ML20248E240

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Forwards Summary of 890712 Meeting w/C-E Owners Group Re Proposed Diverse Emergency Feedwater Actuation Sys (Defas) Portion of ATWS Equipment,Per 10CFR50.62.General Design Features of Defas Consistent W/Intent of ATWS Rule
ML20248E240
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 09/22/1989
From: Poslusny C
Office of Nuclear Reactor Regulation
To: Tison Campbell
ARKANSAS POWER & LIGHT CO.
References
NUDOCS 8910050116
Download: ML20248E240 (3)
v • d • e


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' September 22, 1989 6Dpcket No. 50-368

'Mr. T.' Gene Campbell Vice President, Nuclear-Arkansas Power and Light Company P. O. Box 551 Little Rock, Arkansas -72203

Dear.Mr. Campbell:

SUBJECT:

SUMMARY

OF MEETING WITH THE COMBUSTION ENGINEERING OWNERS GROUP (CE0G) REGARDING THE DEFAS DESIGN FEATURES TO BE INSTALLED PER 10 CFR 50.62 (ATWS RULE)

Enclosed is a summary of the July 12,-1989 meeting.between NRC staff and members of the CE0G to discuss the design features of the proposed diverse emergency feedwater actuation system (DEFAS) portion of ATWS equipment. (A copy of this summary was telefaxed to D. James of your staff.on September 18.) At'this meeting the NRC staff concluded that it would issue this meeting summary to provide comments on the DEFAS design features common to all four licensees' plant specific designs discussed by the CE0G. The comments included in the summary reflect the view that the general design features of the DEFAS concept presented by;the CE0G are consistent with the intent of the ATWS Rule.

The staff now expects Arkansas Power and Light Company to provide a plant specific DEFAS design submittal incorporating comments included in the meeting summary, and expects that each licensee will proceed in an expedited manner with all aspects of. the plant specific DEFAS' design, analyses, and installation.

While the staff-will review each of the CE0G plant specific ATWS designs and issue a Safety Evaluation (SE) for each submittal, it is expected that design, procurement and implementation of the DEFAS portion of ATWS should not be delayed pending issuance of these SEs.

Please have your staff contact me if clarification or additional information on' this ATWS issue is needed, y,

Sincerely, 30 /s/

[jM Chester Poslusny, Jr., Project Manager

  1. o Project Directorate IV

$8 Division of Reactor Projects - III,

"* IV, V and Special Projects ed Office of Nuclear Reactor Regulation M

Enclosure:

@@ As stated 1

'o cc w/ enclosure:

3c: See next page

- Q ' DISTRIBUTION w/o enclosure: PD4 Reading Docketfilen "" NRC PDR Local PDR G. Holahan F. Hebdon P. Noonan C. Poslusny OGC-Rockville E. Jordan B. Grimes D. Lynch ACRS (10) PD4 Plant File H. Li

' *See previous concurrences:

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DATE :09/20/89 :0 20/8d :09/Xt/49  :  :  :  :

OFFICIAL RECORD COPY Document Name: ATWS h[

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[ UNITED STATES y .{ g NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 c

September 22, 1989

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1 Docket No. 50-368 Mr. T. Gene Campbell Vice President, Nuclear -

Arkansas Power and Light Company P. 0. Box 551 Little Rock, Arkansas 72203

Dear Mr. Campbell:

SUBJECT:

SUMMARY

OF MEETING WITH THE COMBUSTION ENGINEERING OWNERS GROUP (CEOG) REGARDING THE DEFAS DESIGN FEATURES TO BE

Enclosed is a summary of the July 12, 1989 meeting between NRC staff and inembers of the CEOG to discuss the design features of the proposed diverse emergency -

j feedwater actuation system (DEFAS) portion of ATWS equipment. (A copy of this r sumary was telefaxed to D. James of your staff on September 18.) At this' i meeting the NRC staff concluded that it would issue this meeting summary to provide coments on the DEFAS design features comon to all four licensees' plant specific designs discussed by the CE0G. The comments included in the sumary reflect the view that the general design features of the DEFAS concept presented by the CE0G are consistent with the intent of the ATWS Rule.

