ML17258A428

Review of Design & Operation of Ventilation Sys for SEP Plants Rochester Gas & Electric Co,Re Ginna Nuclear Power Plant, Revised Draft Technical Evaluation Rept

ML17258A428
Person / Time
Site:	Ginna
Issue date:	11/30/1981
From:	Herrick R FRANKLIN INSTITUTE
To:	Brown S NRC
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ML17258A427	List: ML17258A428
References
TASK-09-05, TASK-3.D.3.4, TASK-9-5, TASK-RR, TASK-TM TER-C5257-409, TER-C5257-409-DFT-R1, NUDOCS 8201110469
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TECHNICAL EVALUATIONREPORT REVIEW OF THE DESIGN AND OPERATION OF VENTILATIONSYSTEMS FOR SEP PLANTS .

ROCHESTER GAS AND ELECTRIC CONPANY .

R.E. GINNA NUCLEAR POWER PLANT NRC OOCKET NO. 50-244 FRC PROJECT C5257.

NRCTACNO. 47068 FRCASSIGreearr M NRC CONTRACT NO. NRC43-78-118 FRc TASH 409 Prepared by Franklin Research Center Author. R C. HarrLck The Parkway at Twentieth Street Philadelphia, PA 19103 FRC Group Leader: R. C. Herrick Prepared for Nuclear Regulatory Commission Lead NRC Engineer: S. Brown Washington, D.C. 20565 Revised, November 30, 1981 I

This report was prepared as an account af work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any wananty, ex-pressed or implied, ar assumes any legal liability or responsility for any third party's use, or the results of such use, af any Information, apparatus, product or process disclosed in this report, ar repn1sents that its use by such third party would not Infringe privately owned rights.

81l231 820i1.<04b cy 050002 0ll Franklin 'Research Center i POR ADOC" PDR A Division of The Franklin institttte P 1he Benjamin Fmnkea Parkway. PAL, Pa: 19103 1215) 448-1000

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~ e TER&5257-409 CONTENTS Station Title Psc86 INTRODUCTIONe ~ ~ e ~ ~ ~ ~ ~ ~

1 REVIEW CRI TERIA ~ ~ ~ ~ ~ ~. ~ ~ ~ ~ ~ 2 RELATED SAFETY TOP ICS ~ ~ ~ ~ ~ ~ ~ ~ '4 TECHNICAL EVALUATIONe ~ ~ ~ ~ ~ ~ ~ ~ 5 4.1 Control Room Area Ventilation ~ 5 4.2 Spent Fuel Pool Area Ventilation System. 5 4.3 Auxiliary Building and Radwaste Area

. Ventilation System . ~ 6 4.4 Turbine Building Ventilation System. 9 Engineered Safety Features Ventilation Systems 9

'.5 4.5.1 Engineered Safeguard Equipment Ventilation and Cooling 10 4.5.2 Relay Room ll 4-5.3 Battery Rooms 12 4.5.4 Auxiliary and Emergency Systems . 12 4.5.$ Diesel Generator Rooms 15 CONCLUSIONS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 16 5.1 Control Room Area Ventilation 16 5.2 Spent Fuel Pool Area Ventilation 16 5.3 , Auxiliary Building and Radwaste Area 5.4 Ventilation System .

Turbine Building

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16 Engineered Safety Peatfires Ventilation .

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5.6 "Safety-Grade Equipment . 19 REFERENCES ~

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TER~5257-409

1. INTRODUCTION .

This review of the design and operation of ventilation systems at the R. E. Ginna Nuclear Power Plant is under Topic IX-5 of the Systematic Evaluation Program (SEP) and consists of the review and assessment oX safety in light of changes in design conditions and criterSa. The purpose of 'argins this review is to assure that ventilation systems at the Quma plant have the capability to provide a safe environment for plant personnel. under al1 modes of operation and to determine whether all safety-related equipment can function properly to assure safe shutdown of the reactoi under norma1 and emergency conditions.'s background for this review< the SEP has been estab1xshed to evaluate the safety of 11 of the older nuclear plants. Comparison af each pXant

,against current licensing criteria is an important part of the SEP, with 137 selected topics being studied. Information for these studies is derived from a wide range of sources, including final safety analysis. reports, more recent drawings and system descriptions, licensee submittals, and onsite review and inspection.

Information for this review included the above sources+ elements of related SEP topics already reviewed for the Ginna plant, and a'plant visit that was held on July 21-22< 1981.

