05000387/LER-2014-007, Regarding Loss of Secondary Containment Pressure During RPS Transfer

Regarding Loss of Secondary Containment Pressure During RPS Transfer

ML14163A316
Person / Time
Site:	Susquehanna
Issue date:	06/12/2014
From:	Franke J Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7184 LER 14-007-00
Download: ML14163A316 (5)

LER-2014-007, Regarding Loss of Secondary Containment Pressure During RPS Transfer

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
3872014007R00 - NRC Website

text

JUN.l 2 2014 Jon A. Franke Site Vice President U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PPL Susquehanna, LLC 769 Salem Boulevard Berwick, P A 18603 Tel. 570.542.2904 Fax 570.542.1504 jfranke@pplweb.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387(388)/2014-007-00 UNIT 1 LICENSE NO. NPF-14 UNIT 2 LICENSE NO. NPF -22 PLA-7184 Docket Nos. 50-387 50-388 Attached is Licensee Event Report (LER) 50-387(388)/2014-007-00. The LER reports a loss of secondary containment pressure during a Reactor Protection System (RPS) transfer.

The condition was determined to be reportable in accordance with 10CFR50.73(a)(2)(v) as an event that could have prevented the fulfillment of the safety function.

There were no actual consequences to the health and safety of the public as a result of these events.

~~w regulatory commitments.

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ittachment: LER 3 87(388)/2014-007 -00 Copy:

NRC Region I Mr. J. E. Greives, NRC Sr. Resident Inspector Mr. J. A. Whited, NRC Project Manager Mr. L. J. Winker, PA DEP/BRP

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0113112017 (01-2014)

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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 />.

!¥-"i Reported lessons learned are incorporated into the licensing process and fed back to industry.

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LICENSEE EVENT REPORT (LER)

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 (See Page 2 for required number of internet e-mail to lnfocollects.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 digits/characters for each block) 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.

r* PAGE Susquehanna Steam Electric Station, Unit 1 05000387 1 OF4

4. TITLE Loss of Secondary Containment Pressure During RPS Transfer

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

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

MONTH DAY YEAR Susquehanna, Unit 2 05000388

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FACILITY NAME DOCKET NUMBER 04 24 2014 2014

- 007

- 00 OL>

2014 05000

9. OEPRAllNG MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 5 D 20.2201(b)

D 20.2203(a)(3)(i)

D 50.73(a)(2)(i)(C)

D 50.73(a)(2)(vii)

D 20.2201(d)

D 20.2203(a)(3)(ii)

D 50.73(a)(2)(ii)(A)

D 50.73(a)(2)(viii)(A)

10. POWER LEVEL D 20.2203(a)(1)

D 20.2203(a)(4)

D 50.73(a)(2)(ii)(B)

D 50.73(a)(2)(viii)(B)

D 20.2203(a)(2)(i)

D 50.36(c)(1 )(i)(A)

D 50.73(a)(2)(iii)

D 50.73(a)(2)(ix)(A) 000%

D 20.2203(a)(2)(ii)

D 50.36(c)(1 )(ii)(A)

D 50.73(a)(2)(iv)(A)

D 50.73(a)(2)(x)

D 20.2203(a)(2)(iii)

D 50.36(c)(2)

D 50.73(a)(2)(v)(A)

D 73.71(a)(4)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50.73(a)(2)(v)(B)

D 73.71(a)(5)

D 20.2203(a)(2)(v)

D 50.73(a)(2)(i)(A)

[8J 50.73(a)(2)(v)(C) 0 OTHER D 20.2203(a)(2)(vi)

D 50.73(a)(2)(i)(B)

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

Specify in Abstract below or in Investigation

3. PAGE 30F4 The procedure steps for bus restoration specified a fan logic reset because the procedure assumed that Filtered Exhaust Fan 1V217B would remain tripped on low flow after the Zone Ill lockout relays were reset thereby requiring a reset in order to restart the fan. However, this assumption was not correct since the low flow trip of Fan 1V217B had already been cleared as a subsequent action during the RPS power supply transfer. The responsible engineer indicated that the system performed as designed by tripping Supply Fan 1V212B since turning off a filtered exhaust fan trips the supply fan and subsequently the exhaust fan.

The relay for 1V212B was bench tested to validate proper response time. The relay test was satisfactory.

CAUSE OF THE EVENT

Apparent Cause-A deficiency with procedure steps that did not account for actual/designed system response.

ANALYSIS/SAFETY SIGNIFICANCE

There were no actual or potential consequences to the health and safety of the public as a result of this event.

This failure only affected normal reactor building ventilation and at no time was the safety-related function of the secondary containment boundary or standby gas treatment system impacted. This event will not be counted as a Safety System Functional Failure for the NRC performance indicator since no loss of safety function occurred.

CORRECTIVE ACTIONS

Key corrective actions include:

1. The Unit 1 and Unit 2 procedures governing RPS transfers and the off-normal procedures for loss of RPS were revised to enhance the method of restoring ventilation by taking the Zone I and Zone Ill filtered exhaust fans to stop after swapping RPS and returning the fans to start after the lockout relays are reset.

2. The Unit 1 RPS transfer procedure will be reviewed to ensure all steps are correct and will not result in unexpected loss of secondary containment and/or other unexpected response; any necessary revisions will be applied to the applicable procedures for both Units 1 and 2.

PREVIOUS SIMILAR EVENTS

3. PAGE 40F4 LER 50-387(388)/2013-004-00: Loss of Secondary Containment Due to Differential Pressure Not Meeting Technical Specification 3.6.4.1 LER 50-387(388)/2013-005-00: Loss of Secondary Containment LER 50-387(388)/2013-006-00: Loss of Secondary Containment due to Differential Pressure not Meeting Technical Specification 3.6.4.1 LER 50-387(388)/2013-008-00: Loss of Secondary Containment due to Failed Solenoid Valve in the Reactor Building Zone I Ventilation Exhaust System LER 50-387(388)/2014-002-00: Secondary Containment Door Found Ajar LER 50-387(388)/2014-004-00: Loss of Secondary Containment Pressure Due to Fan Trip LER 50-387(388)/2014-005-00: Loss Of Secondary Containment Due To Differential Pressure Not Meeting Technical Specification 3.6.4.1