ML20070P591

Responds to NRC Questions on Design Rept for Station Blackout/Electrical Upgrade Project Submitted Via 901127 ltr.Marked-up Pages from Rept Re Diesel Generator Room Ventilation Sys & Diesel Engine Auxiliary Sys Encl

ML20070P591
Person / Time
Site:	Prairie Island
Issue date:	03/20/1991
From:	Parker T NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-68588, TAC-68589, NUDOCS 9103270355
Download: ML20070P591 (10)

Text

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. 1 Northom States Power Company 414 Nicohet Mall Minneapoks, Minnesota 65401 1927 Telephone (617) 330 6500 March 20, 1991 10 CFR 50.63(c)(d)

U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50 282 License Nos. DPR 42 50 306 DPR 60 Reply to Questions on Design Report for the Station Blacknut/ Electrical Safeguards Up. grade Project (TAC Nos. 6858n and 68589)

Reference:

Letter from Thomas M Parker to U S Nuclear Regulatory Commission dated November 27, 1990 titled " Design Report for the Station Blackout / Electrical Upgrade Project

On November 27, 1990 we submitted for NRC Staff review the design report for our project: 1) to add two additionni safeguards emergency diesel generators,

2) to upgrade the safeguards electrien1 distribution system, and 3) to upgrade

1. 121 Cooling Water Pump to become a swing safeguards pump. Through phone discussions with NRR Staff personnel, Mr Armando Masciantonio and Dr Saba Saba, we received several questions. These questions can be answered by revising the pertinent pages of t.he referenced design report. Attached to this letter are marked up pages of that report. The indicated changes will be incorporated into the next formal revision to the design report.

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Northem States Power Company Please contact us if you have any questions related to the responses to the questions, lNN)

Thomas M Parker Manager Nuc1 car Support Services c: Regional Administrator Region III, NRC Senior Resident Inspector, NRC NRR Project Manager, NRC J E Silberg

Attachment:

Marked up pages (pp. 22, 29, 34, 37, 39, 48, 53, and 100) of the Design Report for the Station Blackout / Electrical Upgrado Project t

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5. Combustion Air and Exhaust System

a.

• Intake Air Filter Safety Related ij

b.

• Exhaust Silencer Safety Related  !

c. Interconnecting Safety Related Piping

• Supplied under Diesel Generator Specification M-870.

3.2.2 Diesel Generator Room Ventilation System The diesel generator room normal mode ventilation fans and associated-ductwork and controls will be non-safety p- 1 related. Th.> egue(m i-+ i5 7. v. b . s b A w c- Ad .

All other components of the diesel generator j related3 *~b Safr eTroom . (/ //,4 F

-ventilation opewnok of gastem ct,ewill s e sbe gn e**+*4 safetyser, 3.2.3 Electrical Power Distribution. Instrumentation and Controls f

The electrical power distribution and controls system necessary for operation of safety related equipment _ is classified as safety related (Class 1E). Diesel '

generator power is required in the event of a loss of of fsite power, _ and is required to be available when a 0- r tv ias ceioa (st) =tu etoa tea 1 i= initi t a- ,

Instruments, controls, .and- associated- sensir.g lines having the function to ensure operation of _the diesel generator. units, the engine room ventilation,- or to '

maintain-integrity of Class lE circuits, will be designed safety related. Those that are required for alarming,

-indication and monitoring will-be non-safety related.

1

3. 2. 4_ Fuel Oil Storace and Transfer System The electrical power supply equipment, including pump controls,- instrumentation and cable / raceway will be safety _ related class lE for the equipment associatJd with the four storage tanks and four transfer pumps. Controls i and instrumentation associated with-1-level and:' leak detection of fuel oil for the purpose of indication, I monitoring and alarm will- be- designated as non-safety related.- ..

Power supply'. equipment, controls, instrumentation and circuits / raceway associated with the receiving tank and' recirculating pump will be designated as non-safety related.

t O 22 NSP*06'

, Rev. A /

A 3-way thermostatic valve regulates flow through the oil cooler based on outlet temperature. Any excess oil from the discharge valve and cylinder block internal bearings ,

are returned to the oil cump.

