ML20033H138

Suppls Licensee 890417 Response to Station Blackout Requirements.Rigorous Maint,Operating,Testing Programs Exist within Maint & Operations Organizations to Maintain Emergency Diesel Generator Reliability Value of 0.95

ML20033H138
Person / Time
Site:	McGuire, Mcguire
Issue date:	04/04/1990
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9004180273
Download: ML20033H138 (8)

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Duke Mrr Company?

IIAt 11 hkir Tice Presidint 1

? PG Bar 33198..

^ NuclearPn> duction Charlotte, NC 28242 I

. (704)373 4531:

lDUKEPOWER :

April 4, 1990

.U..S." Nuclear Regula' tory Commission Attentions-Document Control Desk Washington, D. C.g20555

Subject:

. - McGuire Nuclear. Station, Units if and 2 Docket Nos. 50-369 and 50-370 10 CFR 50.63; Requirements for Station Blackout (SBO)~

Gentlemen:

On January.4, 1990 NUMARC issued a letter to all utilities requesting-Based on the'NUMARC-letter, Duke Power Company has performed a review of

^l that supplemental information be provided.to the NRC concerning'SBO.-

its-previous SB0 response to the NRC as well as the supporting-documentation to verify that:

1. - Implementation is consistent with the supplemental' guidance provided j

by the attachments'.to the-January 4,'1990 NUMARC-letter,

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2.

Applicability of NUMARC 87-00-assumptions is documented.in utility.

L files, and 3.

Departures from the accepted NUMARC 87-00 methodohgy are identifi 8 Attached is an updated version'of my April 17, 1989, submittal which provides additional dotails concerning McGuire's SB0' capabilities.' This submittal is based on the NUMARC 87-00 guidance including the-

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clarifications transmitted by the NUMARCiletter' dated January 4, 1990.

Deviations from the.NUMARC 87-00 guidance are specifically noted.

With. regard to Emergency Diesel. Generator target reliability. rigorous

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maintenance, operating, and testing programa exists within'the: Maintenance.

and Operations organizations to maintain the-0.95 reliability'value.-

A program to track the Alternate AC (SSF D/G) reliability target value per Appendix B of NUMARC 87-00 will be-in place within 120 days.after the 1

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notification provided bysthe' Director, Office'of Nuclear Reactor-Regulation.in:accorda'ncefwith 10:CFR 50.63(c)(3).~ There-are no equipment:

. modifications required or-planned ~at'McGuire tofmeet this6 rule.

.Very truly.yours, w Arc,ff C

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'Hal:B.iTucker

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RGM/032790011

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Attachment!

Lcci Mr. S; D; Ebneteri RegionalLAdministrator..RegionEII~

U. S.;. Nuclear Regulatory-Commission-101 Marietta. Street, NW, Suite'29001 Atlanta, Georgia. 30323-Mr. D. H. Hood,cProject. Manager-lj Office of Nuclear Reactor. Regulation U.:S. Nuclear Regulatory Commission -

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-One= White Flint North-d Washington, D._C..-20555 j

i Mr. P. K'. Van Doorn

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NRC Resident' Inspector McGuire Nuclear Station:

Mr. B.-Lee, Jr.

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President-and-CEO Nuclear Management And Resources Council l

1776 Eye. Street, NW Suite 300:

Washington, D. C..

20006-2496' o!

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.McGuira Nuclser' Station'-

Attachment'lY S *.1_Upd tcd Reponn to' Station Bitekout PJgn l'ofL6:

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A.

Station Blackout' Duration =

1NUMARC 87-00,-Section 3 was!used to determine the SBO.; required coping.

5 duration category.. The results show-that McGuire'Unitsil and 2 are:in a

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'the.4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping. duration' category.

The following plant factors were identified in' determining the proposed

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station blackout duration.' -

l'. -AC Power Design Characteristic Group is P1 based on -

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a.

