ML20005E484

Notifies That Listed Operating Conditions Acceptable & Will Ensure Reliability of 115 Kv Offsite Power Source,Per Util Stating That Operational Min of 100% Nominal Voltage Placed on Offsite Power Source

ML20005E484
Person / Time
Site:	Summer
Issue date:	12/21/1989
From:	Bradham O SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 9001050321
Download: ML20005E484 (2)

Text

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WCY7 a 9; ;3 Mr. S. D. Ebneter L

Regional Administrator

'U. S. Nuclear Regulatory Commission Region II, Suite 2900 101 Marietta Street, N. W.

p Atlanta, Georgia 30323

Subject:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 115 KV Offsite Power Operations

Dear Mr. Ebneter:

SouthCarolinaElectric&GasCompany(SCE&G)inaletterdatedDecember7, 1989, stated that an operational minimum of 100% of nominal voltage would be placed on the 115 KV Offsite Power Source. This limit was to be utilized until further stability and/or load flow studies verified other conditions were acceptable. The Systems Planning group has verified, by performing a new grid stability analysis, that the following operating conditions are acceptable and will ensure the reliability of the 115 KV Offsite Power Source:

1)

With both 115 KV/7.2 KV Transformers in service to one Engineered Safety Features (ESF) bus, the minimum allowed voltage is 97.85% of nominal.

2)

With both 115 KV/7.2 KV Transformers in service to both ESF buses, the minimum allowed voltage is 98.98% of nominal.

3)

With only one 115 KV/7.2 KV Transformer in service to one ESF bus, the minimum allowed voltage is 98.88% of nominal.

1 If there are any questions, please contact me at your convenience.

1 1

Very truly yours,

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0. S. Bradham WRH/058:1cd c:

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