L-2011-094, Comment (7) of Larry Nicholson, on Behalf of Nextera Energy, on Draft Regulatory Issue Summary, Adequacy of Station Electric Distribution System Voltages

Comment (7) of Larry Nicholson, on Behalf of Nextera Energy, on Draft Regulatory Issue Summary, Adequacy of Station Electric Distribution System Voltages

ML110800536
Person / Time
Site:	Saint Lucie, Point Beach, Seabrook, Turkey Point, Duane Arnold
Issue date:	03/18/2011
From:	Larry Nicholson Florida Power & Light Co, Nextera Energy
To:	Cindy Bladey Division of Administrative Services
References
76FR2924 00007, L-2011-094, NRC-2011-0013
Download: ML110800536 (4)

Text

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erau ENERG MAR 1 8 2011 L-2011-094 Ms. Cindy Bladey Chief, Rules, Announcements and Directives Branch (RADB)

Division of Administrative Services Office of Administration Mail Stop: TWB-05-BOl M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Industry Comments on Draft Regulatory Issue Summary, "Adequacy of Station Electric Distribution System Voltages" (Docket ID NRC-2011-0013)

Florida Power and Light Company, the licensee for the St. Lucie Nuclear Plant, Units 1 and 2, and the Turkey Point Nuclear Plant, Units 3 and 4, (hereafter referred to as FPL) and its affiliates, NextEra Energy Seabrook, LLC (NextEra Energy Seabrook) the licensee for Seabrook Station; NextEra Energy Duane Arnold, LLC (NextEra Energy Duane Arnold), the licensee for Duane Arnold Energy Center; and NextEra Energy Point Beach, LLC (NextEra Energy Point Beach), the licensee for Point Beach Nuclear Plant, Units I and 2 (collectively referred to as NextEra Energy), appreciates the opportunity to comment on the above listed document, contained in NRC Docket ID NRC-2011-0013.

FPL and NextEra Energy endorse the comments provided by the Nuclear Energy Institute (NEI) and IEEE/Nuclear Power Engineering Committee (NPEC), Subcommittee

4. In addition, we re-highlight NEI's offered comment that the draft RIS greatly oversimplifies the regulatory and licensing aspects of the degraded voltage protection issue. As a result of this oversimplification, the draft RIS combines several generic communications and guidance documents that have affected the licensing bases of individual plants in different ways. Any efforts to standadize the varied approaches to providing protection in the event of a degraded grid voltage condition that are currently captured in the licensing bases of our. individual plants should be undertaken in a manner that considers the overall safety impact of the proposed changes.

Sinceev.

Larry Nicholson Director, Nuclear Licensing NextEra Energy (FPL)

Enclosure:

Attachment, FPL/NextEra Comments on RIS 2011-xx NextEra Energy. Inc.

700 Universe Boulevard, Juno Beach, FL 33408

Comments on RIS 2011 -xx Distribution System Voltages ID

Section, Comment Proposed

Page, Resolutlon and Line #

Pg 6 of 10, This paragraph could be interpreted to require the LOCA Clarify the intent is to show safety related equipment will DVR Setting sequence to be modeled at the DVR dropout setting. LOCA function at the selected DVR dropout setting voltage and Design sequencing modeled at the DVR dropout setting would that it is not expected to start the'LOCA sequence from this Calculations, result in separation of the buses from the Preferred Power voltage level.

Line 8 Source (off-site power) as the voltage would not recover above the DVR reset value.

Clarify that LOCA sequencing is evaluated using minimum switchyard voltage as starting point.

2 Page 6 Having a sustained degraded voltage just above the LVR Clarify degraded voltages to be analyzed to a credible level.

Degraded voltage setling (70%) is not practical without grid collapse Voltage and does not exist in Branch Technical Position #1 (PSB-1).

Relaying Design Calculations.

Line 10 to 13 3

Pg 6 of 10, The statement that the DVR ensures adequate operational Remove starting of equipment at the DVR setpoink as a DVR Setting (starting and running) is the first time in NRC requirement.

Design correspondence that starting equipment at the DVR setpoint Calculations, is expected. The example letter sent to Peach Bottom in Line 12 June 1977 did not require starting of equipment at the DVR setpoint. This requirement should be removed from the RIS since it is not possible to start equipment at the DVR setpoint and not subsequently separate from offsite power.

If the equipment starts at the DVR setpoint, the voltage will dip during the transient and must then recover above the reset point to avoid separation from offsite power. Since the reset point will always be above the DVR dropout point it will be impossible to reset the relay.

4 Pg 7 of 10, It is agreed that no credit is to be taken for voltage Clarity that credit may be taken for automatic load tap DVR Setting controlling equipment external to the Class 1 E distribution changers and/or capacitor banks for minimum switchyard Design CaIcs system for the establishing the degraded voltage relay voltage/voltage drop calculations (or the Offsite/Onsite Line 2 (DVR) settings; however, it should be clarified that for credit Design Interface Calculations).

may be taken for minimum switchyard voltage/voltage drop calculations (or the Offsite/Onsite Design Interface Calculations).

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Comments on RIS 20t1-xx Distribution System Voltages LD

Section, Comment Proposed

Page, Resolution and Line#

5 Pg 8 of 10 NRC Generic Letter 79-36, Enclosure 2, Item 2 states that

]t is recommended that this either be removed, or stated

SUMMARY

OF "For multi-unit stations a separate analysis should be "anticipated transient per station licensing basis".

ISSUES:

performed for each unit assuming (1) an accident in the unit Item 2 being analyzed and simultaneous shutdown of all other units "Offsite/Onsite at the station; or (2) an anticipated transient in the unit being Design analyzed (e.g., unit trip) and simultaneous shutdown of all Lnterface other units at that station, whichever presents the largest Calculations",

load situation."

Subclause (c).

Comment:

NRC Draft RIS re-states NRC GL 79-36 verbatim, with an attempt to clarify "anticipated transient" by adding in parenthesis "(anticipated operational occurrence)"

immediately afterwards. It is not clear what the added parenthetical statement is meant to convey, other than unit trip (which already exists in GL 79-36).

6 Pg 8 of 10 NRC should clarify "simultaneous shutdown" with The wording for the proposed RIS, subclause 2.c should be

SUMMARY

OF consideration to:

revised to indicate "orderly or controlled safe shutdown of ISSUES:

a Most multi-unit station's Licensing Basis consider an the remaining units, as per the station's licensing basis" Item 2 "orderly or controlled safe shutdown" of the other instead of "simultaneous shutdown'. Alternatively, the "Offsite/Onsite unit(s) not being analyzed.

wording "shutdown consistent with the station licensing Design 0

NERC Std TPL-004-0; particularly Category D events basis" could be used instead of "simultaneous shutdown".

Interface per Table 1, where a "loss of all generating units at a Calculations",

station" may result in "portions or all of the Subclause (c).

interconnected systems may or may not achieve a new, stable operating point'.

a IEEE Std 308-1974, Clause 8, subclause 8.1.1 "Capacit describes this as a "concurrent safe shutdown on the remaining units".

7 Section 2, pg 8 These guidelines seem contradictory that you cannot credit Delete "e) Manual toad shedding should not be assumed" or of 10, e) and f) procedurally controlled operator actions to reduce load but add allowance to credit procedurally controlled operator you have to assume the actions will be carried out when actions to decrease load.

load is added.

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