_ Expected frequency'of grid-related LOOPS.does-not exceed once' 1

per 20 years (Section 3.2'.1,!Part 1A, p.:3-3);:

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Estimated frequency of LOOPS dtie to extremely; severe weather f

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places the plant.in ESW Group 1-(Section 3.2.'1, Part 1B, p..

j 3-4);.The estimated. frequency.is 1.08 x.10 -6 per. year.:

Note: Site specific meteorological data-was'used'in this:

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evaluation.

Estimated' frequency of LOOPS due 'to severe. weather. places'the c.

plant in SW Group 11(Section:3.2.1, Part 10, p. 3-7); The estimated frequency.is 0.00189 per-year.

Note: Site specific meteorological.' data was usedlin this evaluation.

d.

The.offsite power system is in the 11/2 Group..(Section:3.2.1,.

Part ID, p. 3-10).

- 2.

The emergency AC power-configuration. group is C based on:: 1(Section 4

3.2.2, Part 2C, p. 3-13)1 a.

There are 2 emergency'AC power supplies per unit not credited as

.i alternate AC power sources (Section 3.2;2,JPart.2A,L p. 3-15);

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1 emergency AC power supply is-necessary.per unit to operate

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safe shutdown' equipment following.a loss.of offsite power (Suction 3.2~.2, Part 2B,'p.13-15).

3. -The target EDG reliability is 0.95.

j A target EDG reliability of 0.95 was determined based on'having'a

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nuclear unit average EDG reliability for the last 100: demands greater than 0.95 consistent with NUMARC'87-00, Section 3.2.'4.

Actual unit averages'used in this determination were 0.985 for Unit 1 and 0.97 for Unit 2-(based on late 1988' data).

With regard to maintaining the 0.95 reliability target value,.a rigorous maintenance, operating, and. testing program exists within-the McGuire Maintenance and Operations organizations.

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'McGuira Nucin r Stction:

'Attrchment 1 i Updtted R=pon s to 'Stction.Blcekout-P gr 2 of.6-4 testing is done in accordance with Technical Specifications. 'A

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component; expert is established within the Maintenance Organization 2

-to; trend. engine performance including: oil' analysis. The Operations

organization is responsible for EDG. testing and for' maintaining a log pursuant _to Reg. Guide 1.108 of all starts:and their proper classification.

4.

An alternate AC (AAC) source is-provided at McGuire which meets:the'-

criteria'specified in NUMARC-87-00, Appendix B.~._ The_AAC' source is

'the Standby Shutdown Facility (SSF) diesel generator which-is the power source for the Standby Shutdown System (SSS).. The SSF' diesel C>

generator is availabic within 10 minutes from the recognition'of an SB0 event.. However, it cannot be started from.the McGuire main' Contro11 Room-which11s'an~ exception'to'the NUMARC 87-00 guidance.

The SSF diesel generator is manually started'from the.SSF Control Room. Testing has demonstrated the' ability of plant operators to=

start the SSF diesel.within 10 minutes from.the, recognition of the-SB0 event which. satisfies the intent:of the NUMARC guidance. The SSF diesel generator has sufficient capacity and capability to,

-operate equipment necessary to maintain a safe shutdown condition.

for the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> SB0 event.

4 The SSF'was originclly designed-to provide'an alternate means'of

. achieving and maintaining hot standby. conditions following a-postulated fire or sabotage event. -Loss'of all' normal and emergency; station power (AC and DC) is assumed:for the postulated. fire and sabotage events; therefore, the SSF diesel generator.and the:SSF are1 also designed-to handle the SBO event.

Specifically, the SSF has.

the capability of maintaining hot standby conditions for a period of-approximately-72 hours following a loss of. plant power.. This is

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well in excess of the SB0 required coping duration of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

The NRC has previously reviewed and approved the SSF design as noted I'

in the McGuire SER Supplement 6 dated February 1983.

B.

