ML20081J144

Application for Amend to License DPR-65,changing Definitions Page 1-6 & Tech Spec 3.2.3,4.2.3.3,4.2.3.4,3.2.4,3.3.3.2 & 4.3.3.2 to Remove Requirement for Explicit Tilt Correction in Total Unrodded Integrated Radial Peaking Factor

ML20081J144
Person / Time
Site:	Millstone
Issue date:	06/14/1991
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20081J147	List: B13837, Proposed Tech Specs Change Definitions Page 1-6 & Tech Specs 3.2.3,4.2.3.2,4.2.3.3,4.2.3.4,3.2.4,3.3.3.2 & 4.3.3.2 to Remove Requirement for Explicit Tilt Correction in Total Unrodded Integrated Radial Peaking Factor ML20081J144
References
B13837, NUDOCS 9106210150
Download: ML20081J144 (4)

Text

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P O BOK 270 HARTFORD, CONNECTICUT 06141-0270 k L J $[.((C(([ f 203) 065-5000 June 14, 1991 Docket No. 50-336 B13837 Re: 10CFR50.90 U.S. Nuclear Regulatory Commission Attn: bocument Control Desk Washington, DC 20555 Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Proposed Change to Technical Specifications Total Unrodded Intearated Radial Peakina Fact _qt Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License No. DPR-65 by incorporating the changes identified in Attachment 1 into the Technical Specifications of Millstone Unit No. 2.

Specifically, the proposed change to the Definitions page 1-6 and to Technical Specification Sections 3.2.3, 4.2.3.2, 4.2.3.3, 4.2.3.4, 3.2.4, 3.3.3.2, 4.3.3.2, Total will remove Unrodded Integrated the Radial requirement Peakingfor an explicf)t Factor (F tilt correction This inthe will support the planned revision to the software which monitors t6e c. ore power distribution.

These proposed revisions support replacing In Core Analysis (INCA) with INPAX and are phrased such that compatibility is established for both INCA and INPAX.

Discussion The core monitoring code presently used, INCA, calculates the core power distribution on an octant basis. As a result, the representative octant

' calculated by INCA must be corrected for azimuthal power tilt. This compensates for the possible omission of the peak pin from the calculated octant. The radial peaking. factor without the tilt correction is currently defined in the technical specifications as the Unrodded Integrated Radial Peaking Factor, (F ). as i the Total .Unroddedr Integrated The tiltRadial corrected value Peaking is curry)tly Factor, (F referred to yhe relationship is presently defined in the technical specifications 5s .Fr " f r(1 + Tq),

where Tq is the calculated tilt. ,

1 The INPAX code will calculate the core power distribution on a full core basis. The tilt effects will be implicitly included in the calculation. As such, there is no need for an additional tilt correction on the calculated value.

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1 U.S. Nuclear Regulatory Commission B13837/Page 2 June 14, 1991 As proposed, phe technical specification will be revised to specify that the calculated F value must include the effect of tilt. The specific method of accounting f5r the tilt will no longer be given. This will allow either the explicit calculation as is currently done with INCA, or the implicit calculation as is done by INPAX. The requirement that the value be tilt corrected will be included in the definition as well as in the 100. The defined term will be changed to the " Total Unrodded Integrated Radial Peaking Factor" rather than the "Unrodded Integrated Radial Peaking Factor" to reflect the fact the untilted value will not be calculated by INPAX.

Summary of Proposed Chanaes to Technical Specifications

1. Definitions. Unrodded Integnied Radial Pealina Factor - F The revisop title will read TOTAL UNRODDED INTEGRATED RADI AL PEAKING FACTOR - F . The reference to " excluding tilt" will be removed and "this value incl 6 des the effect of AZIMUTHAL POWER TILT" will be added.

2. POWER DISTRIBUTION LIMITS. TOTAL INTEGRATED RADI AL PEAKING' FACTOR - FI.

L]MITING CONDITION FOR OPERATl0N (LCO) (Satcification 3.2.3)

The title will by revised to read TOTAL UNRODDED INTEGRATED RADIAL PEAKlfGFACTOR-F. Specificatio9 3 2.3 will no longer include " defined as F - F (1 +r Tq)." "The F value shall include the effect of AZIMtfiHALP6WERTILT,"willbeaddfd.

