ML17125A013

LER 17-003-00 for Susquehanna, Units 1 and 2, Regarding Loss of Secondary Containment Zone 3 Due to Fan Trip

ML17125A013
Person / Time
Site:	Susquehanna, Susquehanna Steam Electric Station Unit 2 05000-387
Issue date:	05/05/2017
From:	Berryman B Susquehanna, Talen Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7604 LER 17-003-00
Download: ML17125A013 (4)

Text

MA Y: .0 5 , 2017 Brad Berryman Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Susquehanna Nuclear, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax 570.542.1504 robert.franssen@talenenergy

.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387(388)/2017-003-00 UNIT 1 LICENSE NO. NPF-14 UNIT 2 LICENSE NO. NPF -22 PLA-7604 ENERGY 10 CFR 50.73 Docket No. 50-387 50-388 Attached is Licensee Event Report (LER) 50-387(388)/2017-003-00.

This LER reports an event involving the loss of Secondary Containment due to a low flow trip of all Zone III fans. This LER is being submitted pursuant to the requirements of 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented fulfillment of a safety function.

Should you have any questions regarding this submittal, please contact Mr. Jason Jennings, Manager-Nuclear Regulatory Affairs at (570) 542-3155.

There were no actual consequences to the health and safety of the public as a result of this event. This letter contains no new regulatory commitments.

B.Benyman

Attachment:

LER 50-387(388)/2017-003-00 Copy: NRC Region I Ms. T. E. Hood, NRC Project Manager Ms. L. Micewski, NRC Sr. Resident Inspector Mr. M. Shields, PA DEP/BRP NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 (04-2017) E st im ate d burd en per r es p o n se to com ply w ith th is m a nd atory co ll ec ti on r eq u es t: 8 0 h o ur s. LICENSEE EVENT REPORT (LER) Repo r ted l essons lea rn e d are in cor p o r ate d in to th e li ce n si ng pr ocess a nd fed b ack to i n d u st ry. I_L ( .i Se nd co mm e nt s r eg a r ding burd e n est im ate t o th e I nf o rm a ti o n Se rv ices Br a n c h (T-2 F 43), U.S. ':J'i (S e e Page 2 for requ i red num b er of for e ac h bl ock) N u clea r Re gul a t ory Co mm issio n , Was h i ngt o n , DC 2 0 555-00 01 , or b y e-mail t o lnf oco ll ec t s. ........

• R eso ur ce@nr c.g ov, a nd t o th e D esk O ffi ce r, O ffi ce o f In fo rm atio n a nd R eg ul a t ory A ffair s, (See NUREG-1 022 , R.3 for instruction and guidance for completing this form NE O B-10 20 2 , (3 1 5 0-0 1 0 4), O ffi ce of M a n a g e m e nt a nd Bud get, W as hi n gt o n , D C 205 0 3. If a m ea n s u s ed t o imp ose an inf o rm a ti o n co ll ec ti on do es n o t di s pl ay a c urrently v a l i d OM B co ntr o l number, htto://www. n rc.gov/reading

-rm/doc-collectio ns/nu regslstafflsr1 022/r3 0 th e NR C m a y not condu c t o r s p o n so r, a nd a pe r son i s n ot r e quired to r es p o nd to, th e inf o rm a tion co ll ec ti o n. 1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE Susquehanna Steam Electric Station Unit 1 05000387 1 OF3 4. TITLE Loss of secondary Containment Zone 3 Due to Fan Trip 5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED SEQUENTIAL FACILITY NAME DOCKET NUMBER MONTH DAY YEAR Y EAR REV MONTH DAY YEAR Susquehanna Steam Electric Station Unit 2 NUMBER NO. 050000388 03 08 2017 2017 003 00 05 2017 FACILITY NAME DOCKET NUMBER O S 05000 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: Check all that apply) 1 D 20.2201(b) D 20.2203(a)(3)(i)

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

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

D 20.2201(d)

D 20.2203(a)(3)(ii)

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

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

D 2 0.2203(a)(1)

D 20.220 3 (a)(4) D 50.73(a)(2)(iii)

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

D 20.2203(a)(2)(i)

D 50.36(c)(1 )(i)(A) D 50.73(a)(2)(iv)

(A) D 50.73(a)(2)(x) 10. POWER LEVEL D 20.2203(a)(2)(ii)

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

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

D 73.71(a)(4) D 20.2203(a)(2)(iii)

D 50.36(c)(2)

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

D 73.71(a)(5) 100 D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii) 50.73(a)(2)(v)(C)

