ML20128L960

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Marked-up Review of Licensee & Applicant Responses to NRC Generic Ltr 83-28,Item 1.2, 'Post-Trip Review:Data & Info Capabilities' for Grand Gulf Nuclear Station,Units 1 & 2
ML20128L960
Person / Time
Site: Grand Gulf  Entergy icon.png
Issue date: 05/21/1985
From:
SCIENCE APPLICATIONS INTERNATIONAL CORP. (FORMERLY
To:
NRC
Shared Package
ML20128L880 List:
References
CON-NRC-03-82-096, CON-NRC-3-82-96 GL-83-28, SAIC-85-1516-2, NUDOCS 8505310529
Download: ML20128L960 (15)
v • d • e


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ENCLOSURE 8

SAIC-85/15t6-2 ll I

REVIEW OF LICENSEE AND APPLICANT RESPONSES TO NRC GENERIC LETTER 83-28, c

(Required Actions Based on Generic Implications of Salem ATWS Events), Item 1.2 l

" POST-TRIP REVIEW: DATA AND INFORMATION CAPABILITIES" FOR GRAND GULF NUCLEAR STATION, UNITS 1 $ 2 . (50-416/0-487)

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-Technical Evaluation Report Prepared by i l

Science Applications International Corporation f!

1710 Goodridge Drive McLean, Virginia 22102

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Prepared for s U.S. Nuc1 car Regulatory Commission f l

Washington, D.C. 20555 C

Contract No. NRC-03-82-096 ,

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! C 8505310529 DR 850521 p ADOCK 05000416 PDR

FOREWORD This report contains the technical evaluation of the Grand Gulf Nuclear Sta t i o n , Un i t.r 1 $ 7-- response to Generic Letter 83-28 (Required Actions Based on Generic Implications of Salem ATWS Events), Item 1.2 " Post Trip Review: Data and Information Capabilities."

For the purposes of this evaluation, the review criteria, presented in part 2 of this report, were divided into five separate categories. These are:

1. The parameters monitored by the sequence of events and the time history recorders,
2. The performance characteristics of the sequence of events, recorders,
3. The performance characteristics of the time history recorders,
4. The data output format, and
5. The long-term data retention capability for post-trip review material.

All available responses to Generic Letter 83-28 were evaluated. The plant for which this report is applicable was found to have adequately '

responded to, and met, categories 2 and 3.

The report describes the specific methods used to determine the cate-gorization of the responses to Generic Letter 83-28. Since this evaluation report was intended to apply to more than one nuclear power plant specifics regarding how each plant met (or failed to meet) the re';;P ;=t: are not presented. Instead, the evaluation presents a catego zation of the l l responses according to which categories of Wr4ments re satisfied and l

which are not. The evaluations are based on pecif criteria (Section 2) i derived from the requirements as stated in t ic letter.

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TABLE OF CONTENTS Section Page Introduction. . . . . . . . . . . . . . . . . . . . . . . . . I

1. Background. . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Review Criteria . . . . . . . . . . . . . . . . . . . . . . . 3
3. Evaluation. . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Re fe re nc e s . . . . . . . . . . . . . . . . . . . . . . . . . . 10 C. Sufr*MT2 nV C o ComT Few T1c4sc.ow . . .

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INTRODUCTION u

SAIC has reviewed the,rsutry'Jsubmittals prepared in response to Generic Letter 83-28, item 1.2 " Post-Trip Review: Data and Information Capability".

The submitta13 (see references) contained sufficient information to determine that the data and information capabilities at this plant are acceptable in the- following areas.

e The sequence-of-events recorder (s) performance charac-teristics.

e The time history recorder (s) performance characteris-tics.

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However, the data and information capabilities, as described in the submittal, either fail to meet the review criteria or provide insufficient

information to allow determination of the adequacy of the data and f l information capabilities in the following areas.

I e The parameters monitored by both the sequence-of-events and time history recorders.

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e The output format of the recorded data.

e The long-term data retention, record keeping, capa-bility.

