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January 26, 1979

Mr. Robert W. ReidChief, Operations Reactors Branch #4Division of Operating ReactorsU.S. Nuclear Regulatory CommissionWashington, DC 20555

Subject: Crystal River Unit 3Docket No. 50-302Operating License No. DPR-72

Dear Mr. Reid:

On January 9,1979, Florida Power Corporation submitted responses and aschedule for responses to the NRC's letters of November 14, 1978,November 21, 1978 and December 20, 1978. As indicated in the letter,responses to nine (9) questions and concerns were scheduled forJanuary 19, 1979.

Enclosed you will find responses to the following:

Enclosure 2 - Questions 23, 30, 56, 68, 71, 73

Enclosure 3 - SRP 25

Enclosure 4 - SRP's 9, 20

Should you or members of your staff wish to discuss our responses to theseNRC concerns, please contact this office.

Very truly yours,

FLORI A POWER CORPORAT ON

QLD M*(W. P. Stewart

Enclosure

WPS/hewWO4

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7 9 0 2 0 2 0 J? 70 4

General Office 3201 Tnirty-fourtn street soutn . P O Box 14042, St. Petersburg, Fionda 33733 e 813-866-5151

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STATE OF FLORIDA

COUNTY OF PINELLAS

W.P. Stewart states that he is the Director, Power Production, of

Florida Power Corporation; that he is authorized on the part of

said company to sign and file with the Nuclear Regulatory

Commission the information attached hereto; and that all such

statements made and matters set forth therein are true and

corre ct to the best of his knowledge, information and belief.

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LOM 3 LLOovW.P. Stewa rt

Subscribed and sworn to before me, a Notary Public in and for the

State and County above named, this 26th day of January, 1979.

CM4 'Notary Pulflic

Notary Public, State of Florida at Large,My Commission Expires: July 25, 1980

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W. P. STEWAR T. DIR ECTORgf POWER PRODUCTIONconsonario,

January 26, 1979

Mr. Robert W. ReidChief, Operations Reactors Branch #4Division of Operating ReactorsU.S. Nuclear Regulatory CommissionWashington, DC 20555

Subject: Crystal River Unit 3

Docket No. 50-302Operating License No. DPR-72

Dear Mr. Reid:

On January 9,1979, Florida Power Corporation submitted responses and aschedule for responses to the NRC's letters of November 14, 1978,November 21, 1978 and December 20, 1978. As indicated in tha letter,responses to nine (9) questions and concerns were scheduled forJanuary 19, 1979.

Enclosed you will find responses to the following:

Enclosure 2 - Questions 23, 30, 56, 68, 71, 73

Enclosure 3 - SRP 25

Enclosure 4 - SRP's 9, 20

Should you or members of your staff wish to discuss our responses to theseNRC concerns, please contact this office.

Very truly yours,

FLORIDA POWER CORPORATIONH

hD0k.'. i

W. P. Stewart

Enclosure

WPS/hewWO4(D7)File: 3-0-3-a-3

General Office 3201 Thirty-foum. street soutn . P O. Box 14042, st. Petersburg, Flanda 33733 813 - 866-5151

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STATE OF FLORIDA

COUNTY OF PINELLAS

W.P. Stewart states that he is the Director, Power Production, of

Florida Power Corporation; that he is authorized on the part of

said company to sign and file with the Nuclear Regulatory

Commission the information attached hereto; and that all such

statements made and matters set forth therein are true and

correct to the best of his knowledge, information and belief.

e

f',rO ,p " QLj 'Cib!

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\-W.P. Stewart

_

Subscribed and sworn to before me, a Notary Public in and for the

State and County above named, this 26th day of January,1979.

-.

Notary g5sblic

Notary Public, State of Florida at Large,My Commission Expires: July 25, 1980

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Question 23 - Prevention of Fire and Smoke Spread

Describe the manner in which fire and smoke are prevented from spreadingfrom area to area via the normal and emergency ventilation systems in allparts of the plant areas. Describe the location, actuation method and fire

rating of dampers used for fire and smoke control in both air supply andreturn air systems. Describe the details of interlocks for ventilationsystem shutdown or mode change that can be utilized for ire and smokecontrol.

RESPONSE

The ventilation systems are described in the Florida Power Corporationsubmittal entitled Fire Protection Program Review, June 1977, pages 5-29through 5-36. As discussed therein, the ventilation systems for theauxiliary building and the intermediate building operate only in a oncethrough mode. Smoke removed from any area in those buildings by theventilation system will be exhausted to the outside, not spread within thebuilding. Air from the turbine building, which is also ventilated in theonce through mode , is exhausted to the outside via ventilators, louvers,and windows. The control complex ventilation system switches to a oncethrough mode upon detection of smoke in the ducts, or under manualcontrol. Rated fire dampers in ventilation ducts penetrating fire walls inthe control complex also assist in preventing the spread of smoke and firewithin the control complex.

