ML20106G893

Safety Evaluation Supporting Amend 101 to License DPR-37

ML20106G893
Person / Time
Site:	Surry
Issue date:	02/01/1985
From:	Office of Nuclear Reactor Regulation
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ML20106G881	List: ML20106G893
References
NUDOCS 8502150090
Download: ML20106G893 (4)

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i SAFETY EVALUATION BY'THE OFFICE OF NUCLEAR REACTOR REGULATION l

1 RELATED TO AMENDMENT NO.i0l TO FACILITY OPERATING LICENSE NO. DPR-37

!l VIRGINIA ELECTRIC AND POWER COMPANY M']

SURRY POWER STATION, UNIT NO. 2

,..R DOCKET NO. 50-281 I

Introduction 3 i 1,

By letter dated January 4,1985, as supplemented January 9 and January 28, i:

1985, Virginia Electric and Power Company (the licensee) submitted an

~ application for a license amendment consisting of a proposed change to the 1

Technical Specifications for Surry Power Station, Unit No. 2.

This proposed Technical Specification would permit the licensei'to perform the next visual I

inspection on inaccessible safety related ' snubbers during the upcoming refueling outage (on or about March 22,1985) instead of on the required date of February 1,1985.

I Discussion' Surry Unit 2 performed a visual inspection of its safety related snubbers during the period of November 9 through November 17, 1984. Seven snubbers in the inaccessible group were found with low hydraulic fluid level in their reservoirs. The Technical Specifications require that another visual inspection on inaccessible snubbers be conducted on February 1,1985 if all seven snubbers were found to be inoperable.

Surry Units 1 and 2 were both upgrading their snubbers by replacing seals on

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all safety related snubbers. Unit I has completed its program, and the

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latest inspection and testing showed remarkable improvement over previous l

records. Unit 2 had not completed its program at the time of last inspection.

l; Four of the seven snubbers in question are located on the pressurizer, and have a comon reservoir. They were declared inoperable because a leakin seal in one of the four snubbers emptied the comon reservoir. The otheig l4 three snubbers in question are attached to the main steam line. Their remote reservoirs were found to be empty due to a leak in the fitting at the valve block in one and leaks in the fittings at reservoirs for the other i

two. However, tubings below these two leaking fittings were found to be i

full of fluid. Surry Unit 2 did not perfonn functional testing on these seven snubbers in the "as found" condition before declarino them inoperable, i

j but the post mortem examination confinned that none of the' control valve blocks of the seven snubbers was degraded.

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g Technical Specifications permit functional testing on questionable snubbers in the "as 'found" condition to detennine whether they are still functionable A

unless the fluid level is below the port 'of the valves. This is because working control valves and ample fluid will make snubbers operable. Of the

'seven snubbeis, two probably should be declared inoperable. These would include the one on the main steam line on which leakage developed in the fitting.at the valve block, and one of the four snubbers with comon 1

reservoir which had a seal leakage that caused the empty reservoir. The 2

A other five should pass the above. mentioned functional test and be declared 3

as operable because they all had working control valves and adequate fluid j

reserves in the tubing between reservoirs and snubbers. These would include the second and third snubbers on the main steam line and the other three N

pressurizer snubbers on the comon reservoir. Since the staff believes that these five snubbers would have passed the "as found" functional testing, the-4]

required visual inspection for the inaccessible snubbers would have been h

substantially later than February 1,1985.

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The licensee requested this amendment because it does not want to perfonn redundant work with unnecessary radioactive exposures to its workers and l

because it will perfonn a complete visual inspection on all safety related snubbers during the coming refueling outage. The outage is scheduled for March 22, 1985.. As an interim measure, the licensee comitted to conduct a partial visual inspection on a substantial portion of the' inaccestible snubbers. This would minimize the radioactive exposures to its workers. This partial visual inspection has been perfonned with no inoperable snubbers found, b

Surry Unit 2 completed its upgrading program during the November 1984 outage. All safety related snubbers were re-sealed including the four pressurizer snubbers with comon reservoir.

In addition, leaking fittings on the three main steam line snubbers were replaced. Since Surry Unit 2 has effectively removed the generic concern of seal degradation and the isolated concern of leaking fittings, the repetition of these incidents within a i

short time is highly,unlikely. The interim measure of a partial visual i

inspection has demonstrated the effectiveness of the upgrading program.