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! 1. Background On February 25, 1984, both of the scram circuit breakers a*t Unit 1 of j the Salem Nuclear Power Plant failed to open upon an automatic reactor trip signal from the reactor protection system. This incident occurred during the plant startup and the reactor was tripped manually by the operator about 30 seconds after the initiation of the automatic trip signal. The failure of the circuit breakers has been determined to be related to the sticking of l the under voltage trip attachment. Prior to this incident; on February 22,

( 1983; at Unit 1 of the Salem Nuclear Power Plant an automatic trip signal .

l was generated based on steam generator low-low level during plant startup.

In this case the reactor was tripped manually by the operator almost coinci-l dentally with the automatic. trip. At that time, because the utility did not have a requirement for the systematic evaluation of the reactor trip, no l investigation was performed to determine whether the reactor was tripped

) automatically as expected or manually. The utilities' written procedures j required only that the cause of the trip be determined and identified the responsible personnel that could authorize a restart if the cause of the j trip is known. Following the second trip which clearly indicated the

, problem with the trip breakers, the question was raised on whether the

! circuit breakers had functioned properly during the earlier incident. The

! most useful source of information in this case, namely the sequence of events printout which would have indicated whether the reactor was tripped '

automatically or manually during the February 22 incident, was not retained after the incident. Thus, no ju,dgment on the proper functioning of the trip system during the earlier incident could be made. ,

l l Following these incidents; on February 28, 1983; the NRC Ev.ecutive Director for Operations (EDO), directed the staff to invest % ate and report

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l on the generic impitcations of these occurrences at Unit 1 of the Salem

! Nuclear Power Plant.' The results of the staff's inquiry into the generic implications of the Salem Unit incidents is reported in NUREG-1000, " Generic Implications of ATWS Events at the Salem Nuclear Power Plant." Based on the results of this study, a set of required actions were developed,and included in Generic Letter 83-28 which was issued on July 8,1983 and sent to all i

licensees of operating reactors, applicants for operating Itcense, and construction permit holders. The required actions in this gene *ric letter consist of four categories. These are: (1) Post-Trip Review, (2) Equipment 2

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i Classification and Vendfr Interface, (3) Post Maintenance Testing, and (4)

Reactor Trip System Reliability Improvements.

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.. 'l The first required action of the generic letter, Post-Trip Review, is the subject of this TER and consists of action item 1.1 " Program Description and Procedure" and action item 1.2 " Data and Information Capability." In the next section the review criteria used to assess the adequacy of the utilities' responses to the requirements of action item 1.2 will be discussed.

2. Review Criteria

.The intent of the Post Trip Review requirements of Generic Letter 83-28 is to ensure that the licensee has adequate procedures and data and information sources to understand the caus$nd progression of a reactor trip. This understanding should go beyond a# simple identification of the course of the event. It should include the capability to determine the root cause of the reactor trip and to determine whether safety limits have been l

exceeded and if so to what extent. Sufficient information about the reactor l trip event should be available so that a decision on the acceptability of a reactor restart can be made.

The following are the_ review criteria developed for the requirements of -

Generic Letter 83-28, action item 1.2:

The equipment that provides the digital sequence of events (SOE) record '

and the analog time history records of an unscheduled shutdown should pro-l vide a reliable source of the necessary information to be used in the post trip review. Each plant variable which is necessary to determine the cause(s) and progression of the event (s) following a plant trip should be monitored by at least one recorder Guch as a sequence-of-events recorder or a plant process computer for digital parameters; and strip charts, a plant }

process computer or analog recorder for analog (time history) variables].

