ML20133G417

Safety Evaluation Accepting Util 831108 Response to Generic Ltr 83-28,Item 1.1 Re post-trip Review.Response to Listed Deficiencies,Including Development of Systematic Safety Assessment Program for Unscheduled Reactor Trips Required

ML20133G417
Person / Time
Site:	Point Beach
Issue date:	07/29/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20133G400	List: ML20133G397 ML20133G417
References
GL-83-28, NUDOCS 8508080675
Download: ML20133G417 (5)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION WI5 CON 5IN ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT, UNIT N05. 1 AND 2 00CKET N05. 50-266 AND 50-301 GENERIC LtIItR 83-28, ITEM 1.1 - PO5T-TRIP REVIEW (PROGRAM DESCRIPTION AND PROCEDURE)

1. INTRODUCTION On February 25, 1983, both of the scram circuit breakers at Unit I of the Salem Nuclear Power Plant failed to open upon an automatic reactor trip signal frem the reactor protection system. This incident occurred during the 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 under vol: age trip attachment. Prior to this incident, en 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 au:omatic trip. Following these incidents, on

! February 28, 1983, the NRC Executive Director for Operations (EDO), directed the staff to investigate and report on the generic implications of these occurrences at Unit 1 of the Salem Nuclear Power Plant. The results of the i

staff's inquiry into the gereric implications of the Salem unit incidents are reported in NUREG-1000, " Generic Implications of ATWS Events at the Salem Nuclear Power Plant." As a result of this investigation, the Commission (NRC) requested (by Generic Letter 83-28 dated July 8,1983) all licensees of operating reactors, applicants for an operating license, and holders of construction permits to respond to certain generic concerns. These concerns are categorized into four areas: (1) Post-Trip Review, (2) Equipment Classification and Vendor Interface, (3) PoN-MaintenanceTestino,and (4) Reactor Trip System Reliability Improvements.

The first action item Post-Trip Review, consists of Action item 1.1,

" Program Description and Procedure" and Action item 1.2. " Data and Information Capability." This safety evaluation report (SER) addresses Action Item 1.1 only.

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!!. REVIEW GUIDELINES The following review guidelines were developed after initial evaluation of t the various utility responses to Item 1.1 of Generic Letter 83-28 and l incorporate the best features of these submittals. As such, these review guidelines in effect represent a " good practices" approach to post-trip  !

review. We have reviewed the licensee's response to Item 1.1 against these '

guidelines:

t A. The licensee or applicant should have systematic safety assessment.  ;

procedures established that will ensure that the following restart ,

criteria are met before restart is authorized.  !

• The post-trip review team has detennined the root cause and f sequence of events resulting in the plant trip.

Near term corrective actions htve been taken to remedy the cause  !

of the trip.

The post-trip review team has perfonned an analysis and determined i that the major safety systems responded to the event within specified limits of the primary system parameters. l i

4 The post-trip review has not resulted in the discovery of a l potentialsafetyconcern(e.g.,therootcauseoftheeventoccurs [

with a frequency significantly larger than expected).

l If any of the above restart criteria are not met, then an independent assessment of the event is performed by the Plant l Operations Review Comittee (PORC), or another designated group with similar authority and experience.

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l B. The responsibilities and authorities of the personnel who will perform ,

, the review and analysis should be well defined.  !

The post-trip review team leader should be a member of plant management at the shift supervisor level or above and should hold

or should have held an SRO license on the plant. The team leader should be charged with overall responsibility for directing the i post-trip review, including data gathering and data assessment and I

he/she should have the necessary authority to obtain all personnel

and data needed for the post-trip review.

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., A second person on the review team should be an STA or should hold a relevant engineering degree with special transient analysis training.

The team leader and the STA (Engineer) should be responsible to concur on a decision /recomendation to restart the plant. A nonconcurrence from either of these persons should be sufficient to prevent restart until the trip has been reviewed by the PORC or equivalent organization.

C. The licensee or applicant should indicate that the plant response to the trip event will be evaluated and a determination made as to whether the

plant response was within acceptable limits. The evaluation should include

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• l A verification of the proper operation of plant systems and equipment by comparison of the pertinent data obtained during the post-trip review to the applicable data provided in the FSAR.

An analysis of the sequence of events to verify the proper functioning of safety related and other important equipment. Where possible, comparisons with previous similar events should be made.

D. The licensee or applicant should have procedures to ensure that all physical evidence necessary for an independent assessment.is preserved. ,

E. Each licensee or applicant should provide in its submittal, copies of the plant procedures which contain the information required in Items A through D. As a minimum, these should include the following:

The criteria for determining the acceptability of restart Thequalifications,responsibilitiesandauthoritiesofkey personnel involved in the post-trip review process The methods and criteria for determining whether the plant variables and system responses were within the limits as described in the FSAR The criteria for determining the need for an independent review.

!!!. EVALUATION AND CONCLUSION

By letter dated November 8, 1983, the licensee of Point Beach Nuclear Plant.

Units 1 and 2, provided information regarding its Post-Trip Review Program

and Procedures. We have evaluated the licensee's program and procedures against the review guidelines developed as described in Section !!. A brief '

description of the licensee's response and the staff's evaluation of the g response against each of the review guidelines is provided below:

A. The licensee has established the criteria for determining the acceptability of restart. Based on our review, we find that the licensee's criteria conform with the guidelines as described in the above Section !!.A and, therefore, are acceptable.

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l 5-l B. The qualifications, responsibilities and authorities of the personnel who will perfom the review and analysis have been clearly. described, i We have reviewed the licensee's chain of comand for responsibility for l post-trip review and evaluation and find it acceptable.

l C. The licensee has not addressed the methods and criteria for comparing the event information with known or expected plant behavior. We reconnend that the pertinent data obtained during the post-trip review l be compared to the applicable data provided in the FSAR to verify proper operation of the systems or equipment." Where possible, comparisons with previous similar events should be made.

D. With regard to the criteria for determining the need for independent assessment of an event, the licensee has indicated that if any of the restart criteria are not met, an independent assessment of the event will be performed. In addition, the licensee has established procedures to ensure that all physical evidence necessary for an independent assessment is preserved. We find that these actions to be taken by the licensee confom to the guidelines as described in the above Sections

!!.A. and D.

I E. The licensee has not provided for our review a systematic safety ,

assessment program to assess unscheduled reactor trips. We recomend that the licensee develop a systematic safety assessment program to j handle unscheduled reactor trips.

Acceptable responses to the above noted deficiencies are required before we can complete our review of the licensee's Post-Trip Review Program and Procedures for Point Beach, Units 1 and 2. We will review these responses when received and report our findings in a supplement to this SER.

I Date:' July 29, 1985

. Principal Contributor:

D. Shum. DHFS .

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