05000285/LER-2011-010-01, Regarding Fire Causes a Circuit Breaker to Open Outside Design Assumptions

Regarding Fire Causes a Circuit Breaker to Open Outside Design Assumptions

ML121850033
Person / Time
Site:	Fort Calhoun
Issue date:	06/29/2012
From:	Bannister D Omaha Public Power District
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LIC-12-0091 LER 11-010-01
Download: ML121850033 (5)

LER-2011-010, Regarding Fire Causes a Circuit Breaker to Open Outside Design Assumptions

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 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)(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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
2852011010R01 - NRC Website

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Omaha Public Power District 444 South 16'" Street Mall Omaha, NE 68102-2247 LlC-12-0091 June 29, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Reference: Docket No. 50-285

Subject:

Licensee Event Report 2011-010, Revision 1, for the Fort Calhoun Station Please find attached Licensee Event Report 2011-010, Revision 1, dated, June 29, 2012. This revision provides the direct cause of the event and updated corrective actions. Changes are noted by revision bars. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(v)(A), (B), (C) and (D). This letter contains no commitments. If you should have any questions, please contact me.

Sincerely,

,.&~

D. J Bannister Vice President and Chief Nuclear Officer DJB /rmc Attachment c:

E. E. Collins, Jr., NRC Regional Administrator, Region IV L. E. Wilkins, NRC Project Manager J. C. Kirkland, NRC Senior Resident Inspector II\\JPO Records Center Employment with Equal Opportunity

NRC FORM 366 (10-2010)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters for each block)

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Fort Calhoun Station

2. DOCKET NUMBER 05000285

3. PAGE 1 OF 4

4. TITLE Fire Causes a Circuit Breaker to Open Outside Design Assumptions

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.

MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 6

7 2011 2011 - 010 -

1 6

29 2012 FACILITY NAME DOCKET NUMBER 05000

9. OPERATING MODE 5

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)

OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)

Specify in Abstract below or in LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET mitigation due to the extensive flooding that occurred along the Missouri River beginning in June 2011.

FCS had declared a Notice of Unusual Event on June 6, 2011, due to rising river level and river projections, and resources were focused on flood response and asset protection. The anomalous operation of circuit breaker 1B3A was determined to be reportable on November 15, 2011. FCS has been systematically addressing issues that have been identified since June 2011 in response to the flooding conditions, switchgear fire, and increased oversight. This LER was submitted beyond the 60-day regulatory reporting requirement due to non-conservative decisions with respect to procedural and regulatory reportability requirements and resource constraints caused by the operating challenges which began in June 2011.

SAFETY SIGNIFICANCE

At the time of the fire on June 7, 2011, FCS was in refueling Mode 5 and shutdown cooling was not lost during the event. However, due to the tripping of both redundant trains of safety-related 480 Vac power, spent fuel pool cooling was lost. Spent fuel pool cooling was restored in approximately two hours with only minimal heat up (3 degrees F) of the spent fuel pool cooling water which had a time to boil of 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Based on this there was no actual impact on the health and safety of the public.

SAFETY SYSTEM FUNCTIONAL FAILURE This event does result in a safety system functional failure in accordance with NEI-99-02.

PREVIOUS EVENTS LER 2011-008 documents the fire associated with this event.