Ea.ch device used to record an analog or digital plant variable should be described in sufficient detail so that a determination can be made as to whether the folicwing performance characteristics are met: ,

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e Each sequence-of-event.s recorder should be capable of detecting i and recording the sequence of events with a sufficient time discrimination capability to ensure that the time responses.asso-ciated with each monitored safety-related system can be ascer-l tained, and that a determination can be made as to whether the

! time response is within acceptable limits based on

FSAR Chapter 15 Accident Analyses. The i recommended guideline for the SOE time discrimination is approxi-mately 100 msec. If current SOE recorders do not have this time discrimination capability the licensee or applicant should show
that the current. time discrimination capability is sufficient for an' adequate reconstruction of the course of the reactor trip. As
a minimum this~should include the ability to adequately recon-struct the accident scenarios presented in Chapter 15 of the plant l FSAR.

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e Each analog time history data recorder s'hould have a sample inter-I-- val small enough so that the incident can be accurately reconstructed following a reactor trip. As a minimum, the licensee or appitcant should be able to reconstruct the course of i the accident sequences evaluated in the accident analysis of the plant FSAR (Chapter 15). The recommended guideline for the sample interval is 10 sec. If the time history equipment does not meet '
this guideline, the licensee or applicant should show that the current time history c,apability is _ sufficient to accurately recon-struct the accident sequences presented in Chapter 15 of the FSAR.

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l e To support the post trip analysis of the cause of the trip and the proper functioning of involved safety related equipment, each analog time history data recorder should be capable of updating and retaining information from approximately five minutes prior to the trip until at least ten minutes after the trip.

e The information gathered by the sequence-of-events and time ,

history data collectors should be stored in a manner that will allow for retrieval and analysis. Thedatamayperetained in either hardcopy (computer printout, strip chart 00tput, etc.)

or in an accessible memory (magnetic disc or tape). This i

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information should be presented in a readable and meaningful format, taking into consideration good human factors practices (such as those outlined in NUREG-0700). ,.

e All equipment used to record sequence of events and time history information should be powered from a reliable and non-interruptible power source. The power source used need not be i safety related.

The sequence of events and time history recording equipment should monitor sufficient digital and analog parameters, respectively, to assure that the course of the reactor trip can be reconstructed. .The parameters monitored should provide sufficient information to determine the root cause

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of the reactor trip, the progression of the reactor trip, and the response of the plant parameters and systems to the reactor trip. Specifically, all' input parameters associated with reactor trips, safety injections and other ,

safety-related systems as well as output parameters sufficient to record the proper functioning of these systems should be recorded for use in the post trip review. The parameters deemed necessary, as a minimum, to perform a )

post-trip review (on(that would determine if the plant remained within its  ;

design envelope) are presented on Tables 1.2-1 and 1.2-2. If the appli- l cants' or licensees' SOE recorders and time history recorders do not monitor all of the parein?ters suggested in these tables the applicant or licensee should show that the existing set of monitored parameters are sufficient to  ;

establish that the plant remaine,d within the design envelope for tha appro- i priate accident conditions; such as those analyzed in Chapter 15 of the ,

l plant Safety Analysis Report. I b

Information gathered during the post trip review is required input for future post trip reviews. Data from all unscheduled shutdowns provides a valuable reference source for the determination of the acceptability of the plant vital parameter and equipment response to future unscheduled shut-downs. It is therefore necessary that information gathered during all post trip reviews be maintained in an accessible manner for the life of the plant.

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Table 1.2-1. PWR Parameter List SOE Time History '

Recorder Recorder Parameter / Signal h) x Reactor Trip (1) x Safety Injection x Containment Isolation (1) x Turbine Trip x Control Rod Position (1)x x Neutron Flux, Power x K Containment Pressure (2) Containment Radiation x Containment Sump Level (1) x x Primary System Pressure (1) x x Primary System Temperature (1) x Pressurizer Level (1) x Reactor Coolant Pump Status (1) x , x Primary System Flow (3) Safety Inj.; Flow. Pump / Valve Status x MSIV Position x x Steam Generator Pressure (1) x x Steam Generator Level (1) x x Feedwater Flow (1) x x , Steam Flow (3) Auxiliary Feedwater System;- Flow,

, Pump /Value Status x AC and DC System Status (Bus Voltage) x Diesel Generator Status (Start /Stop, On/Off) x PORY Position (1.): Trip parameters '

.(2): Parameter may be monitored by either an SOE or time history recorder.