The' staff now expects Arkansas Power and Light Company to provide a plant specific DEFAS design submittal incorporating coments included in the meeting sumary, and expects that each licensee will proceed in an expedited manner with all aspects of the plant specific DEFAS design, analyses, and installation.

While the staff will review each of the CE0G plant specific ATWS designs and issue a Safety Evaluation (SE) for each submittal, it is expected that design,

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procurement and implementation of the DEFAS portion of ATWS should not be delayed pending issuance of these SEs.

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Please have your staff contact me if clarification or additional information on this ATWS issue is needed.

Sincerely,

.>0N CD Chester Poslusny, Jr., Project Manager h

Project Directorate IV Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation l

Enclosure:

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, As stated I

cc w/ enclosure:

See next page

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l Mr. T. Gene Campbell Arkansas Power & Light Company Arkansas Nuclear One, Unit 2 l.

1 CC:

Mr. Early Ewing, General Manager Mr. Charles B. Brinkman, Manager Technical Support and Assessment Washington Nuclear Operations Arkansas Nuclear One Combustion Engineering, Inc.

P. O. Box 608 12300 Twinbrook Parkway, Suite 330 Russellville, Arkansas 72801 Rockville, Maryland 20852 Mr. Niel Carns. Director Nuclear Operations -

Honorable Joe W. Phillips Arkansas Nuclear One County Judge of Pope County P. O. Box 608 Pope County Courthouse Russellville, Arkansas 72801 Russellville, Arkansas 72801 Mr. Nicholas S. Reynolds Bishop, Cook, Percell & Reynolds 1400 L Street, N.W.

Washington, D.C. 20005-3502 Regional Administrator, Region IV U.S. Nuclear Regulatory Comission Office of Executive Director for Operations 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Senior Resident Inspector U.S. Nuclear Regulatory Comission t 1 Nuclear Plant Road Russellville, Arkansas, 72801 Ms. Greta Dieus, Director Division of Environmental Health Protection Arkansas Department of Health i 4815 West Markam Street Little Rock, Arkansas 72201 Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division 1700 Rockville Pike, Suite 525 Rockville, Maryland 20852 i

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August 15, 1989 Docket Nos: 50-361 -

. 50-362 50-368 50-382 50-528 50-529 50-530 MEMORANDUM FOR: John N. Hannon, Director Project Directorate III-3 Division of Reactor Projects - III, IV, Y and Special Projects FROM:' M. David Lynch, Senior Project Engineer

. Project Directorate III-3 L Division cf keactor Projects - III, IV, Y and Special Projects

SUBJECT:

SUMMARY

OF MEETING WITH THE COMBUSTION ENGINEERING OWNERS GROUP (CEOG)REGARDINGTHEDEFASDESIGNFEATURESTOBE INSTALLED PER 10 CFR 50.62 (THE ATWS RULE)

A meeting was held in Bethesda, Maryland on July 12,1989, between members of the NRC staff and representatives of four licensees who form the Combustion

& Engineering Owisers Group CE06). The four licensees are: Louisiana Power 1 Light Con.pany (Waterford)(; Arkansas Power & Light Company (ANO-E); South

.i Califcrnia Edison Company (San Onofre 2 & 3) and Arizona Public Service Company (Palo Verde 1, 2 & 3). A list of attendees is presented in Enclosure 1.

Background

b A previous meeting with the CE06 was held on May 1,1989, te discuss the i

general cesign features of the diverse emergency feeowater actuation system (DEFAS) portiori of the ATWS equipment to be installed per the requirements of 10 CFR 50.62. The meeting on May 1, 1989, discussed the overall approach by the CE06 in designing the DEFAS as contained in the report, CE NPSD-384, which was docketed on April 30, 1989. There was a subsequent telephone conference on June 21,1989 between th wasfocusedonsIxconcerns.eNRCstaffandrepresentativesoftheCEOGwhich identified by the staff regarding the overall design features of the DEFAS. It was agreed by the parties to this telephone conference that these six concerns would form the agenda for the meeting to be held on July 12, 1989, t

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Contact:

H.Li(SIC 8/ DEST),X-10781 D. Lynch (PD/3-3), X-23023 r

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John N. Hannon .