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TE~257W09

2. REVIEW CRITERIA In determining the \

ventilation systems to be evaluated,. Franklin Research Center (FRC) was guided by the purposes of the SEP with its emphasis on the

.review,and assessment of safety margins. In accordance with Assigssment 15, a

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ventilation system or portion thereof is considered essentia1 to safety if it services systems. or parts of systems that are necessary to ensure:

o the integrity of the reactor. coolant pressure boundary o the capability to shut down the reactor and maintain it in a safe condition.

o the capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparab1e to the guidelines of 10CFR100, "Reactor Site'riteria."

The criteria and 'guidelines used to determine if the. ventilation systems meet the topic safety ob)ectives are those provided in the following sections of the Standard Review Plans P

section ~Sub oct 9.4.1 Control Room Area Ventilation System 9.4.2 Spent Fuel Pool Area Ventilation System 9.4 ' Auxiliary and Radwaste Area Ventilation System

'9.4 4 Turbine Area Ventilation System 9 4.5 Engineered Safety Feature Ventilation System In additiori, applicable'portions of related safety topic reviews were used where possible.

In accordance with Task 1, Paragraph E, of Assignment 15, the following criteria will also be used to evaluate those heating, ventilation, and air I

conditioning (HVAC) systems or portions thereof that are relied upon to assure u

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.the operation of safety-related equipment:

1. Whether a single active failure cannot result in loss of the system

'functional'performanc'e capability.

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2. Whether the failure of a non-safety-related portion of a system will affect the performance of the essential portion of the system or will

.result in an unacceptable release, as was defined during licensing review, of radioactive contaminants.

3. Whether the capability exists to detect the need for isolation and ta isolate safety-related portions of the system in tbe event, of

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failures or malfunctions, and the capability of tbe isolated system to function under such conditions.

4. Whether the ventilation systems (except for the control room) have the capability to direct ventilation air from areas of Low radio-activity to areas of progressively higher radioactivity.

5. Whether both control room and engineered safety featnre area ventilation systems have the capability to maintain temperature within the design parameters range for safety-related equipment.

6. Whether the engineered safety feature area ventilation system 'has the capability to circulate air to prevent. accumulation of flammable or explosive fuel vapor mixtures from stored fuel.

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TER~257-409 3~ RELATED SAFETY TOPICS The scope of review for this topic was limited to avoM duplication of effort, since some aspects of the review are covered under related topics.

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These related topics are identified below. Each related talc report contains acceptance criteria and review guidance for its subject'mar.

~P Tapic ~Sub eat II-2 A Severe Weather Phenomena ZZ-3 ' Flooding Potential IZ-4 IZZ-1 Classification of Structures, Components and Systems (Seismic and Quality)

IZZ-2 Wind and Tornado Loadings ZIZ-3 Hydrodynamic Loads ZZZ-4 Missile Generation and Penetration III-5+A'II-5 Pipe Breaks Inside Containment B Pipe Breaks Outside Containment ZIZ-6 Seismic Design Considerations IZZ-12 Environmental Qualification of Safe~Related Equipment VZ 4 Containment Isolation System VI-7.C.1 Independence of Onsite Power VZ-8 Control Room Habitability VZZ-3 Systems Required for Safe Shutdown IX-3 Station Service and Cooling Water ZX-6 Fire Protection XV-20 Radiological Consequence of Fuel Damaging Accidents (Inside and Outside Containment)

TMI ZZI D 3 ~ 4 Control Room Habitability

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TERM5257-409 4~ TECHNICAL EVALUATION 4 1 CONTROL ROOM AREA VENTILATION The function of the control room area ventilation system is to provide a controlled environment for the safety and comfort of controI room personnel and, to assure the operability of control room components during noanal operating>

anticipated operational transient, and 'design basis accident conditions.

However, the control room system is being reviewed, generica11y under 9RI Item III.D.3.4, "Control Room Habitability," to assure comp1iance with, 10CFR50< Appendix A, "General Design Criteria for Nuclear Power Plantsg" Criterion 19, "Control Room." For this reason, the contro1 rocet area ventilation system was not evaluated as a part of this review.