(3): Acceptable recorder options are: (a) system flow recorded on an SOE recorder, (b) system flow recorded on a time history recorder, or (c) equipment status recorded on an SOE recorder, j

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Table 1.2-2. BWR Parameter List SOE Time History

x Control Rod Position x (1) x Neutron Flux, Power x (1) , Main Steam Radiation (2) Containment (Dry Well) Radiation x (1) x Drywell Pressure (Containment Pressure)

(2) Suppression Pool Temperature x (1) x Primary System Pressure x (1),' x Primary System level i x MSIV Position l x (1) Turbine Stop Valve / Control Valve Position  !

x Turbine 8ypass Valve Position i x Feedwater Flow l x Steam Flow (3) Recirculation; Flow. Pump Status f

j x (1) Scram Discharge Level -

x (1) ,

Condenser Vacuum l x AC and DC System Status (Bus Voltage) }

(3)(4) Safety Injection; Flow. Pump / Valve Status x Diesel Generator Status (On/Off, Start /Stop) 4 (1): Trip parameters.

(2): Parameter may be recorded by either an SOE or time history recorder.

(3): Acceptable recorder options are: (a) system flow recorded on an SOE 1 recorder (b) system flow recorded on a time history recor' der, or I (c) equipment status' recorded on an SOE recorder.  : ,

(4): Includes recording of parameters for all applicable systei,s from the L following: HPCI, LPCI, LPCS, IC, RCIC.

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3. Evaluation j The parameters. identified in part 2 of this report as a part of the

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review criteria are those deemed necessary to perform an adequate post-trip review. The recording of these parameters on equipment that meets the guidelines of the review criteria will result in a source of information i that <:an be used to determine the cause of the reactor trip and the plant response to the trip, including the responses of important plant systems. "

The parameters identified in this. submittal as being recorded by the sequence of events and time history recorders do not correspond to the q parameters specified in part 2 of this report.  :

. The information provided in the submittal indicates that the equipment used to monitor the digital and analog parameters meets the minimal requirements set forth in part 2 of this report. The sequence of events and analog time history recorders are powered from a non-interruptable power supply. The monitoring characteristics are all within the guidelines of the review criteria.

The data and information recorded for use in the post-trip review should be output in a format that allows for ease of identification and use of the data to meet the review criterion that calls for information in a readable and meaningful format. The information contained in this submittal does not indicate that this requirement is set. .

M The data and information"used during a post trip review should be retained as part of the plant files. This inform tion could prove useful during future post-trip reviews. Therefore one . :;.'. ...;. presented in part 2 of this report is that information used during a post-trip review be maintained in an accessible manner for the life of the plant. Information

' contained within this submittal does not indicate that this criterion will be met.

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4. Conclusion e

The information supplied in response to Generic Letter 83-28 indicates that the current post-trip review data and information capab411 ties are adequate in the following areas: .

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1. The SOE recorders meet the minimum performance characteristics.

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2. The time history recorders meet the minimum performance character-istics.

The information supplied in response to Generic Letter 83-28 does not ,

indicate that the post-trip review data and information capabilities are adequate in the following areas:

1. - As described in the submittal, sufficient analog and digital parameters are not recorded for use in the post-trip review.
. 2. - As described in' the submittal, the recorded data may not be output in a readable and meaningful format.
3. The data retention procedures, as described in the submittal, may not ensure that the information recorded for the post-trip review

, is maintained in an accessible manner for the life of the plant.

C It is possible that the current data and information capao ities at this nuclear power plant are adequate to meet the intent of these + ii.L. .;..3, but were not completely described. Under these circumstances, the licensee should provide an updated, more complete, description to show in more detail 4

the data and information capabilities at this nuclear power plant. If the information provided accurately, represents all current data and information j capabilties, then the licensee should either show that the present data and information capabilities meet the intent of the criteria in part 2 of this report, or detail future modifications that would enable the licensee to meet the intent of the evaluation criteria.

