ML20154B815

Application for Amend to License NPF-49,revising Tech Specs to State That Penalty for Undetected Fouling of Feedwater Venturis of 0.1% Is Added to Flow Measurement Uncertainty Values If Venturis Not Cleaned Every 18 Months.Fee Paid

ML20154B815
Person / Time
Site:	Millstone
Issue date:	09/02/1988
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20154B818	List: B13007, Proposed Tech Spec Changes Stating That Penalty for Undetected Fouling of Feedwater Venturis of 0.1% Is Added to Flow Measurement Uncertainty Values If Venturis Not Cleaned at Least Once Per 18 Months ML20154B815
References
B13007, NUDOCS 8809140149
Download: ML20154B815 (4)

Text

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M Generel Ottices e Seiden street. Berlin. Connect > cut 2!C5. Ti7<'E P.O 80X 270 L 1 TJ ". h  ; ) 5 September 2, 1988 '

i Cocket No. 50-423 B13007 Re: 10CFR50.90 U.S. Nuclear Regulatory Comission Attn: Document Control Desk Washington, D.C. 20555 f

References:

(1) E. J. Mroczka letter to U-S. Nuclear Regulatory t Commission, Supplemental Information, RTD Bypass Elimination Licensing Report, dated December 23, 1987.  ;

(2) R. L. Ferguson Lotter to E. J. Mroczka, Issuance of Amendment, dated January 20, 1988.

Gentlemen:

l Millstone Nuclear Powr. Itation, Unit No. 3 Proposed Revision to Te "ical Specifications Flcw Heasurementyncertairdy i l

Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby i proposes to amend Operating License No. NPF 49 by incorporating the changes  !

identified in Attachment 1 into the plant Technical Specifications for '

Millstone Unit No. 3.

Specifically, the proposed changes will revise Technical Specification Sections 4.2.3.1.6, 4.2.3.2.6 and the bases for Technical Specification

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Section 3/4.2.4 (page B3/4 2 6) to state that the penalty for undetected fouling of the feedwater venturis of 0.1 percent will be added to the flow l measurement uncertainty values if the venturis are not cleaned at least once  ;

per 18 months. This is to be done before the precision heat balance is made l

to calibrate the reactor coolant flow rate indicators (approximately once per 18 months). l Ciscussion i

In a letter dated December 23,1987 (Reference (1)), NNECO responded to the Staff's concerns related to effects of the venturi fouling on the calorimetric i flow measurement. Specifically, NNECO stated that prior to the start of each i

cycle, the feedwater venturis will be verified to be clean by performing a l

) visual inspection borascope, photography, etc.) through inspection installed during th(e first refueling outage and cleaned when necessary. po If l the venturis are not cleaned, an additional 0.1 percent will be added to the total reactor coolant flow measurement uncertainty values. In addition, i l Technical Specification Sections 4. 2.3.1. 6. 4. 2. 3. 2. 6 and the corresponding '

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+ U.S. Nuclear Regulatory Commission l B13007/Page 2

Septeober 2, 1988  ;

1 bases section will be revised to reflect the above commitment and subNtted to l the NRC for approval. In Reference (2), the NRC required NNECO to submit the  !

! modified Technical Specifications prior to Cycle 3 operation.

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, The Millstone Unit No. 3 Technical Specifications (Sections 3.2.3.1 and l 4

3.2.3.2) require that the indicated reactor coolant system (RCS) flow rate l shall be greater than or equal to 385,210 gpm for four loop operation and  ;

q 304.785 spm for three loop operation. The corresponding flow measurement l uncertainties are 1.8 percent and 12.0 percent for four and three loop i i o)eration respectively. These minimum iMicated RCS flow rate values are i

) o)tained by increasing $.he thermal design flows of 378,400 gpm and 298,800 gpm j

{ for four and three loop operation, respectively, by their corresponding flow  ;

j measurement uncertainties. When the 0.1 percent venturi fouling factor is  !

added, the resulting flew measurement uncertainties are 11.9 percent for four i

loop and 12.1 percent for three loop operation. The Technical Specification  !

minimum indicated RCS flow rate for these conditions is 385,590 gpm for four  !

l loop operation and 305,705 gpm for three loop operation. Therefore, this l I measured flow will still be greater than the minimum flow assumed in the  ;

! design basis analysis. Therefore, the changes do not impact the consequences  !

of any design basis accident.

