ML19327B411

Application for Amends to Licenses DPR-57 & NPF-5,revising Tech Specs for Response Time of end-of-cycle Recirculation Pump Trip

ML19327B411
Person / Time
Site:	Hatch
Issue date:	10/20/1989
From:	Hairston W GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19327B412	List: ML19327B411 ML19327B413
References
HL-752, NUDOCS 8910310129
Download: ML19327B411 (9)

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october 20, 1989 L

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington,'D.C. 20555 i

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PLANT HATCH - UNITS 1, 2 1 NRC DOCKETS 50-321, 50-366 OP' CRATING LICENSES DPR-57, NPF-5 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

DEQF-CYCLE RECIRCULATION PUMP TRIP RESPONSE TIME

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Gentlemen:

In accordance with the provisions of 10 CFR 50.90, as required by 1 10 CFR 50.59(c)(1), Georgia Power Company (GPC) hereby proposes changes '

to the Plant Hatch Unitt 1 and 2 and Technical Specifications (TS),

Appendix A to Operating Licenses DPR-57 and NPF-5.

The proposed changes involve a revision of the Plant Hatch Units 1 I l o and 2 TS relative to the response time of the end-of-cycle recirculation  ;

pump trip (EOC-RPT). l Specifically the proposed TS (nanges will: 1

1. Add a definition of EOC-RPT system response time to the Unit 2 TS  !

l. as well as increase the current retponse time acceptance. 1

2. Add the EOC-RPT systein response time acceptance criteria to the l l Unit 1 TS with a note defining EOC-RPT system response time.

Enclostire 1 provides a detailed description of the proposed changes l and the circumstances necessitating the change request.

Enclosure 2 details the bases for our determination that the proposed L

changes do not involve a significant hazards consideration.

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Enclosure 3 provides page change instructions for incorporating the  :

proposed changes. The propoced changed Technical Specifications pages follow Enclosure 3.

. AM' 8910310129 691020 l PDR ADOCV 05000321 , , j p PDC

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i U.S. Nut. lear Regulatory Commission i october 20, 1989 i Page Two  ;

" l In accordance with the requirements of 10 CFR 50.91, a copy of this l letter and all applicable enclosures will be sent to Mr. J. L. Ledbetter  ;

of the Environmental Protection Division of the Georgia Department of i Natural Resources. GPC requests that the propored wendment be l expeditiously reviewed and issued as soon as possible.  !

Mr. W. G. Hairston, III states that he is duly authorized to execute this oath on behalf c,f Georgia Power Company, and to the best of his I kncwledge and belief, the facts set forth in this letter are true. <

GEORGIA POWER OMPANY DM

' g. VH. G. Hairston, III i Sworn to and subscribed before ce this M day of h Ic2 W 1989. t tw kw YYNcY MNMbds"DE th. n GKM/eb l

Enclosures:

1. Basis for Change Request  !

2. 10 CFR 50.92 Evaluation  !

3. Page Change Instruction  !

c: Georaia Power Comqnny Mr, H. C. Nix, General Manager - Nuclear Plant '

Mr. J. D. Heidt, Manager Engineering and Licensing - Hatch GO-NORMS LLS. Nuclear Regulatory Commisslott. Hashinaton. 0.C.

l Mr. L. P. Crocker, Licensing Proje(t Manager - Hatch U.S. Nuclear Reaulatory Commission. Reaion II Mr. S. D. Ebneter, Regional Adir.inistrator Mr. J. E. Henning, Senior Resident Inspector - Hatch L State of Georgia Mr. J. L. Ledbetter, Commissioner - Department of Natural Researces 0309V

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l ENCLOSURE'1

, , ' PLANT HATCH - UNITS 1, 2 i- NRC DOCKETS 50-321, 50-366 L OPERATING LICENSES DPR-57, NPF-5  ;

REQUEST TO REVISE TECHNICAL SPECIFICATIONS:  !

IE -OF-CYCLE RECIRCULATION PUMP TRIP RESPONSE TIME  !