The lube oil system will be provided with a pre-lube system to maintain constant flow of lubricating oil to ,

critical areas during standby mode to minimize wear during engine starts. To enhance quick engine starts, the pre-lube system maintains lube oil in the " keep warm" temperature through the lube oil standby heat exchanger, heated by the koopwarm portion of the HT cooling water system. The pre-lube system design will include provision for draining lube oil from the engine crankcase. An AC motor-driven pump will be used normally for pre-lube system operation with a DC motor-driven pump for backup operation. Both pumps and the standby heat exchanger will be located in the auxiliarios desh.

A sufficient quantity of lube oil to permit 7 days of continuous operation at rated load will be maintained on site'for e Ldiesel generator. The stored in drums cr a lube oil storage tank. lube oil will be l I?cv /

l oe/de 4f ese own The lube oil storage tank provided for each diesel generator will be located at an elevation to permit filling of each engine crankcase by means of gravity flow, which will be controlled by a manually-operated fill valve.

3.3.4.2 Diesel Lube Oil System Installation Installation requirements for the lube oil system will include providing interconnecting piping for the following equipants

a. From the lubo oil storage tank to the manually-operated fill valvo.

b. Reservoir fill line (funnel) to the luLe oil reservoir.

c. From the engine prolubrication outlet to the auxiliarios desk.

d. From the auxiliarios desk outlet to engine prelubrication inlet connection.

Miscellaneous piping will be required by the diesel engine. This includes providing crankcase relief valve l

discharge piping to be routed to the building sump.

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Rev. 4 The intake and oxhaust louver frames and blades will be steel, and will be tornado missile proof. The intake and exhaust openings will be located at an elevation higher than the maximum probable flood level.

All components of each ventilation t stem will be protected from tornado generated missiles. ,

1 The diesel generator room vent fans will be vane axial-type with direct-drive totally-enclosed-air-over (TEAO) motors.

Fan-developed pressures will be based on the pressur'e ,

drop through ductwork, concrete plenuma and distribution accessories.

All equipment will be f actory inspected and tested in accordance with the applicable equipment specification.

Erection and inspection of equipment will be in

accordance with the design drawings and manufacturer's recommendation.

System testing and balancing will be performed and j evaluated prior to system turnover. Controls on each system will be checked, adjusted and tested to ensure the proper sequence of operations. A final, integrated preoperational test will be conducted with all equipment and controls in operation to verify operation.

])icinulesec 55.6.5 1

ram ~i Aua,/iaag Matat4+-1s 3.3.7 P -Recu+rementa-and /2ev l All interconnecting piping unless otherwise noted herein, 4

will be A!ISI 150 lb pressure class. All miscellaneous piping such as for drain and vent will be rated for 150 lbs. or greater.

All piping joints ar.d connectionc will be we' %d. Where required, such as at pump suction, discharge cunections, and flexible connections, flanges will be acceptable.

All piping material will be carbon steel except the following systems:

Material

a. Starting Air System Stainless Steel j 304 or 304L

b. Combustion Air and Galvanized Carbon Steel

c. Exhaust System Carbon Moly Alloy Steal l

Nsp.06 }$ &

k Rev. DI e

d. Interconnecting ASME Section III Piping (except Manu- (1986), Class 3**

facturer's Standard Piping Sections) ,l' 1

e. Vent & Drain Linen AliSI B31.1-1967 l (for air receiver, ,

beyond First Isolation Valve)

4. Lube Oil System .

a. Lube Oil Storage API-650-1984

~

Tank

b.

• Lube Oil Cooler Manufacturer Std.

c. AC Motor Driven Transfer Pump AliSI BSl.1-1967

d. Tank Vent &

Drain Lines AllSI B31.1-1967 (beyond First Isolation Valve)

e. Engine / Aux. Desk ASME Section III  !

