05000286/LER-2011-001, Regarding Technical Specification Prohibited Condition Caused by an Inoperable 32 Containment Spray Pump Due to High Contact Resistance in the Supply Breaker Closing Circuit
| ML110810069 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 03/10/2011 |
| From: | Joseph E Pollock Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-11-019 LER 11-001-00 | |
| Download: ML110810069 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2862011001R00 - NRC Website | |
text
Entergy Indian Point Energy Center 450 Broadway, GSB3 P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 J. E. Pollock Site Vice President NL-11-019 March 10, 2011 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop O-Pl-17 Washington, D.C. 20555-0001
SUBJECT:
Licensee Event Report # 2011-001-00, "Technical Specification Prohibited Condition Caused by an Inoperable 32 Containment Spray Pump Due to High Contact Resistance in the Supply Breaker Closing Circuit" Indian Point Unit No. 3 Docket No. 50-286 DPR-64
Dear Sir or Madam:
Pursuant to 10 CFR 50.73(a)(1), Entergy Nuclear Operations Inc. (ENO) hereby provides Licensee Event Report (LER) 2011-001-00. The attached LER identifies an event where there was a Technical Specification (TS) prohibited condition for failure to perform TS required actions within the required completion time for an inoperable Containment Spray Pump during past operation, which is reportable under 10 CFR 50.73(a)(2)(i)(B). This condition was recorded in the Entergy Corrective Action Program as Condition Report CR-IP3-2010-03523.
There are no new commitments identified in this letter. Should you have any questions regarding this submittal, please contact Mr. Robert Walpole, Manager, Licensing at (914) 734-6710.
Sincerely, JEP/cbr cc:
Mr. William Dean, Regional Administrator, NRC Region I NRC Resident Inspector's Office, Indian Point 3 Mr. Paul Eddy, New York State Public Service Commission LEREvents@inpo.org
Abstract
On November 12, 2010, during performance of the quarterly functional test of the 32 Containment Spray Pump (CSP) the supply breaker failed to close.
The breaker was fully charged and there were no abnormal indications.
A second attempt to close the breaker failed and the breaker was racked out and visually inspected with no anomalies identified with the breaker or cubicle.
A test of the close circuit was satisfactory and the breaker and cubicle secondary contacts were cleaned and inspected.
With the breaker in the test position it operated successfully, but when racked into the connect position it failed to close.
The trip circuit was verified to operate.
The breaker problem was isolated to the close circuit.
With the breaker racked in and charged, the fuses were removed and the control switch was positioned to close while measuring continuity across the closing circuit.
With the breaker in the test position all indications were as required.
With the breaker in the connect position, an open circuit was measured.
Measurements and contact alignment inspections were performed with no problems identified.
The breaker was replaced with a spare breaker and the quarterly test successfully performed.
The direct cause was the breaker closing circuit was not reset to allow breaker closure.
The apparent cause was a malfunction in the breaker closing circuit resulting in an open circuit.
Engineering's review of a vendor equipment failure evaluation (EFE) concluded the breaker failed to close due to a high contact resistance of the motor cutoff switch.
Corrective actions include breaker replacement and revision of the Preventive Maintenance procedure to include resistance testing of the motor cutoff switch contacts.
The event had no significant effect on public health and safety.
(if more space is required, use additional copies of (if more space is required, use additional copies of (if more space is required, use additional copies of NRC Form 366A) (17)
The Containment Fan Cooler System consisting of five 20 percent capacity FCUs and the Containment Spray System consisting of two 50% trains are divided into trains based on the safeguards power train which supports them.
Containment Spray Train 31 is associated with Safeguards Power Train 5A which is supported by DG 33.
Containment Spray Train 32 is associated with Safeguards Power Train 6A which is supported by DG
- 32.
Fan Cooler Train 5A consists of FCU 31 and FCU 33 (CSP 31); Fan Cooler Train 2A/3A consists of FCU 32 and FCU 34; and Fan Cooler Train 6A consists of FCU 35 (CSP 32).
Five FCUs or two CS trains or three FCUs and one CSP are adequate to meet minimum safeguards function.
During the period of the inoperable 32 CSP, there was minimum safeguards capability available.
An assessment was performed to determine the impact of the condition on Core Damage Frequency (CDF) and Large Early Release Frequency (LERF).
The assessment considered the case of both CSS headers out of service.
The assessment concluded there is no significant impact on CDF or LERF.