B13866, Application for Amend to License NPF-49,incorporating Requirements of Generic Ltr 90-09, Alternative Requirements for Snubber Visual Insp Intervals & Corrective Actions

Application for Amend to License NPF-49,incorporating Requirements of Generic Ltr 90-09, Alternative Requirements for Snubber Visual Insp Intervals & Corrective Actions

ML20081L014
Person / Time
Site:	Millstone
Issue date:	06/25/1991
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20081L016	List: B13866, Application for Amend to License NPF-49,incorporating Requirements of Generic Ltr 90-09, Alternative Requirements for Snubber Visual Insp Intervals & Corrective Actions ML20081L020
References
B13866, GL-90-09, GL-90-9, NUDOCS 9107020307
Download: ML20081L014 (5)

Text

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Docket No. 50-423 B13866 Re: 10CFR50.90 L U.S. Nuclear Regulatory Commission Attention: Document Control Desk l Washington, DC 20555 Gentlemen:

1 Millstone Nuclear Power Station, Unit No. 3 l Proposed Revision to Technical Specifications  ;

l Generic Letter 90-09--Snubber Visual Insoection Intervals 1 l

l Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby l proposes to amend its operating license, NPF-49, by incorporating the changes identified in Attachment i into the Technical Specifications of Millstone Unit No. 3.

Descriotion of the Proposed Chanaes The proposed amendment revises the visual inspection surveillance requirements (Technical Specifications 4.7.10.a and 4.7.10.b) and acceptance criteria (Technical Specification 4.7.10.c) associated with the snuobers. These

changes are rer recommendation of and consistent with the guidance provided in i 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 l adopted'in the attached proposed changes to the Millstone Unit No. 3 Technical i_ Specifications.

l 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.

l The next visual inspection interval may be twice, the same or reduced by as

- much as two-thirds of the previous inspection interval. This interval depends on the number of unacceptable snubbers found in proportion to the size of the population or' category for _each type of snubber included in the previous /

inspection. The new proposed Table 4.7-2 replaces the existing technical ,f ,

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) 9107020307 910625 PDR ADOCK 05000423 f{}0h

a 3 U.S. Nuclear Regulatory Commission

- B13866/Page 2

- June 25, 1991-or a fraction thereof based on the number of inoperable snubbers of each type for the previous inspection period.

The ' alternative provided herein allows inspection intervals to be compatible

= with a month . fuel : cycle. Al so, the interval may be increased to every

-nther refueling outage for plants on a 24-month fuel cycle or up to 48 months for plants with other fuel cycles if few unacceptable snubbers were found from the previous inspection. The proposed Table 4.7-2 establishes three limits for determining the next visual inspection interval corresponding to the 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 4.7-2 for representative sizes of snubber populations or categories. For a population or category that differs from the representative size provided, the values for the limits may be found by intorpolation from the limits provided in Column:: A, B, and C for .

determining the next inspection interval. Where the limit for unacceptable  !

snubbers in Columns - A, B, or C is determined by interpolation and includes a fractional value, the. limit may be reduced to the next lower integer.

~

The limits in columns A,- B, and C of the proposed Table 4.7-2 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 -interval 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 reduced to two-thirds of the previous interval. However, 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 Caiumn B to the difference between the numbers of

. Columns B and C. In addition, the Technical Specification Index would then be revised to reflect addition of the new proposed Table 4.7-2.

- Safety Assessment

. Performance of periodic - visual inspections of snubbers complements the existing functional testing program and provides additional confidence in snubber operability. The existing technical specification surveillance schedule is- based on . the number of - inoperable snubbers found during the

- previous-inspection. In addition, the existing surveillance interval assumes an_18-month refu'eling interval which does not account- for the trend to longer fuel cycles or the impact of extended outages.

The' proposed amendment alleviates this situation by incorporating the alternate inspection schedule provided by the staff in GL 90-09, dated December 11, 1990. The alternate inspection schedule is based on the number

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U.S. Nuclear Regulatory Commission B13866/Page 3 June 25, 1991 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 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 NNEC0 has reviewed the proposed changes in accordance with 10CFR50.92 and concluded that the changes do not involve a significant hazards 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 S0-09. 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 technical specifications as a result of finding snubbers inoperable reaain the same. The change to the Technical Specification Index has no impact on the consequences or

-the probability of an accident previously analyzed. Therefore, the proposed changes do - not affect the probability or consequences of an accident previously evaluated.

2. Create 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

s U.S. Nuclear Regulatory Commission B13866/Page 4 June 25, 1991 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 ;, 1986, 51FR7751) of amendments that are considered not likely to involve a significant hazards consideration. Although the proposed changes are not enveloped by a specific example, the changes would not 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. 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 interval s . 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. 3, 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.

The Millstone Unit No. 3 Nuclear Review Board has reviewed and approved the prcoosed changes and has concurred with the above determinations.

Regarding nur proposed schedule for this amendment, we request issuance at 30ur earliest convenience with the amendment effective within 30 days of issuance.

In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

/

E.J.Ppc~zka /

Senior Vice President cc: See Page 5

o .

U.S. Nuclear Regulatory Commission B13866/Page 5 June 25, 1991 cc: T. T. Martin, Region 1 Administrator D. H. Jaf fe, NRC Project Manager, Millstone Unit Nos. I and 3 W. J. Raymond, Senior Resident inspector, Millstone Unit Nos. 1, 2, and 3 Mr. Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, Connecticut 06116 STATE OF CONNECTICUT)

) ss. Berlin COUNTY OF HARTFORD )

Then personally appeared before me, E. J. Mroczka, who being duly sworn, did state that he is Senior 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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Notary lic~

Uy C:mmLen Exp! ras Ltreh a1,1993