the OCNGS configurations. It is noted that the TVA test i
results are expressed in terms of a correction factor, not percent derating factor.
Based on the above comparisons, it is reasonable to apply ampacity test results from TU and TVA for those configurations discussed above. The TU and TVA barrier 2
construction bounds OCNGS configurations with respect to ampacity testing. The following ampacity derating factors were obtained from the TU and TVA tests and applied to the OCNGS power circuits in the attached Table 1.
4 One-Hour Fire Wrao (Test by TU) 4 1
6.67 to 10.7 percent - Use 11.0 percent for bounding conservatism.
4 Three-Hour Fire Wrao (Test by TVA)
I 13.0 percent plus an additional 5 percent to account for possible variations in the surface emissivities of installed conduits - Use 18 percent for bounding conservatism.
2 b.
NRC Reauest i
+
In its submittal of December 27,1994, the licensee referred to site specific calculations. If those calculations represent the licensee's final determination of ampacity derating parameters for Thermo-lag fire barriers please forward a copy of the subject calculations for staff review. The licensee is requested to provide its site-specific schedule and plans for the resolution of the ampacity derating issue for Thermo-Lag fire barriers.
Response
The site specific calculation referenced in the GPU Nuclear letter dated December 27, 1994 is the B&R Calculation No. 3731-29-E007, Revision 0, " Adequacy of Fire Wrapped Cables for Appendix R Modifications." This calculation and the additional GPU Nuclear Calculation No. C-1302-814-5350-002 are described in detail in i
response to RAI 1.0, item a. above. These calculations are available onsite for NRC review and represent the final determination of ampacity derating far the existing installed Thermo-Lag fire barriers.
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- ~.. _
Attachment - Page 6 As stated in RAI response 1.0 item a. above, the existing OCNGS Thermo-Lag protected Appendix R power circuits can accommodate the design ampacity derating factors derived from the TU/TVA comparison described in RAI 2.0, item a. above.
in addition, there is derating margin available to accommodate any possible Thermo-Lag upgrades, whem applicable. Future Thermo-Lag upgrade designs will evaluate the specific ampacity derating effects for each upgrade installation configuration.
Potential upgrades will be identified as a result of the Thermo-Lag barrier evaluations to be completed by December 31,1995 and implemented no later than December 1998, in accordance with GPU Nuclear letter to NRC (C321-95-2184) dated July 17, 1995.
c.
NRC Reauest At this time the staff is not aware of any existing or planned NEl initiative Aich will address the ampacity derating issue. If a NEl test program or analysis is expm:ted to be utilized by the licensee please provide specific program details and incorporate any input by NEI into the licensee's overall schedule.
Response
GPU Nuclear is currently not planning to utilize any NEl test program or analysis to address ampacity derating for OCNGS. Based on the ampacity derating calculations and TU/TVA test configuration comparisons described above, the ampacity derating factors utilized for OCNGS are adequate. Additional derating for potential future Thermo-Lag upgrades will be evaluated on a case-by-case basis, where appropriate.
l i
d.
NRC Reauest Finally, the staff expects that the licensee will submit in conjunction with the j
resolution of the fire endurance issue, the test procedures or alternatively, a j
description of the analytical methodobgy including typical calculations whicn will be used to determine the ampacity derating parameters for the Thermo-Lag fire barriers that are installed at Oyster Creek Nuclear Generating Station.
Response
The calculations used to determine the ampacity derating parameters for the Thermo-Lag fire barriers installed at OCNGS are described in detail above. These calculations are available for NRC review. No additional testing or analysis is currently planned to address existing ampacity issues.
e Attachment - Page 7 Table 1 Calculation for Thermo-Lan Ampacity Derating for OCNGS DERATED AMPS ITEM CIRCUlT #
CIRCUlT CABLE SIZE CALCU-
' CABLE DUE TO DESCRIPTION LATED /
RATED ACTUAL AMPS AMBIENT.
MULTIPLE FIRE WRAP
' LOAD
@ 30*C'
> 30*C CONDUCTOR-(USING TSI -
(USING AMPS
- S IN DATA) -
.TUfrVA RACEWAY.
DATA) 1 1IGP1402 Inst. PNL 4C Feed to 2-1/C #8 24 55 50 40 36 35.6 RSP 2
1INP1403 Inst. PNL 4C Feeder 2-1/C #12 10 30 27.3 21.8 20 19.4 to Fire Det. Pnl.
