ML17335A025
| ML17335A025 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/05/2017 |
| From: | Audrey Klett Plant Licensing Branch II |
| To: | Teresa Ray Duke Energy Carolinas |
| Klett A, NRR/DORL/LPLII-1 | |
| References | |
| CAC MF7417, CAC MF7418, CAC MF7419, EPID L-2016-LLA-0002 | |
| Download: ML17335A025 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 5, 2017 Mr. Thomas D. Ray Vice President Oconee Nuclear Station Duke Energy Carolinas, LLC 7800 Rochester Highway Seneca, SC 29672-0752
SUBJECT:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 - CORRECTION TO SAFETY EVALUATION FOR AMENDMENT NOS. 406,408, AND 407 REGARDING THE TECHNICAL SPECIFICATIONS FOR ELECTRICAL POWER SYSTEMS (CAC NOS. MF7417, MF7418, AND MF7419; EPID L-2016-LLA-0002)
Dear Mr. Ray:
On November 20, 2017, the U.S. Nuclear Regulatory Commission (NRC or the Commission) issued Amendment Nos. 406, 408, and 407 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17124A608) to Renewed Facility Operating Licenses DPR-38, DPR-47, and DPR-55, for the Oconee Nuclear Station, Units 1, 2, and 3, respectively.
The amendments revised the Technical Specifications to allow sufficient time for the replacement of the stator of each Keowee Hydro Unit (KHU). Following receipt of the amendments, staff from Duke Energy Carolinas, LLC (the licensee) informed the NRC staff of an error in Section 2.2, "Licensee's Proposed Changes," of the NRC's safety evaluation that was enclosed with the amendments. In order to correctly reflect the licensee's proposed changes, the NRC has revised the safety evaluation by deleting the first paragraph on page 5 of the safety evaluation, which stated:
In its application dated February 26, 2016, the licensee stated that the KHU turbine generators are powered through a common intake (penstock) by water taken from Lake Keowee. To isolate one KHU from the common intake for major maintenance activities, both KHUs must be removed from service. The common intake must be de-watered to allow the unit designated for maintenance to be sealed. After sealing the unit designated for maintenance, the common penstock is then re-watered allowing the designated operating unit to be returned to service. Each KHU is individually sealed at its wicket gates, which are internal to the machine, prior to the maintenance. If two KHUs are under maintenance, the dewatering, rewatering, and sealing processes have to be repeated, one at a time.
The licensee informed the NRC staff by electronic mail that its application did not discuss sealing the wicket gates, that sealing the wicket gates was not necessary for the stator work, and that the licensee will only be performing maintenance on one KHU at a time. The licensee also informed the staff that for the Keowee stator work, there is no need to seal the wicket gates. The staff reviewed the licensee's feedback and determined that the above paragraph in
the safety evaluation for Amendment Nos. 406, 408, and 407 was in error and should be deleted. A copy of revised page 5 of the safety evaluation for Amendment Nos. 406, 408, and 407 is enclosed. All changes are indicated by marginal bars. The NRC staff determined that the corrections to the original safety evaluation do not change the staff's previous conclusions in its no significant hazards consideration as published in the Federal Register on July 5, 2016, and regarding the acceptability of the changes approved in Amendment Nos. 406, 408, and 407.
Docket Nos. 50-269, 50-270, and 50-287
Enclosure:
Safety Evaluation Page 5 cc: Listserv Sincerely, Audrey L. Klett, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation The licensee proposed a change to the TS 3.8.1 Required Action C.2.2.3 NOTE to allow use of the 60-hour dual KHU outage to disassemble and reassemble the KHU and return it to a functional condition. In its application dated February 26, 2016, the licensee stated that without this note, entry into Condition L would be required, and the TSs would allow only 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> to restore the KHU and its required underground path or only 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to restore compliance with the LCO in TS 3.3.21, "Emergency Power Switching Logic (EPSL) Keowee Emergency Start Function." The licensee stated in its application that the note for Required Action L allows a 12-hour delay prior to starting the 4-hour completion time clock when entered for the purposes of restoring the KHU undergoing maintenance. The licensee proposed to revise the NOTE for TS 3.8.1 Required Action C.2.2.3 on TS page 3.8.1-4 to state (proposed addition is underlined, and proposed deletion is struck through):
Not applicable to remaining KHU and its required underground emergency power path or LCO 3.3.21 when in Condition H to perform generator field pole rewind stator replacement work.
TS 3.8.1 Required Action C.2.2.5 requires the KHU and its required overhead emergency power path to be restored to operable status within 45 days of discovery of an initial inoperability when Condition C is entered due to an inoperable KHU if not used for that KHU in the previous 3 years. The licensee stated that this 45-day time period is not sufficient to allow the KHU generator stator replacement work to be performed and, therefore, proposed to add a temporary completion time to Required Action C.2.2.5 that would allow 55 days to restore an inoperable KHU caused by the stator replacement to be used once for each KHU. The licensee proposed to replace the expired 62-day completion time for an inoperable KHU that was used for the Keowee field pole rewind work with a 55-day completion time for TS 3.8.1 Required Action C.2.2.5 that is applicable only to the generator stator replacement work. The licensee proposed to replace the expired January 1, 2015, date with a new expiration date of September 30, 2021. The licensee proposed to require verification that the PSW System is operable prior to entering the extended completion time and to preclude discretionary maintenance or testing on the PSW System.
The licensee proposed to revise the NOTE above the 45-day completion time for TS 3.8.1 Required Action C.2.2.5 on TS page 3.8.1-5 to state (proposed additions are underlined, and proposed deletions are struck through):
- 1. Not to exceed 45 days cumulative per rolling 3-year time period for each KHU.
- 2. Not applicable during generator field pole re*11ind stator replacement work.
- 3. Not applicable until 1 year after the KHU is declared OPERABLE following generator field pole rewind stator replacement work for planned work.
SUBJECT:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 - CORRECTION TO SAFETY EVALUATION FOR AMENDMENT NOS. 406,408, AND 407 REGARDING THE TECHNICAL SPECIFICATIONS FOR ELECTRICAL POWER SYSTEMS (CAC NOS. MF7417, MF7418, AND MF7419; EPID L-2016-LLA-0002) DATED DECEMBER 5, 2017 DISTRIBUTION:
PUBLIC RidsACRS_MailCTR Resource RidsNrrDorlDpr Resource RidsNrrDorlLp2-1 Resource RidsNrrDssStsb Resource RidsNrrDeEenb Resource RidsNrrDeEeob Resource RidsNrrLAKGoldstein Resource RidsNrrPMOconee Resource RidsRgn2MailCenter Resource F. Sacko, NRR/DE G. Matharu, NRR/DE P. Snyder, NRR/DSS ADAMS A ccess1on N ML17335A025 o.:
OFFICE DORL/LPL2-1 /PM DORL/LPL2-1 /LA NAME AKlett KGoldstein DATE 12/04/17 12/04/17 OFFICE DORL/LPL2-1 /BC DORL/LPL2-1 /PM NAME MMarkley AKlett DATE 12/5/17 12/05/17 OFFICIAL RECORD COPY
- b 1yema1 DE/EEEB/BC*
JQuichocho 11/30/17