3. Surveillance Reauirement ' Specification 4.2.3.2)

"F T

shall be calculated by the expression FT =Fr (1+Tq) and" will be deTeted. in Specification 4.2.3.2(c), AX1tfuTHAL will be replaced by AZIMUTHAL.

4. Surveillance Reautrement (Specification 4.2.3.3)

. . . each time a calculation of F T7 is required" w.ll be deleted.

5. Surveillance Reauirement (Specification 4.2.3.4)

The section will be deleted.

6. POWER DISTRIBUTION LIMITS AZIMUTHAL POWER TITL-Ta, LC0 Page 3/4 2-10, TITL will be corrected to TILT. Specification 3.2.4, AXIMUTHAL will be revised to AZIMUTHAL. S'ction 3.2.4, ACTION (a) and (b) will be revised to remove the references to the Total Integrated Radial Peaking Factor and replace them with TOTAL UNRODDED INTEGRATED RADIAL PEAKING FACTOR.

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U.S. Nuclear Regulatory Cominission B13837/Page 3 June 14, 1991

7. Instrumentation. INCCRE DETECTORS o LC0 3.3.3.a will be revised from AX1MUTHAL POWER TILT to AZIMUTHAL POWER TILT.

o LCO 3.3.3.2.c, Applicability (c), and Surveillance Requirement 4.3.3.2.a.3, will be revised to read TOTAL UNRODDED INTEGRATED RADIAL PEAKING FACTOR.

8. B 3/4.2 POWER DISTRIBUTION LIMITS. BASES Section 3/4.2.1 LINEAR HEAT RATE, Total Integrated Radial Peaking Factor will be replaced with TOTAL UNRODDED INTEGRATED RADIAL PEAKING FACTOR.

9. B 3/4.2.3 and 3/4.2.4 be revised to read 10TAL UNRODDED INTEGRATED RADIAL This section PEAKING wil}F AND AZIMUTHAL POWER TILT - Tg.

FACTORS r

The sentence including F T7 -F 7 (1 + Tq ) will be deleted.

Sianificant Hazards Consideration The proposed technical specification change has been reviewed against the criteria of 10CFR50.92 and it has been determined not to involve a significant hazards consideration. Specifically, the proposed change does not:

1. Involve a significant increase in the probability or consequences of any accident previously analyzed. The INPAX calculation, which includes the implicit tilt calculation, is more accurate than the INCA calculation.

The use of the tilt correction on an octant calculation is an approximation to the actual value, in the past, an implicit calculation could not be done using an octant methodology. By switching to the full core INPAX code, the more appropriate implicit calculation is possible.

There are no design basis accidents that are impacted by this change to the Technical Specifications. This does not affect or have any potential impact upon any of the design basis types of accidents previously analyzed. There are no failure modes affected by the change. As such, there are no design basis accidents affected by the change.

2. Create the possibility of a new or different kind of accident from any previously analyzed. There are no failure modes associated with this proposed Technical Specification change. Therefore, there are no failure modes which can represent a new unanalyzed accident.

3. Involve a reduction in the margin of safety. There are minor changes to the Bases, however these do not affect the margin of safety. The proposed changes support the planned revision to the software which monitors core power distribution. The more accurate methodology is

l U.S. Nuclear Regulatory Commission B13837/Page 4 June 14, 1991 structured such that compatibility is maintained for INCA and INPAX.

Therefore, there are no changes in the margin of safety as defined in the bases for any Technical Specification.

The Commission has provided guidance concerning the application of standards in 10CFR50.92 by providing certain exampics (51FR7751, March 6, 1986) of amendments that are considered not likely to involve a significant hazards consideration. Although the changes proposed herein are not enveloped by a specific example, the proposed changes will support the planned revision to the software which monitors the core power distribution. NNECO's proposed amendment involves no significant hazards consideration.

The Millstone Unit No. 2 Nuclear Review Board has reviewed and approved the attached proposed revision and has concurred with the above determinations.

NNEC0 respectfully requests that this proposed change be issued prior to the next refueling outage currently planned for March 1992. NNECO also requests this license amendment be effective as of the date of its issuance, to be implemented 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 application.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY s/

E. J. rocz a Seni r 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 STATEOFCONNECTICUT)

) 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 tb 'icensee herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief. Or ,

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Nota'ry PubTic

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