Question 30 - Fire Suppression System Design

Provide the design data for all automatic suppression systems (bothexisting and proposed) including such items as design densities, soaktimes, power supplies and associated alarms. Identify areas ofnoncompliance with appropriate NFPA standards.

RESPONSE

The requested information is given for existing systems in section 5.3.3 ofthe Florida Power Corporation submittal entitled Fire Protection ProgramReview, June 1977, with the following additional information: designdensities are 0.25 gpm/sqf t for the deluge system for the transformers,turbine lube oil piping and reservoirs, hydrogen seal unit, and mainfeedwater pumps. Soak time for maintenance of a 5% halon concentration inthe cable spreading room for a 20 minute time period was demonstrated bypreoperational test. As of this date Florida Power Corporation has notcommitted to install any additional automatic suppression systems at CR 3.Should any automatic fire suppression system be required to resolve theoutstanding concerns expressed by your staf f, FPC will supply theinformation required by Question 30 at that time.

Question 56

When will the results of the planned cable fire tests be provided (Page5-9)?

RESPONSE

See attached report.

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Question 68Provide information on the plant breathing air supply, per the requirementsof Apper. dix A to BTP 9.5-1.

RESPONSE

5.3.5 Ventilation

There are separate ventilation systems for the Reactor Building, theAuxiliary Building, the Control Comples, the Intermediate Building, theTurbine Building, the Diesel Generator Building, and the Fire Service PumpHouse. These systems are discussed individually in the follcwing sections.

5.3.5.1 Reactor Building Ventilation System

The flow diagram of Reactor Building ventilation systems is ahown in Figure5-14. The ventilation systems (1) cool and recirculate air in the ReactorBuilding, and (2) provide capability of purging the building by exhaustingair from it to the outside through the plant vent and supplying outside airinto the building. The Reactor Building air is cooled and recirculated bythree fan-cooler units (two normally operating) which draw air from variouslocations in the building, discharging it into the large open space abovethe operating floor. Emergency cooling of the Reactor Building isperformed using the same equipment. Under post-accident emergencyconditions, the units will operate at reduced speed. The fan motors aretwo-speed , pipe-ve. tilated units with air-to-water heat exchangers. Theyare capable of operation under accident conditions of 281*F and 68.3 psia.Local area ventilation is provided for the operating floor by booster fanswhich supply air through supply ducts. Two booster fans (one normallyoperating) also supply air to the steam generator compartments. Cool airto the reactor cavity is supplied by one of two 100%-capacity fan-coolerunits. There are twelve exhaust fans to exhaust air from thecontrol-rod-drive shroud area.

The purge system provides mear.s for the reduction of concentrations ofairborne radioactivity in the Reactor Building. It is operated only asrequired. The system is designed to remove up to 50,000 cfm air from theReactor Building and supply an equal amount of outside air. Roughing,absolute, and charcoal filters are provided in the purge exhaust to removeradioactive particulates and iodine from the air prior to discharge.

The Reactor Building purge exhaust duct contains detectors for products ofcombustion, temperature and radioactivity. Upon detection of eitherproducts of combustion or excessive temperature, the Reactor Building purgefan is stopped by an interlock, and an alarm sounded in the control room.Interlocks are provided to close the purge exhaust valves in the event ofexcessive particulate, gaseous or iodine activity. The Reactor Buildingpurge supply air is filtered and monitored for combustible gases andproducts of combution. Detection of either causes the purge supply fans tostop and sounds a control room alarm. Purge system fans, filters andinstrumentation are located outside the containment.

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5.3.5.2 Auxiliary Building Ventilation

The Auxiliary Building contains equipment and components which could besources of airborne radioactivity as well as other equipment and componentswhich would not. Its ventilation system is of the once-through type in '

which outside air is taken into the building and distributed to the variousareas, then collected, filtered and dishearged to the outside. The flowdiagram is shown in Figures 5-14 and 5-15.

The Auxiliary Building ventilation supply consists of a supply system foreach of the spent fuel pit and the fuel handling areas, along with a supplysubsystem which supplies outside air to the other areas. The Auxiliary

Building supply system consists of a particulate filter, two 50%-capacityfans, and ductwork. Outside air is drawn into the system and distributedto the various areas of the building. The fuel handling area supplysubsystem consists of a particulate filter and a fan which brings inoutside air. The spent fuel pit supply consists of two fans each of 100%capacity.

