05000366/LER-2016-002, Regarding Group 1 Isolation Received During Turbine Testing
| ML16196A350 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/13/2016 |
| From: | Vineyard D Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-16-1090 LER 16-002-00 | |
| Download: ML16196A350 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3662016002R00 - NRC Website | |
text
David A. Vineyard Vice President-Hatch July 13, 2016 Docket Nos.: 50-366 Southern Nuclear Operating Company Inc Plant Edwin I. Hatch 11028 Hatch Parkway North Baxley. Georgia 31513 Tel 912.537.5859 Fax 912.366.2077 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Licensee Event Report 2016-002-00 SOUTHERN <<\\
NUCLEAR A SOUTHERN COMPANY NL-16-1090 Group 1 Isolation Received During Turbine Testing Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73(a)(2)(iv)(A) Southern Nuclear Operating Company hereby submits the enclosed Licensee Event Report.
This letter contains no NRC commitments. If you have any questions, please contact Greg Johnson at (912) 537-5874.
Respectfully submitted, D. R. Vineyard Vice President-Hatch DRV/cdp Enclosures: LEA 2016-002-00
U.S. Nuclear Regulatory Commission NL-16-1090 Page2 cc:
Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. A. Vineyard, Vice President-Hatch Mr. M.D. Meier, Vice President-Regulatory Affairs Mr. D. A. Madison, Vice President-Fleet Operations Mr. B. J. Adams, Vice President-Engineering Mr. G. L. Johnson, Regulatory Affairs Manager-Hatch RTYPE: CHA02.004 U.S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M.D. Orenak, NRR Project Manager-Hatch Mr. D. H. Hardage, Senior Resident Inspector-Hatch
Edwin I. Hatch Nuclear Plant Unit 2 LER 2016-002-00 Group 1 Isolation Received During Turbine Testing
NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 315C)o()104 EXPIRES: 1013112018 (11*2015)
Estimalad, lhe NRC may nol conduct or sponsor, and a person is nol required 10 leSpond lo, lhe information colleclion.
rPAGE Edwin I. Hatch Nuclear Plant Unit 2 05000 366 1 OF3
- 4. TITLE Grouo I Isolation Received Durina Turbine Testing
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACiunES INVOLVED YEAR ISEOUENTIALJ REV FACILITY NAME pocKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTI' DAY YEAR 07 14 2016 FACILITY NAME pocKET NUMBER 05 23 2016 2016
- 002
- 00
- 9. OPERATING MODE
- 11. T1iiS REPORT IS SUBMrTTED PURSUANT to THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 0 20.2201(b) 0 20.2203(8)(3)0) 0 50.73(8)(2)(ii)(A) 0 50.73(8)(2)(viii)(A) 4 0 20.2201 (d) 0 20.2203(8)(3)(ii) 0 so. 73(8)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 0 20.2203(8}(1) 0 20.2203(8)(4) 0 50.73(8)(2)flii) 0 50.73(8)(2){ix){A) 0 20.2203(8)(2)(1) 0 50.36(c)(1)Q)(A) 18150.73{a)(2)Qv)(A) 0 50.73(a)(2)(x) lU. POWI:fl LI:VI:L 0 20.2203{8){2)(11) 0 50.36{c)(1 )(ii)(A) 0 50.73(8)(2)(v)(A) 0 73.71(8){4) 0 20.2203(8)(2)00) 0 50.36(c)(2) 0 50.73(8)(2)(v)(B) 0 73.71{8)(5) 0 0 20.2203(a)(2)(iv) 0 so.46(8)(3)(il) 0 50. 73(a)(2){v)(C) 0 73.n(a)(1) 0 20.2203(a)(2)(v) 0 50.73(8)(2)Q)(A) 0 50.73(a)(2)(v)(D) 0 73.n(a)(2){i) 0 20.2203(8)(2)(vi) 0 50.73(8)(2)(1)(8) 0 50.73(8)(2)(vii) 0 73.n(a)(2)(ii) 0 50.73(8)(2)(i)(C)
OOTHER Spec:ily 111 AllslraCI belOw or in NRC Form 368A
- 12. LICENSEE CONTACT FOR THIS LER ICENSEE CONTACT rELEPHONE NUMER (1ndudtl A18a Ccds}
Edwin I. Hatch I Carl James Collins-Licensing Supervisor 912-537 *2342
- 13. COMPLETE ONE UNE FOR EACH COMPONENT FAIWRE DESCRIBED IN THIS REPORT
CAUSE
SYSTEM COMPONENT MANU*
REPORTABLE
CAUSE
SYSTEM pOMPONENT MANU*
REPORTABLE FACTURER TOEPIX FACTURER TOEPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR 0 YES {If yes, complete 15. EXPECTED SUBMISSION DATE)
~NO SUBMISSION DATE
!ABSTRACT (Umit 10 1400 spaces, i.e., approximately 15 single-spaced typewritten lines}
On May 23,2016, at 1009 EDT, while personnel were performing turbine testing with Unit 2 offline for planned maintenance, an event resulted in the actuation of containment isolation valves in more than one system. In response to this unexpected signal, 2821-F016 (Steam Line Drain Line Inboard Isolation Valve), 2821-F019 (Steam Line Drain Line Outboard Isolation Valve), and 2831-F019 (Reactor Water Sample Inboard Isolation Valve) went closed, all of which are primary containment isolation valves actuated by Group !Isolation. The Group I Isolation signal initiated based on low condenser vacuum during the turbine testing procedure, a valid condition for actuation that was expected to have been bypassed in the logic during the performance of this procedure. Inadequate procedure usage caused these systems to actuate in a way that was not part of the planned evolution. Although the Unit was shut down when this signal was received, and primary containment isolation was not required to mitigate the consequences of an event, this isolation signal has been determined to have been valid due to the initiation in response to actual plant conditions or parameters which satisfy the requirements for initiation of the system As a corrective action, the operating procedure will be revised to clarify the required conditions to perform Turbine Trip Testing.
