ML20140C239

Forwards Response to 851022 Request for Addl Info on SER Open Item 5 Re Generic Ltr 83-28,Items 1.1 & 1.2 on post-trip Review.Program for Ensuring That Unscheduled Reactor Shutdowns Analyzed Described

ML20140C239
Person / Time
Site:	Vogtle
Issue date:	03/17/1986
From:	Bailey J GEORGIA POWER CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
References
GL-83-28, GN-836, NUDOCS 8603250285
Download: ML20140C239 (4)

Text

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{ 7C Georgia Power Company l Route 2. Box 299A Waynesboro, Georgia 30830 Telephone 404 554-9961 404 724-8114 Southern Company Services, Inc.

Post Office Box 2625 Birmingham. Alabama 35202 Telephone 205 870-6011 l

Vogtle Proj.e ct l

March 17,1986 l

l Director of Nuclear Reactor Regulation File: X7BC35 Attention: Mr. B. J. Youngblood Log: GN-836 l PWR Project Directorate #4 l Division of PWR Licensing A l U. S. Nuclear Regulatory Commission Washington, D.C. 20555 REF: ADENSAM TO FOSTER DATED 10/22/85 NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMBERS CPPR-108 AND CPPR-109 V0GTLE ELECTRIC GENERATING PIANT - UNITS 1 AND 2 SER OPEN ITDI 5: GENERIC LETTER 83-28

Dear Mr. Denton:

The referenced letter requested additional information on Items 1.1 and 1.2 of Generic Letter 83-23. Attached for your staff's review is the VEGP response to this information request.

If your staff requires any additional information, please do not hesitate to l

contact me.

Sincerely, J. A. Bailey Project Licensing Manager JAB /sm f Attachment

! xc: R. E. Conway G. Bockhold, Jr.

R. A. Thomas NRC Resident Inspector J. E. Joiner, Esquire D. C. Teper B. W. Churchill, Esquire W. C. Ramsey M. A. Miller (2) L. T. Gucwa B. Jones, Esquire Vogtle Project File h

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k ATTACHMENT GENERIC LETTER 83-28 1.1 Post - Trip Review (Program Description and Procedure)

Position Licensees and applicants shall describe their program for ensuring that unscheduled reactor shutdowns are analyzed and that a determination is made that the plant can be restarted safely.

Response

1. VEGP has developed an operational procedure 10006-C, " Reactor Trip Review,"

which is a systematic safety procedure that will ensure the following restart criteria are met before restart of the reactor is authorized.

This procedure is used to identify the root cause of the trip and includes the sequence of events. If the cause of the trip is not apparent, a description of the evaluation in progress is required.

The Reactor Trip Review procedure requires corrective action to have been completed or in progress to correct the root cause of the trip.

The post trip review reconstructs the sequence of events on data sheets.

This sequence of events is then analyzed to determine if the events occurred out of normal sequence, degraded trends in equipment occurred, and/or failed or degraded response of equipment to control signals occurred.

The review analyzes +5e trip to determine if safety-related and other equipment operated as expected.

The Reactor Trip Rev'~v looks at all of the above. VEGP classifies reactor trips as Condition I or Condition II. A reactor trip is classified as a Condition I when the cause of the trip is known and has been corrected; all safety-related equipment functioned properly during the trip. A Reactor Trip is classified Condition II when the cause of the trip is not known and/or some safety-related equipment functioned in an abnormal or degraded manner during the trip. If the trip is classified as a Condition II, the Plant Review Board must review the report. The Plant General Manager may authorize a restart prior to Plant Review Board review of the report.

2. The responsibilities and authorities of personnel performing the review and analysis is defined in procedure 10000-C, " Conduct of Operations." The Shift Technical Advisor (STA) will complete the Reactor Trip Report. He has the authority to obtain the necessary personnel and equipment for the post trip review and for gathering and assessing the information.