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REFERENCES .

NRC Generic Letter 83-28. " Letter to all licensees of operating reactors, applicants for operating license, and holders of construction permits regarding Required Actions Based on Generic Implications of Salem ATWS Events." July 8, 1983.

NUREG-1000 Generic Implications of ATWS Events at the Salem Nuclear Power Plant, April 1983.

Letter from L.F. Dale, Mississippi Power and Light to D.G. Eisenhut, NRC, dated September 6,1983 Accession Number 8309080212 requesting extension of time for submittal of response to Generic Letter 83-28.

Letter from J.P. McGaughy, Jr., Mississippi Power and Light to D.G.

Eisenhut, NRC, dated November 4,1983, Accession Number 8311090065 in response to Generic Letter 83-28 of July 8,1983, with attachment.

Plans and Schedules to Address Generic Letter 83-28.

Letter from L.F. Dale, Mississippi Power & Light Company, to H.R.

Denton, USNRC, dated November 2,1984 Accession Number 841120082-providing information in response to items 1.1 and 1.2 of Generic Letter 83-28, with attachments.

Letter from L.F. Dale, Mis 5'ssippi Power & Light Company, to H.R.

Denton, USNRC, dated Novemb 19, 1984, Accession Number 8411260030 providing information in response to items 2.1 and 2.2.2 of Generic Letter 83-28, with attachment.

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Grand Gulf -

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1. Parameters recorded: Unsatisfactory See attached table for discrepancies.
2. SOE recorders performance characteristics: Satisfactory Plant process computers: (2 computers - 1 NSSS,1 BOP) time discrimi-
  • nation is on the order of a few milliseconds but is not specified.

power supply is non-interruptible (It is reasonable to assume that a few milliseconds is less than 100 msee and sample output indi-cates approximately a Imsee time discrimination capability.) -

3. Time history recorders performance characteristics: Satisfactory Plant process computer: sample interval of 5 secs for the period from 4 minutes before to 4 minutes after the trip GETARS: capable of 100 samples /sec for 234 channels for the period from 30 seconds before to 10 minutes after the trip, power supply 4

is non-interruptible (Both devices record all the required analog parameters, except GETARS does not record feedwater flow. Therefore between the two devices the analog recording capability needed to meet the intent of the require-i ments is available.)

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4. Data output format: Unsatisfactory SOE data output includes event descriptor and sensor ID '

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Analog data output: BOP and NSSS computers - parameter name and value and sensor ID are output GETARS - time, parameter name and value are output l 5. Data retention capability: Unsatisfactory l

Data is retained, but for an unspecified period.

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":; ' .. QBWR Parameters for Post Trip Review (circled parameters are not recorded)

-- l SOE Time History I Recorder Recorder Parameter / Signal

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x Reactor Trip l x Safety Injection x Containment Isolation x Turbine Trip

@ Control Rod Position x (1) x- Neutron Flux, Power x (1) Main Steam Radiation (2) Containment (Dry Well) Radiation x (1) x Drywell Pressure (Containment Pressure) ,

(2) Suppression Pool Temperature i x (1) x Primary System Pressure x (1) x Primary System level x- MSIV Position l x(1) Turbine Stop Valve / Control Valve Position x Turbine Bypass Valve Position x Feedwater Flow x

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, Steam Flow l (3) Recirculation; Flow Pump Status l x (1) Scram Discharge Level x (1) Condenser Vacuum x AC and DC System Status (3)(4) Safety Injection; Flow Pump / Valve Status x Diesel Generator Status

.(1): Trip parameters.

(2): Parameter may be recorded by either an 50E or time history recorder.

(3): Acceptable recorder options are: (a) system flow recorded on an SOE <

recorder, (b) system flow recorded on a time history recorder, or l (c) equipment status recorded on an SOE recorder. .

l- (4): Includes recording of parameters for all applicable systems from the following: HPCI. LPC). LPCS, IC, RCIC. M l

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