05000369/LER-2011-001, Regarding Shutdown of Two Units Due to Entry Into LCO 3.0.3 Caused by the Inoperability of All Four Trains of the Nuclear Service Water System Due to Strainer Macro-Fouling
| ML110880096 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 03/21/2011 |
| From: | Repko R Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| M-11-00329 LER 11-001-00 | |
| Download: ML110880096 (13) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat |
| LER closed by | |
| IR 05000369/2011004 (28 October 2011) | |
| 3692011001R00 - NRC Website | |
text
REGIS T. REPKO lDuke Vice President
,Energy McGuire Nuclear Station Duke Energy MGO0 VP / 12700 Hagers Ferry Rd.
Huntersville, NC 28078 980-875-4111 980-875-4809 fax regis. repko@duke-energy. corn March 21, 2011 U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, D.C. 20555
Subject:
Duke Energy Carolinas, LLC McGuire Nuclear Station, Units 1 and 2 Docket No. 50-369, 50-370 Licensee Event Report 369/2011-01, Revision 0 Problem Investigation Process Number M-1 1-00329 Pursuant to 10 CFR 50.73 Sections (a) (1) and (d), attached is Licensee Event Report (LER) 369/2011-01, Revision 0, regarding the shutdown of both McGuire operating Units due to entry into Technical Specification Limiting Condition for Operation 3.0.3, caused by the inoperability of all four trains of the Nuclear Service Water (RN) System as a result of RN strainer macro-fouling.
This report is being submitted in accordance with 10 CFR 50.73 (a) (2) (i) (B), an operation prohibited by Technical Specifications and 10 CFR 50.73 (a) (2) (v) (B), any event or condition that could have prevented fulfillment of the safety function.
The completion of the Unit 1 and Unit 2 nuclear plant shutdowns and the resultant Unit 1 Reactor Protection System actuation is being reported separately under McGuire LER 369/2011-02.
This event is considered to be of no significance with respect to the health and safety of the public. There are no regulatory commitments contained in this LER.
If questions arise regarding this LER, contact Lee A. Hentz at 980-875-4187.
Sincerely, Regis T. Repko Attachment www. duke-energy. com
U.S. Nuclear Regulatory Commission March 21, 2011 Page 2 cc.
V. M. McCree, Regional Administrator U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, Georgia 30303-1257 Jon H. Thompson (Addressee Only)
Senior Project Manager (McGuire)
U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738 J. B. Brady Senior Resident Inspector U.S. Nuclear Regulatory Commission McGuire Nuclear Station W. L. Cox Ill, Section Chief North Carolina Department of Environment and Natural Resources Division of Environmental Health Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1645
Abstract
Unit Status: At the time of the event, Units 1 and 2 were in Mode 1 at 100% power.
Event Description
On January 18, 2011, during testing of the lB Nuclear Service Water (RN) pump while aligned to the Standby Nuclear Service Water Pond (SNSWP),
its associated strainer became fouled with small, bluegill fish.
After further investigation and testing, it was determined that both RN trains on each Unit were potentially inoperable due to macro-fouling from the SNSWP.
Both Units entered TS LCO 3.0.3 and initiated shutdowns.
McGuire requested and received a Notification of Enforcement Discretion (NOED) for both Units to remain in Mode 3 until the macro-fouling source was eliminated.
Event Cause
The causes of this event were lack of an effective macro fouling barrier in the SNSWP, deferral of the fish eradication treatment of the SNSWP in
- 2010, and lack of risk recognition.
Corrective Actions
The SNSWP was chemically treated to eliminate the macro-fouling source and the RN intake lines were flushed.
A periodic chemical treatment was established and a macro-fouling barrier modification is planned.
NRC FORM 366 (10-2010)
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Therefore, this event is considered to have a small risk impact and is of no significance with respect to the health and safety of the public.
ADDITIONAL INFORMATION
The 2011 RN strainer macro-fouling event is not considered recurring.
Although there have been previous macro-fouling challenges to the RN strainers, notably the July 2007 and April 2009 events, these events did not overwhelm the strainers (with backwash in service) rendering the RN system inoperable.
To determine if a recurring or similar event exists, a search of the McGuire Problem Identification Process (PIP) database was conducted for a time period covering 5 years prior to the date of this event.
Based on Duke Energy's definition of a recurring event, similar significant event with the similar event and cause codes; no recurring events were identified associated with macro-fouling of important raw water systems at McGuire.
NRU 'UR1A J66A (lU-2UlU)