05000285/LER-2012-012-01, Regarding Multiple Safety Injection Tanks Rendered Inoperable

Regarding Multiple Safety Injection Tanks Rendered Inoperable

ML12353A618
Person / Time
Site:	Fort Calhoun
Issue date:	12/18/2012
From:	Cortopassi L Omaha Public Power District
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
LIC-12-0187 LER 12-012-01
Download: ML12353A618 (5)

LER-2012-012, Regarding Multiple Safety Injection Tanks Rendered Inoperable

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(8) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 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)(i)(B), Prohibited by Technical Specifications
2852012012R01 - NRC Website

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jjjjjjjj Omaha Public Power D1sIrIcI 444 South Nih Street Mall Omaha, NE 68102-2247 LlC-12-0187 December 18, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Reference: Docket No. 50-285

Subject:

Licensee Event Report 2012w012, Revision 1, for the Fort Calhoun Station Please find attached Licensee Event Report 2012-012, Revision 1, dated December 18, 2012. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(8), 10 CFR 50.73(a)(2)(v)(D), and 10 CFR 50.73(a)(2)(vii)(D).

No commitments are being made in this letter.

If you should have any questions, please contact me.

Sincerely u..

ouis P. Cortopassi Vice President and CND LPC/rjr/epm Attachment c:

E. E. Collins, Jr., NRC Regional Administrator, Region IV L E. Wilkins, NRC Project Manager J. C. Kirkland, NRC Senior Resident Inspector 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 sp onsor, and a person is not required to respond to, th e

information collection.

1. FACILITY NAME Fort Calhoun Station

2. DOCKET NUMBER 05000285

3. PAGE 1 OF 4

4. TITLE Multiple Safety Injection Tanks Rendered Inoperable

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 03 19 2012 2012 - 012 -

1 12 18 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 CONCLUSION The cause of this condition was the failure to recognize that the passive design of the SITs cannot credit the use of active components for operability.

CORRECTIVE ACTIONS

The event was entered into the Corrective Action Program and the following corrective actions were taken. Operating Procedure OI-SI-1, Safety Injection - Normal Operation, the TS Basis for TS 2.3, Emergency Core Cooling System, and the Updated Safety Analysis Report, Section 6.2, Engineered Safeguards Safety Injection System, have been revised to clearly state the SITs operability requirements.

SAFETY SIGNIFICANCE

The cross-connection of the SITs exposed the tanks to a diversion flow path. However, there is a high likelihood that if an event requiring SIT injection had occurred, the SITs being sluiced would have fulfilled their safety function. The valves used for sluicing, HCV-2916, 2936, 2956, and 2976, automatically isolate via a Safety Injection Actuation Signal (SIAS). Therefore, although crediting the use of the SIAS to close these valves is not consistent with the passive safety function of the SITs, the use of this flow path did not result in a loss of the SIT functionality. Additionally, there were only short periods of time (less than one hour at a time) during which multiple (two) SITs were cross-connected.

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

PREVIOUS EVENTS None, however, 22 LERs initiated since January 1, 2010, were identified with the same reporting criteria; 10 CFR 50.73(a)(2)(i)(B), Any operation or condition which was prohibited by the plant's Technical Specifications, 10 CFR 50.73(a)(2)(v)(D), Any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident, and 50.73(a)(2)(vii)(D), Any event where a single cause or condition caused two independent trains or channels to become inoperable in a single system designed to mitigate the consequences of an accident.

None of the LERs reviewed contained the same underlying concern or reason of this event, such as the same root cause, failure, or sequence of events.