HL-5004, Application for Amends to Licenses DPR-57 & NPF-5, Respectively,Revising Changes of Drywell Air Temp LCO from 135 F to 150 F

Application for Amends to Licenses DPR-57 & NPF-5, Respectively,Revising Changes of Drywell Air Temp LCO from 135 F to 150 F

ML20100H739
Person / Time
Site:	Hatch
Issue date:	02/21/1996
From:	Beckham J GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20100H742	List: HL-5004, Application for Amends to Licenses DPR-57 & NPF-5, Respectively,Revising Changes of Drywell Air Temp LCO from 135 F to 150 F ML20100H743
References
HL-5004, NUDOCS 9602280013
Download: ML20100H739 (6)

Text

_ _ . _ _ - _ _ _ _ - - _ . _ _ - . - _ _ - - _ _ - _ . _ _ - _ _ _ _ _ _ _ _ . _ - _ - _ - - - - - --. _. . _ _ - -

Georg4 Power company

. . 40 lnvimess Center Parkway J Post Office Box 1295 Birmingham. Alabama 35201 :

n Telephone 205 877-7279

$J;p aa ,kg=g,,, GeorgiaPower Hatch Project L re s:xten e4ctde system -

February 21, 1996 Docket Nos. 50-321 HL-5004 50-366 U.S. Nuclear Regulatory Commission ATTN: Document ControlDesk Washington, D.C. 20555 Edwin I. Hatch Nuclear Plant Request to Revise Technical Specifications:

Drwell Air Temocrature Gentlemen:

i In accordance with the provisions of 10 CFR 50.90, as required by 10 CFR 50.59(c)(1), l Georgia Power Company (GPC) hereby proposes a change to the Plant Hatch Unit 1 and  ;

Unit 2 Technical Specifications, Appendix A to Operating Licenses DPR-57 and NPF-5, respectively. The proposed revision changes the Drywell Air Temperature Limiting Condition for Operation (LCO) from $ 135 F to $ 150*F.

I The ' proposed change provides a margin for the primary containment Drywell Air Temperature LCO when prolonged summer and high river temperatures are experienced GPC requests the proposed amendment be approved prior to July 1,1996.

Enclosure 1 provides a description of and the justification for the proposed change.

Enclosure 2 details the bases for GPC's determination that the proposed change does not involve a significant hazards consideration. Enclosure 3 provides page change instructions for incorporating the proposed change, the revised Technical Specifications pages, and the corresponding marked-up pages. Enclosure 4 provides, for information, the Bases pages reflecting the proposed change and the correspondmg marked-up pages. The Bases pages

- will be made effective upon receipt of the Technical Specifications amendments.

In accordance with the requirements of 10 CFR 50.91, the designated State official will be sent a copy of this letter and all applicable enclosures.

17003.1 9602290013 960221 ~ M, PDR ADOCK 050003 1

GeorgiaPower d U.S. Nuclear Regulatory Commission - Page 2 February 21, 1996 Mr. J. T. Beckham, Jr. states he is Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company, and to the best of ,

his knowledge and belief, the facts set forth in this letter are true.

Sincerely, J/

, y _

J. T. Beckham, Jr.

Sworn to andsubscribedbefore me this.d}? day of <M ,1996.

A

. Notary Public _,_ _

WCOWMWJNDFflESfGBRERS,1g>

DLP/eb

Enclosures:

1. Basis for Change Request

. 2. 10 CFR 50.92 Evaluation

3. Page Change Instructions and Revised Technical Specifications Pages

. 4. Revised Bases Pages cc: Georeia Poutr Company l Mr. H. L. Sumner, Nuclear Plant General Manager i NORMS U.S. Nuclear Regulatory Commission. Washington. D.C.

Mr. K. Jabbour, Licensing Project Manager - Hatch )

l U.S. Nuclear Regulatory Commission. Region H Mr. S. D. Ebneter, Regional Administrator Mr. B. L. Holbrook, Senior Resident Inspector - Hatch State ofGeorgia Mr. J. D. Tanner, Commissioner - Department of Natural Resources I

l HL-5004

_ _ _ . _ _ _ _ _ _- l

- . - .- - ~ . - . - _ - . - _ . - - . -- _.- . ..

Enclosure 1 ,

Edwin I. Hatch Nuclear Plant Request to Revise Technical Specifications: i i

Drywell AirTemperature

• i i

Ba=In for Channa Reaye=t i

Proposed Channe 4 This proposed revision changes the Drywell Air Temperature Limiting Condition for Operation (LCO) from $ 135 F to $ 150 F. A correction to an FSAR reference notation

. was made. l

]

Basis for Pronosed Change

- As a part of the Plant Hatch Power Uprate Program (Ref. I through 3), the pertinent i

' design basis analyses for the following areas of containment system performance were evaluated at an initial drywell average air temperature of 150 F:

• Short-term and long-term containment pressuie and temperature responses to a  :

design basis accident (DBA) loss of coolant accident (LOCA).  ;

r 4

1 l

• Drywell pressure and temperature responses to small steam line breaks.

The short-term response evaluation utilized the M3CPT computer code. The long-term

response and the small steam line break evaluations utilized the SHEX computer code.

(Response to Question 19 of Ref. 2 provides details of the evaluations.) The analyses results are as follows:

e Operation with the drywell temperature at $ 150 F will not result in any safety concerns associated with primary containment system performance.

j'

• Peak drywell pressures will remain below design drywell pressures, and drywell structure temperatures will remain below design temperatures.

