05000333/LER-1994-001, :on 940224,HPCI Sys Had Declared Inoperable Due to Turbine Shaft Seal Leakage.Caused by Corrosion of Gland Seal Casing & Pitting.New Turbine Shaft Seals Installed.W/
| ML20065G342 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 04/06/1994 |
| From: | Harry Salmon, Simpson D POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| JAFP-94-0193, JAFP-94-193, LER-94-001, LER-94-1, NUDOCS 9404120247 | |
| Download: ML20065G342 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(x) |
| 3331994001R00 - NRC Website | |
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1 James A.ntzPatrick Nuclear Power Plant -
P,0, Boa 41
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. Lycoming, New York 13093 315 342-3840' ewY0.rkPower M
UthOrity -
Harry P. Salmon, Jr.
nosident Manager April 6, 1994' JAFP-94-0193-i
. United States Nuclear Regulatory Commission Document Control Desk Mail Station P1-137 Washington, D.C.
20555
SUBJECT:
DOCKET NO. 50-333 LICENSEE EVENT REPORT:
LER-94-001-01:
High Pressure Coolant-Injection System Declared Inoperable Due to Turbine Shaft Seal Leakage
Dear Sir:
This updated report is submitted in accordance with-10CFR50.73 (a) (v).
This update deletes Corrective Action #5, which was to balance the HPCI-gland exhaust system.
In preparation'for performing _this action, it was determined.to be unnecessary based upon other. actions completed which have minimized deterioration of the gland-seal casing and-shaft-seal area.
In addition, vendor system experts no longer recommend balancing of the system.
Questions concerning this report may be addressed to Mr. Donald Simpson at (315) 349-6361.
Very truly yours,
/
l
/
l HARRY P.
SALMON, JR.
HPS:
- tic Enclosure cc:
USNRC,_ Region I USNRC Resident Inspector INPO Records Center 9404120247 940406 PDR: ADDCK 05000333
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NRC FOR,M 366 U.S. C JCLEAR REEJLATOY Capet!SSIO APPROVED BY 015 NO. 3150-0104 (5 02)
EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH LICENBEE EVENT REPORT (LER)
$4,3"To"^s[3" RNRDING" o
S BUR EN STI TE b THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, (See reverse for required nunber of digits / characters for each block)
ON, C 20555 0001 AND TO THE R
MANAGEMENT AND BUDGET, WASHI E lQH. DC 20503.
FACILITY NAE (1)
DOCKET IB8eER (2)
PAGE (3)
James A.
FitzPatrick Nuclear Power Plant 05000333 01 OF 04 TITLE (4) High Pressure Coolant Injection System Declared Inoperable Due to Turbinn R h n f't-Anal T.nn}arrn EVENT DATE (5)
LER Mt9EER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
M(DTH DAY YEAR YEAR MONTH DAY YEAR 05000 NUMBER NUMBER FACILITY NAME DOCKET NUMBER Ol+
94 02 24 94 94 001 01 05000 OPERATING TH IS REPORT IS susMITTED PURSUANT TO THE REautRrwNTs of 10 CrR 1: (Check one or more) (11)
N G DE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b) 20.405(a)(1)(1) 50.36(c)(1)
X 50.73(a)(2)(v) 73.71(c) pg, 100 LEVEL (10) 20.405(a)(1)(ti) 50.36(c)(2) 50.73(a)(2)(vil)
OTHER 20.405(a)(1)(lii) 50.73(a)(2)(1) 50.73(a)(2)(vill)(A)
(Specify In act 20.405(a)(1)(lv) 50.73(a)(2)(li) 50.73(a)(2)(vilf)(B) e 20.405(a)(1)(v) 50.73(a)(2)(111) 50.73(a)(2)(x)LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER (include Area Code)
Mr. Donald Simpson, Senior Licensing Engineer (315) 349-6361 i
COMPLETE ONE t INE FOR EACH C[MPOWENT FAf tURE DESCRIBfD IN THle REPORT (13)
CAUSE
SYSTEM COMPONENT MANUFACTURER OS
CAUSE
SYSTEM COMPONENT MANUFACTURER D
4 SUPPLEN NTAL REPORT EXPECTED (14)
MONTH DAY YEAR DPEC M 7ES SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE).
