ML20127N313

SER Re Util 831104 Response to Generic Ltr 83-28,Item 1.2, Post-Trip Review (Data & Info Capability). Licensee post-trip Review Data & Info Capabilities Acceptable

ML20127N313
Person / Time
Site:	Farley
Issue date:	06/12/1985
From:	NRC
To:
Shared Package
ML20127N308	List: ML20127N303 ML20127N313
References
GL-83-28, NUDOCS 8507010526
Download: ML20127N313 (10)

Text

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ENCLOSURE 1 SAFETY EVALUATION REPORT FOR -

GENERIC LETTER 83-28 ITEM 1.2 - POST-TRIP REVIEW {-.

(DATAANDINFORMATIONCAPABILITY)

JOSEPH M. FARLEY NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS.: 50-348, 50-364 I. INTRODUCTION l On February 25, 1983, both of the scram circuit breakers at Unit 1 of the Salem Nuclear Power Plant failed to open upon an automatic reactor trip signal from the reactor protection system. This incident occurred during the l plant start-up 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 the i

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 was generated based on steam generator low-low level during plant start-up. In this case, the reactor was tripped manually by the operator almost coincidentally with the automatic trip. Following these incidents, on February 28, 1983, the NRC Executive Director for Operations (ED0), directed the staff to investigate and report on the generic implications of these occurrences at Unit I of the Salem Nuclear Power Plant. The results of the staff's inquiry into the generic implications of the Salem unit incidents are reported in NUREG-1000, " Generic Implications of the ATWS Events at the Salen Nuclear Power Plant." As a result of this investigation, the Comission (NRC) requested (by Generic Letter 83-28 dated July 8, 1983) all licensees of operating reactors, applicants for an operating license, and holders of 0507010526 850612 PDR ADOCK 0D000348 p PDR

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. 4 construcdon pemits to respond to certain generic concerns. ~Thhe concerns are categorize, ,into four areas: (1) Post-Trip Review, (2) Equipment Classification and Vendor s Interface, (3) Port-Maintenance Testing, and

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(4) Reactor Trip Shstem Reliabilf t Vrprovements.

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q The fft st action iten, Post-Trip Review, consists of Action Item 1.1, I

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" Program Description and Procedure" and Action Item 1.2, " Data and Inforw tion Cahability." This safety evaluation report (SER) addresses Action Item 1.2 only. t

1 II. REVIEW GintELDlES

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The following review guidelines were developed after initial evaluation of the various utDity responses to Item 1.2 of Generic- Letter 83-28 and incor), orate the beit features of these sLbnittals. As such, these review guidelines in effect represent a " goo 6 practices" approach to post-trip review. Wihave reviewed the licensee's response to Item 1.2 against these

. guidelines': '

s, A. The equipment that provides the digital sequence of events (SOE) record e, <

and the analog time history records of <an unscheduled shutdown should 3

y provide ,a reliable source of the necessary information to ' ne* used in the l

post-trip review. Each plant, variable (Sich is necessary to determine I theecause and progression of the events following a plant trip should be

. monitored by at least one recorder (such as a slen:re. nce-of-events

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l; recorder or 3, plant process computer) for digital parameters; and~ strip

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charts, a plant process computer or analog recorder for analog (time history) variables. Performance characteristics guidelines for SOE and time history recorders are as follows:

Each sequence of events recorder should be capable of detecting and recording the sequence of events with a sufficient time discrimination capability to ensure that the time responses associated with each monitored safety-related system can be ascertained, 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 recomended guidelines for the SOE time discrimination is approximately 100 milliseconds. If current SOE recorders do not have this time discrimination capability the licensee should show that the current time discrimination capability is sufficient for an adequate reconstruction of the course of the reactor trip and post-trip events. As a minimum this should include the ability to adequately reconstruct the transient and accident scenarios presented in Chapter 15 of the plant FSAR.

Each analog time history data recorder should have a sample interval small enough so that the incident can be accurately reconstructed following a reactor trip. As a minimum, the licensee should be able to reconstruct the course of the transient and accident sequences evaluated in the accident analysis of

e 4-Chapter 15 of the plant FSAR. The recomended guidel_ine for the sample interval is 10 seconds. If the time history equipment does not meet this guideline, the licensee should show that the time history capability is sufficient to accurately reconstruct the transient and accident sequences presented in Chapter 15 of the FSAR. To support the post-trip analysis of the cause of the trip and the proper functioning of involved safety related equipnent, each analog time history data recorder should be capable of updating and retaining infomation from approximately five minutes prior to the trip until at least ten minutes after the trip.

