05000395/LER-1917-002, Regarding Low Feedwater Flow to the B Steam Generator Causes Automatic Reactor Trip

From kanterella
(Redirected from 05000395/LER-2017-002)
Jump to navigation Jump to search
Regarding Low Feedwater Flow to the B Steam Generator Causes Automatic Reactor Trip
ML17237C012
Person / Time
Site: Summer 
(NPF-012)
Issue date: 08/25/2017
From: Lippard G
South Carolina Electric & Gas Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
818.07, CR-17-03674, RC-17-0114 LER 17-002-00
Download: ML17237C012 (4)
v • d • e


LER-1917-002, Regarding Low Feedwater Flow to the B Steam Generator Causes Automatic Reactor Trip
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation
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)(v), Loss of Safety Function
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)
3951917002R00 - NRC Website
v • d • e

text

SCEStG A SCANA COMPANY George A. Lippard Vice President, Nuclear Operations 803.345.4810 August 25, 2017 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555

Dear Sir / Madam:

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS), UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2017-002-00)

LOW FEEDWATER FLOW TO THE 'B' SG CAUSES AUTOMATIC REACTOR TRIP Attached is Licensee Event Report (LER) 2017-002-00, for the Virgil C. Summer Nuclear Station (VCSNS). This report describes the Reactor Trip due to low Feedwater flow to the 'B' Steam Generator. This report is submitted in accordance with 10CFR50.73(a)(2)(iv)(A).

Should you have any questions, please call Mr. Bruce Thompson at (803) 931-5042.

Very truly yours, RLP/GAL/ts Attachment K. B. Marsh S. A. Byrne J. B. Archie N. S. Cams J. H. Hamilton G. J. Lindamood W. M. Cherry C. Haney S. A. Williams NRC Resident Inspector L. W. Harris Paulette Ledbetter J. C. Mellette ICES Coordinator K. M. Sutton INPO Records Center Chris Crowley Marsh USA, Inc.

R. J. Schwartz NSRC RTS (CR-17-03674)

File (818.07)

PRSF (RC-17-0114)

V. C. Summer Nuclear Station

  • P. 0. Box 88
  • 29065
  • F (803) 941-9776
  • www.sceg.com

NRC FORM 366 (04-2017)

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

J (See Page 2 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.aov/readina-rm/doc-collections/nureas/staff/sr1022/r3/t APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME V.C. Summer Nuclear Station, Unit 1
2. DOCKET NUMBER 05000 395
3. PAGE 1 OF
4. TITLE Low Feedwater Flow to the 'B' Steam Generator Causes Automatic Reactor Trip
5. EVENT DATE
6. LER NUMBER
7. REPORT DATE
8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YFAR SEQUENTIAL REV NUMBER NO.

MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 06 29 2017 2017 -

002 00 08 25 2017 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)(ii)(A) 50.73(a)(2)(viii)(A) 1

]

20.2201(d) 20.2203(a)(3)(H) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 1 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 1 20.2203(a)(2)(i) 50.36(c)(1 )(i)(A) 0 50.73(a)(2)(iv)(A) 50.73(a)(2)(x)

10. POWER LEVEL 100 20.2203(a)(2)(H) 50.36(c)(1 )(ii)(A) 50.73(a)(2)(v)(A) 73.71(a)(4)
10. POWER LEVEL 100 l] 20.2203(a)(2)(iii) 50.36(0(2) 50.73(a)(2)(v)(B) 73.71(a)(5)
10. POWER LEVEL 100

] 20.2203(a)(2)(iv) 50.46(a)(3)(H) 50.73(a)(2)(v)(C) 73.77(a)(1)

10. POWER LEVEL 100

] 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 73.77(a)(2)(i)

10. POWER LEVEL 100 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii) 73.77(a)(2)(H)
10. POWER LEVEL 100 50.73(a)(2)(i)(C)

OTHER Specify in Abstract below or in =(04-2017) beo^

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.aov/readina-rm/doc-collections/nureas/staff/sr1022/r3/)

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3.0 SAFETY SIGNIFICANCE

A PRA sensitivity study was performed as a result of this reactor trip. This trip was modeled as a partial loss of main FW.

VCSNS uses a frequency for partial loss of main FW of 0.206/yr based on a generic frequency of 0.1615/yr updated with plant specific experience of 3 events in 10.8 years.

For the sensitivity study, the partial loss of main FW initiating event frequency was set to 1,0/yr. The resulting change in CDF is 2.70E-07/yrand the resulting change in LERF is 1.17E-08/yr. The baseline CDF and LERF for the model (version 8a2) used for this study are 3.28E-06/yr and 1.01 E-07/yr respectively, so the changes constitute an 8% increase in CDF and an 11% increase in LERF.

The changes in CDF and LERF described above are not considered significant.

4.0 PREVIOUS OCCURRENCE No previous occurrence within the last three years.

5.0 CORRECTIVE ACTIONS

A temporary IPCS computer point was added to monitor accumulator pressure forXVB01611B, FW Isolation Valve 'B'. A troubleshooting plan was also performed to provide backup monitoring to IPCS for Feedwater Regulator Valve and Feedwater Isolation Valve limit switch position indication.

The potential failed components were replaced per the Failure Modes Analysis and post maintenance testing was successful.

The following components associated with the 'B' FW Regulating Valve IFV00488-FWwere replaced under Work Order 1708087:

- Primary XACT Feedback Transducer IFY00488A-ZT
- Solenoid Valve IFV00488-20A-FW
- Solenoid Valve IFV00488-20B-FW
- Quick Exhaust Valves IFV00488-EV2 and IFV00488-EV3
- Contacts 7 and 8 on relay K636
- NSC Card FY488C1 (C7-326)

The following components were sent off for testing:

- K636 Contacts 7/8 Cartridge: No issues identified by Applied Technical Services
- IFV00488-20A-FW and IFV00488-20B-FW ASCO Solenoid Valves: Inadequate solder connection identified at magnet wire on IFV00488-20B-FW. The report from Exelon PowerLabs is being generated. Page 3

of 3

Retrieved from "https://kanterella.com/w/index.php?title=05000395/LER-1917-002,_Regarding_Low_Feedwater_Flow_to_the_B_Steam_Generator_Causes_Automatic_Reactor_Trip&oldid=5114632"