Procedure' Description Plant procedures have been reviewed and modified, as necessary, to meet the guidelines in NUMARC 87-00, Section 4 in the following areas. The following procedures have been reviewed:

Station Blackout Response Guidelines Emergency-Procedure for Loss of All AC Power - EP/1(2)/A/5000/09 Standby Shutdown Facility Operations - OP/0/A/6100/17 AC Power Restoration Emergency Procedure for Loss of All AC Power - EP/1(2)/A/5000/09 Emergency Procedures for Capacity Shortage m.-----...

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' LMcGuirs Nucle:r Sth. tion-Attcchinentil-q 4 UpdttidrResponsa to1 Station B1tekoutf

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Severe Weather Cuidelines

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1 Procedure for N'atural Disaster-and Earthquake - RP/0/A/5700/06 Procedure for! Earthquake.- RP/0/A/5700/07

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C. - Proposed Modifications and Schedules-

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g 1There are no plant modifications required to use the SSF diesel

generator as the-. AAC power source.- 'lhere are no procedure revisions necessary-to utilize the'AAC Power Source.-

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'D.

Coping With a Station Blackout McGuire is a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping duration category plant-with 10 minute'--

alternate AC capability. The AAC source.(i.e Lthe'SSF diesel generator) has the capacity and' capability toLpower equipment necessary; 1*

to achieve and maintain hot standby conditions for the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. required' coping duration. This capability.is independent of any, normal org emergency plantipower system (AC'or DC) and fully bounds any postulated'-

SB0 scenario up to-and including evacuation 'of -the main control room; -

A more probable SB0 scenario would utilize a combination of-. normal plant l

. systems and certain SSF capability to achieve'and-maintain hot standby'.

j conditions from the main control room.. Therefore,(all'of the NUMARC.

87-00 coping aspects are, discussed in the following. paragraphs.'-

1.

Condensate Inventory.for Decay Heat Removal-It has been determined from Section=7.2.'1 of NUMARC 87-00;that 75,452 gallons of water are required?for-decay heat removal.for the-i j'

four hour. required coping duration.

Plant Systems During an SBO event at-McGuire the turbine-driven auxiliary feedwater pumps would be aligned _to the'following: normal sources of condensato grade water:

1.

Auxiliary feedwater condensate storage tank - 45,000 gals.-

-(This tank is shared between Units)

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Upper Surge Tanks - 85,000 gals.

3.'. Condenser Hotwell - 170,000 gals.

Therefore, ther'e is sufficient condensate inventory available for y

the four hour required coping duration.: No plant modifications or i

procedure changes are necessary to use these water sources.

s SSF Feature In addition to the normal condensato sources noted above, the-SSF I

also has the ability to align to the Condenser Circulating Water 4

System (RC) which has the capability to maintain hot standby conditions for approximately 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. No plant modifications or' procedure changes are necessary to use-these water sources.-

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McGuira Nucic:r Stdtion ~

Attichment'l-l

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2.

Class 1E Battery Capacity-Plant System.

The vital'1 & C batteries power the 125-VDC and 120 VAC vital I-&lC a

power system,'Las; described in FSAR. Sectio'n 8.3.2.~1.4. 'This system

'in turn supplies power lto the Class"1E instruments andicontrols.that-l

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would be used to achieve'and maintain hot' standby. conditions:from the main Control Room following,an.SBO event.1 A plant specific

' battery capacity calculation'is-not required-because>the design of Lthe-vital battery systemLallows cross-tieing the blacked-out Unit'sf

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' batteries to the non-SBO. Unit battery charger.

SSF Feature The SSF is'also provided with'a 250/125 VDC power system.which-is separate from the-125 VDC and 120 VAC. vital I & C powet-system. The SSF DC power system batteries are charged by the AAC' source and are also available to power the SSF instruments and controls necessary-to achieve and maintain hot standby conditions from the SSF' Control.

t Room following an SB0 event..

3.

Compressed Air.

l No air operated valves are relied upon to maintain hot standby.

conditions from the SSF.

4.

