ML20058N078

Submits Info Re pressure-temp Operating Limits for Facility, Per Generic Ltr 88-11.Util Recalculated Adjusted Ref Temp for Each Belt Line Matl as Result of New Displacement Per Atom Values

ML20058N078
Person / Time
Site:	Oyster Creek
Issue date:	08/09/1990
From:	Devine J GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
500-90-1963, C320-90-729, GL-88-11, NUDOCS 9008130201
Download: ML20058N078 (2)

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g OPU Nuclear Corporation mBA One Upper Pond Road :

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. August 9, 1990-500-90-1963-C320-90-729 4

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_U..S.~ Nuclear Regulatory Commission

-Attentions, Document Control Desk Mail 1 Station Pl-137o Washingto1, DC. 20555

- Oontlemen t '

Subjects - Oyster Creek Nuclear Generating Station Docket No. 50-219 Pressure-Temperature Operating Limits

.for Oyster Creek Reactor Vessel In response to Generic: Letter 68-ll,1"NRC position on Radiation Embrittlement "of Reactor Vessel Materials and its: Impact on Plant Operations", GPU. Nuclear.

submitted on' July 26, 1989 results of our analysis concerning-the

pressure-temperatures (P-T) operating limits using the calculational methods

-identified:in Revision 2 of Regulatory Guide 1.99.

Subsequently, a GPUN consultant discovered that the displacement per atom'-(dpa) values _used:in the. anal sis were possibly incorrect. The error was later i

. confirmed by the' supplier of the dpa values,.Battelle-Columbus Laboratory.

(BCL).1 BCL traced the error to-the treatment of the flux' ratios used in the

dpa calculations..-They also emphasized that the neutron flux calculations,-

including the: basic material properties and dpa cross section used,'and the-results concerning the1 fast: flux andidosimetry,are all correct' and are not-7,

'affected'by thedpa error.

..As a result of the-new dpa values GPUN recalculatad an Adjusted Reference s

1 Temperature-(ART) for each belt-line material of the Oyster Creek reactor vessel using' Regulatory Guide 1.99 Rev. 2 guidelines. The results of the calculation indicated'a 16'F increase in ART over that reported on y

July.26,.1989.

Therefore, the new ART is estimated to be 145'F at 15 effective

~ full' power years'(EFPY). -It is projected that 15 EFPY will be reached during Lthe third quarter in 1994 (approximately in the middle of Cycle 14).

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)g 0 0 012. 0GPU Nuclear Corporation is a subsidiary of General Public Utilities CorporatL.n

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,, PRESSURE-TEMPERATURE OPERATING.LIMIST

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'FOR' OYSTER' CREEK REACTOR VESSEL--

C C320-90-729

,PA'GE 2' 1

As_it wasl reported in our July 26, 1989 letter, another set of P-T operating curves;for the Oyster. Creek reactor vessel will be implemented by the end of:

13R'(May, 1991). This plan complies with the schedule set forth in Generic Letter 88-11 which required licensees to update and fully implement new P-T curves within two (2) plant outages (approximately 3. years) after.the effective

,date (May, 1988).of Revision 2 to Regulatory Guide 1.99, " Radiation Embrittlement of Reactor Vessel Materials."

Very truly yours, j

\\

J. C. DeVine, Jr.

l Vice President & Director l

Technical Functions i

JCD/YN/crb cc: Administrator" l

Region I U.

S. Nuclear Regulatory Commission j

475 Allendal=. Road 1

King of Prussia, PA 19406 NRC Resident Inspector oyster Creek Nuclear Generating Station-

. Forked River, NJ 08731 i-L:

Mr. Alex Dromerick,.Jr.

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U. S. Nuclear Regulatory Commission Mail Station P1-137-Washington, DC. 20555 t

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