ML20079R799

Forwards Response to Criteria for Resolution of NUREG-0737, Item II.K.3.5, Automatic Trip of Reactor Coolant Pumps, Stated in NRC 830208 Generic Ltr 83-10C.Westinghouse Owners Group Program Addressing Criteria Will Be Evaluated

ML20079R799
Person / Time
Site:	Vogtle
Issue date:	06/16/1983
From:	Foster D GEORGIA POWER CO., SOUTHERN COMPANY SERVICES, INC.
To:	Adensam E Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.05, TASK-TM GL-83-10C, NUDOCS 8306240274
Download: ML20079R799 (5)

Text

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, , Georgia Power Company Post Offica Box 4545

- Atlinta, Georgia 30302 Telephone 404 526-6526 Southern Company Services, Inc.

Post Office Box 2625 Georgia Power Birmingnam, Alabama 35202 reiennone 205 8704oii Southern companyservices D. O. Foster Vice President and General Manager Vogtle Project June 16, 1983 Elinor G. Adensam, Chief Licensing Branch #4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMBERS CPPR-108 AND CPPR-109 VOGTLE ELECTRIC GENERATING PLANT - UNITS 1 AND 2 GENERIC LETTER 83-10c ITEM II.K.3.5.

Dear Ms. Adensam:

The criteria for resolution of NUREG-0737, Item II.K.3.5 " Automatic Trip of Reactor Coolant Pumps," are stated in NRC Generic Letter 83-10c dated February 8, 1983. The Westinghouse Owners Group (WOG), of which Georgia Power Company is a member, has developed a two-part program to address the criteria stated in the Generic Letter. Georgia Power Company will evaluate the WOG program for applicability to the Vogtle Electric Generating Plant (VEGP). The results of this evaluation will be submitted to the NRC within three months of receipt of the WOG generic program. For those criteria which are plant specific (i.e. not addressed by the WOG), Georgia Power Company has provided the attached response. This attachment includes a summary of the criterion being addressed by the WOG and the response by Georgia Power Company for plant specific criteria.

Should you have any questions, please inquire.

Sincerely,

/

a a D. O. Foster DOF/KWK/sw

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Ms .1 Elinor G. Adensam ' '

' June 16, 1983

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R.'A. Thomas D.'E. Dutton-L. T..Gucwa G. Bockhold,.Jr.

J. A. Bailey G. F. Trowbridge,-Esq.

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ATTACHMENT Detailed Response to-the Criteria in Generic Letter-83-10c

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I. ; Pump Operation Criteria:Which Can Result in RCP Trip During Transients and Accidents

1. -Setpoints for RCP Trip:

-The' Georgia Power. Company respo'nse to this section will be based on Revision 1 to the Westinghouse Owner's Group ~ Emergency-Response Guidelines (ERGS) scheduled for completion by~ July l31, 1983. VEGP's

-Emergency Operating Procedures >(EOPs)'will be developed from these

-ERGS in accordance with GPC's' schedule-to implement the provisions of Supplement 1 to NUREG-0737 related to E0Ps.

a) Westinghouse and the: Westinghouse Owners Group are developing

' revised RCP trip criteria which will assure that the need to trip the RCPs will be indicated to.the Operator'for LOCAs Lwhere RCP trip _is considered necessary. The criteria will also ensure continued forced RCS flow for:

1) steam generator tube-rupture (up to the design bases,-

double-ended tube rupture)

2) the'other more likely non-LOCA transients where forced circulation is desirable (e.g. steam line breaks equal; to or smaller than I stuck open PORV)

The criteria _being considered 'for RCP trip are:

1) RCS wide range. pressure < constant (to be determined) 2). RCSsubcooling< constant [(tobedetermined)

3) Wide range RCS-pressure < function of secondary pressure (to'be determined)

Instrument uncertainties will be accounted for. Environ-mental. uncertainty will be included if appropriate.

No partial or staggered RCP trip schemes will be considered.

4 Such schemes are unnecessary and increase the requirements for training, procedures and decision making ~by the operator during transients and accidents, b) _The RCP trip criteria selected will be such'that the operator will be instructed to trip the RCPs before voiding occurs at the RCP.

Page 2 c) The criteria developed in Item la above is not expected to

lead to RCPitrip for.the moreLlikely non-LOCA and SGTR transients.- However,-since continued RCP operation cannot -

'be guaranteed, the Emergency' Response Guidelines provide

-guidance for the use of alternate methods for depressurization.