3 112P1406 Halon Syst Protection 2-1/C #12 5.5 30 27 19 17 16.9 4'11-861 HVAC Contral PNL 2/C #10 20 40 36 25 23 22.3 5*
12-600 Battery Charger C1 3-1/C #2/0 12.5 195 177.5 177.5 163 158 Actual 6'12-601 Battery Charger C2 3-1/C #2/0 12.5 195 177.5 177.5 163 158 Actual 7
12-602 Battery Room C 1-3/C #10 4.3 40 36.4 36.4 33.5 32.4 Ventilation Fan F1 8
12-603 Battery Room C 1-3/C #10 4.3 40 36.4 36.4 33.5 32.4 Ventilation Fan F2 9
12-604 Battery Roorn C Vent 1-3/C #10 24 40 36.4 36.4 33.5 32.4 Heater / Fan 10*
12NP0825 "A" SWGR Rm HVAC 3-1/C #12 17.5 30 27.3 21.8 20 19.4 Fan
t i
Attachment - Page 8 Table 1 Calculation for Thermo-Lan Amoacity Deratine for OCNGS 4
ITEM CIRCUIT #
- CIRCUIT -
CABLE SIZE '
CALCU- '.
- CABLE"
' DERATED AMPS.-
- DUE TO.
1 DESCRIPTION
- LATED /
RATED--
i ACTUAL--
AMPS AMBIENT MULTIPLE '.
FIRE WRAP LOAD:
- @ 30*C
> 30*C '
CONDUCTORS (USING TSI (USING AMPS IN RACEWAY
. DATA)
' TU/TVA -
t DATA) j 11*
12NP0826 "A" SWGR RM HVAC 3-1/C #12 17.5 30 27.3 21.8 20 19.4 Fan 12*
12GP0816 Power to Valve 4-1/C #10 10 40 36 25 23 22.3 V-14-37 13*
12GP0817 Power to Valve 3-1/C #12 10.25 30 27.3 19.1 17 17 V-14-32 l
14 122PO845 Refueling Platform 3-1/C #6 30 75 68 48 44 42.7 j
15*
14-25 460V USS IB2 3-1/C 399 475 475 475 437 423 500 MCM f
16*
14-28 460V USS IB3 3-1/C 2/0 150 205 205 205 188-182 i
17 14-31 400 HP Emerg. Serv..
3-1/C 2/0 67 205 205 205 188 182 i
Water Pump 1-3 1/C #6 18' 62-93 125V DC to 460V 2-1/C #6 56 150 136.5 109.2 100.5 97.2 SWGR 1B3 19'62-100 125V DC to 4160V 2-1/C #4 56 95 86.5 69.2 63.7 61.6
{
SWGRID 20'62-153 125V DC POWER to 2-1/C 2/0 85 195 177 177 163 157 DC-2 PNL l
Attachment - Page 9 Table 1 1
Calculation for Thermo-Lan Amoacity Derating for OCNGS ~
- DERATED AMPS 1
ITEM CIRCUlT #
CIRCUIT CABLE SIZE CALCU- -
CABLE DUE TO :
l l
DESCRIPTION LATED / -
RATED
. ACTUAL
' AMPS AMBIENT MULTIPLE FIRE WRAP FIRE WRAP i
LOAD
@ 30*C
> 30*C CONDUCTORS (USING TSI (USING.
AMPS.
~ IN RACEWAY DATA)
TU/TVA 1 I
DATA) -
21'62-158 125V DC to 460 SWGR 2-1/C #2 56 130 118.3 118.3 108 105 1A2 22'62-161 125V DC Power to 2-1/C 2/0 150 195 177 177 163 157 PNL F j
23 62-165 DC Power to RPS PNL I-2/C #10 15 40 36.4 25.5 23.4 22.7 f
6XR j
24 62-168 DC Power to PNL 1IF 1-2/C #10 5
40 36.4 25.5 23.4 22.7 I
l 25 62-169 DC Power to PNL IF/2F 1-2/C #12 14 30 27.3 19.1 17 17 l
26 62-170 DC Power to PNL 3F 1-2/C #10 10 40 36.4 25.5 23 22.7 27' 62GP0229 125V DC Power to 460V 2-2/C #6 56 150 136.5 109.2 100 97
}
SWGR IB3 l
28' 62GP0228 DC Power to 4160V 2-1/C #4 56 95 86.5 69.2 63 61.6 SWGRID i
3 29' 62GP0225 DC Power to V-16-2 11-1/C #8 18.5 55 50
' 35 32 31 30*
62GP0226 DC Power to V-16-14 11-1/C #8 18.5 55 50 35 32 31 l
i h
I I
~
Attachment - Page 10 Table 1 Calculation for Thermo-Lan Amoacity Derating for OCNGS j
' DERATED AMPS :
ITEM CIRCUIT # -
CIRCUlT
CABLE SIZE'
- CALCU-CABLE-1DUE TO i
DESCRIPTION.
