05000287/LER-2020-001, Manual Reactor Trip Due to Reaching Feedwater Heater Level Limit in Operating Procedure
| ML20161A404 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/09/2020 |
| From: | Dalton S Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA-20-0176 LER 2020-001-00 | |
| Download: ML20161A404 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 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), 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)(i) |
| 2872020001R00 - NRC Website | |
text
( ~ DUKE ENERGY RA-20-0176 June 9, 2020 Attn: Document Control Desk U. S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2746 Duke Energy Carolinas, LLC Oconee Nuclear Station Unit 3 Docket Number: 50-287 Renewed Operating Licenses: DPR-57 10 CFR 50.73 Sheila Dalton Manager, Nuclear Supporl Services Oconee Nuclear Station Duke Energy ON01SC 17800 Rochester Hwy Seneca, SC 29672
- 0. 864.873.3657 f: 864.873.3401 sheila.dalton@duke-energy.com
Subject:
Licensee Event Report 287/2020-001, Revision 00- Unit 3 Manual Reactor Trip Due to Reaching Feedwater Heater Level Limit in Operating Procedure Licensee Event Report 287/2020-001, Revision 00, is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.
There are no regulatory commitments associated with this LER.
There are no unresolved corrective actions necessary to restore compliance with NRC requirements.
If there are questions, or further information is needed, contact Sam Adams, Regulatory Affairs, at (864) 873-3348.
Sincerely, Sheila Dalton Manager, Nuclear Support Services Oconee Nuclear Station Enclosure
RA-20-0176 June 9, 2020 Page2 cc (w/Enclosure):
Ms. Laura Dudes, Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Shawn Williams, Project Manager (by electronic mail only)
U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-0881A Rockville, MD 20852-2738 Mr. Jared Nadel NRC Senior Resident Inspector Oconee Nuclear Station
NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 04/30/2020 (04-2020)
- 1. Faclllty Name
- 2. Docket Number
, 3. Page Oconee Nuclear Station Unit 3 05000287 1 OF3
- 4. Title Unit 3 Manual Reactor Trip Due to Reaching Feedwater Heater Level Limit in Operating Procedure
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved Sequential Rev Facility Name Docket Number Month Day Year Year Month Day Year NA Number No.
05000 04 10 2020 2020 001 0
06 09 2020 Facility Name Docket Number NA 05000
- 9. Operating Mode
- 11. This Report Is Submilled Pursuant ID the Reaulranenls of 10 CFR §: (Check all that aDDlvl 1
0 20.2201(b)
D 20.2203(a)(3)(i) 0 50. 73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) 0 20.2201(d)
D 20.2203(a)(3)(ii) 0 50. 73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 0 20.2203(8)(1) 0 20.2203(8)(4)
D 50. 73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i) 0 50.36(c)(1 )(i)(A)
~ 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. Po-rlevel D 20.2203(a)(2)(ii) 0 50.36(c)(1 )(ii)(A)
D 50. 73(a)(2)(v)(A) 0 73.71(8)(4)
D 20.2203(a)(2)(iii)
D 50.36(c)(2)
D 50. 73(a)(2)(v)(B) 0 73.71(8)(5) 032 D 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(C) 0 73.77(8)(1)
D 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 73.77(a)(2)(ii)
D 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
D 50. 73(a)(2)(vii)
D 73.77(a)(2)(iii)
D 50.73(a)(2)(i)(C)
D Other (Specify in Abstract below or in CAUSAL FACTORS An ongoing Root Cause Evaluation (RCE) has detennined that the unit trip was due to an over1y restrictive heater level limit placed in the operating procedure that did not account for the various heater levels that occur during power reductions.
CORRECTIVE ACTIONS
Immediate:
Planned:
- 1.
Perfonned a pressure test on each 3F1 heater tube and detennined no thru-wall leak existed.
- 2.
Calibrated the level control valve and level transmitter for 3F1 heater with no issues identified.
- 3.
Perfonned visual inspection of piping downstream of 3F1 heater's level control valve verifying no flow restrictions.
- 4.
Revised the applicable Unit 3 operating procedure to correct the procedural guidance for tripping the reactor at the appropriate 'F' heater level.
- 1.
Revise the applicable operating procedures for Units 1 and 2 consistent with changes made to the Unit 3 procedure.
- 2.
Complete the on-going RCE and implement corrective actions identified therein.
SAFETY ANALYSIS
The Unit 3 manual trip on April 10, 2020 was uncomplicated and had no impact on public health and safety. The 3F1 Feedwater Heater level and the manual trip from 32% power did not affect the post-trip response of the plant.
Feedwater flow to the steam generators was maintained throughout the event and no equipment problems were experienced that required unusual operator actions. No Emergency Core Cooling System (ECCS) or other safety system actuations occurred in response to this event, and no issues were identified with operator response or procedures. Thus, it is concluded that the impact of this event on overall plant risk is insignificant and had no impact on public health and safety.
ADDITIONAL INFORMATION
A review of Duke Energy's Corrective Action Program did not identify any Oconee LERs or events in the last 3 years that involved the same underlying concerns or reasons as this event.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX]. This event is considered INPO Consolidated Events System (ICES) Reportable. There were no releases of radioactive materials, radiation exposures or personnel injuries associated with this event. Page 3 of 3