TXX-6480, Interim Deficiency Rept CP-86-83 Re Use of Separation Barrier Matl on Power Cables & Power Raceways.Initially Reported on 861208.Nonconformance Rept CE-87-4577 Dispositioned.Next Rept Will Be Submitted by 870828
| ML20214U685 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 06/05/1987 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-86-83, TXX-6480, NUDOCS 8706110297 | |
| Download: ML20214U685 (3) | |
Text
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Log. #'TXX-6480
_P """
File # 10110 L
O 908.3 C
C Ref # 10CFR50.55(e) nlELECTRIC MiHism G. Gmmil c m in, n,ana,,
June 5, 1987 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.
20555 i
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 SEPARATION BARRIER MATERIAL ON POWER CABLES AND 4
1 POWER RACEWAYS SDAR: CP-86-83 (INTERIM REPORT)
Gentlemen:
On December 8,1986, we verbally notified your Mr. Ian Barnes of _ a deficiency i
involving the use of Separation Barrier Material (SBM) on power cables and power raceways. Our last interim report submitted was logged TXX-6338, dated March 20, 1987. We have concluded that this issue is reportable under the provisions of 10CFR50.55(e) and the required information follows.
DESCRIPTION i
j Contrary to the established design requirements, thermal SBN was installed on power cables and associated raceways without considering -the effects of the material on the ampacity of the cables.
As previously noted (in TXX-6338), calculations have concluded that, due to significant conservatism in cable sizing design, the specific cables noted in the initiating nonconformance and cables in raceways did not exceed their j
insulation temperature rating during start-up testing.
i Further evaluation of the deficiency, conducted to assure the cable sizing design is sufficiently conservative to counteract the derating effects of SBM, i
has resulted in the identification of 32 inadequate power cable installations.
{
These cables, listed in Attachment A, could have exceeded the ampacity rating i
previously assumed for plant operations (i.e., 40 year design life). _ These._
l cables are currently documented by Nonconformance Reports (NCRs).
l SAFETY IMPLICATION SBM installed on power cables and/or power raceways requires derating of the l
cables' power carrying capacity (ampacity) to compensate for change in the-l operational environment.
By failing to address the derating factor,~the power i
cables could exceed the design temperature rating. -Cable operation above the l
temperature rating is unpredictable. Actual failure of the cable insulation would be determined by the degree of temperature increase, the time spent operating over the rating, and other factors - which makes the point of actual failure indeterminate. However, failure could cause Class IE power systems to
.O.
become inoperative.
8706110297 870605 ~~
400 North Olhe Street t II. HI Dallas. Texas 75201 l
PDR ADOCK 05000445 t k 1
TXX-6480 June 5, 1987 Page 2 of 2 This issue represents a significant final design deficiency as approved and released for construction and, were it to have remained uncorrected, could have adversely affected the safety of plant operations.
CORRECTIVE ACTIONS As a result of the analysis, NCR CE-87-4577 has been dispositioned to require removal of all SBM from power cables / raceways except where specifically designated for radiant energy shield purposes in the containment buildings.
To preclude additional instances of this deficiency, construction procedure CP-CPM 10.3, " Application of the Thermolag Fire Protection System", will be revised to adequately control the installation of SBM.
Our next report, statusing corrective actions, will be submitted by August 28, 1987. At that time, the construction schedule will be developed to the extent necessary to forecast actual completion dates.
Very truly yours, 4
l' W. G. Counsil WJH/dl Attachment c - Mr. R. D. Martin - Region IV CPSES Resident Inspector - 3 copies
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1 AtCachment TXX-6480 June 5, 1986
- Page 1 of 1 Attachment A The following raceways contain the listed cables that would have insufficient
'ampacity for design life plant operatioris if B&B SBM were left in place:
Raceway No.
Cable No.
C12$05099 A9100562 C12905984 A$100450 C12G05247 A$100562 C12G06343 EG100197A CO2912407 E9006954 C12913221 E(100818 C12918156 EG100227A C12018157 E(100227B CO2918344 E0000376 C12G21190 EG105547 C22000418 E0200443, 444, 561 C22G05996 EG200194 T12$RBK06,07,08 A0100224Z T12KCBR14, 15 NK001103, NK00ll33 T12KRBT23, 24, 25, 26, 27 NK101940Z-43Z, 46Z-48Z SIZ-53Z, 55Z-57Z T12KABN46 NK001178, NK101802, 803 s