05000387/LER-1917-007, Regarding Secondary Containment Declared Inoperable Due to Supply Air Flow
| ML17282A019 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/09/2017 |
| From: | Berryman B Susquehanna, Talen Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-7641 LER 17-007-00 | |
| Download: ML17282A019 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 3871917007R00 - NRC Website | |
text
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 Brad.Berryman@TalenEnergy.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-388 (387)/2017-007-00 UNIT 2 LICENSE NO. NPF -22 UNIT 1 LICENSE NO. NPF-14 PLA-7641 TALEN~
ENERGY 10 CFR 50.73 Docket No. 50-388 50-387 Attached is Licensee Event Report (LER) 50-388(387)/2017-007-00. The LER reports an event involving a loss of secondary containment differential pressure due to changes in supply air flow. This event was determined to be reportable in accordance with 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented fulfilment of a safety function.
There were no actual consequences to the health and safety of the public as a result of this event.
B. Berryman Attachment: LER 50-388(387)/2017-007-00 Copy:
NRC Region I Ms. T. E. Hood, NRC Project Manager Ms. L. H. Micewski, NRC Sr. Resident Inspector Mr. M. Shields, P A DEP/BRP
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017) htt[1://www.nrc.gov/reading-mn/doc-collections/nuregs/staff/sr1 022/r30 the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 13. PAGE Susquehanna Steam Electric Station Unit 2 05000388 1 OF3
- 4. TITLE Secondary Containment Declared Inoperable Due to Supply Air Flow
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR REV MONTH DAY YEAR Susquehanna Steam Electric Station Unit 1 NUMBER NO.
05000387 08 08 2017 2017
- - 007
- - 00 2017 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERAllNG MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 0 20.2201(b) 0 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) 0 20.2201 (d) 0 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 0 20.2203(a)(1) 0 20.2203(a)(4) 0 50.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A) 0 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A) 0 50. 73(a)(2)(iv)(A) 0 50.73(a)(2)(x)
- 10. POWER LEVEL D 20.2203(a)(2)(ii)
D 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(v)(A) 0 73.71(a)(4)
D 20.2203(a)(2)(iii)
D 50.36(c)(2) 0 50.73(a)(2)(v)(B) 0 73.71(a)(5) 100 0 20.2203(a)(2)(iv) 0 50.46(a)(3)(ii)
~ 50.73(a)(2)(v)(C) 0 73.77(a)(1) 0 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(D)
D 73.77(a)(2)(i) 0 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(ii) 0 50.73(a)(2)(i)(C) 0 OTHER Specify in Abstract below or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT
~~LEPHONE NUMBER (Include Area Code)
!Nicole Pagliaro-Licensing Specialist-Nuclear Regulatory Affairs 1(570) 542-6578
- 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 X
VA FAN N/A y
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR D YES (If yes, complete 15. EXPECTED SUBMISSION DATE}
lSI NO SUBMISSION DATE V\\BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On August 8, 2017 at approximately 2043 hours0.0236 days <br />0.568 hours <br />0.00338 weeks <br />7.773615e-4 months <br />, Secondary Containment Zone 2 experienced a loss of differential pressure following the replacement of the Zone 2 ventilation supply side filters.
Technical Specification Surveillance Requirement (SR) 3.6.4.1.1 was not met. Zone 2 differential pressure was recovered following the slight adjustment of the Reactor Building Zone 2 inlet dampers at approximately 2052 hours0.0238 days <br />0.57 hours <br />0.00339 weeks <br />7.80786e-4 months <br />. Zones 1 and 3 were not affected. This event is being reported under 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented fulfillment of a safety function.
The cause was determined to be increased supply air flow following the replacement of the supply side filters. An action to revise future work instructions to ensure operations support is available to adjust Zone 2 differential pressure control following Zone 2 Supply side filter replacement.
There were no actual consequences to the health and safety of the public as a result of this event.
NRC FORM 366 (04-2017)
CONDITIONS PRIOR TO EVENT
Unit 1 - Mode 1, approximately 100 percent Rated Thermal Power Unit 2 - Mode 1, approximately 100 percent Rated Thermal Power YEAR 2017
- 3. LER NUMBER SEQUENTIAL NUMBER
- - 007 There were no structures, systems, or components that were inoperable at the start of the event that contributed to the event.