Interconnecting (1986), Class 3** l Piping

f. Lube Oil Storage AliSI B31.1-1967 -

Ttnk Fill Line l

5. Combustion Air and Exhaust System

a.

• Intake Air Filter Manufacturer Std. l

b.

• Exhaust Silencer Manufacturer Std.  !

c. Pipino --- -

1 fl. Exhaust AM&B M (1986),

fabricated per SA 691 Class i G M. Stress annlyzed per ASME Section III Class 3 components using ANSI B31.1 (1986) stress allowables, kN I AM G kc.R Ccass 3

2. Intake AJ " ' - "'

1 (1986), j fabricated per SA 134 .

Stress analyzed- per ASME Section III Class 3 components using B31.1 3

(1986) stress allowable i Asm G Sf M %

• Supplied under Diesel Generator Specification M ,

• • With exceptions as listed in Section 3.3.8.1.

NSP D6 37

. _ - - .,_ __ _ _ .m.-.__. _ _ . . _ _ _ _ _ _ _ _ _ _ . _ _ - - _ _ _ _

i i s

I o The auxiliary desk (one for each engine), located near the diesel generator unit, will include gauges to indicate engine temperatures and pressures. .

The bench board control panel, located in the diesel generator control room, will include instruments and  !

controls for the diesel generator and auxiliaries plus -

the fuel oil transfer pumps, engine room ventilation, and control room ventilation fans.

- A vertical panel, located in the diesel generator control room, will be provided to include additional instruments and controls for the diesel generator and auxiliaries.

• A generator exciter panel, located in- the diesel generator _ control room, will include excitation, voltage regulation, and field flashing equipment, and current and voltage transformers for protective relays and power measuring instruments.

3.3.10.2 Trips and. Interlocks l

All protective trips other than engine overspeed and generator differential overcurrent will be bypassed upon '

receipt of an automatic emergency start signal in response to a safety injection signal and will be aaauaciated in th- ==in coatrot roo=- "o Prot ctiv-O trips will be bypassed upon receipt of an automatic bus undervoltage start signal.

Protective trips will be provided to automatically. shut down the diesel engine and/or trip the diesel generator breaker, and protect the diesel generator units from possible damage or degradation during routine testing.

Protective trips Awill be in accordance with vendor recommendations and will consist of, but not be limited to the following: -

Ao Logu 44 eAcH e rac

^

o Overspeed '/2 Engine Lube Oil Low-Low Pressure VJ o

o Jacket Water High-High Temperature %

o Jacket Water Los Pressure W o Crankcase High Pressure </i o Lube Oil Sump Low Lev d m fe High Temperature Y' fI.2-o Generator _ Bearing o Engine Bearing High-H gh Lube 011 Temperature %

o Reverse Power 'h

-o Generator Differential current '//

o Generator Phase overcurrent </, s o Generator Overvoltage e/f o- Loss of Excitation </,

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NSPa06 39 l

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

l l .

Rev. D' f i

Fill inlet connection and vent outlet connection will be protected from flood conditions and will bo positioned above the maximum probable flood level. ,

3.4.2,2 Underground Storage Vault The emergency storage tanks will be installed it. a ,

Seismic Category I reinforced concreto vault enclosure located below seismic grade lovel and adjacent to the west wall of DS/D6 Diccol Generator Building. The vault will provide the required 3-hour rateci firo protection barrier, including D5/D6 west wall penetrations, for enclosed fuel supply tanks, and in addition, will withstand the effects of tornado generated missiles, site flood, and buoyancy force considerations. The vault will be a vital area.

The vault will be divided into two compartments by a concrete partition wall to separate each pair of tanks serving a single diesel generator cet and provide fire and flood protection between each diesel generator sets fuel supply equipment.

The vault will be sized to provido a minimum clearance of 15 inches from all tank surfaces, as well as allowing convenient accessibility to the tanks for inspection and repair. Leakproof hatches will be provided on top of the vault for tank internal and external inspection access and to allow removal of tank internal strainers and baffles and other appurtenances. Level instrumentation will be bottom mounted.