4~2 SPENT FUEL POOL AREA VENTILATION SYSTEM As a part of the auxiliary building ventilation system,, the spent fuel pool area ventilation system serves to control airborne radioactivity in,the spent fuel pool area during normal operating, anticipated operational tran-sient, and design basis accident conditions. This is accomplished by ducting a'ort:ion of the air from t5e auxiliary building's outside air supply and conditioning system to the spent fuel pool area where it is directed across both the spent fuel pool and the decontamination pit to separate exhaust air collectors. Air collected from both the decontamination pit and spent fuel pool collectors is drawn by and ducted to auxiliary building exhaust fan No C. While the exhaust air from the decontami'nation pit is ducted directly to fan No. C;.exhaust air from the spent fuel pool water surface is drawn through a filter assembly constructed to provide a choice of charcoal and/or roughing filters. This combination filter assembly is a recent addition to the Ginna plant.

A review of Ginna's fuel handling accident analysis in Section 14.2.1 of the FSAR .indicates that the ventilation. system is not essential for preventing r

or mitigating the consequences.,of accidents thag could result in potential exposures comparable to the exposure guidelines of 10CFR100, Reactor Site

.Criteria." No further review or assessment is included..

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TERM5257-409 4 ' AUXILIARYBUILDING AND RADWASTE,AREA VENTILATION SYSTEM l

This system provides clean, filtered, tempered air to al1 regions of the operating floor of the auxiliary building, including the spent fue1 pool and decontamination pit areas. The system exhausts air from a11 regions of the auxiliary building and its specific equipment rooms and work areas by means oK four separate exhaust subsystems, in addition to providing exhaust for the-service building and intermediate building Other than the spent. fue1 pool and decontamination pit area, which has a dedicated air supply and exhaust path within this system, the auxiliary building supply air ia directed to the open work areas of the main operating floor from which a major portion of the ventilating air makes its way.down to the. intermediate and'basement levels of the puxiliazy building by means of stairwells and other floor openings Separate exhaust ducts collect the air in specific regions of all floors. In this manner, the air is directed fromregions of low radioactivity potential on the general operating floor to areas of progressively greater radioactivity potential on'the intermediate and basement levels in satisfaction of one acceptance criterion of Section 2 During normal plant operation, outside air is intzoduced and tempered by one air handling unit, then collected from all regions of the auxiliary build-ing as well as from the service building and the intermediate building by a closed ducting system, and then filtered through a large HEPA filter and exhausted through the plant vent stack. The large< redundant exhaust fans assure an adequate flow of exhaust air to create sufficiently low pressure to promote air leakage into< rather than out of, the auxiliary building Air-actuated dampers on all system branches, as well as on the outside air inlet and exhaust, piovide for isolation of a region when necessary. A1though the environmental qualification of the isolation dampers is not documented, conditions within the auxiliary building during normal operation or following a design basis accident are expected to remain at atmospheric pressure with temperatures ranging between 50 and 104 P (see'Appendix A, Reference 19) ..

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.C During shutdo~ with a loss of..offsite power, the air handling unit supplying outside air shuts down and is isolated by its dampers< and the large main exhaust fans shut down with closed redundant dampers; however, a reduced llll Franklin Research Center A DMshn d lhe Franklin lectue

TERM5257-409 quantity of air is circulated and exhausted by redundant fans in each of the separate exhaust collector subsystems. These fans are autotsatically connected to the emergency diesel<<powered buses.

A more detailed review of each exhaust collector subsystem foUows. Note that these discussions consider mainly the supply and exhaust of ventilation air.. Specific cooling of safety-related equipment is reviewed later in this report.

The first of the foui subsystems, the ventilatihn systea for the spent I

fuel pool and decontamination pit areas, although a subsystem of the auxiliary building ventilation system, is discussed in Section 4.2 of this report.

Two exhaust subsystems deliver air to a combined HEPA and charcoal filter< installed in recent years on the intermediate level One of these lines collects exhaust air from the general operating floor area, the boric acid tank ar'ea, and the drumming station, while the other co11ects exhaust air from selected areas of the intermediate amd basement floors- Both exhaust lines are equipped with air-actuated isolation dampers mounted in each line just before the. filter. Both isolation dampers are actuated from the motor controller of auxiliary building exhaust fan No. 1G. With .a loss of the isolation signal, each damper fails to the open position to allow continued ventilation.

The remaining exhaust subsystem also collects air from the basement and intermediate levels, including the waste evaporator area, the waste holdup tank area, the concentrate holdup tank< and the gas decay tank areas. Within this subsystem, the volume control tank and reactor coolant filter areas are served with an additional booster exhaust fan, No. 1P. This exhaust air sub-system servicing radwaste areas employs a charcoal filter, reduxBant fans, and air-actuated isolators at its discharge. The line into which it discharges is serviced by exhaust fan No. 1G before reaching the main HEPT filters and the main exhaust fans that deliver the exhaust to the plant venting stack.

