ML18082B278

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Responds to NRC 800818 Request for Degraded Grid Voltage Analysis Info.Analysis Was Previously Performed & Submitted on 800303 & 791010.Requested Assumption Re Start of Nonclass IE Motor Not Valid for Analysis
ML18082B278
Person / Time
Site: Salem  PSEG icon.png
Issue date: 09/24/1980
From: Librizzi F
Public Service Enterprise Group
To: Varga S
Office of Nuclear Reactor Regulation
Shared Package
ML18082B279 List:
References
NUDOCS 8010060271
Download: ML18082B278 (2)


Text

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Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201 /430-7000 September 24, 1980 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 2-0555 Attention: Mr. Steven Varga, Chief Operating Reactors Branch #1 Division of Licensing Gentlemen:

DEGRADED GRID VOLTAGE ANALYSIS SUPPLEMENTAL INFORMATION SALEM GENERATING STATION UNITS NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 The degraded grid voltage analysis requested in your August 18, 1980 letter has already been .performed for previous requests for degraded grid voltage protection information. The analysis assumed both of the 500/13.8 kV transformers in service and a minimum of 0.978 of the off-site grid voltage value and included the following considerations: *

1) A trip of Unit 1 and a LOCA on Unit 2.
2) No credit for the 13.8/4.16 automatic load tap changer oper-ating during the transient.
3) No credit for manual load shedding.

No overloading problems exist because the second level of under-voltage prot~ction will prevent a degraded voltage condition. In addition, relay action places the vital buses of both units on the emergency diesel generators and allows safe shutdown. So, no fur-ther analysis is necessary.

95-2001 (200M) 2-78

Dir. of Nuclear

  • Reactor Regulation
  • 9-24-80 The requested assumption of the start of a large non-Class IE motor is not a valid assumption for Salem's* degraded grid voltage analysis because the largest non-Class IE motor is the 4 kV, 6000 HP reactor coolant pump (RCP) motor, and a blocking circuit of second level of undervoltage protection was required to permit starting this motor.

The second level of undervoltage protection is automatically blocked at the start of the RCP motor and will not drop out. Our March 3,

  • .1980 letter (Attachment 1) completely describes, in detail, the second level of undervoltage protection.

Previous analyses submitted October 10, 1979 (Attachment 2) have already considered systems below 480 V.

If you have any questions, do not hesitate to contact us.

Very truly yours, re:/,)

Vra~;/p.

t. (

K~zi

/,?/(

General Manager -

Electric Production Attachments