ML20092C147

Application for Amend to License DPR-65,changing Tech Specs 3.7.8 & 4.7.8 Re Generic Ltr 90-09, Snubber Visual Insp Intervals

ML20092C147
Person / Time
Site:	Millstone
Issue date:	02/03/1992
From:	Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20092C150	List: B13973, Proposed Tech Specs Changes Per Generic Ltr 90-09, Snubber Visual Insp Intervals ML20092C147
References
B13973, GL-90-09, GL-90-9, NUDOCS 9202110303
Download: ML20092C147 (5)

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- (203) 6(M000 february 3, 1992 Da.cket No. 50 3M fuBD Re: 10CfR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Proposed Change to Technical Specifications Generic letter 90-09. Snubber Visual Insoection Intervals Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating Licensing No. DPR 65 by incorporating the changes identified in Attachment 1 into the Technical Specifications of Millstone Unit No. 2.

Descriotion of the Proposed Chances The proposed amendment revises the action statement and the visual inspection surveillance requirements (Technical Specifications 3.7.8 and 4.7.8) associated with the snubbers. These changes are per recommendation of and consistent with the guidance provided in Generic Letter (GL) 90 09,

" Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions," dated December 11, 1990. The Staff proposed wording for ,

these technical specification sections has been adopted in the attached proposed changes to the Millstone Unit No. 2 Technical Specifications.

The proposed changes provide an alternate method for determining the next interval for the visual inspection of snubbers. This is based upon the number of unacceptable snubbers found during previous inspection, the total population or category size for each snubber type, and the previous inspection interval.

1he next visual inspection interval may be twice, the same, or. reduced to as much as two thirds of the previous inspection interval. This interval depends on the number of unacceptable snubbers fourd in proportion to the size of the i population or category for each type of snubber included in the previous inspection. The new proposed Table. 4,7-3 replaces the existing technical  ;

specification requirements for determining the next visual inspection '

interval. Generally, the existing technical specification requirements establish inspection intervals of 18 months (length of a nominal fuel cycle) or a fraction thereof based on the number of inoperable snubbers of each type '

for the previous inspection period. '

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ViS. Nuclear Regulatory Commission B13973/Page 2 february 3. 1992 The- alternative provided herein allows inspection intervals to be umpatible l cle Also, the interval may be increased to every with otherarefueling 24 month fuel cfor p.lants on a 24-month fuel cycle or up to 48 months outage l for plants with other fuel cycles if few unacceptable snubbers were found from l the previous inspection. The proposed Tabic 4.7 3 establishes three limits '

for determining the next visual inspection interval corresponding to the i population or category size for a given type of snubber. The three limits are listed in Columns A, B, and C of the proposed Table 4.7-3 for representative sizes of snubber populations or categories, for a population or category that differs from the re)resentative size provided, the values for the limits may be found by interpo' ation from the limits provided in Columns A, B, and C for determining the next inspection interval. Where the limit for unacceptable snubbers in Columns A, B, and C is determined by interpolation and includes a fractional value, the limit shall be reduced to the next lower integer.

The limits in Columns A, B, and C of the proposed Table 4.7-3 are applied as '

follows to determine the next inspection interval: If the number of unacceptable snubbers is less than or equal to the number in Column A, the next inspection interval may be twice the previous interval but not greater than 48 months, excluding the technical specification provisions to extend surveillance intervals. If the number of unacceptable snubbers is greater than the number in Column A but less than or equal to the number in Column B, the next inspection i,1terval shall be the same as the previous interval. If the number of unacceptable snubbers is equal to or greater than the number in Column C, the next inspection interval shall be _ two thirds of the previous interval, llowever, if the number of unacceptable snubbers is less than the number in Column C and greater than the number in Column B, the next inspection interval shall be reduced proportionally by a factor that is one-third of the ratio of the difference between the number of unacceptable snubbers and the number in Column B to the difference betaeen the numbers of Columns B and C.

