05000353/LER-2014-001, Regarding Inoperable Reactor Enclosure Secondary Containment Integrity Due to Open Airlock

Regarding Inoperable Reactor Enclosure Secondary Containment Integrity Due to Open Airlock

ML14049A082
Person / Time
Site:	Limerick
Issue date:	02/18/2014
From:	Dougherty T Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LG-14-012 LER 14-001-00
Download: ML14049A082 (5)

LER-2014-001, Regarding Inoperable Reactor Enclosure Secondary Containment Integrity Due to Open Airlock

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(i)(B), Prohibited by Technical Specifications
3532014001R00 - NRC Website

text

10CFR50.73 LG-14-012 February 18, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 2 Facility Operating License No. NPF-85 NRC Docket No. 50-353

Subject:

LER 2014-001-00, Condition That Could Have Prevented Fulfillment of the Reactor Enclosure Secondary Containment Integrity Safety Function This Licensee Event Report (LER) addresses a condition that could have prevented fulfillment of the reactor enclosure secondary containment integrity safety function. Both airlock doors on one reactor enclosure airlock were briefly opened simultaneously. The airlock design does not prevent simultaneous door opening. This LER is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(v)(C).

There are no commitments contained in this letter.

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

Respectfully, Original signed by Thomas J. Dougherty 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 4

4. TITLE Inoperable Reactor Enclosure Secondary Containment Integrity Due to Open Airlock

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 12 18 2013 2014 -

001

- 00 02 18 2014 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

Cause of the Event

This event was not prevented by the design of the reactor enclosure airlocks since there is no mechanical interlock and the door open indicating light does not prevent simultaneous opening of both airlock doors.

Corrective Action Planned A modification is being evaluated for the airlock doors.

Previous Similar Occurrences Unit 1 LER 2014-002 was submitted due to a reactor enclosure airlock breach caused by a weakness in the airlock design. Unit 1 LER 2014-001 was submitted due to a reactor enclosure airlock breach caused by a weakness in the airlock design. Unit 2 LER 2013-003 was submitted due to a reactor enclosure airlock breach caused by a weakness in the airlock design. Unit 2 LER 2013-002 was submitted due to a reactor enclosure airlock breach caused by a non-functional airlock door open indicating light not providing the correct door status.