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Summary The staff concluded early in the meeting on July 12 as a result of the CEDG presentation that there would be such differences in the DEFAS equipment to be insta11eo by the four licensees that a finci NRC acceptance of the DEFAS desigr.

features could only be given following a staff review of the plant specific submittals. On this basis, the staff will r.ct issue a generic SER on the CE report citec above. However, there was sufficient information presented in the meetings on May I and July 12,1989, to permit the staff to make specific comments on the DEFAS cesig;1 features which would be common to all four licensees' plant specific designs. The intent of the staff connents was to reflect the view that the general design features of the DEFAS concept presented by the CEOG was consistent with the intent of the ATWS rule. It was clearly noted by the staff, however, that staff acceptance of the DEFAS design.was ,

contingent on a review of the' plent specific submittals.

A sumary of the staff's coments on the information presented at the two meetings citeo above is presentea below. Enclosure 2 is a copy of the slides presented by the CEOG on July 12, IS89.

Staff Comments on the CEOG CEFAS Destgr. Features The following is the staff's understarcing of the Diverse Emergency Feeowater l Actuation System (DEFAS) as presented in the meetings held on May 1 and July 12, 1989. The DEFAS cot.sists of sensors, signal conditioning, trip recognition, coincidence logic, initiation logic, and other circuitry and equipment needed te conitor plant conditions and initicte emergency feedwater actuatier. during conditions indicative of an ATWS. The purpose of the DEFAS is to mitigate ATWS

I The LEFAS initittion signals cause actuation of the auxiliary / emergency

[ feeowater pumps and valves only if there is a demand for auxiliary /er.iergency i feedvater actuation system (EFAS) si by the plant protection system (PPS)gnal.

and this signal The occurrence has not of the EFAS been generated actuation signal by the PPS concurrent with the absence of an enable from the diverse scram system (DSS),, indicates that an ATWS condition does not exist and that emergency feedwater actuation by the DEFAS is not necessary. Under these conditions, the DEFAS actuation will be blocked through logic in the auxiliary relay cabinet.

The staff's understanding of the functional requirements for the DEFAS is that:

- DEFAS must initiate emergency feedwater flow for conditions indicative of an A1WS where the EFAS has failed.

- The DEFAS will not be required to provide mitigation of an accident such as isolating feedwater flow to a rupturea steam generator.

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DEFAS will stop feedwater flow to the affected steam generator after reaching a pre-determined level setpoint at about 30 minutes after actuation; .thereafter, manual operator intervention will control the system.

DEFAS will utilize logic and redundancy to achieve a 2-out-of-2 initiation, as a minimum.

DEFAS will utilize steam generator water level as the parameter indicative of the need for EFAS actuation.

DEFAS will interface with the actuated components via the existing auxiliary relay cabinet (ARC) relays. These relays are not used in' the reactor trip system.

DEFAS will be blocked by the EFAS to prevent control / safety interactions and to disable DEFAS when the EFAS actuates.

DEFAS will be blocked by the main steam isolation system (MSIS) signal to prevent control / safety interactions and to disable the DEFAS when conditions for MSIS exist.

DEFAS will be enabled by a signal from the DSS indicating DSS actuation.

DEFAS will include capabilities to allow testing at power.

DEFAS will include features that provide alarms, plant computer data 7 and other operator interfaces to indicate system status and meet

[ operability requirements.

t DEFAS setpoints will be coordinated with the existing PPS setpoints so that a competing condition between the PPS and DEFAS will be prevented.