NO y
DATE (15)
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)
The plant was operating at 100 percent power on 2/24/94 with the reactor i
mode switch in Run.
The High Pressure Coolant Injection (HPCI) system had j
been declared inoperable in order to perform scheduled surveillance testing.
During initial roll of the turbine, operators observed an approximate 3 to 4 foot plume of steam from the inboard shaft seal which did not diminish as the turbine came up to speed.
The turbine was tripped and the limiting condition for operation for HPCI system inoperablity continued.
The shaft seal was replaced and the HPCI system declared operable on 2/26/94.
The steam seal leakage was caused by minor corrosion on gland seal surfaces and shaft sealing surfaces due to moisture within the turbine casing.
Increased monitoring for leakage past the HPCI steam supply valve during standby conditions and corrective maintenance on the gland seal casings will improve turbine steam seal performance.
LER-89-014 describes a similar event where the HPCI system was declared inoperable due to moisture intrusion in the lubricating oil system.
NRC FORM 366 (5-92)
NRC FC;M 3664 U.S. MuttEAR REcutATORY CxzettsSlou APetovtD BY UMB No. 3150-0104 (5 92)
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LICENBEE EVENT REPORT (LER)
EE"#TrOE$ AERI('5YoSSNAcE BRAu$
1 g g ). y.S. N glE R,80 0104),9,i R,Y RE tA TEXT CONTINUATION p955 99 HE A k
REDUCTION PROJECT (31 OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON. DC 20503.
FACILIiY MAMF (1)
DOCKFT WJMRfR (2) t FR 1RDETR (6?
PAGF (3)
James A.
FitzPatrick Nuclear I
YEAR N
02 OF 04 Power Plant 05000333 94 01 001 TEXT (If more space is reoJtred. ylp ock11tional copies of NRC Form 366A) (17)
EIIS Codes are in []
Event Description
On February 24, 1994, the plant was operating at 100 percent power with the reactor mode switch in Run.
Preparations had been completed for performing a quick start transient monitoring test on the High Pressure Coolant Injection (HPCI) (BJ] system turbine.
A Limiting Condition for Operation (LCO) was entered in accordance with Technical Specification 3.5.C.1.
At 0833 hours0.00964 days <br />0.231 hours <br />0.00138 weeks <br />3.169565e-4 months <br />, the turbine was rolled with steam.
Operators stationed at the turbine to observe the HPCI response observed a 3 to 4 foot plume of steam from the inboard turbine shaft seal.
As the turbine came up to speed the leak did not diminish.
The turbine was immediately tripped and the HPCI system declared inoperable.
The limiting condition for operation was continued.
ENS notification was completed at 0958 hours0.0111 days <br />0.266 hours <br />0.00158 weeks <br />3.64519e-4 months <br /> in accordance with 10CFR50.72.
The steam seal was replaced and the turbine shaft inspected for damage.
The maintenance turbine engineer concluded based upon equipment failure evaluation that the installed seal had not failed, that the leakage observed was minor and would have had no significant effect on HPCI performance.
Post maintenance testing on the HPCI turbine was performed and HPCI declared operational at 0056 hours6.481481e-4 days <br />0.0156 hours <br />9.259259e-5 weeks <br />2.1308e-5 months <br /> on 2/26/94.
The HPCI system was inoperable for approximately 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />.
CMM The HPCI system seal leakage was caused by minor corrosion of the gland seal casing and pitting of the turbine shaft in the seal area.
The gradual degradation of these components was due to exposure to a damp environment over an extended period of time because of past seat leakage of the HPCI steam supply isolation valve (Cause Code X).
Frequent periodic testing and previous ineffectiveness of the gland exhaust system contributed to the ll observed degradation.
Because the HPCI system is normally in a standby condition, the wetted environment permitted accelerated corrosion of the gland seal casing which prevented the carbon ring seals from providing an adequate (radial) seal when steam is admitted to the turbino.