The January 28, 1985 submittal provided additional supporting information.

il' However, this amendment would have been granted without this letter, Therefore, this letter does not change our conclusion in this regard.

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The staff concludes, based on the above, that the proposed amendment to li delay the full visual inspection to the coming refueling outage is acceptable.

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j' Emergency Circumstances The NRC Project Manager was infonned on January 3,1985, of the need for the amendment and the application was submitted by letter dated January 4,1985 i

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3-r;l and supplemented by letters dated January 9 and January 28, 1985. We have f

reviewed the facts concerning this request. The' facts were that the licensee's. focus had been on.the detailed examination of the snubber's l.

failure mechanism and'its implications and on' alternative ~ methodologies and F

- analyses, rather"than on schedulin'g implications. Also, these efforts were hampered by the unavailability of key personnel during the: holiday season.

7 We conclude that the licerisee has made a timely submittal,! that reactor shutdown would be required'without NRC action, that action by the licensee could not preclude this situation without reactor shut 'down, and that the licensee did not purposely create this situation in order to avoid the nomal notice period for license amendments.

L No Significant Hazards Consideration Detemination ej The Commission's regulations in 10 CFR 50.92 state that the Comission may 3

make a final detemination that a license amendment involves no significant

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hazards considerations if operation of the facility in accordance with the

' amendment would not:

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'(1)

Involve a significant. increase in the probability or consequences of an accident previously evaluated; or -

(2) Create the possibility of a new or different kind of accident from any

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accident perviously evaluated; or (3)

Involve a significant reduction in a margin of safety.

The amendment will modify the Technical Specification 4.17.A on a one-time basis to extend the snubber (shock suppressors) inspection to the 1985 refueling outage which is scheduled to begin on or about March 22, 1985.

Based on inspection results during the last visual snubber inspection, the next inspection interval was detemined to be 62 days i 25 percent, or no later' than February 1,1985.. Since visual and functional testing of the snubbers will be perfomed during the refueling outage, the licensee states

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that the inspection now would result in unnecessary personnel exposure.

The licensee has performed a visual inspection of the oil reservoir level of i

a significant number of snubbers which can be inspected practicably (oil

,i loss is the predominant. failure mode of these snubbers).

• Since a large' j

sample of the snubbers has been inspected with acceptable results, th.e

i possibility of undiscovered failure is low and the function of the total population of snubbers is reasonably assured. Thus, the reduction in margin of safety is considered to be insignificant.

The Commission has considered licensee's proposed change in light of the i!

above three criteria.

First, while there may be some small increase in the l1 probability of. snubber failure during the extended surveillance interval,

[.1 the Comission concludes because of the above compensatory inspection measures, this increase is not significant. The consequences of previously l}

evaluated accidents are unaffected by the proposed extension of the

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inspection interval. Second, since accidents which might be caused by the lj w,.mm

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possible failure of one u 1 ore snubbers during the extended inspection I

interval are the same as those previously evaluated, the proposed amendment does not create the possibility of a new or different kind of accident from any accident.previously evaluated. Third, since all snubbers were examined

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i'n November 1984',' all failed snubbers were repaired, and the licensee has inspected a significant number of snubbers during the current interval, the

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reduction in a safety margin is considered to be insi On these grounds, the proposed amendment extending the enubbeignificant.

inspection interval does not involve significant hazards considerations.

State Consultation In accordance with the Comission's regulation, consultation was held with the State of Virginia by telephone on January 11, 1985. No coments were made by the State on this amendment.

Environmental Consideration This amendment involves a change in an inspection or surveillance requirement.

t The 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 Comission i

has furth'er determined that this amendment involves no significant hazards consideration. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Sec 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 this amendment.

Conclusion We have concluded, based on the considerations discussed above, that: (1) this amendment will not, (a) significantly increase the probability or consequences of accident previously evaluated, (b) create the possibility of a new or different accident from any previously evaluated or (c) signifi-cantly reduce a margin of safety, and, therefore, this amendment does not involve significant hazards considerations; (2)'there is reasonable l

assurance that the health and safety of the public will not be endangered by i

operation in the proposed manner, and (3) such activities will be conducted in compliance with the Comission's regulations and the issuance of this amendment will not be inimical to the comon defense and security or to the health and safety of the public.

Dated: February 1, 1985 Principal Contributors:

Horace Shaw Don Neighbors Ken Johnston o

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