ML20028H039

Application for Amend to License DPR-51,reducing Heat Rate at Axial Locations Between 4 Ft & 8 Ft

ML20028H039
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/26/1990
From:	James Fisicaro ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20028H040	List: ML20028H039 ML20028H041
References
1CAN099007, 1CAN99007, NUDOCS 9010050274
Download: ML20028H039 (3)

Text

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U. S. Nuclear Regulatory Commission Document Control Desk ,

Mail Station P1-137 Washington, DC 20555 l

Subject:

Arkansas Nuclear One - Unit 1 ,

Docket No. 50-313 License No. OPR-51 Technical Specification Bases Change Request LOCA Limited Maximum Allowable Linear Heat Rate Gentlemen:

Arkansas Nuclear One (ANO) has identifled a change to Figure 3.5.2-5 which is in the ANO-1 Technical Specification Bases 3.5.2. This figure shows the LOCA analysis defined maximum allowable heat rate, which provides the bases fte the power-imbalance envelope. The proposed change will reduce the heat rate at axial locations between four feet and eight feet from the bottom of the core only.

-As reported by Babcock & Wilcox (B&W) Nuclear Technologies, in B&W 1etter JHT/90-43, dated March 19, 1990, from J. H. Taylor to T. E. Morley (NRC), a new analytical methodology using a more conservative critical heat flux 1 correlation yielded peak cladding temperatures greater than the 10CFR50.46 limit of 2200 F. This methodology assumed a 16.5 kw/ft heat rate at the six foot elevation at the beginning of life (BOL).

Recent analysis performed specifically for ANO-1 by B&W Nuclear Services, reduced.the LOCA linear heat rate limits at the six foot elevation to 16.1  !

kw/ft at the BOL and middle of life (MOL). This reduction results in restoring the margin for the peak cladding termperature such that when Technical. Specification allowed quadrant tilt, rod insertion and axial imbalance limits are considered, the peak cladding _ temperature does not exceed the 2200aF limit. B&W determined in previous fuel cycle reload analyses for other B&W designed plants that a reduction in the six foot elevation linear heat rate limit to 16.1 kw/f t did not impact the plant cya. Ling margins, i.e. rod insertion or axial imbalance limits.

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Page 2 September 26, 1990 Further investigation by B&W concluded that the same considerations should be applied to later core life - after 1000 mwd /mtU. Specifically, the LOCA linear heat rate limit at the six foot elevation should be reduced from 18 kv/ft to 16.5 kw/ft.

As this is a change to the Bases of the Technical Specifications, a "No Significant Hazards Determination" is not required. A review of this change, in accordance with 10CFR50.59, has concluded that an unreviewed safety question is not involved as a result of this change.

We request that this change be issued with the next scheduled amendment.

If you have any questions pertaining to this request, please feel' free to contact me.

Very truly yours,

,c)Gn James J Fisicaro Manager, Licensing JJF:RWC:fc Attachment cc: Mr. Robert Martin U. S. Nuclear Regulatory Commission Region IV

-611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 NRC Senior Resident Inspector Arkansas: Nuclear One - ANO-1 & 2 Number 1, Nuclear Plant Road

' Russellville, AR 72801 Mr. Thomas W. Alexion i NRR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-0-18 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852' t

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.4 i U. S. NRC Page 3 September 26, 1990-  ;

i Mr.-Chester Poslusny NRR Project Manager, Region IV/ANO-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-D-18 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852 Ms. Greta Dicus, Director Division of Radiation Control and Emergency Management Arkansas Department of Health 4815 West Markham Street Little Rock, AR 72201

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