The morecomplex ventilating system" shown on Ginna Drawing No. 33013-533 (dated Sept.'30> 1975) is a re'vision of the original ventilating system. The major changes include the addition of the int:ermediate: level charcoal and HEPA 0

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TER~257-409 filters and exhaust fan No. 16. As previously mentioned, dischar'ge ducts from two separate areas discharge to the intermediate HEPA filter and each area may be isolated by air-actuated dampers. The exhaust from the radwaste area charcoal filter, powered by redundant exhaust fans< discharges to the'interme-

.diate HEPA filter output side. Auxiliary building exhaust fan No. 1G acts's a booster fan in this line. This review indicates that, dqring an emergency-shutdown when the plant is, operating under onsite diesel power, these fan loada are arranged on ei'ther the A or B diesel~wered buses. While a single failure (one diesel failure) will not cause the system to fail (with backflow into: ..

areas of lesser radiation), it is noted that, with a failure to diesel unit A, exhaust fan No. 1G will shut down, thus reducing the exhaust removal fran areaa of the operating floor and areas at the intermediate and basement levels While this will not prevent a safe shutdown, it could inhibit personnel access-to these areas.

Final exhaust air handling from the auxiliary building is provided by a large HEPA filter, redundant fans'auxiliary bui3ding exhaust fans Nos 3A and lB); and associated isolation dampers. It is noted that these final large fans operate on 4160 V power and are not connected to the emergency diesel buses A loss of offsite power would. leave the ventilation exhaust function to the smaller fans in each subsystem, augmented only by any natural draft gained from the plant vent stack. Any positive pressure developed in the final ducting located in the intermediate building could cause contaminated exhaust air to leak from the ducting to the intermediate building controlled access area.

This would be in violation of the acceptabi,lity criterion (Section 2) for ducting air from. regions of low radioactivity potential to regions of higher radioactivity potential Under these same emergency shutdown conditions using onsite diesel power it is noted that a number of exhaust subsystem ducts discharge at the inlet to the'ain HEPA filter< each of which is powered by at least one exhaust fan or a redundant parallel set o'f two exhaust fans. Without draft augmentation from the plant'ent stack, it is possible.-that the pressure-flow characteristics of, these parallel. subsystems. are not"matched.sufficiently and that the subsystem providing the highest pressure potential at this point could cause exhaust air to flow backward through one or more exhaust. subsystems. Note that the duct

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TER~257-409 from the intermediate level HEPA filter has exhaust'an No. 1G in seriea with the other parallel fan set in this subsystem. Although fan No.. 1G has been as an axial flow fan (with automatically controlled variable-pitch 'dentified blades) that maintains only a differential pressure of 4.5 inches of. water

.across the fan; the pressure-flew characteristics of the other fans are not known. With an outage on diesel unit B, one fan on 'each redundant fan set will shut down, thus lessening the flow in each subsystem and increasing the influence of added series fan No. 1G on the one line from the radwaste area.

Therefore, it is .recommended that the situation be investigated to assure that exhaust air from the radwaste area cannot flow backward into 'the intermediate building and/or into the controlled access area interface with the service building . Note that the air handling units supplying outside air to each of these areas are not powered by the primary emergency diesel generator bat, only by buses connectable to the diesel power source.

4 4 TURBINE BUILDING VENTILATION SYSTEM The turbine building, while not requiring an HVAC system, uses roof-ment fans, wall vent fans, windows, and unit heaters for ventilation and temperature control. The fans are not supplied by emergency diesel-generated power, and loss of these fans would not be critical to a safe shutdown The turbine building does not house systems required for safe shutdown.

Although it is the source for ventilation air to other rooms that do coatain 4

safety-related systems, revisions are currently being made to the plant to provide outside air ducts to these systems. The turbine building venti1ation sys'em appears. to be in accordance with the acceptance criteria of Section 2.0.

4~5 ENGINEERED SAFETY FEATURES VENTILATION SYSTEMS The engineered safety features ventilation systems include those ventilat-ing and cooling systems that service equipment required following an accident

.or needed to assure a safe shutdown of the plant. Equipment and/or areas serviced by these ventilating and cooling systems include the following=

engineered safeguard equipment.

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TER~257M09 o battery rooms o auxiliary and emergency systems o diesel generator rooms.