The On-Shift Operations Supervisor (0S05) functions as the senior management representative for plant operations on shift and must hold a SR0 License.

He concurrently assesses the information for the Reactor Trip Report with the STA, and classifies the trip. He provides approval for startup af ter Condition I trips.

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3. The OSOS has the'overall authority for directing the post trip review process.

The STA has the responsibility for the post trip analysis. They concurrently classify the trip as Condition I or Condition II.

4. The operating staff will make a report on data sheets, " Reactor Trip Personnel Statements," of the Reactor Trip Review procedure. If it is necessary for a more accurate analysis, the operating crew on duty during the trip may be available to the review team for interviews.

A time history of the event is required in the Reactor Trip Review procedure on data sheet " Sequence of Events." The information for this should be available from the Computer Alarm Printout, Pre / Post Trip Logs, and the ERF Computer Printout. Chart records will be included, where necessary.

5. The Reactor Trip Review procedure evaluates the plant response to a trip.

A determination is made as to whether the response was within acceptable limits. The data from the review is compared to VEGP Technical Specifications to verify proper operation. If responses were within acceptable limits, the trip is classified as a Condition I trip.

A sequence of events is reconstructed. This sequence is used to verify automatic functions and to identify any off normal occurrences.

6. If the plant response is not within acceptable limits, the transient is considered a Condition II event. For these events, the Plant Review Board reviews the Reactor Trip Review. The Post Trip review collects the information necessary for an independent assessment. This report is maintained for the life of the plant. The Plant General Manager may authorize restart following a Condition II event.

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7. The procedure which contains the criteria for determining the acceptability for a restart is 10006-C, " Reactor Trip Review."

The procedure that has the responsibilities and authorities of key personnel involved in the Post Trip review process is 10000-C, " Conduct of Operations."

The procedure that deals with determining whether the plant variables and system responses were withic specified limits is 10006-C, " Reactor Trip Review."

The procedure which nas the criteria for determining the need for an independent review is 10006-C, " Reactor Trip Review."

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1.2 Post - Trip Review (Data and Information Capability)

Position Licensees and applicants shall have or have planned a capability to record, recall, and display data and information to permit diagnosing the causes of unscheduled reactor shutdowns prior to restart and for ascertaining the proper functioning of safety-related equipment.

Adequate data and information shall be provided to correctly diagnose the cause of unscheduled reactor shutdowns and the proper functioning of safety-related equipment during these events using systematic safety assessment procedures (Action 1.1). The data and information shall be displayed in a form that permits ease of assimilation and analysis by persons trained in the use of systematic safety assessment procedures.

Response

The sequence-of-events recorder is capable of detecting and recording all sequence-of-events contact changes in the order of occurrence, with the elapsed time from the first ccatact change printed in milliseconds. The resolution of this sequence is 1 msec. This sequence is sufficient to reconstruct the course of the reactor trip.

The analog time history data recorder can have a sample interval as low as one second. This is sufficient to reconstruct the accident sequences of FSAR Chapter 15.

The analog time history logs continually update on a rotational sequence. The data is stored on a buffer. The log makes 40 data collections. The interval for these collections must be greater than 5 sec. This would give a pre-trip history of 3.3 mins. A greater collection interval would provide a longer pre-trip history. The post trip log is inactive until a trip signal is received. When the trip signal is received, the post trip log will record data for 40 collections and then print. The interval for data collections can be varied.

The information gathered by the sequence-of-events and time history data collectors is stored in computer memory as it is collected and is printed on a printer.

The equipment used for sequence-of-events and time history information recording has 3 power sources. This will insure a reliable supply of power to the equipment.

The sequence-of-events recorder has space for 64 data points, and the trip log has 65 data points. This allows sufficient space to monitor all suggested pa ramete rs. The data points selected may be changed to record various different parameters. However, the selection will include parameters necessary to verify proper functioning of the safety-related systems.

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