Within the Auxiliary Building, there are subsystems to cool air within thebuilding and direct it into the compartments containing the spent fuelcoolant pumps and the decay heat closed cycle cooling water pumps. Thereis also a small fan to recirculata air in the area containing the airlockwhich provides personnel access to the Reactor Building.

The Auxiliary Building main exhaust subsystem consists of ductwork tocollect air from the various compartments and areas throughout thebuilding, particulate, absolute and charcoal filters and four exhaust fanseach of 50% capacity. Exhaust air from the controlled access area of theControl Complex (el. 95') is handled by this subsystem.

All air from the Auxiliary Building ventilation system is filtered by theparticulate and charcoal filters, then exhausted to the atmosphere throughthe plant vent from a point near the top of the cylindrical section of thecontainment. Intakes to the system are located on the sides of theAuxiliary Building.

5.3.5.3 Control Complex

The Control Complex is divided for purposes of ventilation into two zones,the controlled access area (el. 95') and the remainder of the building.The flow diagram is shown in Figure 5-16. Except for the controlled accessarea and the top floor of the Control Complex (which contains theventilation equipment for the complex), the Control Complex ventilation isof the recirculating type, but may be converted to once-through byoperation of dampers. Air is supplied to the various areas by either thenormal duty supply units or the emergency supply subsystem. The normalduty units consist of particulate filters and fans, while particulate. filters, absolute filters, and charcoal filters, and fans make up theemergency supply subsystem.

Supply air is heated or cooled as necessary, then distributed to thevarious areas of the complex. Air from those areas with recirculationcapability is returned by Control Complex return fans. Powe r-ope rateddampers are provided to allow recirculation from the return fans to the

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supply system or to exhaust all taturn air and to supply only outside airto the Control Complex. The outside air intake and discharge points are onthe Control Complex roof, separated by a distance of more than forty feet.

The upper floor of the Control Complex has a relief fan system whichexhausts ventilation air from this area to the atmosphere at a point on theroof well separated from the intake.

The controlled access area (parts of which may contain radioactivity)receives air from the Control Complex supply system. Air is also suppliedto the exhaust and sample hoods from the Turbine Building by a supply fan.Air from the controlled access area is collected and directed by exhaustfans to the Auxiliary Building exhaust system for filtering and discharge.

The Control Complex is equipped with UL-approved, three-hour-rated firedampers to isolate the various areas. Closure of these dampers isinitiated by a fusible link upon the occurrence of high temperature at thedampe r. These dampers are also arranged to be automatically closed byproducts-of-combustion and/or temperature detectors, as descried in Section5.3.3.1 and Table 5-3. Upon actuation of one of these detectors, anelectric circuit is closed, melting the fusible link of its associateddamper, thereby allowing it to close. Rooms are isolated by automaticclosure of dampers in the supply and return air ducts upon detection offire by a detector either in the room or in the return air duct. A controlroom alarm is also initiated. All dampers in the cable spreading roomducts are also automatically closed in the event the Halon system isinitated.

The Control Complex ventilation system normally operates in therecirculation mode (except for the controlled access area) with outside airsupplied as required to make up for the air exhausted from the controlledaccess area. If an engineered safeguards signal occurs, dampers areactuated to stop the supply of air to the controlled access area and placethe remainder of the Control Complex in a full recirculation mode. Upondetection of radioactivity in the Control Complex atmosphere exceeding apresent level, an emergency supply unit is started and the normal dutyunits stopped and isolated. This routes the supply air through the HEPAand charcoal filters in the supply units prior to its return to the ControlComplex arecs.

A POC detector in the return air system automatically changes the system toonce-through, exhausting all return air to the outside. A control roomalarm is also initiated.

Another P0C detector in the air inlet duct to the Control Complex closes afire damper in the duct and initiates a control room alarm in the eventthat products of combustion are detected in the incoming air.

A products-of-combustion detector in the controlled access exhaust hoodsupply fan intake closes a damper in that duct on detection of fire, andinitiates a control room alarm.

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5.3.5.4 Intermediate Building Ventilation System

The Intermediate Building, which houses the emergency feedwater pumps, mainsteam isolation valves, and Reactor Building purge supply equipment, has aonce-through ventilation system. Air is supplied by two 100%-capacitysupply fans, first passing through a particulate filter. It passes firstthrough the emergency feedwater pump room, then through the remainder ofthe Intermediate Building, and is exhausted by two 100%-capacity fans.There are fire dampers in the air intake and between the pump room and theremainder of the Intermediate Building. The fir damper in the air intakeis closed automatically either by its fusible link or upon detection ofhigh temperature by a temperature detector in the air intake. The damperswhere the air leaves the pump room are closed by the dampers' fusible linkor upon detection of high temperature in the pump room. A products-of-combustion detector is also provided in the pump room. The temperature andPOC detectors also initiate control room alarms.