The underground storago vault will be insulated suf ficiently to protect the fuel oil from reaching a minimum system operating temperature. The vault temperature will be indicated y an6 monitored by / ge y J operationc. y yte y ,4 ,aj a,% l The vault will be provided for containing leakage of the tank contents and any accumulated seepage wa r. The

, vault floor will slope to a sump, which will t 'tain a leak detector., Leak detection instruments wail be \

provided to alert presence of fuel or water in the sump. ,/

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w . cm/u n o eb A~b 4 5<~ rm %u ble n. oa,.. < a The detailed structural design requirements for the concreto vault structure will be as specified in Section 4.0 The vault's walls and bottom will be provided with a waterproof membrane. All hatches and penetrations on the top slab will be leak-tight, use.cs j'l 48 \

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3.4.2.6.2 Design and Fabrication Codes i )

Desian & Fabrication Code .

1. Tanks j

_ a. Emergency Storage Tanku ASME,Section III (1986), Class 3** ,

j b. Receiving Tank API 650-1984 1 -

2. Pumps

a. Transfer Pumps Viking Pump -

Manufacturer's Std.

b. Recirculating Pump Viking Pump Manufacturer's 5td t

3. Piping, Pipe Support Components and Valves

a. Fuel 011 Transfer Piping ASME Section III System (except vent and (1986), Class 3**

drain lines)

b. Receiving Tank Piping & ANSI B31.1-1967 Recirculating Piping Q

System

c. Storage Tank Vent ASME Section III i (1986), Class 3**

Drain Lines

d. ANSI B31.1-1967 o

after First Isolation >

Valve

~** With cxceptions as listed in Section 3.4.2.6.1.

! 3.5 DESIGN STANDARDS In addition to the codes and standards listed in the ,

design-requirements givenNUREG above 0800, in SectionA 2.4.2.6.IEEE standards, (gg pnd-g 2.'.0 7 the following and I regulatory guides are adopted in whole as design criteria requirements for the DS and 06 Diesel Gen 0rator and-Auxiliary Systems as described in Section 3.0.

Within the existing plant- boundary the existing design

! criteria as defined- in the USAR will apply except u noted otherwise in this document.

O W1P*D6 53 w...._......_,._..a__,....-_..___._._,___--___._____._____-___________

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l

. .. l 6

l Rev. 6 5.3.6 Emeraency Resoonse Comnuter System 1

T.5e Emergency Response Computer System (ERCS) will serve .'

as an aid to the control room operator in monitoring the status of the DS and D6 diesel generators. It may replicate some functions of the engine monitoring system, local control panels or the hard-wired control room -

instrumentation. Instead, it will only monittr specific inputs and provide data to fulfill a specific need for the operator. Areas identified to date include o Annunciator system support to identify, on demand, a spezific input that generated a group alarm.

o operations data logging of turveillance testing events.

o Provide analog process information of parameters occasionally required.

523.7 D5/D6 Control Scheme Tie-In with Existina Plant Whenithe local Generator Control Mode switches, located in the D5 and D6 Control Rooms, are in the remote position, control of the D5 and D6 cmergency diesel '

generators is transferred to the Main Control Room.

Emergency start, manual start and stop, voltage adjust, speed control, main breaker control and synchronizing are among the controls that will be available in the Main control Room.

Tho design of the control circuitry between the DS and D6 Control Rooms and the Main Control Room will include the intermediate termination of all control cables at terminal cabinets located in the Relay Room and then circuit continuation to the Main Control Room.

The DS and D6 tie-in to the existing plant will also include all appropriate alarm circuits to the annunciator cabinets.

5.1.8 Main control Room "G" Panel Modification The existing controls for the safeguards diesel generators and 'their associated 4160V buses located-on the Main Control Room "G" Panel will he replaced and additional controls for the new diesel generators will be installed. The existing panel will be replaced and smaller controls wi? I be installe/ to accommodate the additional controls in the origir- sace. o Annunciator Revi alarms for the new diesel gene installed concurrently with the "GtLpanel,r;M--d work. be

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