4.5.1 En ineered Saf uard i ent Ventilation and Cool Definition and identification of the following safeguard systems are taken from the Qinna FSAR:

o safety injection system o containment spray system o hydrogen recombiner.

4.5.1.1 Sa'fety Injection System The safety injection system acts to limit the release of fissica products from the reactor fuel by maintaining core cooling. This keeps the Me1 in place, limiting the metal-water reaction to an insignificant, amount. The safety injection system is comprised of both high and low pressure eXectric motor-driven centrifugal pumps located on the basement level of the auxiliary building.

Cooling of the pump-drive motors is by two redundant, stand-alone air cooling units that are shared with the containment spray pumps and from which the cooled air is ducted to a point adjacent to the cooling intake vents of each drive motor. The cooling units comprise a water-cooled heat exchanger and a blower. Service water is the cooling medium. The redundant, moling units are'onnected to the 1C and 1D electrical motor control centers that, in turn, are connected'eparately to diesel-powered buses 14 aad 13, respec-tively, when offsite power is not available. A single active failure will not cause .a total loss of cooling. Should the service water supply fai1, the main auxiliary building ventilation system will circulate air to prevent a rapid rise in temperature. With a loss of this pdrtion of the auxiliary building's ventilation system, the coolers will provide motor coo1ing The FRLR states that the coolers were designed to Seismic Class I

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2 TERM5257-409 4.5.1.2 Containment Spray System The containment spray system is an engineered safety feature initiated by a set of high containment pressure signals and designed to reduce. the pressure and radioactivity levels within the reactor containment.

~ Cooling of the p~rive motors on the basement leve1 of the auxiliary building is by the redundant, service watermooled air cooling units shared with the safety injection pump motors and described in Section 4.5 1 1 of this report. In a similar manner as for the safety injection pump motorst the cooling air is ducted to a point adjacent to the cooling vents of the two drive motors. By the same reasoning employed for the safety injection pump motors, the ventilation and cooling system for the containment spray pump motors is considered to be satisfactory with respect to the acceptability criteria discussed in Section 2.

4..5.1.3 Hydrogen Recombiner As described in the ESAR, the hydrogen recombiner consists of two full-rated subsystems, each capable of maintaining the ambient H concentration at 2 V/0. While the associated gaseous fuel and combustor systems are not serviced by the ventilation systems under review in the study, the control panel is located in the intermediate building and is cooled by that building's ventilation system. In response to a question to the Ginna plant engineering staff regarding the ventilation and cooling needs of the control panel, the Licensee has replied that the intermediate building ventilation should maintain the environment in the area of the recombiner panel. below 104 P.

4. 5. 2 ~aela Room The relay room contains two self-contained, watermooled heat pump air cooling units that maintain a low-normal room temperature. Power to these cooling units is supplied. by the iB motor control center thatt whi1e not auto-matically'onnected to the emerge/cy Aiesei~enerated power, in the event of a loss of offsite power 'can be connected by the operator to the diesel power via

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In addition< a filtered wall vent to an outside air source was noted.

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TER~257-409 The .ventilation and cooling system for the battery rooas has been modified to include a refrigerated air handling system. This equipaeat is Located in the main .equipment (air conditioning) room for the control. room. Qool air from this system is ducted to both battery rooms. While the system recizculates the air, enough new air is introduced to prevent any appreciabLe, hydrogen accumu1a-,

tion in the rooms.

For backup, a dc fan,'owered by. the batteries, supplies air harem the control room's main air handling room to cate battery room aad throagh a normally open vent into the second battery room. The vent, hetweea the two battery rooms is equipped with a fire damper. Isolation dampers axe inc1uded on the blower system.

It should be noted that, at the time of the plant visiC~ modiXications were being 'made to install an exhaust duct that will direct, the exhaust air 1

from the main air handling room and battery'rooms to an ouCaide ver instead of venting it into the lower level of the turbine building Reference 18 indicates that additional battery-powered fans are to be

.installed in the future to assure that sufficient air handling capacity is provided to maintain the battery rooms at acceptable ambient conditions 4.5.4 Auxilia and Emer enc S stems FRC defined and identified the auxiliary and emergency systems in accordance with the FSAR. The following essential systems were seea to require ventilation and/or cooling.

4.5.4.1 Chemical and Volume Control System The chemical and volume control system is located in the auxiLiary building where its ventilation and cooling needs are supplied by the auxiliary building. ventilation system.