5.3.5.5 Turbine Building

The Turbine Building has nine supply fans, with fire dampers located in theintakes. Each damper automatically closes upon high temperature in its fandischarge, or by the fusible link in the damper. Turbine Building air isexhausted through gravity ventilators, windows and wall louvers.Thermavent gravity roof dampers are provided for the Turbine Building roof.The dampers are equipped with 160*F fusible links.

The Turbine Building switchgear rooms are equipped with a recirculatingventilation system. It consists of two 100%-air-handling units consistingof filters, cooling coils, and fans. The air handling units are connectedby ductwork to the switchgear rooms. Supply and return ducts are equippedwith fire dampers which close on detection of high return air temperature.Products-of-combustion detectors are also located in the return air ducts.Both POC and temperature detectors sound control room alarms.

5.3.5.6 Diesel Generator Rooms

Each diesel generator room has two 100%-capacity fans which supply air tothe room. The air exhausts through wall louvers. A separate fancirculates air between the diesel control room and the diesel generatorroom. Fire dampers are provided between each diesel generator room and itscontrol room. A products-of-combustion detector closes the mampers ondetection of fire and initiates a control room alarm.

5.3.5.7 Fire Service Pump House

The Fire Service Pump House has two 100%-capacity supply fans with aparticulate filter which supply outside air. A products-of-combustiondetector initiates a control room alarm in the event of fire.

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Question 71

How of ten and by what means are "POC" interlocks tested for the reactorbuilding purge supply and exhaust fans (Page 5-31)?

RESPONSE

The product of combustion interlocks are tested semiannually. Theprocedure of this check is outlined in Surveillance Procedure 190 of3/30/78.

Question 73

Verify that the tGrbine building is a free standing building in that itwill not affect the control complex or intermediate building by itsstructural f ailure due to a fire in the turbine building.

RESPONSE

The turbine building was designed and constructed as a free standingstructure. It is joined to the control complex and the intermediatebuilding will not af fect the control complex or the intermediate building.

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SRP-25 - Diesel Generator Control Room Smoke DetectorStaff Concern

The lower smoke detector located in the diesel generatorcontrol room is not effective in its present location.,

Staff Position

Relocate the smoke detector to high bay in diesel generator

control room (s).

RESPONSE

POC's in the emergency diesel generator control rooms willbe relocated by 4/79. Ref: WR#4433.

SRP-9 - Control Room KitchenetteStaff Concern

The control room kitchenette is located in a safety-relatedarea and presents an unprotected fire hazard.

Staff Postion

Remove stove, kitchen equipment and kitchen cabinets frombehind control panels.

RESPONSE

Electric stove and oven in the control room weredisconnected 12/7/78, WR #4148. Cabinets on order PR#740-4587; completion expected by 4/79.

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SRP-20 - Station VentilationStaff Concern

Failure of exhaust ventilation in battery rooms could lead tobuild-up of explosive hydrogen concentrations.

Staff Position

Relocate exhaust ducting to ceiling of battery room. Provide air

flow monitoring on battery room exhaust by surveillance or alarmsystem.

RESPONSE

The batteries are of a type which has a very low hydrogen productionrate when under charge. The potential ef fects of loss of ventilationin the battery room has been addressed in the Crystal River Unit 3Final Safety Analysis Report, Section 8.2.2.6. The FSAR states:

"The Battery chargers normally supply the d-c system load and thefloat charge to the batteries. The chargers are also capable ofsupplying a 24-hour equalize charge. The chargers are supplied with ahigh/ low voltage alarm relay to monitor the d-c system. The highalarm point is set at 137 vde to protect against battery overchargingduring normal operation.

" Battery Hydrogen Evolution was calculated under worst case conditionsof the battery rooms at a temperature of 77'F and the batteries beingovercharged at the high voltage alarm point of 2.35 volts per cell.The results are as follows:

"1. Under the condition that the battery rooms were completely sealedfrom outside air it was found that it would require 210 hours toproduce sufficient Hydrogen in the rooms to yield an explosivemixture (four percent by volume). This calculation was completedfor comparison basis only as this condition is abnormal to plantope ration.

"2. Under the condition that the control complex air handling systemis in the emergency recirculation mode as described in Section9.7.2.7.h with 0 percent outside air admission it was found thatit would require 6500 hours to produce sufficient Hydrogen in thecontrol complex to yield an explosive mixture (four percent byvolume)."

Because of the long time required to build up a flammable concentra-tion of hydrogen, and the surveillance program which requires periodicvisits to each battery room, it is concluded that a ventilation flowalarm is not justified.

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