ML18081A855

Submits Addl Info Re Adequacy of Offsite Power Sys in Response to NRC 791001 Request.Sys Functioned as Designed. Forwards LERs 77-032/03L-0,77-037/03L-0,77-045/03L-0, 77-046/03L-0 & 78-035/03L-0

ML18081A855
Person / Time
Site:	Salem
Issue date:	01/03/1980
From:	LIBRIZZI F P Public Service Enterprise Group
To:	SCHWENCER A Office of Nuclear Reactor Regulation
Shared Package
ML18081A856	List: ML18081A855 ML18081A857 ML18081A858 ML18081A859 ML18081A860 ML18081A861 ML18081A862 ML18081A863 ML18081A864 ML18081A865 ML18081A867
References
NUDOCS 8001080492
Download: ML18081A855 (4)

Text

Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201 /430-7000 January 3, 1980 Mr. Albert Schwencer, Chief Operating ReactorsrBranch

1. 1 Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, _D. C. 20555

Dear Mr. Schwencer:

ADEQUACY OF OFFSITE POWER SYSTEMS SALEM GENERATING STATION, UNIT NO. 1 DOCKET NO. 50-272 Pursuant to your letter of October 1, .1979, we have investigated the four events for which you requested information and also fied one additional instance where an offsite power feed was available.

This additional event is described in our Reportable Occurrence Letter, _LER 78-35/03L, dated July 20, 1978, a copy of which is enclosed.

For all occurrences addressed by this response, there were no total losses of offsite power, no conditions of graded voltage or frequency on the grid, and no adverse effects on safety related buses. All systems functioned as designed.

We, hereby, submit the following information for each identified event by LER Number and Report Date: Item A LER 77-28, May 13, .1977 rno:J-1978 Fl \K\RSOF SEll\1C'E

1. At the time of this event there were two offsite power circuits in service and one, 500 KV line #5Q24, was lost. 2. The event was caused by a forest fire proximately 36 miles from the station. 3. transmission lines are not in the same geological area, specifically to provide separation for events such as this. 4. 5. 6. 7. No voltage fluctuations were experienced prior to or during the outage. No frequency decay was experienced prior to or during the outage. Power was unavailable on the affected line for 45 minutes. April 18, .1977 95-2001 (200M) 2-78

-. . . .

• A. Schwencer LER 77-37, May 2, 1977 1. At the time of this event there were two offsite power circuits in service and one, 500 KV line #5023, was lost. 2. The event was caused by a forest fire proximately 37 miles from the station. 3. The transmission lines are not in the same geological area, specifically to provide

• separation for events such as this. 4. No. voltage fluctuations were experienced prior to or during the outage. 5. No frequency decay was experienced-prior to or during the outage. 6. Power was unavailable on the affected line for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, 17 minutes. 7. May 14, 1977 LER 77-45, July 8, 1977 1. At the time of this event there were two offsite power circuits in service and one, 500 KV line #5024, was lost. 2. Operation of the Generator Breaker over protection relays during a 100% erator Trip Test caused the line outage. See the attached LER for complete tion. 3. The breakers which isolate No. 1 Unit Generator affect only the #5024 500 KV line protective circuitry on flashover protection, therefore, _the other 500 KV line was unaffected.

4. No voltage fluctuations were experienced prior to or durinef the outage. 5. No frequency decay was experienced prior to or during the outage. 6. Power was unavailable on the affected line for 4 hOurs, 41 minutes. 7. June 26, 1977 1-3-80 A. Schwencer LER 77-46, July 17, 1977 1. At the time of this event there were two offsite power circuits in service. They, in turn, .were feeding both station power transformers for two feeds into the 13 KV buses. One station power transformer was deenergized by the event. Both offsite sources (500 KV lines) remained in vice. 2. This event was caused by personnel error while testing the bus section 1-5 500 KV GCB. Protective relaying was not tagged out while testing the breaker. During the test, the protection circuits saw an apparent stuck breaker and operated bus section 1-8 500 KV Breaker to isolate the apparent fault. This deenergized the No. 2 Station Power 500/13 KV Transformer.

1-3-80 3. The protective action, by design, isolated only that portion of 500 KV Bus that would have been affected by a fault on the breaker being tested. The remainder of the 500 KV yard was unaffected.

4. No voltage fluctuations were experienced prior to or during the outage. 5. No frequency decay was experienced prior to or during the outage. 6. Power was unavailable for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, 44 minutes on the affected station power transformer.

7. June 28, 1977 LER 78-35/03L, July 20, 197 8 1.

offsite circuits in service at the time of this event; none were lost, but one of two interconnecting station power transformers between the offsite network and onsite class lE equipment was lost during the occurrence.

A. Schwencer 1-3-80 LER 78-35/03L, July 20, 1978 (Cont.) Ttern: B Item: C 2. Operator error in not fully racking-in the 13KV Gas Turbine output breaker was the cause of this event. Opening this breaker in this condition caused protective relay operation that opened 13 KV Bus Section 4-5 Breaker and loss of No. 2 Station Power Transformer.

3. Protective relaying only affected the 13 KV Bus Breaker necessary to clear the apparent fault and the rest of the 13 KV equipment remained intact. 4. No voltage fluctuations were expereinced prior to or during the outage. 5. No frequency decay was experienced prior to or during the outage. 6. The No. 2 Station Power Transformer was returned to service in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, 23 minutes. 7. June 30, 1978 There was no total loss of offsite power events. LER 78-35/03L, with report date of July 20, 1978, was identified as an additional currence and is included above in Item A information.

If you have any further questions on this matter, we will be pleased to discuss them with you. Enclosure Very truly yours,

• Franl< P.'

General Manager -Eledtric Production