05000331/LER-2014-004, Regarding Unplanned Inoperability of High Pressure Coolant Injection

Regarding Unplanned Inoperability of High Pressure Coolant Injection

ML14210A355
Person / Time
Site:	Duane Arnold
Issue date:	07/25/2014
From:	Richard Anderson NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NG-14-0183 LER 14-004-00
Download: ML14210A355 (4)

LER-2014-004, Regarding Unplanned Inoperability of High Pressure Coolant Injection

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
3312014004R00 - NRC Website

text

NEXTeraM ENERGYNQ ARNOLD July 25, 2014 NG-14-0183 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Duane Arnold Energy Center Docket 50-331 Renewed Op. License No. DPR-49 Licensee Event Report #2014-004 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

ic~hard L. Anderson Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC cc:

Administrator, Region III, USNRC Project Manager, DAEC, USNRC Resident Inspector, DAEC, USNRC NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)

(02-2014)

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.

vIw.

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections R(LER)

Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. or by E

EE EPORT internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of 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 digits/characters for each biock) control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE Duane Arnold Energy Center 05000-331 1 OF 3

4. TITLE Unplanned Inoperability of High Pressure Coolant Injection

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEARSEOUENTIAL REV FACILITY NAME DOCKET NUMBER YEAR NUMBER NO.

MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 05 30 2014 2014-004 00 07 25 2014 N/A N/A

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

E] 20.2201 (b)

[]

20.2203(a)(3)(i)

[I 50.73(a)(2)(i)(C)

El 50.73(a)(2)(vii)

D 20.2201(d)

- D 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)

LI 50.73(a)(2)(viii)(A)

LI 20.2203(a)(1)

D 20.2203(a)(4)

El 50.73(a)(2)(ii)(B)

EL 50.73(a)(2)(viii)(B)

__ 20.2203(a)(2)(i)

EL 50.36(c)(1)(i)(A)

LI 50.73(a)(2)(iii)

L] 50.73(a)(2)(ix)(A)

10. POWER LEVEL LI 20.2203(a)(2)(ii)

LI 50.36(c)(1)(ii)(A)

LI 50.73(a)(2)(iv)(A)

LI 50.73(a)(2)(x)

E] 20.2203(a)(2)(iii)

LI 50.36(c)(2)

LI 50.73(a)(2)(v)(A)

L] 73.71(a)(4)

LI 20.2203(a)(2)(iv)

LI 50.46(a)(3)(ii)

LI 50.73(a)(2)(v)(B)

EI 73.71(a)(5) 100%

20.2203(a)(2)(v)

LI 50.73(a)(2)(i)(A)

LI 50.73(a)(2)(v)(C)

LI OTHER Specify in Abstract below or in 20.2203(a)(2)(vi) 5 (a)(2)(i)(B) 50.73(a)(2)(v)(D)

I.

Description of Event

On May 30, 2014, at 1043, while operating at 100% power, during the performance of a routine Technical Specification (TS) required Surveillance Test Procedure (STP), the 'A' side High Pressure Coolant Injection (HPCI) (BG) isolation logic was activated. The logic activation occurred while attempting to block open contacts of HGA relay E41A-K43, HPCI Auto Isolation Logic Steam Line High Differential Pressure. The root cause of this event was the design of the HGA relay makes the act of installing relay blocks very difficult and prone to inadvertent actuation. On May 30, 2014, at 1209, HPCI was returned to operable status after resetting the isolation logic and returning the system to standby readiness condition.

This resulted in an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> reportable event. The Resident Inspector was notified, and Event Notification 50154 was made pursuant to 10 CFR 50.72(b)(3)(v)(D) due to a condition at the time of discovery that prevented the fulfillment of the HPCI safety function.

There were no radiological releases associated with this event. There were no other structures, systems or components inoperable at the start of this event that contributed to the event.

II.

Assessment of Safety Consequences

There were no actual safety consequences associated with this event; the potential safety consequences were minimal. During the time period that HPCI was inoperable, all other Emergency Core Cooling Systems were fully capable of performing their safety functions.

This event did result in a safety system functional failure.

Ill.

Cause of Event

A Root Cause Evaluation was completed. The evaluation identified the following root cause:

The design of the HGA relay makes the act of installing relay blocks very difficult, and prone to inadvertent actuation.

IV.

Corrective Actions

On May 30, 2014, at 1209, HPCI was returned to operable status after resetting the isolation logic and returning the system to standby readiness condition.

The following actions will be taken to address the root cause of this event:

Eliminate the use of HGA relay blocks in all STPs where inadvertent actuation could cause an un-planned shutdown, LCO, system unavailability, or a reportable event.

V.

Additional Information

Previous Similar Occurrences:

A review of DAEC Licensee Event Reports from the past 5 years identified one similar occurrence, reference LER 2012-004.

EIIS System and Component Codes:

BG - High Pressure Core Spray System (BWR)

Reoortina Reauirements:

This event is being reported as an 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, 10CFR50.73(a)(2)(v)(D).