-This guidance will be used in the development of the Vogtle E0Ps.

d) The Emergency Response Guidelines contain specific guidance for detecting, managing and removing coolant voids that result from flashing. .The symptoms of such a situation are described-in these guidelines and in detail in'the background document for the guidelines.. Additionally, explicit guidance for

, operating-the. plant with a vaporous void'in the' reactor vessel 1 head is'provided in'certain cases where such operation is-needed. . Vogtle E0Ps and a training program will be developed from Revision.l of the-ERGS in accordance with Georgia Power Company's schedule to implement-Supplement-1 to NUREG-0737

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related to EOPs.

e) The VEGP designLutilizesLa non-safety related,' seismic Category.

1 auxiliary component cooling water (ACCW) system to provide cooling water to, the , reactor, coolant- pump , lube oil, coolers,

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motor coolers and thermal. barriers. . Seal water _is.provided to the reactor coolant' pumps via the chemical and volume control-system. .The containment _ penetrations for the seal water supply and the ACCW supply.to the reactor coolant. pumps have been designated as essential.' The isolation' valves for these pene-

.trations are remote-manual without automatic isolation pro-visions. The valves are equipped with motor operators and fail as_is if electrical. power-is lost. The-ACCW pumps-are powered from Class.lE'4160v switchgear? Given a safety injection (SI) signal with offsite power available,'the~ running ACCW pump

will . continue to. function ensuring Ladequate cooling water 'for the reactor coolant pumps. 11f offsite power ~is lost coincident with the SI signal, the ACCW' pumps are shed from the Class lE buses'until-the sequencer has completed its function. -At this point, the operator can manually . restart the ACCW pumps using 4 the onsite-power supply prior to restarting the' reactor coolant pumps for those conditions under which the reactor coolant' pumps will be functioning.

f) Discussed in la and Ic.

2. Guidance for Justification of Manual RCP Trip The Georgia Power Company response to this section of requirements will be addressed as a part of the WOG program which is scheduled to be completed by the end of 1983. GPC will review the generic program and will provide the NRC with an assessment of the appli-

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4 cability of_the. generic program to VEGP within-three months of' receipt of the WOG, generic response.-

a)~ A significant. number [of[ analyses:have been performed by

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-Westinghouse;for the Westinghouse Owners Group using the

-currently: approved Westinghouse Appendix K~ Evaluation Model.

for small break-LOCA.-.This Evaluation ModelLuses the WJLASH Code. These. analyses demonstrate'for.small break LOCAs oficoncern,.if the RCPs are' tripped 2 minutes follow-

.ing the onset of. reactor: conditions corresponding to the RCP trip setpoint,-the predicted transient is nearly identical to-those presented'in the' Safety. Analysis Report.

This, the WOG; analyses demonstrate the. validity of this approach._

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WN: b) HBetticr(e'Ema~ e't analyses'will b'e performed for- a limiting iWestinghouse: designed plant using the WJLASH computer code'

, zwith better estimate assumptions. These analyses will be used,to determine'the minimum-time available for operator action for a range of break sizes such that the ECCS acceptance criteria of 10 CFR 50.46 are not exceeded. It is expected that the minimum. time available for manual RCP trip will exceed'the guidance contained in N660. This will-

-justify manual RCP trip.

3. : Other Considerations a) Georgia Power' Company will provide the NRC information concerning level of quality of instrumentation used in-determining-the-need for RCP trip three months after receipt-of Revision 1 of the WOG Emergency Response Guide-lines scheduled to be completed July 31, 1983.

b) The Emergency Response Guidelines will.contain guidance for the timely. restart of the RCPs when' conditions which will support safe pump start-up and operation are established.

GeorgiafPower Company will incorporate this guidance in the development of VEGP Emergency Operating Procedures in accordance with the schedule to implement Supplement 1 to NUREG-0737 related to E0Ps.

c) The VEGP training program will be~ developed to train opera-tors in the use of EJPs developed from Revision 1 to the Emergency' Response Guidelines. The training program will emphasize the operator's responsibility for tripping the RCPs in the event of a small break LOCA. Operators will also be trained-in the prioritization of actions.following engineering safety features. actuation. -

II. -Pump Operat' ion Criteria Which'Will Not Result In RCP Trip During Transient and Accidents Georgia Power Company agrees with' Westinghouse and the Westinghouse Owner's Group that the preferred-and safest method of' operation following a.small break!LOCA is--to manually trip the RCPs. _Therefore,

'we will not' address the criteria contained'in this section.

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