05000298/LER-1997-001, :on 970130,six Containment Penetrations Susceptible to Thermally Induced Overpressurization.Caused by Failure to Recognize Potential Failure Modes in GL 96-06. Evaluated Six Affected Penetrations
| ML20135A096 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 02/18/1997 |
| From: | Moeller C, Peckham M NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-96-06, GL-96-6, LER-97-001, LER-97-1, NLS970034, NUDOCS 9702260446 | |
| Download: ML20135A096 (5) | |
text
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P.0, BOX NEB 68321 Nebraska Public Power District
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NLS970034 February 18,1997 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
Subject:
Licensee Event Report No.97-001 Cooper Nuclear Station, NRC Docket 50-298, DPR-46 The subject Licensee Event Report is forwarded as an enclosure to this letter.
Sincerely, 9
M. F. Peckham Plant Manager
/crm Enclosure cc: Regional Administrator USNRC - Region IV Senior Project Manager USNRC - NRR Project Directorate IV-1 Senior Resident Inspector USNRC 260034 h M-g ' '
NPG Distribution INPO Records Center W. Turnbull MidAmerica Energy 9702260446 970218 PDR ADOCK 05000298 g
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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY CMB NO. 3150 o104 14 95)
EXPIRES 04/30/98 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THl3 MANDATORY INFORMAil04 COLLECTION REQUES1: 50.0 HRS. REPORTE0 LESSONS LEARNED ARE INCORPORATE 0 IN LICENSEE EVENT REPORT (LER) y,$E S8 " j0 M,AC i B
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TH N Tw C R0$ A NT A H U S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20MH001. AND TO THE j
{See reverse for required number of PA,P,ER,R(R U,C PROJECT 0150-0104L OFFICE OF MANAGEMENT AND BUOGET,
, g digits / characters for each block)
FJ.CluTY NAME n)
DOCKET NUMBER (2)
PAGE (31 COOPER NUCLEAR STATION 05000298 1OF3 TITLE (4) l Six Containment Penetrations Susceptible to Thermally induced Overpressurization EVENT DATE (5)
LER NUMBER (6)
REPORT DAT E (7)
OTHER FACILITIES INVOLVED (B)
SE0VENTIAL REVISION MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NUMBER 01 30 97 97 -- 001 00 02 18 97 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREM INT i OF 10 CFR 5: (Check one c r more) (11)
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MODE (9) 20.2201(b) 20.2203(a)(2)(v) 50.73(a)(2)(i) 50.73(a)(2)(viii) i POWER 20 2203(a)(1) 20.2203(aH3)(i)
Y 50.73(a)(2)(ii) 50.73(a)(2)(x) j 100 LEVEL (to) 20.2203(a)(2)(in 20.2203(a)(3)(iii 50.73(a)(2)(iii) 73.71 j
20 2203(a)(2Hii) 20 2203(aH4) 50.73(aH2Hiv)
OTHER 20.2203(a)(2)(iii)
So.36(cH1) 50.73(aH2Hv) specify in Abstract below 20.2203(aH2)(iv)
So.36(c)(2)
So.73(a)(2Hvii)
LICENSEE CONTACT FOR THIS LER (12)
N/.ME TELEPHONE NUMeER (Include Area Codel j
Chris R. Moeller, Senior Staff Licensing Engineer (402) 825-3811 COMPLETF ONE LINE FOR EACH COMPONENT FAILURE DEliCRIBED IN THIS REPORT (13)
R R " BE
CAUSE
SYSTEM COMPONENT MANUFACTURER
CAUSE
SYSTEM COMPONENT MANUFACTURER ONPRD NPRD SUPPLEMENTAL REPORT EXPECTED (14)
MONTH DAY YEAR EXPECTED YES SUBMISSION (if yes, complete EXPECTED SUBMISSION DATE).
X NO DATE (15)
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single spaced typewritten lines) (16)
While performing engineering evaluations in response to NRC Generic Letter 96-06, it was determined that six containment penetrations are susceptible to thermally induced overpressurization during certain design basis accidents. At 1340 hours0.0155 days <br />0.372 hours <br />0.00222 weeks <br />5.0987e-4 months <br /> on January 30,1997, it was determined that this situation was reportable as a condition outside design basis.