Tapered dowels, which align the upper and lower gland casing, were found to be worn and could also have contributed to the observed leakage.
Minor pitting of the turbine shaft in the seal area had cut groves into the two inboard seal rings, thereby providing a second (axial) path for steam Icakage.
m3C f owM 366A d-92)
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lutC FCM 366A U.S. NUCLEAR RLGJLATORT CDOllSSION APPROVED BY (se NO. 3150-0104
($.92)
EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 hrs.
^
LICENSEE EVENT REPORT (LER) 7[NF0EE A REC DS NAGE BRAN TEXT CONTINUATION g,$gg,gMg33y, N LEAR REGULATOR ON REDUCTION PROJECT 1 0-0104),
OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON. DC 20503.
FACILITY MAfE (1)
DOCKET IRAWE R (?)
LER IEDGER (6?
l PAE (3)
SEQUENTIAL REVI5!UN YEAR James A.
FitzPatrick Nuclear 05000333 03 OF 04 94 01 Power Plant 001 TEXT (If more sonce is reaulrtd. use addition 6L cooies of NRC Form 366A) (IT)
Analysis The HPCI system is an engineered safety feature designed to provide a highly reliable source of water to the reactor vessel at sufficient pressure and volume to maintain reactor core coverage through a broad spectrum of postulated accident conditions.
If this sys".em is not available, core coverage is still assured by the Automatic Depressurization [SB] System together with other low pressure emergency core cooling systems including the two redundant trains of Core Spray [BM] and the two redundant trains of Low Pressure Coolant Injection (LPCI) [BO].
Because the HPCI system was conservatively declared inoperable upon the observation of steam seal leakage this event is reportable under 10CFR50. 73 (a) (2) (v) as a condition that could have prevented the fulfillment of the safety function of a system needed to remove residual heat or mitigate the consequences of an accident.
The safety significance of this occurrence is low because subsequent inspection showed the seals were in good condition and that the minor leakage was due to. gradual degradation of the gland casing and shaft pitting.
Turbine shaft pitting had not degraded appreciably since a March, 1992 inspection in part due to implementation of vendor recommendations regarding the gland seal and exhaust system, which have minimized further degradation.
Based upon observed leakage during the test performance and subsequent inspection findings, there is reasonable assurance that the HPCI system could have performed its intended function.
The leakage observed was minor and not of sufficient magnitude as to result in a system isolation due to I
steam leak detection or high ambient temperature.
Corrective Actions
1.
New turbine shaft seals were installed on 2/25/94.
2.
The HPCI steam supply isolation valve is not leaking past the seat at this time.
The most recent apparent leakage occurred in February, 1993. ' Plant operators have initiated periodic monitoring of the HPCI turbine casing temperature during standby conditions to provide early identification of steam supply isolation valve leakage.
The HPCI turbine gland seal casing will be replaced or refurbished 3.
during the 1994 refuel outage.
4.
The HPCI turbine shaft pitting condition will be evaluated and an action plan developed by June 30, 1994.
l-
]
1 atC FogM 366A U.S. OCLIAR REGA.AIC]Y COMMISSION APPROVED BY CNB NO. 3150-0104
,(5-92)
EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENBEE EVENT REPORT (LER)
THE INFORMATION AND RECORDS MANAGEMENT BRANCH l
TEXT CONTINUATION (m as 7/14), U.S. NUCLEAR REGULATORY COMMISS10N, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJici (31$0-0104),
OFFICE OF MANAGEMENT AND BUDGET. WASHil(GTON. DC 20503.
FACILITY NAMi (1)
DOCKET MlMRER (?)
LER MlMRfR (65 PAGE (3)
James A.
FitzPatrick Nuclear ygAn SEQUENTIAL REVISION Power Plant 05000333 94 01 04 OF 04 1
001 TEXT (If more space is reauir i use additional cooles of MRC Form 366A) (IT)
Additional Information
Failed Component Identification:
None i
Previous Similar Events
LER-89-014, Reported the HPCI system declared inoperable due in part to steam i
supply isolation valve leakage which resulted in water contamination of the lubricating oil system.
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