I DEFAS will be interfaced with existing sensors and output devices by a j fiber optic (F.0.) technique which has been approved by the NRC for .

nuclear plant safety related system application. The DEFAS is fiber optically isolated via qualified devices and physically and electrically )

separated from the existing PPS. It does not degrade the existing j separation criteria of the PPS.

DEFAS logic will use two microprocessor based programmable itgic controllers (PLC). Each licensee will perform software verification andvalidation(V&Y). The record of the V8V process will be available for staff audit during the post-implementation inspection.

DEFAS equipment will be qualified for anticipated operational occurrences.

DEFAS will be des'igned under the suitable Quality Assurance procedures 1 consistent with the requirements and clarification of 10 CFR 50.62 l contained in Generic Letter 85-06.

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John N. Hannon i . j DEFAS logic power will be separate and independent from the existing FPS power. Each DETAS logic power supply is capable of providing 120 YAC uninterruptable power for up to one hour following the loss of its power bus.

DEFAS will use a single-board computer with solid state I/O modules as contrasted with the PPS which uses analog bistable trip units.

Therefore, the DEFAS logic is diverse from the PPS.

Based on the review of information docketed on April 30, 1989 and the meeting presentations on May 1 and July 12,1989, the staff comunented that the proposed CEOG oesign for a diverse emergency feedwater actuation system is in general agreement with the ATWS rule and guidance published in Federal Register Vol.

49, No. 124, dated June 26, 1984. However, since there may be differences in hardware equipment between the' various' plants ' staff acceptance of the DEFAS portion of the ATWS implementation for the afliected plants can only be made after receipt of the plant specific designs.

During the meeting, the following technical issues were discussed; the staff positions were stated for each issue.

(1) The interlock from the DSS allows the DEFAS to initiate feedwater flow only if a DSS actuation has occurred.

The staff expressed its concern whether the timing of the DSS actuation is sufficient to allow the actuation of emergency feedwater to perform its mitigation function. The CEOG provided an analysis demonstrating the

effect of DEFAS timing on peak pressure. The typical difference in time i

' between the reactor system pressure reaching the RTS setpoint and reaching the DSS setpoint is about 8 seconds. The tisiing of DEFAS actuation has a i negligible effect on the peak reactor vessel pressure for the limiting i ATWS event. Accordingly, the staff commented that the design basis of the DSS for interlocking the DEFAS initiation would be appropriate.

I (2) Power sources common for final actuation oevice between the existing RTS and the DEFAS.

It is the staff's understanding that the DEFAS cabinet circuitry uses independent power sources which are backed up by batteries for up to one hour. The DEFAS inputs to the auxiliary relay cabinet are through qualified isolators. A fault at the DEFAS cabinet will not propagate to the auxiliary relay cabinets. The staff commented that this is consistent with the intent of the ATWS rule. However, because some components located in the auxiliary relay cabinets will be shared for both EFAS and DEFAS and hence share RPS power, it is the staff's position that each individual licensee should provide an analysis to demonstrate that power supply faults (e.g., overvoltage and undervoll.ge conditions, degraded frequencies, and overcurrent) will not compromise the RTS, the EFAS or the DEFAS equips.ent. This analysis should include consideration of alarms for early detection of degraded voltage and frequency conditions to allow for operator corrective action while the affected circuits / components are still capable of performing their intended

functions. This will be reviewed on a plant specific basis.

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(3) Operator actions -

The DEFAS will secure feeding the affected steam generator after reaching a pre-determined level setpoint (about 30 minutes after actuation);

thereafter, manual operator intervention will control the system. The staff comented that an operator action after 30 minutes from automatic actuation is consistent with staff policy.

(4) Separation from existing system ency The DEFAS feedwater finalThe system. actuation devices ATWS rule arestates guidance common toimp that the existing emerp'ementation must be such that separation criteria applied to the existing protection system are not violated. .The DEFAS.will,use qualified F.0. 1solators for interfacing with the existing EFAS. The separation criteria applied to.

the existing protection system will not be violated. The staff comented that this is consistent with the intent of the ATWS rule. '

(5) Assumption on control system failure impact to the accident analysis.

