ML20151X769

Requests NRC Concurrence to Proceed W/Implementation Increased Setpoint as Provided by Tech Spec Amend 144 to Eliminate Unnecessary Challenges to Containment Isolation Sys & Undesirable Reactor Coolant Conductivity Excursions

ML20151X769
Person / Time
Site:	Hatch
Issue date:	04/28/1988
From:	Mcdonald R GEORGIA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
SL-4571, TAC-62758, NUDOCS 8805040246
Download: ML20151X769 (2)

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333 N tr ( nt A cmr N Wa Ge qa KnOS L epwe 40: KEt' 6 f 6 0 45 At na Geog a 3)32 Georgia Power Executive Department SL-4571 2017C X7GJ17-H600 April 28, 1988 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Rashington, D. C. 20555 PLANT HATCH - UNIT 1 NRC DOCKET 50-321 OPERATING LICENSE DPR-57 REACTOR HATER CLEANUP SYSTEM TEMPERATURE ISOLATION SETPOINTS Gentlemen:

Plant Hatch Unit 1 Technical Specifications (TS) Amendment 144, issued August 10, 1987, provided a higher temperature setpoint for instrumentation which isolates the reactor water cleanup (RHCU) system upon detection of high ambient temperature in the RHCU equipment rooms (TS Table 3.2-1, Item 9.). Prior to physically changing the instrument setpoint in the plant, GPC determined that a discrepancy was contained in the anajysis supporting the Unit I revised setpoint. By letter of Octd,er 26, 1987, GPC notified NRC of the discrepancy and also of GPC's it. tent not to physically implement the setpoint change for Plant Hatch dnit i until the discrepancy was resolved and NRC concurrence was obtained.

GPC has now thoroughly reviewed the analyses and bases for the setpoint change for Unit 1. Information provided to NRC in GPC's letter of January 23, 1987 indicated that the Plant Hatch Unit 2 RHCU room

' temperature versus time curves bounded those of Unit 1, and, therefore, could be conservatively applied to determine the allowable degree of setpoint increase for Unit 1. It was subsequently determined that the Unit 2 curves may not bound the Unit 1 curves in all cases. GPC therefore requested our Architect / Engineers to perform a Unit 1 specific analysis, using Unit 1 design input information (i.e. Unit 1 specific temperature versus time curves), to determine if the originally requested setpoint change could still be justified. Based on the results of this analysis, we have determined that the Unit 1 setpoint change granted by i TS Amendment 144 is supportable, on the same analytical basis as provided in GPC's previous correspondence referenced above. Equipment

! qualification temperatures and reactor coolant inventory loss values for Unit 1 are maintained at or below the values which were previously l reported when the Unit 2 curves were used.

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U. S. Nuclear Regulatory Commission April 28, 1988 Page Two Therefore, GPC hereby requests NRC concurrence to proceed with implementation of the increased setpoint on Plant Hatch Unit 1 as provided by is Amendment 144. He request that this approval be granted on a timely basis to preclude unnecessary RHCU isolations during the warmer summer months. These isolations result in unnecessary challenges to the conte.inment isolation system and undesirable reactor coolant conductivity excursions.

If you have any questions in this regard, please contact this office at any time.

Sincerely, f

. OOD R. P. Mcdonald Executive Vice President, Nuclear Operations REB /lc c: Georaia Power Comoany Mr. J. T. Beckham, Jr., Vice President - Plant Hatch Mr. L. T. Gucwa, Manager Nuclear Safety and Licensing GO-NORMS U. S. Nuclear Regulatory Commission. Washinaton. D. C.

Mr. L. P. Crocker, Licensing Project Manager - Hatch U. S. Nuclear Regulatory Commission. Region L[

Dr. J. N. Grace, Regional Administrator Mr. P. Holmes-Ray, Senior Resident Inspector - Hatch l 2017C

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