ML20127A036

SER Supporting Licensee Response to Generic Ltr 83-28, Action Item 1.1, Program Description & Procedures, Re post-trip Review.Response Acceptable

ML20127A036
Person / Time
Site:	Fort Saint Vrain
Issue date:	05/07/1985
From:	NRC
To:
Shared Package
ML20127A031	List: ML20127A027 ML20127A036
References
GL-83-28, TAC-52759, NUDOCS 8506200537
Download: ML20127A036 (6)

Text

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Enclosure I

' SAFETY EVALUATION REPORT FOR GENERIC LulER 83-28. ITEM 1.1 - POST-TRIP REVIEW (PROGRAM DESCRIPTION AND PROCEDURE)

FORT ST. VRAIN NUCLEAR GENERATING 5TATION, UNIT 1 DOCKET NO.: 50- EM I. INTRODUCTION 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 plant start-up and the rFactor 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 detemined to be related to the sticking of 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 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 (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 staff's inquiry into the generic 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 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 construction pemits to respond to certain generic concerns. These concerns are categorized into four areas: (1) Post-Trip Review (2) Equipment ClassificationandVendorInterface,(3) Post-Maintenance Testing, and l (4) Reactor Trip System Reliability Improvements. 1 l

The first action item, Post-Trip Review, consists of Action Item 1.1, "Progran Description and Procedure" and Action Item 1.2, " Data and Infomation Capability." Thissafetyevaluationreport(SER) addresses Action Item 1.1 only.

8506200537 850606 DR ADOCK050g27 4

-2 II. REVIEW GUIDELINES The following review guidelines were developed after initial evaluation of the various utility responses to Item 1.1 of Generfc Letter 83-28 and 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 anainst these guidelines: -

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 determined the root cause and sequence of events resulting.in the plant trip.

Near terin corrective actions have been taken to remedy the cause of the trip.

The post-trip review team has performed an analysis and determined

that the major safety systems responded to the event within specified limits of the primary system parameters.

i The post-trip review has not resulted in the discovery of a potential safety concern (e.g., the root cause of the event occurs with a frequency significantly larger than expected).

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

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 b'e 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 post-trip review, including data gathering and da't'a assessment and i he/she should have the necessary authority to obtain all personnel ,

and data needed for the post-trip review.

1 A second person on the review team should be an STA or should hold

a relevant engineering degree with special transient analysis training.  !

t The team leader and the STA (Engineer) should be responsible to f concur on a decision /reconnendation to restart the plant. A I nonconcurrence from either of these persons should be sufficient to

} prevent restart until the trip has been reviewed by the PORC or equivalent organization.

j C. The licensee or applicant should indicate that the plant response to the

) trip event will be evaluated and a detemination made as to whether the i

plant response was within acceptable limits. The evaluation should

• j include:

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.

i 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.

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.t.

I D. The ifcensee er applicar.t shesig have preced res te eesare tAat all physical evice ,ce recessary fer an indeperde**. assessaeet is presened.

t

d. Each liceesee er a

Olicant secr;1d profee in its s;teittal, cesfes cf tP4 plant pet <et.rts aAich ccetain tre infermetice, regaired is !!ces A i

thrw e. D. As a minisun, these sto;1d incisde th+ fc11orfrg:

I The criteria fer determinfrg the acce;tability et restart The cis,alificatices, res;cesittlities a d astrerities cf lef perstmeel involved ir. tbe post-trip review pnce<,5 The methods a4 criteria fcr determinfe; seether the plant variaties med systen res;ceses were wittic the limits as descrited in the FSAtt The criteria for determinir.; the need fer ac fedepe-dent review.

III. EVAtt'ATIOE Amo CCacLUSIDE ly letter dated herea6er 4, IM3, the licensee cf fert St. Yrain belear Generatieg Statfee previded fefernetice regardte; its Pest-Tri; neview Prgae a*d Precef;res. nie have eval ated tre lice-see's p*ctem- a-d procefares asafest the review paidelires develc9ed as described fr.

Sectice 11. A trief descriptien cf the liceesee's respcese a-d tAe staff's esalsatica of the res:cese apalest each of the review 941de11ees is mf tec I teltw:  !

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A. IP4 lice see's criteria fcr deternir.frg tre acce;tatility cf restart l 1rclude: a strificatice tAat t*e reacter sectectice systen eed t*e I e giretred safety features ard systees =Aich are inscrtatt to reaeter  !

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safety have performed as required; verification of the cause of the trip and the adequacy of subsequent corrective action; and conduct of an

analysis to evaluate the plant transient behavior. We find that the licensee's criteria for detemining the accept' ability of restart are acceptable.

B. The qualifications, responsibilities and authorities of the personnel who will perfom the review and analysis have been clearly described.

l The licensee indicated that the Station Manager, who bases his decision

] on the above cited restart acceptability criteria, shall have the final authority to grant or deny authorization of plant restart. We have reviewed the licensee's chain of comand for responsibilities for post-trip review and evaluation, and find them acceptable.

I C. The licensee has described the methods and criteria for comparing the event information with known or expected plant behavior. Based on our review, we find them to be acceptable.

D. With regard to the criteria for determining the need for independent assessment of an event, the licensee has indicated that if the cause of the trip cannot be positively determined, or if the plant response demonstrated an abnormal behavior that has not been corrected or results

, in Technical Specification start-up constraints, an independent assessment of the event will be performed by the Transient Review Committee. In addition, the licensee has established procedures to ensure that all physical evidence necessary for an independent l assessment is preserved. We find that these actions to be taken by the l licensee conform to the guidelines ar described in the above Sections II.A. and D.

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i E. The licensee has provided for our review a systematic safety assessment program to assess unscheduled reactor trips. Based on our review, we find that this program is acceptable.

Based on our review, we conclude that the licensee's Post-Trip Review Program and Procedures for Fort St. Vrain Nuclear Generating Station p are acceptable. -

Date: May 7, 1985 Principal Contributor: -

D. Shum -

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