ML20101T539

Application for Amend to Licenses DPR-24 & DPR-27,consisting of Tech Spec Change Request 101 Re Limiting Safety Sys Settings & Related Bases for Reactor Coolant Pump Trip to Protect Against DNB in Event of Reduced Primary Sys Flow

ML20101T539
Person / Time
Site:	Point Beach
Issue date:	01/30/1985
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	Harold Denton, John Miller Office of Nuclear Reactor Regulation
Shared Package
ML20101T541	List: ML20101T539 ML20101T553
References
TAC-56844, TAC-56845, NUDOCS 8502060218
Download: ML20101T539 (4)

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Wisconsin Electnc powcacouesur 231 W. MICHIGAN, P.O. BOX 2046, MitWAUKEE, WI 53201 January 30, 1985 CERTIFIED MAIL Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. NUCLEAR REGULATORY COMMISSION Washington, D. C. 20555 Attention: Mr. J. R. Miller, Chief Operating Reactors, Branch 3 Gentlemen:

DOCKET NOS. 50-266 AND 50-301 TECHNICAL SPECIFICATION CHANGE REQUEST NO. 101 UNDERFREQUENCY TRIP SETPOINT POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 In accordance with the requirements of 10 CFR 50.59, Wisconsin Electric Power Company (Licensee) hereby submits its application for an amendment to Facility Operating Licenses DPR-24 and DPR-27 for Point Beach Nuclear Plant, Units 1 and 2, respectively. The purpose of this amendment is to incorporate certain changes and revisions into the. Point Beach Technical Specifications. These proposed changes to the Technical Specifications cover the limiting safety. system settings and related bases for the reactor coolant pump (RCP) trip which protects against DNB in the event of reduced primary system flow resulting from system disturbances which cause frequency decay.

Analyses conducted for the Licensee by Westinghouse Electric Corporation have demonstrated that the underfrequency setpoints for the RCP trip, as stated in 15.2.3.1.B (8) (a) of the Technical Specification for each unit, can be reduced from the present limit of 57.5 Hz to 55.0 Hz without violating the DNB design basis. With the reduced underfrequency trip setpoint the Point Beach units would have a greater probability of staying on line during recoverable transmission system transients. It is also less likely that a spurious RCP trip will occur. Thus, the proposed change in_the underfrequency setpoint will enhance Wisconsin Electric system reliability and primary coolant system dependability.

In addition, Specification 14.3.1.A.l.c(2), referred to in the Basis at the top of page 15.3.1-3a, is corrected to 15.3.1.A.l.c(2) which is clearly what was intended.

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'Mr. H..R. Denton January 30, 1985 In support of the proposed Technical Specification change for reducing the underfrequency setpoint a reanalysis of the complete loss-of-flow transient was performed by Westinghouse. The analysis methodology and assumptions were consistent with the FSAR analysis and the same as those used for the analysis of this incident for licensing the use of Westinghouse designed 14x14 optimized ~ fuel assemblies (OFA). The following changes were made in-the analysis in support of the proposed Technical Specification changes:

1. Reactor coolant system (RCS) flow was assumed to decay linearly in response due to a frequency decay at a constant ' rate of 5 Hz per second. The 5jHz per second decay rate has been determined to be conservative for the Wisconsin Electric system.

2. Reactor trip occurs on a~RCP underfrequency signal at a setpoint of 54.5 Hz.

3. Reactor trip delay time was' assumed to be 0.6 seconds.

The' analysis bounded. cores consisting entirely of standard fuel,. cores consisting. entirely of OFA fuel,.and transition cores containing both fuel types. Operation at either 2000 psia or 2250 psia was considered. The difference'between the Unit 1 and Unit 2 steam generators _was also taken into account in order to cover both Point ~ Beach units. The attached Figure 14.1.8-4' represents.the

' resulting DNBR for the limiting fuel type using the. Westinghouse

. Improved Thermal _ Design Procedure o (ITDP) and the.WRB-l' correlation.

' Specific evaluations for standard fuel using' standard methods-were also performed.- The Westinghouse ITDP and WRB-1 correlation were used-for OFA fueled cores and transition cores.

1 In Attachment 1, Figures 14.1.8-2 andil4.1.8-4 summarize L the-results of.the. reanalysis. Table 14.1.8-12-presents the I: time sequence of events. Attachment 2.contains the related page.

i changes for the Point Beach Technical Specifications for Unit 1 and Unit 2.

i Based on the results of.the reanalysis we have concluded-u that the proposed amendment to the. Point Beach Technical Specifications

i. will not constitute a.significant hazards consideration as set _.

forth in 10 CFR 50.92.: Under the-proposed. amendment the complete loss-of-coolant flow transient discussed above~would be more limiting than theLcomplete-loss-of-flow. transient analyzed for use of OFA fuel- using the 57.5 value for the underfrequency . trip.

However,.the DNB' design basis has.not been violated. . The analytical-

'. ' methods.used to demonstrate conformance.with the. Technical Speci-L fications and regulations.are not changed from the established I-i

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Mr. H. R. Denton January 30, 1985 Westinghouse methodology which has previously been found acceptable to the NRC. Therefore, these changes are within the scope of the NRC's example vi, "a change...where the results of the change are clearly within all acceptable criteria...", (48 Federal Register 14870) as not likely to involve a significant hazards consideration.

As required by 10 CFR Part 170, we have enclosed herewith our check in the amount of $150 as our application fee for these license amendments. As further specified in the Commission's regulations, we enclose herewith three signed originals and, under separate cover, forty copies of this license amendments application. Please contact the Licensee if you.have any questions concerning this submittal or schedule for noticing and licensing at Point Beach.

Very truly yours,

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Vice Pres dent-Nuclear Power C. W. Fay Enclosures (Check No. 827902)

Copies to NRC Resident Inspector R. S. Cullen, PSCW Subscribep and sworn to before me this 3d X day of January 1985.

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Notary Public, State of Wgsconsin My Commission expires M44 Y,/974.

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