• For Unit 2, the peak ambient drywell air temperature is below the drywell structure design temperature of 340 F.

e For Unit 1, the peak ambient drywell air temperature is slightly above the drywell structure design temperature of 281 F during the initial 15 seconds of the limiting accident. An evaluation concluded that the actual drywell structure design temperature is not exceeded.

t,

[ HL-5004 El  :

, .- - - - . - _ _ _ . - - - ~ _ - - . - - . - . - - - .- --

a p

Enclosure 1 Request to Revise Technical Specifications:

Drywell Air Temperature ,

Basis for Change Request I l

Drywell equipment required to mitigate the effects of a DBA is qualified to operate under i environmental conditions expected during normal operations followed by those predicted

, for an accident. Based upon the design bases analyses described above, accident

equipment qualification is adequate for the proposed change.

The effect of ambient temperature on drywell equipment qualified life is evaluated 1 periodically based upon input from individual temperature elements located within the drywell rather than the average bulk temperature. Component life is evaluated based upon j past and predicted elevation-dependent temperatures in the area of the component. While f prolonged drywell temperatures > 135*F are not anticipated, any increase in the ,

elevation-dependent temperatures will be factored into the qualified life calculations. ,

The reactor water level measurement instrumentation located in the drywell is the only  ;

2 safety-related instrumentation that may be affected by a change in the drywell allowable

temperature. Originally, water level instrumentation was calibrated assuming the entire drywell temperature was 135 F. Upon implementation of the Unit 2 Power Uprate

. Program, the calibration methodology changed in that calibrations are now based upon i

! historical actual temperatures in the vicinity of the instrument sensing lines, thereby

providing more accurate level measurements (Ref. 4). The same methodology change will l become effective upon implementation of the Unit 1 Power Uprate Program in April 1996.

Reactor water level calibrations were evaluated assuming drywell temperatures up to

. 170*F. The results showed that a change in calibration endpoints from 135 F to 170*F 4 had a negligible effect upon setpoint available margins. This temperature bounds the  ;

,. expected actual temperature in the vicinity of the instrument sensing lines, assuming the

, drywell average allowable temperature is < 150 F. Since the instrument calibration impact t is negligible, no changes in instrument setpoints are required.

Based on the design bases analyses assumptions being met and the continued qualification i' of drywell equipment per 10 CFR 50.49, the revision of the Drywell Air Temperature LCO is acceptable.

l I

i HL-5004 El-2

• Enclosure 1 Request to Revise Technical Speci6 cations:

Drywell AirTemperature Bt. sis for Change Request

References:

1. GPC letter HL-4724," Request for License Amendment: Power Uprate Operation,"

dated January 13,1995.

2. GPC letter HI 4812," Response to Request for AdditionalInformation: Power Uprate Submittal," dated April 5,1995.

3. GPC letter HI 4865," Response to Second Request for Additional Information:

Power Uprate," dated June 20,1995.

4. General Electric Service Information Letter 470, Supplement 1, dated April 20,1989.

1 s

i i

i e

HL-5004 El-3 t

Enclosure 2 Edwin I, Hatch Nuclear Plant Request to Revise Technical Specifications:

Drywell AirTemperature 10 CFR 50.92 Evaluation Proposed Channe This proposed revision changes the Drywell Air Temperature Limiting Condition for Operation (LCO) from 5135 F to $ 150'F. A correction tc an FSAR reference notation was made. This typographical error is strictly editorial.

10 CFR 50.92 Evaluation Georgia Power Company (GPC) reviewed the proposed Technical Specifications change and determined the change does not involve a significant hazards consideration based upon the following:

1. The proposed change does not involve a significant increase in the probability or ,

consequences of an accident previously evaluated. The probability (frequency of occurrence) of previously evaluated accidents is not a function of the ambient drywell air temperature. Irstrumentation setpoint calculations were assessed, and the  :

increased ambient drywell air temperature does not affect any instrumentation setpoints or allowable values.  ;

The design basis accidents were reevaluated utilizing the increased drywell air temperature as an initial assumption. The results indicated that no regulatory limits or equipment design requirements will be exceeded as the result of the proposed change.

Therefore, the change in drywell air temperature does not result in a significant l increase in the probability or consequences of any previously evaluated accidents. l

2. The proposed change does not create the possibility of a new or different kind of accident from any accident previously analyzed. Revising the Drywell Air Temperature LCO does not physically modify the plant nor does it modify the  ;

operation of any existing equipment.

3. The proposed change does not involve a significant reduction in a margin of safety.

Design bases analyses performed utilizing 150 F as the initial drywell temperature demonstrate that design and regulatory limits are not exceeded. Equipment in the drywell required to mitigate the effects of a DBA is qualified to operate under environmental conditions expected for an accident. Analysis results do not affect instrumentation setpoints or calibration, or accident equipment qualification.

1 I

e

- HL-5004 E2-1 I

I

1

• Enclosure 2 Request to Revise Technical Specifications: '

Drywell Air Temperature 10 CFR 50.92 Evaluation Equipment qualified life is evaluated by an existing program which uses elevation-dependent drywell temperature rather than bulk average temperature.

Therefore, the margin of safety associated with safety and other limits identified in the Technical Specifications are not significantly reduced. .

HL-5004 E2-2