D 73.77(a)(1) D 20.2203(a)(2)(v)

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

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

D 73.77(a)(2)(i)

D 20.2203(a)(2)(vi)

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

D 50.73(a)(2)(vii)

D 73. 77(a)(2)(ii)

D 50.73(a)(2)(i)(C) 0 OTHER Specify i n Abstrac t be l ow or in NRC F or m 366A 12. LICENSEE CONTACT FOR THIS LER LI C EN S EE CO NT AC T NUMBER (I n c l ude A r ea Code) !Nicole PaQiiaro, Licensing Specialist-Nuclear Regulatory Affairs

13. COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT MANU-REPORTABLE CAUSE SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX 14. SUPPLEMENTAL REPORT EXPECTED 15. EXPECTED MONTH DAY YEAR D YES (If yes , complete 15. EXPECTED SUBMISSION DATE) IZI NO SUBMISSION DATE (Lim it to 1400 spa c es , i.e., appr ox ima t ely 15 s ingle-s pa c ed type w ritt e n lin es) On March 8, 2017 at approximately 0239 hours0.00277 days <br />0.0664 hours <br />3.95172e-4 weeks <br />9.09395e-5 months <br />, Secondary Containment Zone Ill (Unit 1&2 Reactor Building) differential pressure lowered to less than the Technical Specification (TS) limit of 0.25 in w.g. due to due to Load Center Breaker 2B240-021 (supply breaker to 2Y246) being returned to service w i thout Motor Control Center (MCC) Breaker 2B246-023 (supply breaker to 2Y246) restored.

As a result, TS 3.6.4.1 Surveillance Requirement (SR) 3.6.4.1.1 was not met due to the loss of vacuum. The condition is being reported in accordance with 10 CFR 50.73(a)(2)(v)(C) as an event or condition that could have prevented fulfillment of a safety function.

The cause of the event was less than adequate procedure use and adherence.

Corrective actions included a communication to Operators and a revision to the Procedure and Work Instructions Use and Adherence procedure to perform a second check for non-conditional procedure steps. There were no actual consequences to the health and safety of the public as a result of this event. NRC FORM 3 66 (04-2017)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150*0104 EXPIRES: 3/31/2020 (04-20 1 7) LICENSEE EVENT REPORT (LER} CONTINUATION SHEET (See NUREG-1 022, R.3 for instruction and gu i dance for completing this form http://W'NW.nrc.gov/reading-rm/doc

-collections/nureos/stafftsr1 022/r3 l) 1. FACILITY NAME Est im at e d 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 incorpo r ated into the l icensing process and fed back to indu stry. Send comments regarding burden estimate to th e Inf ormation S ervices Bran c h {T-2 F43), U.S. Nuclear Regu l atory Com m is s ion, Wa s hington, DC 20555-000 1 , or by e-mail t o lnfocollects

.Resou r ce@nr c.gov , a nd to the Desk Office r , Office of In fo rm at i on a nd Regulatory Affa i r s , NEOB-10202, {3150-0104), Offi c e of Management and Budget, Washington , DC 20503. If a means used to impose a n information co ll ection does not display a curren tl y valid OMS control number, the NR C may not cond u c t o r sponsor , an d a perso n is not required to r espond to, the inf o rma tion collection. 2. DOCKET NUMBER 3. LER NUMBER YEAR Susquehanna Steam Electric Station Unit 2 05000-387 SEQU ENTIAL NUMBER REV NO. NARRATIVE CONDITIONS PRIOR TO EVENT Unit 1 -Mode 1, approximately 1 00 percent Rated Thermal Power Unit 2 -Mode 5, approximately 0 percent Rated Thermal Power 2017 -003 There were no structures, systems , or components that were inoperable at the start of the event that contributed to the event. Unit 2 was in a refueling outage and Zone II was relaxed. EVENT DESCRIPTION

-00 On March 8 at approximately 0239, during work to replace Load Center Breaker 2B240-021 (supply breaker to 2B246) [EllS: BKR] and inspect MCC Breaker 2B246-023

[EllS: BKR], both units Zone Ill HVAC [EIIS: NA] differential pressure was lost when Operations commenced the restoration phase prematurely.

The error occurred when Load Center Breaker 2B240-021 (supply breaker to 2B246) [EllS: BKR] was returned to service without MCC Breaker 2B246-023

[EllS: BKR] restored.