{t i Sianificant Han is Consideration i

! In accordance with 10CFR50.92, NNECO has raviewed the proposed changes and f j concluded that they do not involve a signif nant hazards consideration. The '

j basis for this conclusion is that the three criteria of 10CFR59.92(c) are not l 4

compromised. The proposed changes do not involve a significant hazards }

consideration because the changes would not:

q 1. Involve a significant increase in the probability or consequences of an l accident previously analyzed. Application of a penalty factor will increase the acceptance criteria of the limiting condition for operation l

for the indicated or calculated RCS flow to take into account the potential for venturt fouling. This assures that the calculated RCS flow by heat balance method or indicated RCS flov will be greater than the RCS 1

flow assumed in the design bhsis analysis. Therefore, the prcposed changes do not impact the consequences of any design basis accident. The proposed changes do not have the potential to initiate any event, l

! therefore, the changes do not increase the probability of occurrence of q any design basis event.

I 1 2. Create the possibility of a new or different kind of accident from any j

previously analyzed. The proposed changes do not impact the operation of  ;

any component or system. The proposed changes do not introduce any new t single failures. Therefore, the proposed changes do not create the possibility of a new or different kind of accidant from those previously analyzed, i  !

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U.S. Nuclear Regulatory Commission B13007/Page 3 September 2, 1988

3. Involve a significant reduction in a margin of safety. The proposed changes will require the addition of 0.1 percent penalty to the RCS flow measurement acceptance criteria if the feedwater flow 'terturis are not cleaned every 18 months. The RCS ficw calculated by heat balance method will still be required to meet the Technical Specification limits.

Therefore, the proposed change does not reduce the margin of safety.

Moreover, the Commission has provided guidance concerning the ar.plications of standards set forth in 10CFR50.92 by providing certain examples (March 6.

1986. EB7751) of amendments that are considered not likely to involve a significant hazards consideration. The changes proposed herein are most closely enveloped by example (ii), a change that constitutes an additional limitation not presently included in the Technical Specifications. If the feedwater venturis are not ir.spected and cleaned, an additional 0.1 percent will be added to the total RCS flow measurement uncertainty values thereby increasing the acceptance criteria of the limiting condition for operation for the RCS flow. The calculated flod by heat balance measurement or indicated flow must meet the Technical Specification limits. This flow will be greater than the flow assumed in the design basis analysis. Therefore, the proposed change *, do not impact the consequences of any design basis accident.

Based upon the information contained in '.his submittal and the environmental 1 assessment for Millstone Unit No. 3, there are no significant radiological or nonradiologi:al irpacts associated with the proposed action, and the proposed license amendment will not have a significant effect on the quality of the ,

human envirer.1ent. '

l The Hillstone Unit No. 3 Nuclear Review Board has reviewed and approved the proposed changes and has concurred with the above determination.

In accordance with 10CFR59.91(b), we are providing the State of Connecticut

, with a copy of this proposed amendment.

Pursuant to the requirements of 10CFR170.12(c), enclosed with this amendment request is the application fee of $150.00.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

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. ,4 r'oczka f Senior Vice President '

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i U.S. Nuclear Regulatory Consiission  :

813007/Page 4 l

1 September 2, 1988  ;

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) cc W. T. Russell, Region ! Administrator  !

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0. H. Jaffa, NRC Project Manager, Millstone Unit Nos. 2 and 3 l l W. J. Raymond, Senior Resident inspector, Millstone Unit Nos. 1, 2 and 3

) i l Kevin McCarthy, Director  !

Radiation Control Unit '

q Department of Environmental Protection  :

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Hartford, CT 06116  !

STATE OF CONNECTICUT  !

} ss. Berlin j j COUNTY OF HARTFORD t

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! Then perse.nally appeared before me E. J. Mroczka, wno bein duly sworn, d' I j state that he is Senior Vice President of Northeast Nuclear nergy Company

! Licensee herein, that he is authorized to execute and file the forego.

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information in the name and on behalf of the Licensees herein, and that f. t i statements contained in said information are true and correct to the best St  ;

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his knowledge and belief.  !

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