ML18092B495

Submits Suppl Info on Listed Items Re Installation of trip- a-unit Protective Relay Scheme,Per 870327 Meeting W/Nrc

ML18092B495
Person / Time
Site:	Salem, Hope Creek, 05000000
Issue date:	04/03/1987
From:	Corbin McNeil Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18092B496	List: ML18092B495 ML18092B497 ML18092B498 ML18092B499
References
NLR-N87061, NUDOCS 8704070322
Download: ML18092B495 (4)

Text

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Public Service Electric and Gas Company Corbin A. McNeill, Jr. Public Service Electric and Gas Company P.O. Box236, Han cocks Bridge, NJ 08038 609 339-4800 Vice President -

Nuclear April 3, 1987 NLR-N87061 U. S. Nuclear Regulatory .Commission Document Control Desk Washington, D. C. 20555 Gentlemen; INSTALLATION OF TRIP-A-UNIT PROTECTION SCHEME SUPPLEMENTAL INFORMATION SALEM AND HOPE CREEK GENERATING STATIONS DOCKET NOS. 50-272, 50-311, AND 50-354 On March 25, 1987 Public Service Electric and Gas Company (PSE&G) forwarded for your review, a copy of its Safety Evaluation for the installation of a Trip-A-Unit protective relay scheme for Salem Unit No. 1. In response to questions received from your staff, PSE&G representatives attended a meeting in your offices on March 27, 1987 to clarify information provided in the Safety Evaluation. At the close of that meeting, PSE&G committed to provide additional information relative to the following:

1) Power level restrictions applicable to all Artificial Island Units when the trip-a-unit scheme is either energized or deenergized.

2) Conditions during which the trip-a-unit scheme would be energized and deenergized.

3) The availability of offsite power upon failure of the trip-a-unit scheme and subsequent loss of all Island Units when the Island generation is at 3162 MW.

4) The availability of offsite power following a failure of the trip-a-unit scheme and subsequent loss of all Island Units with the Island at maximum generating capacity.

5) The minimum expected voltage following the loss of all Artificial Island Units and the Salem - Deans circuit.

6) The voltage profile at the 4160v vital busses following the loss of all Units and the Salem - Deans circuit.

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NRC Document Control Desk 2 April 3, 1987 Items 1 and 2 were addressed in our letter dated March 30, 1987.

As identified in that response, the remaining items would be addressed in a revised Safety Evaluation. That Safety Evaluation and selected reference materials are provided as Enclosure 1. A brief Summary of each item is given in the following paragraphs.

Item 1 - Generating Limits As identified in Operating Instruction OI 7-B-04, electrical generation limits based on stability considerations have been established for each of the Artificial Island Units.

The limits for three Unit operation are given below. The limits applicable to the various combinations of two Unit operation are summarized in Attachment 3 to the Safety Evaluation.

CONDITION SALEM 1 SALEM 2 HOPE CREEK Trip-A-Unit Available 1162 1000 1000 Trip-A-Unit Unavailable 790 790 750 One Transmission Line Out 650 650 650 Of Service Item 2 - Trip-A-Unit Operation As indicated above, during three unit operation an Island generation limit of 2330 MW is imposed when the trip-a-unit scheme is unavailable. Operating Instruction OI 7-B-04 also requires that power be reduced to this limit and trip-a-unit disabled whenever any one of the following conditions exist;

- Severe thunderstorm and/or lightning activity within 50 miles of Salem, Deans, or New Freedom.

- Severe icing conditions.

- Winds in excess of 50 mph as measured at either Camden or Deans switching stations or at Artificial Island.

- Whenever forest fires are reported in the vicinity of the Salem/Deans right-of-way.

- Required maintenance/repair work.

NRC Document Control Desk 3 April 3, 1987 Additional restrictions on generation apply for th~ various combinations of two Unit operation. These restrictions are summarized in Attachment 3 to the Safety Evaluation. Appropriate revisions have been made to the Salem And Hope Creek operating procedures to incorporate these requirements and limitations.

Items 3 aJd 4 - Availability of Offsite Power As identified in the attached Safety Evaluation, the Stations are each provided with the required sources of offsite power during the outage of the Hope Creek - Keeney line. Additional analyses have been performed which demonstrate that the stability of the PSE&G bulk power system is maintained following a loss of the Salem - Deans line with a failure of the trip-a-unit scheme and the subsequent loss

• of all Artificial Island Uni ts from an Island generation level of 3424 MW (i.e. maximum gross generating capacity). Because the 3424 MW case represents a more stressful condition for system stability considerations, this same conclusion would apply to the case where the Units are operating at the presently reduced level of 3162 MW.

Item 5 - Minimum Expected Grid Voltage For the case of Island generation at the 3390 MW level, subsequent to the transient described above, the minimum expected steady state voltage at the 500 KV level is 1. 04 per unit. This value exceeds the 1.01 value which was used for degraded grid analyses. Under these circumstances, adequate voltage will be maintained at the vital busses.

Item 6 - Vital Bus Voltage Profiles As indicated above, the value assumed in the analysis of degraded grid conditions bounds that which would result from the identified transient. Representative voltage profiles for the Salem Units at the 1.01 per unit value are contained in Reference 3.7 of the attached Safety Evaluation.

NRC Document Control Desk 4 April 3, 1987 We trust that the above information will be useful in your review of this matter. If there are any further questions, please feel free to contact us.

Sincerely, C II !Vl c!UJJf /~

C: Mr. Donald C. Fischer Project Manager - Salem Mr. David Wagner Project Manager - Hope Creek Mr. Thomas J. Kenny Senior Resident Inspector - Salem Mr. Robert W. Borchardt Senior Resident Inspector - Hope Creek