The CEOG presented justification to show that the DEFAS design will have ,

minimel impact on the accident analysis. With the DSS. ESAS, anc MSIS i interlocks, the Owners Group indicated that a single failure would not cause the DEFAS to erroneously actuate such that it could adversely impact FSAR Chapter 6 ar.d 15 event analysis. The staff acknowledged that the Standard Review plan required a consideration of the effects of control i system action and inaction when assessing the transient response of the l plant. The staff agreed that the conceptual design proposed by the CEOG i acequately minimized the potential for improper actuation of the DEFAS during non-ATWS accident conditions. , ,

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In the course of the meeting, the CEOG asked the staff to consider reviewing

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[F a set of assumptions which would be used in performing plant specific 10 CFR 50.59 analyses of modifications to be made when installing the ATWS )

4 hardware. The staff responded that preparation of an analysis xirsuant to a i 10 CFR 50.59 licensee review was the sole responsibility of eact licensee and that the staff would neither do a prior review nor consider approving any such analysis. However, the staff stated that it would review the pertinent aspects of a design and analysis submitted in compliance with 10 CFR 50.62 (the ATWS rule). In this regard, the staff indicated that its coseents, as documented i above, on the infomation submitted at the meeting on May 1,1989, and at this meeting, reflects its view that the proposed DEFAS design is in general agreement with the intent of the ATWS rule. The staff also ee.phasized that the four Itcensees should proceed with all aspects of the plant specific designs and analyses.

With regard to implementation of the DEFAS portion of the ATWS design, the staff stated its position that the licensees in attendance should proceed in an expedited manner to design, procure and install the hardware for the DEFAS. While the staff will review each of the CEOG plant specific ATWS k

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John N. Hannon I designs and issue an SER for each submittal, the staff also stited that design, procurement and implementation by the licensees of the DEFAS portion of ATWS should not be delayed pending issuance of these SERs. The staff noted that 10 CFR 50.62(d) required each licensee to " develop and submit a proposed schedule (forimplementation)...Eachshallincludeanexplanationofthe schedule along with a justification if the schedule calls for final implementation later than the second refueling outage after July 26,1984..."

As done in prior reviews of other ATWS submittals, the staff again stated its position that delays attributable to disagreements over minor technical points is not sufficient basis for a schedular exemption request pursuant to 10 CFR 50.62(d). This position derives from the staff's comments on the CEOG's ATWS discussions on May 1 and July 12,1989, as documented above, thereby clarifying the major technical issues. In this regard, the staff promised a relatively quick review of plant specific'ATWS submittals in recognition of the differences in plant hardware between each of the affected CE plants.

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M. David Lynch, Senior Project Engineer Project Directorate III-3 Division of Reactor Projects - III, IV, Y and Special Projects 6

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ENCLOSURE 1 LIST OF ATTENDEES i JULY 12, 1989 i

NRC LP&L M. D. Lynch D. W. Gamble D. Wigginton R. W. Prados T. Carnes M.'Meisner V. Thomas

! J. Mauck-A. Thadant H. L1 i S. Newberry SCE i.

C. Poslusty I. Katter.

W. Hodges L. Tran- D. Mercurio J. Werriel J. Redmon-D. Hickman C. Diamond J. Hannon A.Nolan(EG8G)

,. ACRS CE E

I M. Ryan S. Lcng Im J. Kapinos F NUS AP&L M. Cheok M. W. Tull R. A. Barnes APS K. L. McCandless Clark i

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PRESENTATION ON THE RESPONSE TO THE NRC REQUEST FOR ADDITIONAL INFORMATION .