Safety Assessment Performance of periodic visual inspections of snubbers complements the existing functional testing program and provides additional confidence in l snubber operability. The existing technical specification surveillance l schedule is based on the -number of inoperable snubbers found during the previous inspection. In addition, the existing surveillance interval assumes an 18-month refueling interval which does not account for the trend to longer fuel cycles or the impact of extended outages.

l The proposed amendment alleviates this situation by incorporating the

! alternate inspection schedule provided by the Staff in GL 90-09. The l

alternate inspection schedule is based on the number of unacceptable snubbers found during the previous inspection in proportion to the sizes of the various snubber populations and may be as long as 48 months with good overall visual inspection __results, As determined by the Staff, the alternate schedule for visual inspections maintains the same confidence level in snubber operability 1

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U,S. Nuclear Regulatory Commission B13973/Page 3 february 3, 1992 as the existing schedule while allowing the flexibility to perform visual inspections and corrective actions during plant outages. Because this line-item technical specification improvement will reduce future occupational radiation exposure and is highly cost effective, the alternate inspection schedule is consistent with the Commission's policy statement on technical specification improvements.

Sionificant Hazards._ Consideration  !

NNECO has reviewed the proposed changes in accordance with 10CFR50.92 and concluded that the changes do not involve a significant harards consideration.

The basis for this conclusion is that the three criteria of 10CFR50.92(c) are -

not compromised. The proposed changes do not involve a significant hazards consideration because the changes would not:

1. Involve a significant increase in the probability or consequences of an accident previously analyzed.

The proposed changes incorporate the alternate schedule for visual inspection of the snubbers recommended by the NRC in GL 90-09. As determined by the Staff, this alternate schedule for visual inspections maintains the same confidence level as the existing schedule. In addition, the ACTIONS required by the existing tech.wal specifications as a result of finding snubbers inoperable remain the same. The change to the Technical Specification Index has no impact on the cone ~mencer, or the probability of an accident previously analyzed. Theretire, the proposed changes do not affect the probability or consequentra of an accident previously evaluated.

'2. Caate the possibility of a new or different kind of accident from any previously analyzed.

The proposed changes do not affect any plant operations, the potential for an unanalyzed accident is not created, and no new failure modes are introduced. The proposed changes will not affect the operability of the snubbers to perform their intended function during normal or- accident conditions.

3. Involve a significant reduction in the margin of safety.

As stated in GL 90 09, the alternate schedule for visual inspections maintains -the same confidence level as the existing schedule. In addition, the proposed changes do not affect any of the ACTIONS specified in technical specifications which result from identification of-inoperable snubbers. .Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Moreover, the Commission has provided guidance concerning the application of standards in 10CfR50.92 by providing certain examples (March 6,1986,

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U;S. Nuclear Regulatory Commission B13973/Page 4 february 3, 1992 SlFR7751) of amendments that are considered not likely to involve a significant hazards consideration. Although the proposed changes are not enveloped by a specifie example, the changes would not involve a significant increase in ..ie probability or consequences of an accident previously analyzed. The proposed changes incorporate the alternate schedule for visual inspection of the snubbers recommended by the NRC in GL 90 09. This alternate schedule for visual inspections maintains the same confidence level as the existing schedule when coupled with functional testing, while allowing the flexibility to perform visual inspections and corrective actions at extended intervals. This will reduce future occupational radiation exposure. This alternate inspection schedule is consistent with the Commission's policy statement on technical specification improvements.

Based upon the information contained in this submittal and the environmental- assessment for Millstone Unit No. 2, there are no significant radiological or nonradiological impacts associated with the proposed action, and the proposed license amendment will not have a significant effect on the quality of the human environment.

NNECO respectfully requests that this proposed change be issued prior to the start of the next refueling outage currently planned for June 1992. NNECO also requests that this license amendment be effective as of the date of its issuance to be implemented within 30 days of issuance.

In accordance with 10CFRM.91(b), we are providing the State of Connecticut with a copy of this proposed amendment application.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

3. F. Opeka bok v

Executive Vice President cc: T. T. Martin, Region 1 Administrator G. S. Vissing, NRC Project Manager, Millstone Unit No. 2 P. Habighorst, Resident inspector, Millstone Unit No. 2 W. J. Raymond, Senior Resident inspector, Millstone Unit Nos.1, 2, and 3 ow- - ,+--m.- w w.e , - . , e-- , ,,a

U S. Nuclear Regulatory Commission B13973/Page 5 february 3, 1992 STATE Of CONNECTICVT ss. Berlin COUNTY Of HARif0RD Then personally appeared before me, J f. Opeka, who being duly sworn, did state that he is Executive Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensee herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief.

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