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'.-.'.- '. TERM5257-409 medium. To assure that the pumps and drivegutaiR ire cjicxXed~>.the cooled air is ducted directly to them from the cooXe'rs"',,=, ~'.+"~;~"=-i -,-'.- .

Emergency onsite die ~~ ~p1X~'aaMmatica11y to the cooling fans by means of motor.- control~~atNO.~~:aha'=.XEk ~'s:-places one -

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cooler on diesel A and th e'other on di'eS: . ~ie $5~>> .We capacity of each cooling unit is suff icient. to'aiagd~rcce jiahM~frm&ng, temperatures The cooling units we I ~,lT" @

Class I criteria..

4.5.4.2 Auxili ry Coolant System .. - ~ ,=,.4=;.". --+":=~~:-'.-2::-

The auxiliary coolan t system, compri.sed.of the:.resxdaid...heat removal loop and the component cooling water, loop,-'~ocaMQ:. 4ii.~+~~nry building and is a system essential to safety. 'e '.. =";-'.'~g'.,.:+"=-=-. '3 ~=.::==-'.:

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Within the residual heat removaL 1cxip~,the.'1ectzi&mcrto~~iiven pumps circulate reactor. coolant through hest.excbangeziMo:tiaimf~the.'heat to the component cooling water system which, in turn, transfers it to service water for return to the heat sink, Lake Ontario. The heat exchangers are located on the basement and intermediate levels. of-.-.the. auxi1iary'- building.- and add to the overall heat removal load of the auxiliary building ventilation system. The residual heat removal pumps are located ir. a pit beneath the basement floor and are cooled by coolers comprised. of.Tin-type~ service~ter-cooled, heat exchangers and electric motorMriven fans. that- direct..the-. cooling air directly to the pumps and drive motor vent openings:The coolers hexa designed and installed in accord'ance with Seismic-CLass C,dziteria't."..:tbe ~e of plant construction. During post-accident conditions-'.and. during..shutdowns where

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offsite power is not availablethe redundajsLwoaKng;.'ixniM are'ransferred automatically to separate diesel>>powecet%1$ es.-'= ~,

The component cooling water;loop serai'as. t5e int ermecKary heat removal system< removing heat from the residu~'a@iemoval"3.oap'as well as providing cooling water to many other componen(s+,Thi's,'-f.s ~LW a-.systear essential to I

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TER~257M 09 The primary ventilation and cooling requirements of the component cooling water system are associated with its'irculation pump motors. Theae motors are located on the main operating floor of the auxiliary building +here cooling is 'provided by the ambient air of the operating floor provide'd by the auxiliary building supply air handling unit from an outside air saaxce Since the operating floor is not subjected to the heat dissipation of the-lower floors and since it is close to the source of cooled supply air f tbsp pump motors of the component cooling water system do not require additzeaal cooling directed to the motor vents.

While the ventilation and cooling syst'ems for the residual heat, remova1 and component cooling water loops appear to satisfy the acceptance ariteria for normal operation and the usual scenarios of post-accident concord:ions, there is a concern that the residual heat removal system'could be aasceptible to a single failure. Consider the possibility of a major pump sea3L 3.eak or a coolant pipe rupture in the residual heat removal system in the peep pit High pressure reactor coolant could be released into the pump pit anal would flash to steam, producing a hot, highly humid atmosphere. PRC's concern is that this environment may produce failures in one or both residual heat removal pump motors in the pit to render the residual heat. removal aystem inoperative. A severe 1eak could possibly affect the residual heaC removal pump cooling unit mounted immediately above the pump pit on the basement floor. At that location, the highly humid atmosphere may be drawn ento the coolers and, if not entirely condensed by the cooling coils, retund a condensing atmosphere to the residual heat removal pump motor vents:

4.5.4 3 Circulating Water Screen House The circulating water system provides, by means of four safe~related service water pumps, the water used for heat removal from the reactor during shutdown operations. Ventilation of the screen house, in which the. service:

water pumps are located, 'is provided by exhaust fans in the bui1diaig roof and manually controlled lowered vents inde walls. power to the rooK exhaust fans is supplied via-bus 17 that .is connectable by operator action to the diesel-generated power during emergencies.

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TSR~257M09 An onsite inspection showed that windows and doors (both personnel and vehicle access doors) may be opened to increase the flow of ambient air through the screen house when necessary. The inspection aLso revea1ed the use of portable fans to increase the circulation of air around each of three

. operating service water pumps. Although special motor coo1ing systems were stated to be not necessary for the service water pumps, it, appareat1y has been advantageous on.hot summer days to reduce the motor operating temperatures wjth the portable fans.