. LATED /
RATED ACTUAL AMPS -
. FIRE WRAP LOAD
@ 30*C
. AMBIENT
- MULTIPLE'.
l FIRE WRAP AMPS
. > 30*C '
CONDUCTORS
. USINGTSI
. USING
(
(
IN RACEWAY.
- DATA).
- TUrrVA-i
- DATA) -
31' 86-71 4160V SWGR ID 2 X 3-1/C 543 950 950 950 845 779 j
3-Hour Wrap 500 MCC l
32 21-2038 Drywell Personnel 2/C #12 6.25 30 27 13.5 12.4 12 i
33 12-317 Valve NG02C 4-1/C #12 6
30 27 13.5 12.4 12 i
34 12-318 Valve NG02E 4-1/C #12 6
30 27 13.5 12.4 12 35 12-320 Valve NG03C 4-1/C #12 6
30 27
'13.5 12.4 12 36 12-321 Valve NG03E 3-1/C #12 6
30 27 13.5 -
12.4 12 i
37 12-323 Valve NG08-C 4-1/C #12 0.91 30 27 13.5 12.4 12 4
38 12-324 Valve NG08-E 4-1/C #12 0.91 30 27 13.5 12.4 12.
39 12GP0827 Valve NG03-E 4-1/C #12
'10 30 27 14.0 13 12.4 40 12-328 Valve NG02-B 4-1/C #12 6
30 27 13.5 12.4 12 41 12-330 Valve NG03-B 4-1/C #12 6
30 27 13.5 12.4 12 42 12-332 Valve NG08-B 4-1/C #12 6
30 27 13.5 12.4 12 43 12-335 Valve V-17-54 4-l/C #12 4.9 30 27 13.5-12.4 12 44 12-341 A Valve V-1-107 4-1/C #12 0.69 '
30 27 13.5 12.4 12 l
l l
1 i
Attachment - Page 11 Table 1 Calculation for Thermo-Lac Ampacity Derating for OCNGS ITEM CIRCUlT # -
CIRCUIT CABLE SIZE CALCU-CABLE-DERATED AMPS
' DESCRIPTION LATED /
RATED DUE TO '
ACTUAL AMPS -
LOAD
@ 30*C -
AMPS AMBIENT MULTIPLE FIRE WRAP FIRE WRAP
. > 30'C CONDUCTORS (USING TSI ~
(USING IN RACEWAY DATA) -
TU/TVA DATA) 45 12-342 Valve V-14-37 4-1/C #12 10.3 30 27 13.5 12.4 12 46 12-329 Valve NG02-D 4-l/C #12 6
30 27 13.5 12.4 12 47 12-331 Valve NG-03-D 4-1/C #12 6
30 27 13.5 12.4 12 48 12-333 Valve NG-08D 4-1/C #12 0.91 30 27 13.5 12.4 12 49 12443 Valve V-5-166 4-1/C #12 0.91 30 27 13.5 12.4 12 50 12-446 Valve V-5-148 4-1/C #12 0.91 30 27 13.5 12.4 12 51 12-325 Valve V-16-1 4-1/C #12 4.9 30 27 13.5 12.4 12 52 11-293 SRM #1 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 53 11-294 SRM #2 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 54 11-297 IRM #1 Motor Feed 3-l/C #16 0.29 18 16 8
7.3 7.1 55 11-298 IRM #2 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 56 I l-299 IRM #3 Motor Feed 3-l/C #16 0.29 18 16 8
7.3 7.1 57 11-300 IRM #4 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 58 11-295 SRM #3 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1
(
i
P Attachment - Page 12 Table 1
}
l Calculation for Thermo-Im Ampacity Derating for OCNGS t
t
. ITEM -
CIRCUIT #
CIRCUIT DESCRIPTION-
. CABLE SIZE _
CALCU-
-CABLE
. DERATED AMPS
- 1 LATED /
RATED-DLE TO 1
ACTUAL AMPS :
l LOAD:
@ 30'C-AMPS -
' AMBIENT:
MULTIPLE
. FIRE WRAP '
- > 30'C
- CONDUCTORS
-(USING TSI (USING.
..IN RACEWAY.
' DATA)
TUTIVA '
i DATA) ~
l 59 11-2 %
SRM #4 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 i
60 11-301 IRM #5 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 61 11-302 IRM #6 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 62 11-303 IRM #7 Motor Feed 3-1/C #16 0.29 18 16 8
7.3 7.1 63 11-304 IRM #8 Motor Feed 3-1/C #16 -
0.29 18 16 8
7.3 7.1 i
64*
86-66 EDG-2, Diff. Protn 4-1/C 5
40 36 28.8 26.5 25.6 i
19/22 65*
86GC0016 EDG-2, Diff. Protn 4-1/C #10 5
40 36 25.2 23.2 22.4
[
- Appendix R Circuit r
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a
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