ML20092A301

Safety Evaluation Supporting Amend 182 to License DPR-16

ML20092A301
Person / Time
Site:	Oyster Creek
Issue date:	09/06/1995
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20092A297	List: ML20092A293 ML20092A301
References
GL-90-09, GL-90-9, NUDOCS 9509080315
Download: ML20092A301 (4)

Text

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pusco UNITED STATES y-j j

NUCLEAR REGULATORY COMMISSION t

WASHINGTON. D.C. 2055 5 0001

,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 182 TO FACILITY OPERATING LICENSE NO. DPR-16 GPU NUCLEAR CORPORATION AND JERSEY CENTRAL POWE2 & LIGHT COMPANY OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219

1.0 INTRODUCTION

By letter dated June 26, 1995, GPU Nuclear Corporation (GPUN\\the licensee) proposed changes to the Technical Specifications (TS) for the Oyster Creek Nuclear Generating Station. The amendment proposes removing the snubber visual examination schedule in the existing TS and replacing it with a refueling outage based visual examination schedule as shown in Table 4.7-2,

" Snubber Visual Inspection Interval" of Enclosure B to Generic Letter (GL) 90-09, " Alternate Requirements for Snubber Visual Inspection Interval and Corrective Actions." The proposed change revises the snubber visual inspection intervals to match the schedule developed by the NRC staff for use with a 24-month refueling interval. GPUN also proposed to revise the bases for the snubber visual inspection interval to be consistent with the bases described in Generic Letter 90-09.

2.0 EVALUATION The snubber visual examination schedule in the existing TS is based on the permissible number of inoperable snubbers found during the visual examination.

Because the existing snubber visual examination schedule is based only on the absolute number of inoperable snubbers found during the visual examination irrespective of the total population of snubbers, licensees with a large snubber population find the visual ext,nination schedule excessively restrictive.

The purpose of the alternative visual examination schedule is to allow the licensee to perform visual examinations and corrective actions during plant outages without reduction of the confidence level provided by the existing visual examination schedule.

The new visual examination schedule specifies the permissible number of inoperable snubbers for various snubber populations.

The basic examination interval is the normal fuel cycle up to 24-months.

This interval may be extended to as long as twice the fuel cycle or reduced to as small as two-thirds of the fuel cycle depending on the number of unacceptable snubbers found during the visual examination.

The examination interval may vary by i25 percent to coincide with the actual outage.

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. During the recent 15R refueling outage, one snubber failed a scheduled visual inspection. This failure was located on the main steamline. An engineering evaluation was performed by GPUN as pr Technical Specifications which determined that no damage had occurred on any snubber.

This snubber was in service since 1977.

There were thirteen additional snubbers on the main steamline.

Eleven of these were replaced and two were tested satisfactorily and reinstalled (one was originally installed in 1988 and the other in 1993).

The sample size for mechanical snubber visual inspections was 100% as required by technical specifications.

The sample size for mechanical snubber functional inspections was increased from 10% to 42% since one functional failure was found on the other main steamline and subsequently was replaced.

This snubber was in service since 1977.

It was determined that the causes of the snubber failures were sustained high temperatures and high frequency vibration for an extended length of service.

l The high temperature caused the snubber grease to degrade, whereupon the extended high frequency vibration caused excessive wear.

The snubbers had been in service since 1977.

Tne existing Technical Specification would require a reactor shutdown and drywell entry one year into the operating cycle solely for the purpose of performing an inspection on the snubbers which were replaced or reinctalled on

'the main steam system in 15R.

The purpose of this change request is to amend the technical specifications to not require the reactor shutdown, and update the Technical Specification requirements to those previously approved in Generic letter 90-09.

The exact wording of GL 90-09 has been utilized by GPUN to the greatest extent practical. However, minor changes have been requested to allow for the design specifics of the Oyster Creek Plant.

Each change from the prescribed wording in GL 90-09 is discussed and evaluated separately.

GPUN proposes the following plant specific wording changes:

Section 4.5.Q.1 GL 90-09 wording:

... performance of the following augmented inservice inspection program in addition to the requirements of 4.0.5."

Technical specification change request (TSCR) wording:

"... performance of the following inspection program."

Reason for the chance: Oyster Creek controls the inspection and testing of the snubbers in the Technical Specifications and not in the Augmented Inservice Testing Program.

Further, Section 4.0.5 referenced in the Generic letter states in Section e "Nothing in the ASME Boiler and Pressure Vessel Code shall be construed to supersede the requirements of any Technical Specification."

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, The staff agrees with GPUN that since Oyster Creek controls the inspection and testing of the snubbers in the TS and not in the Augmented Inservice Testing Program the wording change is appropriate.

Section 4.5.Q.1.a GL 90-09 wording:

" based on the criteria of Table 4.7.2 and the first inspection interval determined using the criteria shall be based upon the previous inspection interval established by the requirements in effect before Amendment (*)"

TSCR wording:

... based on the criteria provided in Table 4.5-1."

Reason for the Chance:

1) Table 4.7.2 in the Generic Letter is Table 4.5-1 in the TSCR, 2) Although there was a single visual failure during the last interval, all snubbers in the same temperature and vibration environment were aither replaced or tested satisfactorily and reinstalled. There is no need to perform a plant shutdown for the sole purpose of inspecting snubbers which have seen one year of service when the single failed snubber had been in service for seventeen years.

The replacement /reinsta11ation of all snubbers in a similar application (main steam system) has effectively removed the failure mechanism for the single visual inspection failure that was observed last outage. Additionally, the replacement /reinsta11ation of all the snubbers in similar applications (main steam system) has significantly decreased the probability of occurrence and consequences of any accident previously evaluated as all snubbers in thf s application have been functionally tested during the last surveillance interval. Therefore, the one time increase in interval from the existing 12 months to 24 months is within the inspection interval which would have been in effect for the majority of the snubbers had the single failure not occurred.

The staff agrees with GPUN that since all snubbers were either replaced or tested satisfactorily and reinstalled there is no need to perform a plant shutdown for the reasons stated above.

Section 4.5.Q.l.b GL 90-09 wording:

...A11 snubbers found connected to an inoperable common hydraulic fluid reservoir shall be counted as unacceptable for determining the next inspection interval.

TSCR wording:

--Sentence was deleted--

GPUN has stated that Oyster Creek does not have any snubbers sharing a common reservoir.

The staff finds this change acceptable but notes that if Oyster Creek Nuclear i

Generating Station implements this type of system, GPUN must submit the appropriate changes.

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GPUN has proposed changes to TS 4.5.Q.a and the associated Bases that are consistent with the guidance provided in GL 90-09 for the replacements of the visual examination schedule with Table 4.7-2 (including footnotes 1 through 6) of the Generic Letter 90-09. On the basis of its review of this matter, the staff finds that the proposed changes to the TS for the Oyster Creak Nuclear Generating Station are acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the New Jersey State official was notified of the proposed issuance of the amendment. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendment changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (60 FR 39440).

Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, i

that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, j

and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

j Principal Contributor: Alexander W. Dromerick Date: September 6, 1995

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