ON CE NPSD-384 DESIGN FOR.A DIVERSE EMERGENCY FEEDWATER ACTUATION SYSTEM CONSISTENT WITH 10CFR50.62 GUIDELINES l

ARIZONA PUBLIC SERVICE COMPANY  ;

ARKANSAS POWER AND LIGNT COMPANY i LOUISIANA POWER AND LIGNT COMPANY 4

[ SOUTHERN CALIFORNIA EDISON COMPANY r

i JULY 12, 1989 <

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. . i PRESENTATION OUTLINE s 1

0 STATEMENTOFINFORMATIONREQUESf 0 RESPONSE TO QUESTION 0 DISCUSSION O REQUESTED NRC POSITIONS k

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e m QUESTION 1 PROVIDE AN ANALYSIS FOR AN AWS TO ILLUSTRATE THAT THE TIMING OF THE DSS ACTUATION IS SUFFI-CIENT TO ALLOW THE ACTUATION OF EMERGENCY FEEDWATER FOR MITIGATION 9

RESPONSE

Y CENPD-158, REVISION 1 CONCLUDES THAT AUX. FEED.

DELIVERY HAS NO IMPACT ON THE LIMITING EVENT OR THE PEAK RCS PRESSURE CENPD-263 CONCLUDES THAT THE TIMING 0F AUX.

FEED. DELIVERY HAS A SMALL IMPACT ON THE

LIMITING AWS EVENT I

I SUBSEQUENT ANALYSES PERFORMED TO DETERMINE THE k

SENSITIVITY OF DEFAS TIMING ON PEAK PRESSURE SHOWS NEGLIGIBLE EFFECT ON PEAK PRESSURE FOR LIMITING ATWS EVENT 3

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SEQUENCE OF EVENTS LOFW ATWS WITH DSS BUT NO TRIP 3410 MWT CLASS TIME (SEC) EYEHI 0.0 LOSS OF ALL NORMAL FEEDWATER 37.6 LOW SG LEVEL AUXILIARY FEEDWATER j

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~ ACTUATION SIGNAL '

62.0 DSS SETPOINT REACHED  !

86.6 MAXIMUM RCS PRESSURE l 90.3 AUX. FEED. DELIVERED FOR SONGS 2

&3 91.6 AUX. FEED DELIVERED FOR WSES-3 j 114.7 DEFAS INITIATED FLOW DELIVERED j SONGS 2&3 116.0 DEFAS INITIATED FLOW DELIVERED FOR WSES-3 116.6 AUX. FEED DELIVERED FOR WSES-3 135.0 AUX. FEED. DELIVERED FOR ANO-2 159.4 DEFAS INITIATED FLOW DELIVERED FOR ANO-2 i .

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SEQUENCE OF EVENTS LOFW ATWS WITH DSS BUT NO TRIP i 3800 l#r CLASS j TIME (SEC) EVENT 0.0 LOSS OF ALL NORMAL FEEDWATER ,

1 22.8 LOW SG LEVEL AUXILIARY FEEDWATER {

ACTUATION SIGNAL

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32.0 DSS SETPOINT REACHED i

68.8 AUX. FEED DELIVERED 75.t DEFAs 82.0 MAXIMUM RCS PRESSURE r

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AUXILIARY FEEDWATER TIMING SENSITIVITY ASSUMED PLANT CLASS LLSG SIG. AFW DELIVERY PEAK PRESSURE (SEC) (SEC) (PSIA) 3410 MWT 38 58* 4250 3410 MWr 38 ** 4290 e

i 3800 MWr 23 33* 3800 3800 MWr 23 ** 3820 i

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  • NOT ACHIEVABLE. FOR DEMONSTRATION PURPOSES ONLY.

