ML080160509

Response to Request for Additional Information on the Proposed Amendment for Loss of Voltage Signal (Lovs) Relay Replacement, Proposed Change Number (PCN-577)

ML080160509
Person / Time
Site:	San Onofre
Issue date:	01/15/2008
From:	Scherer A Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PCN-577, TAC MD5112, TAC MD5113
Download: ML080160509 (4)

Text

A. Edward Scherer r EDISON SOUTHERN CALIFORNIA Director Nuclear Regulatory Affairs An EDISON INTERNATIONAL Company January 15, 2008 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Docket Nos. 50-361 and 50-362 Response to Request for Additional Information on the Proposed Amendment for Loss of Voltage Signal (LOVS) Relay Replacement, Proposed Change Number (PCN) 577 (TAC Nos. MD5112 and MD5113)

San Onofre Nuclear Generating Station, Units 2 and 3

Reference:

March 30, 2007 letter from B. Katz (SCE) to Document Control Desk (NRC),

Subject:

San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362, Proposed Change Number (PCN)-577, LOVS Relay Replacement

Dear Sir or Madam:

By letter dated March 30, 2007 Southern California Edison (SCE) submitted the referenced Proposed Change Number (PCN)-577, LOVS Relay Replacement. In a telephone conversation on January 7, 2008, NRC staff requested'additional information regarding the submittal. The NRC staff question and the SCE response are contained in the enclosure.

This submittal contains no new regulatory commitments.

If you have any questions or require additional information, please contact Ms. Linda T.

Conklin at (949) 368-9443.

Sincerely, Enclosure cc: E. E. Collins, Regional Administrator, NRC Region IV N. Kalyanam, NRC Project Manager, San Onofre Units 2 and 3 C. C. Osterholtz, NRC Senior Resident Inspector, San Onofre Units 2 and 3 74bo I P.O. Box 128 San Clemente, CA 92674

ENCLOSURE NRC QUESTION In the LAR dated March 30, 2007, the licensee stated the following on Page 1 of : "The 115.5 V initial voltage (110% of the 105 V setpoint) to 57 V minimum voltage is selected based on the available manufacturer's relay curves which provided the specific time at 57 V when voltage is dropped from 115.5 V."

The Technical Specification change request also states for the requested time delay "(voltage change from 115.5 V to 57.0 V)".

Staff reviewers could not confirm the above from the manufacturer's catalog for the BEI-27 relay. The curves provided for the relay provide the operating time in terms of voltage difference from the pickup setting (nominal 105.0 V) and the time dial.

SCE RESPONSE Applicable inverse timing characteristic curves for the loss of voltage relay are shown in the manufacturer's enclosed Figure 3-2 using range 3. The horizontal scale of Figure 3-2 (range 3) shows voltage difference (0 to 48 volts) from the relay pickup setting. The manufacturer's catalog for the model BE1-27 relay describes that the inverse time curves were generated with prefault voltages at 10% higher than pickup for the model 27 relay curves (page 1-5, enclosed).

Figure 3-2 therefore shows that a relay with a voltage tap setting of 105 V will operate as follows:

1) When the system voltage drops from a prefault voltage of 115.5 V (110% of relay pickup voltagel05 V) to 105 V (0 V difference from the relay pickup setting), the relay will take more than 4 seconds to operate ifthe time dial is set at #7, or more than 10 seconds for time dial setting at #20.

2) When the system voltage drops from a prefault voltage of 115.5 V (110% of relay pickup voltagel 05 V) to 57 V (57 V = 105 V -48 V), the relay will operate within 0.4 seconds if time dial is set at #7 or more than 1.0 second for time dial setting at

1. 20.

Figure 3-2 does not give relay operating times when the system voltage drops from 110% of the relay pickup setting to zero volts. The manufacturer does not provide relay operating times for this case because they do not have official test data.

Therefore, it was determined that the allowable time delay in the proposed Technical Specification (0.69 to 1.0 second, inclusive) should be measured when the voltage changes from 115.5 V (prefault voltage = 110% of LOV relay pickup setting) to 57 V (105 V- 48 V), which is the lowest voltage shown in the Figure 3-2.

Page 1 of 3

Inverse Time Inverse curve types are defined by the Style Chart and are represented by the curves shown in Section 3, Functional Description. Inverse time is adjustable from 01 to 99 in increments of 01. Incrementing the time dial varies the inverse curve along the Y axis. A setting of,00 designates instantaneous timing.

Inverse Time Accuracy Within +/-5% or 50 ms (whichever is greater) of the indicated time for any combination of time dial setting and pickup setting and is repeatable within +/-2% or 50 ms (whichever is greater) for any combination of time dial and tap setting. Curves were generated .

with prefault voltages at 10% greater than pickup for the 27 curves and 10% less than pickup for the 59 curves. For prefault voltages that are greater in difference from the pickup setting, the timing accuracy is +/-10% or 100 ms (whichever is greater).

UL Recognition UL Recognized per Standard 508, UL File No. E97033. Note:

Output contacts are not UL Recognized for voltages greater than 250 V.

Isolation Meets IEC 255-5 and exceeds ANSI/IEEE C37.90 one minute dielectric test as follows:

All Circuits to Ground: 2,828 Vdc (excludes communication ports).

Communication Ports to Ground: 500 Vdc.

Input Circuits to Output Circuits: 2;000 Vac or 2,828 Vdc.

Surge Withstand Capability: Qualified to IEEE C37.90.1-1989 StandardSurge Withstand Oscillatory Capability(SWC) Tests for Protective Relays and Relay Systems (excluding communication ports).

Fast Transient Qualified to IEEE C37.90.1-1989 Standard Surge Withstand Capability(SWC) Tests for Protective Relays and Relay Systems.

(Excluding communication ports).

Electrostatic Discharge (ESD) Four kilovolts contact discharges and 8 kilovolts air discharges CE Certified applied in accordance with Qualification EN61000-4-2.

Radio Frequency Interference Qualified to IEEE C37.90.2-1995 Standardfor Withstand Capability Of Relay Systems to Radiated ElectromagneticInterference from Transceivers.

Impulse Test Qualified to IEC 255-5.

Shock 15 g in each of three mutually perpendicular axes.

Vibration .2 g in each of three mutually perpendicular axes swept over the range of 10 to 500 Hz for a total of si x sweeps, 15 minutes each sweep.

Temperature:

Operating -400 C (-400 F) to +70' C (+158' F)

Storage -650 C (-850 F) to +1000 C (+2120 F)

Weight 14 pounds maximum.

Case Size All units supplied in an Sl size case.

Page 2 of 3 BEl-27/59 General Information 1-5

100 10 lo1

-1.0 0.1 C 48 44 40 36 a,? 28 24 20 16 12 8 4 *,*0 Ranqe3 96 88 80 72 64 56 48 40 32 24 16 8 '0 Range 4 02867-23 Voltage Difference From Pickup 0 Figure 3-2. Undervoltage, Short Inverse Timing CharacteristicCurve .. ..10 TV 1000 100 O0 10 en CL 1.

1.0 1 i i - i i0.1 48 44 40 36 32 : 28 24 20 16 12 8 4 0 Range 3 96 88 80 72 64 56 48 40 32 24 16 8 0 Range 4 D2857-24 Voltage Difference From Pickup 06-09-03 Figure 3-3. Undervoltage Medium Inverse Timing CharacteristicCurve P'age 3 of 3 BE127/59 Functional Description 3-3