05000400/LER-2012-003, For Shearon Harris, Unit 1, Regarding Primary Shield Cooling Fan Fails to Secure as Required
| ML12363A046 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 12/20/2012 |
| From: | Kapopoulos E Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP-12-140 LER 12-003-00 | |
| Download: ML12363A046 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 4002012003R00 - NRC Website | |
text
PDuke E Energy Ernest J. Kapopoulos, Jr.
Plant General Manager Harris Nuclear Plant 5413 Shearon Harris Rd New Hill NC 27562-9300 919-362-2000 December 20, 2012 Serial: HNP-12-140 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Shearon Harris Nuclear Power Plant, Unit 1 Docket No. 50-400 Subject: Licensee Event Report 2012-003-00 Ladies and Gentlemen:
Carolina Power & Light Company submits the enclosed Licensee Event Report (LER) 2012-003-00 in accordance with 10 CFR 50.73. This report describes a condition where a Primary Shield Fan, S-2B-SB, failed to remain secured after engaging the Main Control Board hand switch. This LER is submitted within 60 days following discovery of the condition in accordance with 10 CFR 50.73(a)(2)(i)(B) as an event that resulted in a condition prohibited by plant Technical Specifications. The root cause evaluation is ongoing and this LER will be supplemented following completion of the evaluation.
This document contains no regulatory commitments. Please refer any questions regarding this
,submittal to Dave Corlett at (919) 362-3137.
Sincerely, Enclosure: LER 2012-003-00 cc:
Mr. J* D. Austin, NRC Sr. Resident Inspector, HNP Ms. A. T. Billoch Col6n, NRC Project Manager, HNP Mr. V. M. McCree, NRC Regional Administrator, Region II
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA/Privacy Section (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail LICENSEE EVENT REPORT (LER) to infocollects.resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of (See reverse for required number of Management and Budget, Washington, DC 20503. Ifa means used to digits/characters for each block) impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Shearon Harris Nuclear Power Plant, Unit 1 05000400 1 of 4
- 4. TITLE Primary Shield Cooling Fan Fails to Secure as Required
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR EUE R
ENO.
None FACILITY NAME DOCKET NUMBER 10 26 2012 2012-003-00 12 20 2012 None
- 9. OPERATING
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
MODE El 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii) 0 20.2201 (d)
Z 20.2203(a)(3)(ii)
ED 50.73(a)(2)(ii)(A)
[1 50.73(a)(2)(viii)(A) 1 Ej 20.2203(a)(1)
LI 20.2203(a)(4)
DI 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
DI 20.2203(a)(2)(i)
[I 50.36(c)(1)(i)(A)
.0 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER [I 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A)
[I 50.73(a)(2)(iv)(A)
LI 50.73(a)(2)(x)
LEVEL El 20.2203(a)(2)(iii)
[I 50.36(c)(2) 0I 50.73(a)(2)(v)(A)
LI 73.71 (a)(4)
DI 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii) 0I 50.73(a)(2)(v)(B)
El 73.71 (a)(5) 100%
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
Z 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or I
_in
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
Event Description
At 10:18 EDT on October 26, 2012, during the monthly equipment swaps, supply fan S-2B-SB [FAN],
Primary Shield Fan, failed to remain secured after engaging the Main Control Board hand switch. An attempt to secure the fan was completed 2 times. Each time, the S-2B-SB fan cycled OFF and subsequently after the release of the hand switch the fan cycled back ON. The S-2B-SB fan was the only affected fan and the opposite train was not affected by this condition as demonstrated by the proper operation of the S-2A-SA on October 26, 2012.
On October, 31, 2012 at 15:26, Off-Normal Tag 2012-0909 was hung on breaker 1 B21-SB-4B (S-2B-SB) [BKR] to open the breaker due to fan not remaining secured when stopped. On November 1,
.2012, per Work Order 2156801, the 42 seal-in contact [CNTR] was replaced for 1B21-SB-4B cubicle feeding the S-2B-SB Primary Shield Fan. The S-2B-SB fan was successfully started and secured from the MCB hand switch for post maintenance testing.
From time of discovery on October 26, 2012 at 10:18, until the breaker was opened on October 31, 2012 at 15:26 was a total of approximately 5 days.
Cause of Failures The root and primary contributing cause have not yet been determined as the Root Cause Evaluation (RCE) is ongoing. This LER will be supplemented upon completion of the evaluation and will discuss the result of the evaluation, the cause and planned corrective actions.
I
Safety Consequences
Preliminary results of the investigation are as follows:
For the Primary Shield Fan load, upon loss of power to the 1B-SB ESF bus, the 6.9kV Circuit Breaker 1B-SB-10 feeding the 1B3-SB Power Center is opened resulting in de-energization and load shed of the 1B3-SB Power Center and associated loads. The 42 starter coil de-energizes and the main contactors open shedding the load from the distribution system. Once the loading of the diesel generator has begun, operation of the under voltage relays is blocked. All the above was unaffected by the condition.
Essential loads are divided into eight "load blocks" for automatic loading via the Emergency Sequencer.
There are time delays known as "design intervals" between individual load blocks to allow motors from one load block to accelerate and to allow bus voltage to recover prior to starting motors in the next "load block."
The Emergency Safeguards Sequencer sends a start signal to the Primary Shield Fan during load block
- 6. However, due to the defective 42 seal-in contact, the Primary Shield fan is re-energized when the bus is repowered. Therefore, the sequencer would perform its function of energizing the fan, but in this case the action is redundant because the fan is already running. There is no failure in the sequencer functionality.
The Harris emergency diesel generators are capable of starting a 1300 hp load at any point of load sequencing including being the last load to sequence (with the resulting steady-state load being equal to the Emergency Diesel Generator rating). The Primary Shield Fan is rated at 40 hp and therefore is well within the design capability of the EDG. Based on the loading margin for the Emergency Diesel Generator there is no impact to the ability for the EDG to provide power to the engineered safety feature loads. However, the Primary Shield Fan (S-2B-SB) would not have been initially energized through the load sequencer and therefore would not meet verbatim compliance with Technical Specifications 4.8.1.1.2.
Corrective Actions
Completed Corrective Actions
- The 42 seal-in contact was replaced and the S-2B-SB fan tested satisfactorily
" Applicable plant procedures have been revised to address the condition when breakers for selected loads started from the sequencer fail to open and the corresponding impact on operability.
Planned Corrective Actions
- Will be determined following completion of the ongoing Root Cause Evaluation.
Previous Similar Events
A review of previous events will be performed following completion of the Root Cause Evaluation which will determine the cause of the event and be included in the supplement to this LER.
Commitments
This report contains no regulatory commitments.