Effects of Loss of Ventilation g.+

Plant System With regard to the main Control-Room complex, the assumption in NUMARC 87-00, Section 2.7.1 that the Control Room will not exceed 120"F has been assessed. The main Control Room will.not exceed 120" during an SB0 event; therefore, the main Control Room is not a dominant area of concern. The main Control Room is shared between

i units and is served by a shared. ventilation system (VC/YC). This ventilation system is capable of being powered from either unit;-

therefore, the Control Room temperature will be maintained at approximately 75'F-with a possible short. duration excursion above 75"F (but not exceeding 120*F) for the period required to realign VC/YC to an operable EDG (approximately 45 minutes).

1 The Train "A" Unit 1 and.2 essential switchgear rooms will not exceed 120*F during an SB0 event, therefore, the Train "A" switchgear rooms are not dominant areas of concern.

The Turbine Building is not a dominant area of concern as there would not be a significant change in the Turbine Building environment as a result of a SBO.

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'M JAttachmentili I

, i McGbiri Nucli i Station i

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• T ':Updnted Risponts to Station'Bigekoute

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-d y,m The outboard lDoghousesEare not~aidominant_ area:of c.oncern as thep b

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' are vented to the~outside environment and'are not provided with? '

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. forced! ventilation; -Therfore,:the'SB0 environment would not be j

different from.the normal operating l environment.s. The. inboard' Et iDoghouses,;however, are? dominant areas of: concern.and temperatures.

would be expected-to exceed 151*F.

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The turbine-driven auxiliary feedwater pump room:is a dominant area; q

-of. concern at~McGuire. Using a: plant specificicalculation, the j

steady state; ambient' air temperature in'this;areaiduring an SB0' d

cinduced-loss of ventilation is 143'F.

ag The following dominantiareas of) concern (DACs) were;identifiedL

.at McGuire (Note: Plant: specific calculations and' assumptions. were,

used to determine these.DAC. temperatures):.

DAC-Temperature.

-Containment' 201*F.

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Annulust

176*F-y,

' Auxiliary Feedwater Pump; Rooms

-143*F q

Mechanical Penetration Rooms 188'F-

_I Inboard Doghouses 151'F,

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-Reasonable assurance-of.the operability of SB0 response equipment'in

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the above dominant. areas of' concern has been addressed using NUMARC' l

87-00, Appendix F and/or~ the Topical Report..No;modificationsior i

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procedure changes are required to provide rdasonable~as'surance fo'r

-equipment operability.-

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4 SSF Feature The SSF'has its own ventilation. system whichsis. powered from the"AAC:

J source (SSF' diesel generator), therefore, thejSSF is.not a dominant.

area of concern. Areas other than the SSF that'contain SB0 response-.

~j equipment that is used in conjunction-with the SSF are addressedJ

.above.

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5.

Containment Isolation

-Plant System.

The plant list of containment isolation valves has been reviewed to j

verify that valves which must be. capable of being closed or that.

i must be operated under station blackout conditions can.be positioned j

(with indication) independent of the' preferred and blacked-out j

unit's Class 1E power supplies. No plant modifications and/or-asso.:iated-procedure changes were determined to be required to -~

ensure that appropriate containment integrity can be provided under

-SB0 conditions.

SSF Feature s

Same as above.

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>2:. - - McGuirs Nuc1*2tr Station;

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6 '. Reac' tor;Cholant-Inventory SSF' Feature Th'e AAC ' source,: powers the necessary'make-up system to maintain.

. adequate; reactor. coolant-systemiinventory to ensure that the' core'is; m

cooled'.for; the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> < required coping duration..

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.h standby makeup pumpipowered from thd.SSFidiesel generatordis3 located'in-the. annulus--of;each' unit toL. supply makeup to the Reactor.

tCoolant' System..1The pump.is: sized to accommodate normal.systemi fleak' age. 'ReactorJ. Coolant Pumpiscal leakage;:- and ' additional? flow: for;

, system' makeup.f.

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