ML18142A749

Proposed Second Level of Undervoltage Protection - Relay Setpoints

ML18142A749
Person / Time
Site:	Ginna
Issue date:	09/30/1977
From:	White L Rochester Gas & Electric Corp
To:	Schwencer A Office of Nuclear Reactor Regulation
References
Download: ML18142A749 (7)

Text

DISTRIBUTION AFTER ISSUANCE OPERATING LICENSE NRC FORM 195 U S NUCLEAR REGULATORV COMMI tl-'I BI NRC DlSTRlBUTlON FCA PART 50 DOCKET MATERlAL OCTET NUMBER FILE NUMBER

.TOI A Schwencer FROM

Roshester Gas G Elec Corp Rochester, NY L D White OATE OF OOCUMENT 9-50-77 GATE RECEIVE 0 lo-S-77 E L.ETTER ABORIGINAL ElCOPY OESCRIPTION QNOTORIZEO jBUNCLASSIFIEO g~+ie.t R 7

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PROP INPUT FORM ENCL,OSURE NUMBER OF COPIES RECEIVEO lzra&e lp specific relay setpoint data pertaining to design analysis for second level of underyolhage protection

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PLANT NAME:

Ginna 10-3-77' ehf SAFETY BRANCH CHIEF:

7 FOR ACTION/INFORMATION REG FlLE INTERNALD RIBUTION IST I GE (2)

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/II 8//I////II ROCHESTER GAS AND ELECTRIC CORPORATION o

89 EAST AVENUE, ROCHESTER, N.Y. l4649 LEON D. WHITE. JR.

VICC PAESIOENT TCLEPHONC6-2700 September 30, 197

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>>0 Director of Nuclear Reactor Regulation Attention:

A. Schwencer, Chief Operating Reactors Branch Nl U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Proposed Second Level of Undervoltage Protection Relay Setpoints

Dear Mr. Schwencer:

In conformance with our July 21, 1977 letter transmitting the Ginna Station Design Analysis for a second level of under-voltage protection, we are enclosing specific relay setpoint data.

The second level "setpoint" is shown as an allowable zelay operating range which ensures equipment operability during a postulated design basis accident concurrent with a degraded bus voltage condition.

All the safeguard motors and motor operated valves were reviewed to detexmine the time required for.each piece of equipment to reach its upper long term temperature of 130'C, operating at, full load and with bus voltages in the degraded region.

The results of this review yielded,the worst case curve shown on Figure 2.3-1.

The area under this curve now becomes the allowable operating region for the second level undervoltage relays.

In addition to the second level operating region, we are enclosing the new setpoint for the existing "loss of voltage" relays which along with the second level operating region will be incorporated into the Ginna Station Technical Specifications as required by your June 3,

1977 letter.

We intend to apply for an ammendment to the Operating License by December 1977.

As you requested, we are transmitting 39 additional copies of this letter and 40 copies of the data.

Very truly yours, L. D. Whit

, Jr.

Enclosures

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R. E. Ginna Unit gl Docket No. 50-244 Second Level Under Voltage Protection SET POINT DATA

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Undervoltage Protection Ginna Station 1.

Loss of Voltage Protection (LVP)

Relay operating times:

TLVP <

8 ~ 5 5 < Seconds Remarks:

For safeguards bus voltages less than or equal to 80% of 460 volt base (368 volts) the protective relays must operate with inherent time delays of less than 8.5 seconds as justified in the Design Analysis.

2.

Second Level Protection (SL)

The second level relay opexating times are voltage dependent with the operating region shown on Figure 2.3-1.

Remarks:

The second level relays must detect and respond to a degraded voltage.

The actual relay operating times will be con-siderably faster than the enclosed curve.

This'can be seen from a typical second curve shown on Figure II of the Design Analysis.

The curve defines the operating time needed to clear a degraded voltage so as to prevent equipment overheating.

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8 q5 00 1600 1400 1200 1000 r

800 600 f

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Second Level

'Under Voltage Protection I.

Figure 2. 3-1

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Secondary Volts (120 Volts)

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60 Primary Volts (480 Volts)

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240 Percent Volts

,(460 Volt Base) 52/

70 80 90 92 320 368 70%

80%

103.5 414 90%

ft 120 480 104%

jSafeguards Bus Voltage 4

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