BASIS FOR CHANGE REOUEST Both units at Plant Hatch are equipped with end-of-cycle recirculation pump trip (EOC-RPT) system instrumentation. The EOC-RPT system is -

designed to improve fuel thermal margin by tripping both recirculation i pumps upon sensing Turbine Stop Valve (TSV) closure or Turbine Control t Valve (TCV) fast closure. Tripping of the recirculation pumps results in reduced core flow which causes a smaller net oositive void reactivity ,

addition to the system during pressurization events. This ress1ts in a  !

lower power ine.rease and consequently smaller change in critical power  ;

ratio. The net result is to reduce the thermal severity of turbine trip, t generator load rejection, and feedwater controller failure events. l The increase in thermal margin depends on how fast core flow is reduced.

There is a time delay associated with opening the pump motor breakers.

• and the actual coastdown of the pumps. The coastdown time of the pumps  !

is a physical parameter based on pump design and inertia, and is not i expected to change unless major modifications are performed. Plant l Technical Specifications (TS) require testing of the time delay associated with opening the breakers and associated logic (EOC-RPT ,

L response time). This response time is the subject of this proposed l change.

l PROPOSED CHANGE 1: I Proposed Change I will add a definition of EOC-RPT response time to the i Unit 2 Technical Specifications (similar to that contained in the '

Standard Techr.ical Specifications [STS)) and change the EOC-RPT resporse ,

time acceptance criteria in Unit 2 Table 3.3.9.2-3 to 175 milliseconds  ;

(ms) for the test associated with TCV fast closure and to 155 ms for the  ;

test associated with TSV closure. '

BASIS FOR PROPOSED CHANGE 1: -

Amendment 69 to the Unit 2 Technical Specificatiora added operability and ,

surveillance requirements for the Anticipated Transient Hithout Scram  !

(ATHS) and EOC-RPT instrumentation. Included was a requirement to verify the EOC-RPT system response time. The requirements, including the verification of instrumentatioh response time, were based on the STS for i i- a BWR/4 plant.

0309V HL ~/63 El-1 1

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ENCLOSURE I (Continued) l REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

g' END-OF-CYCLE RECIPC1JLATION PUMP TRIP RESPONSE TIME i The EOC-RPT response time acceptance criteria approved in Amendment 69 )

l- was less than or equal to 135 as for both TSV closure and TCV fast closure. This time was taken from Unit 2 FSAR Section 5.5.16.2 and is the time required to open the breakers. (The main power breakers for ,

both recirculation pump motors are closed during normal operation.) In l order to be consistent with the time delay for RPT actuation used in the FSAR analyses, signal generation and logic response as well as the breaker opening time should be considered in the response time criteria.

The STS definition of EOC-RPT Response Time is the time interval between the initial movement of the TCV or TSV and the " complete suppression of the electric arc between fully open contacts of the recirculation pump i circuit breaker." Our proposed definition is similar to the STS l definition, but has been clarified relative to " initial movement" of the  !

associated valves as discussed below. This discussion focuses on what will be measured during the response time i?st versus what is assumed in the applicable safety analyses.

Turbine Control Valves (TCVs) - Fast closure of the TCVs above 30%

reactor power initiates an anticipatory reactor scram and RPT. The fast i closure signal is providad by pressure switches on the electrohydraulic control (EHC) oil lines. Oil pressure decreases rapidly following a l generator load rejection, and once it drops below the trip setpoint, a o

pressure switch actuates and sends an initiating signal to both th

"e. result of its response to a trip signal will continue to be as  :

described in the FSAR. No othar response or function will be possible because these changes will not result in physical changes to the logic system ita inputs, or its outputs.

0309V HL-763 E2-2

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.- l ERCLOSURE 2 (Continued) l l

REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

END-OF-CYCLE RECIRCULATIOf' PLMP TRIP RESPONSE TIME  !

This proposed change does not involve a significant decrease in the ,

margin of safety, because the EOC-RPT acceptance criteria is consistent  ;

with that currently assumed in the FSAR and subsequent reload analyses,  !

Adding the acceptance criteria constitutes an additional limitation not l presently included in the TS and clarifles the surveillance frequency a110ws consistency between the testing requirements for both ut;its.

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