05000353/LER-2015-004, Regarding Valid Manual Actuation of the Primary Containment Isolation System

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Regarding Valid Manual Actuation of the Primary Containment Isolation System
ML15232A734
Person / Time
Site: Limerick Constellation icon.png
Issue date: 08/20/2015
From: Libra R
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
LG-15-105 LER 15-004-00
Download: ML15232A734 (4)


LER-2015-004, Regarding Valid Manual Actuation of the Primary Containment Isolation System
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation

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)(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
3532015004R00 - NRC Website

text

LG-15-105 10CFR50.73 August 20, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 2 Renewed Facility Operating License No. NPF-85 NRC Docket No. 50-353

Subject:

LER 2015-004-00, Valid Manual Actuation of the Primary Containment Isolation System This Licensee Event Report (LER) addresses a valid manual actuation of the primary containment isolation system in response to a low delta pressure condition in reactor enclosure secondary containment. The manual actuation affected primary containment isolation valves in more than one system.

This LER is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(iv)(A).

There are no regulatory commitments contained in this letter.

If you have any questions, please contact Robert B. Dickinson at (610) 718-3400.

Respectfully, Original signed by Richard W. Libra Vice President - Limerick Generating Station Exelon Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, LGS

NRC FORM 366 (01-2014)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (01-2014)

LICENSEE EVENT REPORT (LER)

(See Page 2 for required number of digits/characters for each block)

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 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 and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to Infocollects.Resource@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 Limerick Generating Station, Unit 2
2. DOCKET NUMBER 05000353
3. PAGE 1 OF 3
4. TITLE Valid Manual Actuation of the Primary Containment Isolation System
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 06 21 2015 2015 -

004

- 00 08 20 2015 FACILITY NAME DOCKET NUMBER 05000
9. OPERATING MODE
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 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)
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) 100 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 normal ventilation system. Per TS 3.6.5.1.1, Reactor Enclosure Secondary Containment Integrity surveillance requires pressure within the reactor enclosure secondary containment to be maintained greater than or equal to 0.25 inches of vacuum water gauge.

Cause of the Event

The cause of the event was a trip of the reactor enclosure ventilation system that resulted in a low reactor enclosure secondary containment delta pressure condition. The cause of the ventilation system trip was a REECE system flow transmitter output drift to a value less than the low flow trip setpoint.

Corrective Action Completed The failed flow transmitter was replaced.

The reactor enclosure ventilation system was restored to service and continues to operate normally with the TCC installed.

Corrective Action Planned Troubleshooting is planned to support removal of the TCC that was installed to defeat the REECE system low flow trip.

The preventive maintenance (PM) activity for the REECE system flow transmitter will be reviewed and revised as necessary.

Previous Similar Occurrences On May 21, 2013, Limerick Unit 1 submitted LER 2012-003-01 which reported a valid manual actuation of the primary containment isolation system. The event was due to a reactor enclosure ventilation system trip that resulted in manual actuation of the primary containment isolation system.

Component data:

Cause

B (Design, Manufacturing, Construction/Installation)

System:

VA (Reactor Building Environ Control System)

Component:

FT (Transmitter, Flow)

Manufacturer:

B384 (Brandt Ind)

Model:

PI-DPT2000