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' a QUESTION 2 , l PROVIDE A DISCUSSION OF SGLL AS AN ALTERNATIVE l TO THE DSS INTERLOCK I

l REAL ISSUE WILL EARLIER AUX. FEED ACTUATION MITIGATE AN ATWS EVENT FOR LATER TIMES IN THE CYCLE

RESPONSE

FOR LIMITING ATWS SCENARIO, AUX. FEED TIMING HAS LITTLE IMPACT ON PEAK PRESSURE l

FOR THE 3410 MWr CLASS THERE IS NO TIME IN THE CYCLE WHICH YIELDS ATWS PEAK PRESSURES BELOW

! LEVEL C STRESS LIMITS (CENPD-263)

FOR THE 3800 Mktr CLASS THERE MAY BE A SMALL

[ IMPACT ON PEAK PRESSURE FOR LATER TIMES IN CORE CYCLE, I.E., BELOW LEVEL C STRESS LIMITS (CENPD-263) r 7 i

4 3410 Wr PLANT CLASS LOFW Ahl5 PEAK PRESSURE VERSUS HDDERATOR TEMPERATURE 5000 .

4500 -

MTC 9 50% CYCLE LIFE

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'  % RCS PRESSURE

@M PZR PRESSURE -

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$ FLANGE LEAKAGE g) 3500 -

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  • L EL C S R ESS LMIT 3000 1 .

1 2500 '

[k 0 -1. 0 -2.0

, -3.0 H0DERATOR TEMPERATURE COEFFICIENT,10-4 DRH0/F l

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LOFW ATWS PEAK PRESSURE VERSUS HODERATOR TEMPERATURE C0 EFFICIENT 5000 , , , , ,, ,

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C STRESS L .

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-3.0 HODERATOR TEMPERATURE COEFFICIENT, 10-4 DRH0/F l

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. . 1 QUESTION 3 TESTING CAPABILITIES

RESPONSE

l TEST PROCEDURES WILL BE DETERMINED ONCE THE FINAL DESIGN IS ESTABLISHED ON A PLANT. SPECIFIC ,

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QUESTION 4 _

V&V PROGRAM FOR PROGRAINABLE LOGIC CONTROLLERS l l

RESPONSE

WSES DESIGN DOES NOT USE PLCs

-V&V PROGRAM WILL BE ESTABLISHED ON A PLANT SPECIFIC BASIS AT AN APPROPRIATE LEVEL FOR NON-SAFETY SYSTEMS l

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'. . QUESTION 5 .

CURRENT PLANS AND PROCEDURES FOR AMSAC (DEFAS)

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RESPONSE <

PLANS UNDER CONSIDERATION:

0 IF FEASIBLE, REPAIR AT POWER ON A SCHEDULE ~

. CONSISTENT WITH SAFETY SIGNIFICANCE

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0 IF NOT FEASIBLE, REPAI'R AND PLACE IN SERVICE UPON ENTERING MODE 1 AFTER NEXT REFUELING OUTAGE 0 .IF NOT REPAIRABLE DURING THE OUTAGE, DETERMINE LONG-TERM CORRECTIVE ACTIONS t

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ASSUMPTIONS REGARDING CONTROL SYSTEM FAILURES AND IMPACT ON 10CFR50.59 NEGATIVE FINDING FOR INSTALLATION

RESPONSE

IMPACT ON CHAPTER 15 EVENTS ,

O C0l+10N MODE FAILURE POSTULATED BY ATWS RULE NOT ASSUMED 0 A SINGLE FAILURE WILL NOT CAUSE THE DEFAS TO ADVERSELY IMPACT CHAPTER 6 AND 15 EVENTS j

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REQUEST FOR NRC POSITIONS 0 CE NPSD-384, SECTION 5 CONCERNS:

APPLICATION OF 10CFR50.59 VERSUS SRP SECTION 7.7 POWER SOURCES C0FNOM FOR FINAL ACTUATION DEVICE BETWEEN EXISTING RTS AND DEFAS SEPARATION FROM EXISTING SYSTEM -

DEFAS FINAL ACTUATION DEVICE IS C0bHON TO EXISTING AUX. FEED SYSTEM OPERATOR ACTION REQUIRED AFTER DEFAS HIGH SG LEVEL SETPOINT REACHED i

e O DOCUMENTED NRC POSITIONS TO FACILITATE I DESIGN AND IMPLEMENTATION '

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