The apparent cause for this condition is the failure to recognize and address the potential failure modes described in Gsneric Letter 96-06 during original plant design and construction (NUREG 1022, Appendix B, Cause Code B). An evaluation of the structuralintegrity of the bounding configuration demonstrates that continued operability is assured for all six penetrations. Evaluation of the six affected penetrations to quantify the impact and required corrective actions is continuing. Corrective actions planned or taken to resolve this issue will be communicated to the NRC in follow up response to Generic Letter 96-06.
NRC FORM 366 (4 95)
- U.S. NUCLEAR REGULATORY COMMISSION (4 95)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
SEQUENTIAL REVISION YEAR NUMBER NUMBER COOPER NUCLEAR STATION 05000298 2
OF 3
97 -- 001 00 TEXT (11 more space is required, use additional copies of NRC Form 366A) (11)
PLANT STATUS At the time of discovery, the plant was at full power operation.
EVENT DESCRIPTION
in response to Generic Letter 96-06, a review of all containment penetrations was performed to identify those piping s:gments that are normally isolated or that isolate in response to a valid loss-of-coolant accident (LOCA) signal.
Only those completely filled with water were considered as the compressibility of either gas or steam will naturally limit the potential pressure increase to acceptable limits. The following penetrations were identified as a result of thir. review:
P:netration No. (1)
Size
Description
X8 3"
Main Steam Drainline X12 20" Residual Heat Removal Shutdown Cooling Suction X14 6"
Reactor Water Clean-Up Suction X18 3"
Drywell Equipment Sump Discharge X19 3"
Drywell Floor Sump Discharge X2O 4"
Demineralized Water Header Supply (2)
X41 3/4" - 1 "
Reactor Recirculation Sample Line Notes:
(1) A complete loss of plant instrument air was assumed in developing this listing due to the f set that the station air compressors are non-essential and will be de-energized following a LOOP.
I (2) Manually isolated whenever containment integrity is required.
Of these penetrations, six were subsequently determined to be susceptible to the affects of thermally induced ovsrpressurization (specifically X8, X12, X14, X18, X19, and X20).
CAUSE
j Th3 apparent cause for this condition is the failuro to recognize and address the potential failure modes described in Ganeric Letter 96-06 during original plant design and construction.
The cause classification for this condition is Design, Manuf acuring, Construction / Installation (NUREG 1022, Appendix B, Cause Code B).
SAFETY SIGNIFICANCE
An evaluation of the structural integrity of the bounding configuration demonstrates that, while minor yielding will occur (on the order of 4% or less), continued operability is assured for all six penetrations. Therefore, while these penetrations are susceptible to overpressurization, the safety-significant concerns described in Generic Letter 96-06 will not occur.
'U.S. NUCLEAR RE,1ULATORY COMMISSION 14 95)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
SEQUENTIAL REVISION YEAR COOPER NUCLEAR STATION 05000298 NUMBER NUMBER 3
OF 3
97 -- 001 --
00 TEXT fit more space is required, use additional copies of NRC Form 366A) (17)
CORRECTIVE ACTIONS
Evaluation of the six affected penetrations to quantify the impact and required corrective actions is continuing.
Corrective actions planned or taken to resolve this issue will be communicated to the NRC in follow up response to Gsneric Letter 96-06.
PREVIOUS EVENTS 7
None.
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NRC FOR*J 3664 64 951
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,l ATTACHMENT 3 LIST OF NRC COMMITMENTS l
Correspondence No: NLS970034 The following table identifies those actions committed to by the District in this document. Any other actions discussed in the submittal represent intended or planned actions by the District.
They are described to the NRC for the NRC's information and are not regulatory commitments.
Please notify the Licensing Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.
COMMITTED DATE
COMMITMENT
OR OUTAGE None
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l PROCEDURE NUMBER 0.42 l
REVISION NUMBER 3 l
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