ML053430256

GE-NE-0000-0046-3343-NP, Rev 1, Oyster Creek, License Amendment Request Increase Safety Valve As-Found Setpoint Tolerance from 1% to 3%, Attachment 5

ML053430256
Person / Time
Site:	Oyster Creek
Issue date:	12/02/2005
From:	General Electric Co
To:	Office of Nuclear Reactor Regulation
References
GE-NE-0000-0046-3343-NP, Rev 1
Download: ML053430256 (6)

Text

ATTACHMFNT 5 Oyster Creek Generating Station Docket No. 50-219 License No. DPR-16 License Amendment Request "Increase Safety Valve As-Found Setpoint Tolerance from +/-1% to +/-3%"

GE-NE-0000-0046-3343-RO, Oyster Creek SSV Set-point Tolerance Change Effects on Anticipated Operational Occurrences, NON-PROPRIETARY VERSION

GE Energy - Nuclear General Botnic Company 1989 L*o Orchard S&t San Jose, CA 95125 GE-NE-0000-0046-3343-NP Revision I Class I November 2005 Non proprietaryVersion Oyster Creek SSV Set-point Tolerance Change Effects on Anticipated Operational Occurrences

Noni-proprielaryVersion (;F-NE-0000-0046-3343-NP Non-Proprietary Notice IMPORTANT NOTICE This is a non-proprietary version of GE-NE-0000-0046-3343-P, Rev 1, which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here ((

IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully The only undertakings of GE respecting information in this document are contained in the contract with Exelon, which authorizes this work and nothing contained in this document shall be construed as changing the contract. The use of this information by anyone other than Exelon, or for any purpose other than that for which it is intended, is not authorized; and with respect to any unauthorized use, GE makes no representation or warranty, express or implied, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document, or that its use may infringe privately owned rights.

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Nont-proprietawy Version GE-NE-0000-0046-3343-NP Revision Histoly Revision 1:

1. Changes to create proprietary version of the document to satisfy 10 CFR2.390.

Changes include the addition of the affidavit, and proprietary markings; revised headers and proprietary notices, and the deletion of references. No technical changes were made.

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a Non-proprietaryVersion GF-NE-0000-0046-3343-NP Summary This report documents the results of a sensitivity study performed for the Oyster Creek Generating Station (Oyster Creek) to determine the effect on the ((

l] of a -3% tolerance on the opening set point of the Spring Safety Valves (SSVs). The ((

l] analysis case for Oyster Creek Cycle 20 was run with the SSVs set to open when pressure was (( )) below the (( )) opening set point. (( )) the change in [l )) results were determined to be (( )) relative to the original Cycle 20 case. Therefore, changing the SSV opening pressure set points by -3% will have no effect on the core operating thermal limits.

Note that this report identifies the effects on Anticipated Operational Occurrences (A0O) based thermal limits of a change in the SSV opening pressure set point tolerance from

-1% to -3%. The results discussed in this report are ((

))

Evaluation Exelon is evaluating the potential to relax the Oyster Creek SSV opening pressure set point tolerance. Currently, Oyster Creek technical specifications require a SSV opening pressure set point tolerance of +/- 1%. Exelon is evaluating a relaxation of this requirement to +/- 3% for Oyster Creek. The purpose of this report is to document the effect on the

(( )) of a change in the negative side of the SSV opening pressure set point tolerance to -3%. Note that the Oyster Creek Cycle 20 reload analysis assumed a SSV opening set point of (( )) in the ASME overpressure analysis.

This evaluation addressed the effect of this tolerance relaxation on the ((

)) Specifically, the evaluation addressed the effect of the lower limit (-3%) of the tolerance band. This evaluation was performed by first re-running the original Cycle 20 limiting core thermal limits case, ((

)) Note, the reload licensing ((

)) analyses (( )). Subsequently, [

] was run for the same conditions with ((

)) the -3% tolerance point.

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Non-proprietaryVersioni GF-NF-0000-0046-3343-NP Results for these (( )) show that the point of (( )) occurs about

[)) The ((

)) also occurs )) which is why there is no change to the thermal-mechanical results. Given that the ((

1] cases, ((

)) The results of the analysis confirm this expectation. These (( ]

cases adequately represent the thermal limit transients for the purpose of evaluating the impact of the -3% tolerance. The analysis results support ((

)) the SSV opening pressure tolerance band to -3% for AOO application.

))

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