4.5.5 Diesel Generator Rooms Since the two diesel-powered generators supply redundant onsite electrical power, the diesel generator systems are obvioua1y safety related and must be serviced adequately by their respective ventf1ation systems. The diesel generators (with associated electrical switchgear) are housed in adjacent, but separate, rooms, each serviced by a ventilation system. Each room is ventilated by two inlet fans supplying outside air, with one fan in each room discharging a copious supply of air directly on the electrical-switchgear cabinets. Excess air is discharged through automatic, pressure-actuated roof vents. No refrigeration or service water air cooling is used.

Each ventilation system is automatically connected to its respective diesel-generated power source when the diesels are started. This assures a continuation of ventilation for. equipment cooling and for the removal of any hydrocarbon gasses. Combustion intake air to each diesel is via separate outside air sources.

Heating of each room is by unit steam heaters (two per room). Should one of these steam lines break, only its respective diesel generator would be affected. The other diesel would continue independently, to supply emergency power while the steam line is being isolated.

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TEf~5257M09 5<< CONCLUSIONS 5<<1 CONTROL ROOM AREA VENTILATION Ventilation of the control room is not reviewed here since it is a part of the generic study< "Control Room Habitability<" being reviewed under TNZ Item ZII.D.3,4. That study r is to assure. compliance with lGCFR50, Appendix A<

"Ground Design Crite'ria for Nuclear Power Plants," Criteri'on 19, ControL Room."

5 ~2 SPENT FUEL POOL AREA VENTILATION The spent fuel pool area ventilation system including the decontaamination pit area was not considered to be a safety-related system within the definition of this review. Consequently, it was not reviewed in depth However< during the plant visit it was noted that the exhaust air co11ected along the side of the spent fuel pool area was more recently fitted with e filter that may operate as a charcoal and/or roughing filter; Discharge from this filter is directed to the main HEPA filter in the auxiliary building ventilation system.

5 ~3 AUXILIARYBUILDING AND RAGWASTE AREA VENTILATION SYSTEM Although the ventilation system ductwork and special component air cooling units were designed and installed to Seismic Class I criteria at the time of plant construction, the system generally includes non-safety grade equipment. Although the anticipate'd environments during normal plant.

operation.and following design basis accidents include atmospheric pressure and a.temperature range of 504 to 104oF, safety grade equipment must be addressed (see Section 5.6).

Zn general, the ventilation of the auxiliary building, appears to be .

adequate and does promote the flow of air from areas of low radioactivity potential to areas of higher radioactivity -potential. Howev'er,'wo cond'itions exist that could possibly violate Mat requirement, both of rhich occur with the main exhaust fans shut down when offsite power is not 'available and the plant is operating on emergency diesel power 0II Franklin Research Center A Dlvbbn ot The Franklin hedge

I Iv TER~257M 09 first condition I

The is one in which exhaust air, with a higher radio-activity potential, could leak into the intermediate buildirag.housing the

.controlled access area. With the main exhaust fans shut down, the positive pressure created on the input side of the HEPA filter could cause exhaust leakage into the intermediate building if there is insufficient partial vacuui created by the plant vent stack.

The second possibility could occur under the same main exhaust. fan shut-down conditions with the plant v'ent stack providing insufficient partial vacuum on the system. With four separate exhaust subsystems discharging to a common point at the HEPA filter input, it is possible that, the flow-pressure characteristics of the fans could be sufficiently mismatched to produce backflow through an operating fan (isolation dampers open) and thus introduce higher radioactive exhaust to an area of generally lower raiUnactivity potential.

It is recommended that both possibilities be investigated to assure that

~

exhaust air always flows from areas of low radioactivity potential to areas of high radioactivity potential.

5~4 TURBINE BUILDING While it does not house systems required for safe shutdown, the turbine building does serve as the source of air for ventilation to the control room's HVAC system equipment room and the battery rooms. However during the plant visit, modifications were observed that will provide outside air to these areas as well as return their exhaust to an outside vent The turbine building ventilation system appears to satisfy the acceptance criteria cited herein.

5 5 ENGINEERED SAPETY PEATURES VENTILATION The engineered safety features covered in this review are:

o engineered safeguard equipment safety in)'ection system containment spray system Ill Franklin Research'enter.

