05000331/LER-2012-001, Regarding Inoperability of Low Pressure Coolant Injection Due to Discharge Line Voiding

Regarding Inoperability of Low Pressure Coolant Injection Due to Discharge Line Voiding

ML12032A041
Person / Time
Site:	Duane Arnold
Issue date:	01/31/2012
From:	Wells P NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NG-12-0045 LER 12-001-00
Download: ML12032A041 (4)

LER-2012-001, Regarding Inoperability of Low Pressure Coolant Injection Due to Discharge Line Voiding

Event date:
Report date:
Reporting criterion:	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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3312012001R00 - NRC Website

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" _______. ______ ------------- _____ ~I_- : ___ ~ ________________ _

January 31,2012 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Duane Arnold Energy Center Docket 50-331 License No. DPR-49 Licensee Event Report #2012-001-00 NEXTera M

ENERGV~

DUANE

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ARNOLD NG-12-0045 10 CFR 50.73 Please find attached the subject report submitted in accordance with 10 CFR 50.73. This letter makes no new commitments or changes to any existing

commitments

Peter Wells Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324

NRC FORM 366 (10-2010)

PRINTED ON RECYCLED PAPER 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 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 Records and FOIA/Privacy Service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202 (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to 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.

1. FACILITY NAME Duane Arnold Energy Center

2. DOCKET NUMBER 05000331

3. PAGE 1 OF 3

4. TITLE Inoperability of Low Pressure Coolant Injection Due to Discharge Line Voiding

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 N/A DOCUMENT NUMBER 05000 12 02 11 2012 001 0

01 31 12 FACILITY NAME N/A DOCUMENT NUMBER 05000

9. OPERATING MODE

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)

X 50.73(a)(2)(vii) 1 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)

10. POWER LEVEL 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) 100%

20.2203(a)(2)(iv) 50.46(a)(3)(ii)

X 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)

X 50.73(a)(2)(v)(D)

VOLUNTARY LER

12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)

Robert J. Murrell, Engineering Analyst (319) 851-7900 CAUSE SYSTEM COMPONENT MANU-FACTURER REPORTABLE TO EPIX

CAUSE

SYSTEM COMPONENT MANU-FACTURER REPORTABLE TO EPIX N/A N/A N/A N/A N/A

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED MONTH DAY YEAR X

YES (If yes, complete 15. EXPECTED SUBMISSION DATE)

NO SUBMISSION DATE 03 8

2012 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

On December 2, 2011, while operating at 100% power, with no Technical Specification (TS) Limiting Condition for Operability (LCO) in effect, Ultrasonic Testing (UT) examination of the B Residual Heat Removal (RHR) (IEEE System Code BO) injection line identified an air void of approximately 1.5-2 cubic feet. A void of this size had not previously been analyzed and therefore, the Low Pressure Coolant Injection (LPCI) system was declared inoperable at 1311. On December 3, 2011, after operating RHR in the torus cooling mode, venting of the system, acceptable UT examination results, and completion of an engineering evaluation, LPCI was declared operable at 1650. The cause of this event was inadequate design of the B RHR inject line vent pipe location. This design deficiency was corrected on December 9, 2011.

During the time that LPCI was inoperable, all other Emergency Core Cooling Systems (ECCS) were fully operable and capable of performing their safety functions. As of the date of this Licensee Event Report (LER), the impact of the void discovered on December 2, 2011 is unknown. Engineering analysis of the void is currently ongoing and a supplemental LER is expected to be submitted by March 8, 2012.

Based on the information known at the time of discovery, this event did result in a Safety System Functional Failure and was reported under 10CFR50.72(b)(3)(v)(B) on December 8, 2011, reference Event Notification 47511.

(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)

PRINTED ON RECYCLED PAPER IV.

Corrective Actions

On December 9, 2011, a modification was completed that installed a new vent at the high point on the B LCPI inject line. This modification was successful in reducing the void size to less than 0.1 cubic foot.

To address the extent of condition and contributing causes for this event, the following actions will be completed.

1. Review the high point vent locations for horizontal piping for the GL 2008-001 systems to ensure the vent connections are installed on horizontal piping runs at the top center of the applicable pipes.

2. Operating procedures will be revised to ensure that GL 2008-001 horizontal piping section are examined by UT upon return to service following maintenance or re-alignment to standby readiness conditions from secondary modes of operation to preclude unacceptable voiding.

3. Installation of a similar vent on the A LPCI inject line.

V.

Additional Information

Previous Similar Occurrences:

A review of License Event Reports from the past 5 years did not identify any previous similar occurrences where a system was incapable of performing its safety function as a result of excessive voiding.

EIIS System and Component Codes:

BO - Residual Heat Removal/Low Pressure Coolant Injection System

Reporting Requirements

This event is being reported as an Event or Condition that Could Have Prevented Fulfillment of a Safety Function, 10CFR50.73(a)(2)(v)(B and D) and a Common-cause Inoperability of Independent Trains or Channels, 10CFR50.73(a)(2)(vii). Additionally, this event was reported under 10CFR50.72(b)(3)(v)(B),

Specified System Actuation, reference Event Notification 47511.