Unit 2 Zone Ill isolation dampers [EIIS:DMP]

were temporarily aligned to an alternate power supply during the work. When Operations attempted to restore Zone 3 HVAC damper control power to normal, there was no power available from Distribution Panei2Y246. The Unit 2 division II Zone Ill isolation dampers [EllS: DMP] failed to their safety "closed" position causing a low flow trip of all Unit 2 Zone Ill fans [EllS: FAN]. This resulted in Zone Ill differential pressure lowering to less than the TS 3.6.4.1 allowable limit of 0.25 in w.g. fA. timeline of events is as follows: 0100: MCC 2B246 de-energized by opening Load Center Breaker 2B240-021

[EllS: BKR] which is the supply breaker to MCC 2B246 [EllS: BKR]. 0145: Load Center Breaker 2B240-021

[EllS: BKR] was closed per work release RLWO 1873012 to energize MCC 2B246 [EllS: BKR] and utilize the RB elevator. 0200: Replacement breaker arrived at work site. Load Center Breaker 2B240-021

[EllS: BKR] was opened per twork release RLWO 1873012 to de-energize MCC 2B246 [EllS: BKR] and continue job. 0230: Operations team directed that MCC 2B246 could be re-energized while work continued on MCC Breaker 2B246-023

[EllS: BKR]. 0235: Commenced MCC 2B246 bus restoration. 0239: Operations place the Control Power Supply to Unit 2 RB Dampers to normal. Unit 2 Zone Ill Division II dampers [EllS: DMP] closed due to loss of control power causing Unit 2 Zone Ill fans [EllS: FAN] to trip on low flow. NRC FORM 3668 (0 4-2 017) Page 2 of 3 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150*0104 EXPIRES: 3/31/2020 (04-20 1 7) LICENSEE EVENT REPORT (LER) CONTINUATION SHEET (See NUREG-1 022 , R.3 for instruction and guidance for completing this form http://www. nrc. gov/read ing-rm/doc-collectionsln u reqslstaff/sr1 022/r3 D 1. FACILITY NAME E stimated burden per response to comp ly wit h this mandatory collectio n request: 80 h ou r s. Repo rt ed l essons lea rn ed are incorporated into the licensing process and fed back to industry.

Send comments r egard ing burden es tim ate to th e Inf orma ti on Services Branch (T-2 F4 3), U.S. Nuclear Regulatory Commission , Washing t on, DC 20555-0001, o r by e-mai l Ia lnf ocollects.Resource@nrc

.gov , and to the Desk Officer, Office of Information and Regulatory Affai r s , NEOB-10202, (3150-0104), Office of Management and Budget, Washington , DC 20503. If a means used to imp ose an inf ormation collection does not display a curren tly valid OM B co ntr ol number, the NRC may n ot conduct or s p onsor, and a person i s not r eq uired to respond to, th e information co l lection. 2. DOCKET NUMBER 3. LER NUMBER YEAR Susquehanna Steam Electric Station Unit 2 05000-387 SEQ UENTIAL NUMBER REV NO. 2017 -003 -00 CAUSE OF EVENT The cause of the event was less than adequate procedure use and adherence.

ANALYSIS/SAFETY SIGNIFICANCE Secondary Containment Zone Ill pressure was not maintained above the TS 3.6.4.1 required vacuum of 0.25 in w.g. with respect to outside atmosphere. The event was caused by a loss of power to the Unit 2 Zone Ill isolation dampers , which caused them to close. This resulted in the shutdown of the Unit 2 Reactor Building fans and a loss of Zone II I vacuum. This event is being reported pursuant to 10 CFR 50. 73(a)(2)(v)(C) as a condition that could have prevented fulfillment of a safety function to mitigate the consequences of an accident by controlling the release of radioactive material.

There was no actual safety consequence as a result of this event. Engineering analysis of this event has determined that secondary containment could have performed its safety function of isolating, as assumed in the accident analysis, and also of re-establishing 0.25 in w.g. vacuum (drawdown) within the assumed accident analysis time (1 0 minutes).

This event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator.

CORRECTIVE ACTIONS Corrective actions included a communication to Operators and a revision to the Procedure and Work Instructions Use and Adherence procedure to perform a second check for non-conditional procedure steps. PREVIOUS SIMILAR EVENTS LER 50-387(88)/2016-003-00, "Unit 2 Zone 3 HVAC unable to maintain Zone 3 dP >0.25 in wg ," dated May 6, 2016 (PLA-7459)

LER 50-387(388)/2015-002-00, "Loss of Secondary Containment Due to Failure of Running Fans," dated June 10, 2015 (PLA-7329)

NRC FORM 3666 (04-2017)

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