PLANT AND SYSTEM IDENTIFICATION
General Electric-Boiling Water Reactor (BWR)
Energy Industry Identification System codes appear in the text as (EllS Code XX)
DESCRIPTION OF EVENT
On May 23,2016, at 1009 EDT, with Unit 2 at zero percent rated thermal power, a full Group I Isolation signal was received during the performance of a turbine operability test [EllS Code TA; Main Turbine System]. In response to this unexpected signal, 2B21-F016 (Steam Line Drain Line Inboard Isolation Valve), 2B21-F019 (Steam Line Drain Line Outboard Isolation Valve), and 2B31-F019 (Reactor Water Sample Inboard Isolation Valve) [EllS Code TF; Turbine Drains and Miscellaneous Piping System] went closed.
The turbine testing evolution was stopped and investigation commenced to determine the cause of the Group I isolation.
Investigation revealed the Condenser Low Vacuum trip was not bypassed as expected prior to the test performance per the Turbine Testing Trip Overrides and Valve Stroking procedure. There were no inoperable structures, systems, or components (SSCs) which contributed to this event.
CAUSE OF EVENT
The cause of the actuation of the Group I isolation signal during Turbine Testing was due to inadequate procedure usage.
Poor communications between maintenance and operations personnel resulted in false assumptions that the Group I isolation trips were bypassed. Causal factors included procedure weaknesses which resulted in improper interpretation of critical steps.
CORRECTIVE ACTIONS
Immediately following the Group I isolation, Turbine Testing was halted. The operating procedure is being revised to clarify the required conditions to perform Turbine Trip Testing. Lessons learned were communicated among the Operations department. Additional training and qualification actions were taken to address the human performance aspects of this event.
NRC FORM 386A 11*2015)
\\¥)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LEA)
CONTINUATION SHEET APPROVED BY OMB: NO. 3150.0104 EXPIRES: 1013112018 Eslimaled burden per response 10 comply with !his manda!Oiy collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Repolled IIISSOilS leamed are incorporaled into lhe licensing process and fed back to indusby. Send commeniS regarding burden estimate lo lhe FOIA. Privacy and lnf0111131ion Cdledions Branch (T*S F53), U.S. Nuclear RagulaiOI'f Commission, Wuhinglon, DC 20555-0001, or by inlemel e-mail to lnfocdii!CIS.ResouroeOnrc.gav, and lo the Desk Officer, Office of Information and Regula!ory Alfairs, NEOB*10202, (3150-0104), Office of Management and Budgel Washington, DC 20503. II a 11181115 used lo impose an information collection does not display a CUIIllndy valid OMB c:ontro1 number, !he NRC may nOI condue1 or sponsor, and a person is nol required lo respond to, lhe lnformalion collldion.
- 3. LER NUMBER Edwin I. Hatch Nuclear Plant Unit 2 05000-366 YEAR J SEQUENTIAL I REV NUMBER NO.
2016
- - 002
- - 00 NARRATIVE REPORT ABILITY ANALYSIS AND SAFETY ASSESSMENT This event is reportable under 10 CFR 50.73(a)(2)(iv)(A) as an event or condition that resulted in automatic actuation of general containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs). This isolation signal was valid in response to actual plant conditions induced by testing, and impacted isolation valves in the Nuclear Boiler System and the Reactor Recirculation System.
This turbine testing was being conducted with the reactor offline when the drywall was open for maintenance activities.
The received Group I isolation signal was valid due to conditions measured by the appropriate instruments, however the isolation was not necessary to protect against an actual radiological event in progress. The main steam isolation valves were already closed prior to the start of the testing. Based on this information this reported condition had low safety consequence.
ADDITIONAL INFORMATION
Other Systems Affected: Isolation valves in the Nuclear Boiler System and the Reactor Recirculation System automatically went closed.
Failed Components Information
None.
Commitment Information: This report does not created any new licensing commitments.
Previous Similar Events
LEA 2009-005-0 On May 15, 2009 at 05:19 EDT, Unit I was in the cold shutdown mode with reactor power at 0 CMWT. At that time a Group I isolation signal on actual low condenser vacuum was generated when Operations personnel moved the reactor mode switch to the run position per subsection 7.1 of special purpose procedure 42SP-05-1209-PI-I-I. "Test of Nuclear Instrumentation Response to Diverse Logic System Actuations." Because the Main Steam Isolation Valves (MSIVs) were open at the time the Group I isolation signal was generated, they closed per design resulting in a reactor scram trip signal on MSIVs less than 90 percent open with the mode switch in the run position. Since the unit was in the cold shutdown condition at the time of the event, all controls rods were already inserted fully and therefore no rod motion occurred.
However, the Main Steam Line Drain and Reactor Water Sample Line isolation valves also closed per design on the Group I isolation signal. Operations personnel returned the reactor mode switch to the shutdown position and reset the isolation and scram signals. Operations personnel left the MSIVs in the closed position. This event was caused by a personnel error resulting in the development of an inadequate procedure. The cause was that the test procedure was developed without the necessary steps to defeat the lower condenser vacuum isolation logic. The event in May 2016 was due to human performance of not following a procedure as written; therefore, the corrective actions from the 2009 event would not be expected to have prevented the condition reported in this LEA.