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

B. 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 and post-trip events can be reconstructed. The parameters monitored should provide sufficient infomation to determine the root cause of the unscheduled shutdown, the

, progression of the reactor trip, and the response of the plant parameters and protection and safety systems to the unscheduled shutdowns. 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 pos.t-trip review that woul'd determine if the plant remained within its safety limit design envelope are presented in Table 1. They were selected on the basis of staff engineering judgment following a complete evaluation of utility submittals.

If the licensee's SOE recorders and time history recorders do not monitor all of the parameters suggested in these tables the licensee should show that the existing set of monitored parameters are sufficient to establish that the plant remained within the design envelope for the accident conditions analyzed in Chapter 15 of the plant FSAR.

C. The information gathered by the sequence of events and time history recorders should be stored in a manner that will allow for data retrieval and analysis. The data may be retained in either hardcopy, (e.g., computer printout, strip chart record), or in an accessible memory (e.g., magnetic disc or tape). This infomation should be presented in a readable and meaningful fomat, taking into consideration good human factors practices such as those outlined in NUREG-0700.

D.- Retention of 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 subsequent unscheduled shutdowns. Information gathered during the post-trip review is to be

retained for the life of the plant for post-trip review co parisons of subsequent events.

III. EVALUATION AND CONCLUSION By letter dated November 4,1983, Alabama Power Company provided information regarding its post-trip review program data and information capabilities for Joseph M. Farley Nuclear Plant Units I and 2. We have evaluated the licensee's submittal a; gainst the review guidelines described in Section II.

Licensee deviations from the Guidelines of Section II were reviewed with the licensee by telephone on May 23 and 29, 1985. A brief description of the

-4 licensee's responses and the staff's evaluation of the response against each

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of the review guidelines is provided below: ,

A. The licensee has described the performance characteristics of the equipment used to record the sequence of events and time history data needed for post-trip review. Based on our review, we find that the sequence of events recorder characteristics conform to the guidelines described in Section II A, and are acceptable. The time history recorder characteristics conform to these guidelines, except for pre-and post-trip recording durations. During our telephone calls with the licensee, the licensee stated that time history recorder duration is supplemented with strip chart recorders powered by non-interruptible power sources. Based upon this information, we find that the licensee meets the intent of the guidelines described in Section II A.

l B. The licensee has established and identified the parameters o be monitored and recorded for post-trip review. Based on our. review of the licensee's submittal and on information obtained during our telephone reviews, we find that the parameters selected by the licensee include all but one of those identified in Table 1. The licensee stated that while PORV position is not recorded on a sequence of event recorder, there are indirect indications in the control room which, when combined with special procedures, provide the desired infomation. The staff finds this alternative acceptable.

The licensee does not record all of the sequence of events and time history parameters in the specific manner reconinended in Table 1.

However, based upon information provided by the licensee during our telephone reviews, we find that the licensee has alternative data sources for thoses parameters not recorded on the sequence of events recorders and time history recorders. These include: (1)analarm typewriter, (2) the SPDS with hardcopy capability, and (3) strip chart recorders with non-interruptible power supplies. Consequently, we find that the licensee's selection of parameters meet the intent of the guidelines described in Section II B and is, therefore, acceptable.

C. The licensee has described the means for storage and retrieval of the information gathered by the sequence of events and time history recorders, and for the presentation of this infonnation for post-trip review and analysis. Based on our review, we find that this information

will be presented in a readable and meaningful format, and that the storage, retrieval and presentation conform to the guidelin.es of Section II C.

D.

The licensee's submittal indicates that the data and information used -

during post-trip reviews will be retained in an accessible manner for the life of the plant. Based on our review, we find that the licensee's program for data retention conforms to the guidelines of Section II D, and is acceptable.

Based on our review, we conclude that the licensee's post-trip review data and information capabilities for Joseph M. Farley Nuclear Plant Units I and 2 are acceptable. '

Principal Contributor:

J. J. Kramer 9

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TABLE 1 PWR PARAMETER LIST -

SOE Time History Recorder Recorder Parameter / Signal (1) 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 x 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

SOE Time History Recorder Recorder Parameter / Signal

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(3) Auxiliary Feedwater System: Flow.

Pump / Valve Status x

AC and DC System Status (Bus Voltage) x Diesel Generator Status (Start /Stop, On/Off) 4 x

PORV 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.

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