A DHskon af The Freon Insense

TER~257-409 hydrogen recombiner o relay room o battery rooms o auxiliary and emergency systems chemical and volume control system auxiliary coolant system circulating water screen house

' ~

diesel generator rooms Equipment cooling using either refrigerated or service water air cooling systems, as required, is the main sub)ect af this review under the engineered safeguard equipment and the auxiliary and emergency systems categories Redundant emergency bus-powered coolers used for these equipmeat items were designed and installed to Seismic Class I criteria at the time of plant construction. No other quali.fication documentation was noted The relay and battery rooms employ refrigerated air cooling of the rooms rather than cooling of specific equipment. The history of perfcmaance is said to be good. Qualification includes Seismic Class I criteria.

The diesel generator rooms are ventilated by two outside air supply fans with one fan ducted to discharge outside air directly on the e1ectrica1 switchgear cabinet in each room. Power for the fans is automatically switched to that room's respective diesel-generated power when the diesels are started. Excess air from each room. is exhausted through pressure-actuated roof vents.

The ventilation systems for the relay room, diesel generator rooms, chemical and volume control system, and the circulating water screen house appear to satisfy the acceptance criteria cited here.

As discussed in Section 4.5 4.2< the ventilation and cooling systems for the residual heat removal system appear to satisfy these acceptance criteria except for consideration of a major seal leak or pipe rupture in the residual heat'emoval pump pit. For this .condition; concern was expiessed in Section 4.5.4.2 that the hot humid environ'ment in"roduced to the pump pit could cause both of the redundant (parallel) pump motors to fail, that is, the residual 9P Franklin Resenrch Center

TER~257M09 heat removal pumping system could be susceptible to a single failure. It is recommended that the Licensee investigate this possibility in greater depth.

5~6 SAPETY GRADE EQUIPMEHT A "safety grade" systems as defined by NUREG-0138, is one that is qualified'o Seismic Category I (Regulatory Guide 1.29) and quality group C or better (Regulatory Guide 1.26) and is operated by electrical instruments and controls that meet IEEE criteria for nuclear power plant protection systems (IEEE Std 279) ~ The Ginna plant was constructed, for the mast part, prior to the issuance of these documents; as a consequence, much of the equipaent used in the ventilation systems is.not documented to be of safety grade 'Ther'efore, the .Licensee is'encouraged to determine which of these ventilation systems, if any, are required to enable the safety equipment, located in the areas serviced, to perform their respective functions. If it is determined that ventilation is required for any of the safety systems thus serviced, then the appropriate upgrading of its associated ventilation equipment should be considered.

~ g Otj Franklin Research Center A Dhblon d The Fnnk5n heOute

TKRM5257M09 6 REPERENCES

l. 10 CPR Part 50, Appendix A, General Design Criterion 2, Design Basis for Protection Against Natural Phenomena"

2. 10 CPR Part 50, Appendix A, General Design Criterion 4,,"Enviroamental and Missile Design Bases" 3 10 CPR Part 50, Appendix A, General Design Criterion 5g Shar~ of Structures, Systems and Component

4. Standard Review Plan, Section 9.4.1, "Control Room Area Venti1ation System"

5. Standard Review Plan, Section 9.4.2, "Spent Fuel Pool Area Venal'ation System"

6. Standard Review Plan, Section 9.4.3, "Auxiliary and Radwaste.Area Ventilation System" 7; Standard Review Plan, Section 9.4.4, "Turbine Area Ventilation System"

8. Standard Review Plan, 9.4.5, "Engineered Safety Feature Ventilation System"

9. Standard Review Plan, Section 9.5.1, "Pire Protection Systems" "10. Regulatory Guide 1.13; "Spent Fuel Storage Facility'Design Basis"

11. Regulatory Guide 1.26, "Quality Group Classifications and Standards for Water, Steam and Radioactive-Waste-Containing Components of Nuclear Power Plants"

12. Regulatory Guide 1,29 "Seismic Design Classification"

13. Regulatory Guide 1.105< "Instrument Setpoints" 14'. Regulatory Guide 1.117, "Tornado Design Classification"

15. Branch Technical Position ASB 9.5-1, "Guidelines for Fire Protection for Nuclear Power Plants"

16. SEP Topic VII-3< "SEP Review of Safe Shutdown Systems oflice for the R E Ginna Nuclear Power Plant, Revision 2," April 19S1

17. SEP Topic VII-3r "Electrical, instrumentation and Control Peatures of Systems Required for Safe Shutdown," Final Draft, Pebruary 1981

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