EVENT DESCRIPTION
REV NO.
- - 00 On August 8, 2017 at approximately 2043 hours0.0236 days <br />0.568 hours <br />0.00338 weeks <br />7.773615e-4 months <br />, Secondary Containment Zone 2 [EllS Code: VA]
experienced a loss of differential pressure (dP) following replacement of the Zone 2 ventilation supply side filters. All fans were running; however, the 'B' discharge damper controller output was found to be outside of its normal operating band.
The following is a timeline of events:
8/8/17: The filters on Zone 2 ventilation supply side were replaced during day shift.
8/8/17 2030: The Control Room received Reactor Building (RB) [EllS Code: NG] FAN ROOM Elevation 779' 2C275 PANEL trouble ALARM.
8/8/17 2043: Operations reported the local alarm was for RB hi-lo DP and RB Zone 2 dP is 0.15" vacuum water gauge. All fans are running, but noted that PDD-27578B (2V205B Discharge Damper) is indicating dual indication.
8/8/17 2044: Entered Technical Specification 3.6.4.1 for Unit 1 and Unit 2 due to Secondary Containment inoperable with Zone 2 dP <0.25" vacuum water gauge.
8/8/17 2052: Operations restored building dP to >0.25" vacuum water gauge after slight adjustment to the Zone 2 inlet dampers and swapping Zone 2 Exhaust Fans ("A" in-service, "B" inStandby.
8/8/17 2112: Exited condition for Technical Specification 3.6.4.1 for both units.
As a result, Technical Specification Surveillance Requirement (SR) 3.6.4.1.1 was not met. Zone 2 differential pressure was recovered to > 0.25" vacuum water gauge following slight adjustment of the Reactor Building Zone 2 inlet dampers at approximately 2052 hours0.0238 days <br />0.57 hours <br />0.00339 weeks <br />7.80786e-4 months <br />. Zones 1 and 3 were not affected.
CAUSE OF EVENT
The cause was determined to be increased supply air flow following the replacement of the supply side filters and less than adequate written communication in the work instructions on the impact of filter replacements on reactor building differential pressure.
NRC FORM 3668 (04-2017)
Page 2 of 3 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020 (04-2017)
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 i ng-rm/doc-collections/n u regs/staff/sr1 022/r30
- 1. FACILITY NAME Susquehanna Steam Electric Station Unit 2
ANALYSIS/SAFETY SIGNIFICANCE
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 2. DOCKET NUMBER YEAR 05000388 2017
- 3. LER NUMBER SEQUENTIAL NUMBER
- - 007 REV NO.
- - 00 An engineering evaluation was performed and concluded that secondary containment could have performed its safety function of isolating as assumed in the accident analysis and also of re-establishing 0.25 inches vacuum (drawdown) within the assumed accident analysis time (1 0 minutes). Therefore, the subject event did not cause a loss of safety function. This event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator based on the engineering analysis that shows there was no loss of ability to fulfill the safety function.
CORRECTIVE ACTIONS
Corrective actions include revising the Preventative Maintenance work instructions to ensure operations support is available to monitor output of the discharge damper controller and to adjust the inlet damper as needed during filter replacement.
PREVIOUS SIMILAR EVENTS
The following are recent LERs involving loss of secondary containment due to fan issues:
LER 50-388/2017-006-00 "LER for Loss of Secondary Containment Zone II differential pressure-ENS for Loss of Safety Function," dated September 6, 2017.
LER 50-388/2017-005-00 "Loss of Secondary Containment due to trip of 2V217 A Zone II Filtered Exhaust fan,"
dated August 18, 2017.
LER 50-387 /2017-004-00 "LER for Loss of Secondary Containment Zone 3 differential pressure-ENS for loss of Safety Function," dated August 4, 2017.
LER 50-387/2017-003-00 "Loss of Secondary Containment Zone 3 due to fan trip," dated May 5, 2017 LER 50-387/2016-003-00 "Unit 2 Zone 3 HVAC unable to maintain Zone 3 dP >0.25"WG," dated May 3, 2016 LER 50-387 /2015-013-00, "Loss of Secondary Containment due to failure of running fans," dated February 2, 2016.
NRC FORM 3668 (04-2017)