ML20052G280
| ML20052G280 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/10/1982 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| TASK-03-04.C, TASK-3-4.C, TASK-RR LSO5-82-05-014, LSO5-82-5-14, NUDOCS 8205180202 | |
| Download: ML20052G280 (29) | |
Text
{{#Wiki_filter:' ~ May 10,1982 Docket No. 54213 LS05 05-014 Mr. W. G. Counsfl. Vice President Nuclear Engineering and Operations Connecticut Yankee Atomic Power Company Post Office Box 270 Hartford, Connecticut 061 01
Dear Mr. Counsil:
SUBJECT:
SEP TOPIC III-4.C. INTERNALLY GENERATED MISSILES HADDAM NECK PLANT Enclosed is our final evaluation of SEP Topic III-4.C. This evaluation compares your facility as described in the Safety Analysis Report you supplied on February 12, 1982 and other infonnation available on Docket 50-213 with criteria used by the staff for licensing new facilitfes. The evaluation concludes that there are some components vulnerable to internally generated missiles. The evaluation will be a basic input to the integrated assessment of your facility and may be changed in the future if your facility design is changed or if NRC criteria relating to this topic is modified before the integrated assessment is completed. 5609 Sincerely, s ) l Crislainidd by( m W6(02) Dennis M. Crutchfield, Chief g Operating Reactors Branch No. 5 j Division of Licensing 6,5/o/6/
Enclosure:
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^ ^ __ 1 ^ Haddam Neck Docket No. 50-213 ev sed 3/30/82 Mr. W. G. Counsil CC Day, Berry & Howard Counselors at Law One Constitution Plaza Hartford, Connecticut 06103 Superintendent Haddam Neck Plant RFD #1' Post Office Box 127E East Hampton, Connecticut 06424 Mr. Richard R. Laudenat Manager, Generation Facilities Licensing Northeast Utilities Service Company P. O. Box 270 Hartford, Connecticut 06101 Board of Selectmen Town Hall Haddam, Connecticut 06103 State of Connecticut 0Ffice of Policy and Management ATTN: Under Secretary Energy Division 80 Washington Street Hartford, Connecticut 06116 ~U. S. Environmental Protection Agency Regicn I Office ATTN: Regional Radiation Representative JFK Federal Building Boston, Massachusetts 02203 Resident Inspector ~ Haddam Neck Nuclear Power Station c/o'U. S..NRC East Haddam Post Office East Haddam, Connecticut 06423 Rcnald C. Haynes, Regional Administrator Nuclear Regulatory Commission, Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 l -l
SAFETY EVALUATION HADCAM NECK PLANT SYSTEMATIC EVALUATION PROGRAM TOPIC: III-4.C INTERNALLY Gr.NERATED MISSILES I. INTRODUCTION Missiles which are generated internally to the reactor facility (inside or ou'tside containment), may cause damage to structures, systems and components that are necessary for the safe shutdown of the reactor facility or accident mitigation and to the' structures, systems and compenents whose failure could result in a significani release of radioactivity. The potential sources of such missiles are valve bonnets, and hardware retaining ' bolts, relief valve parts, instrument wells, pressure containing equipment such as accumu-lators and high pressure bottles, high speed rotating machinery, and rotating ~i segments (e.g., impe11ers and fan blades). Scope of Review The scope of review is as outlined in the Standard Review Plan (SRP) Section 3.5.1.1, " Internally Ganerated Missiles (Outside Containment)," and SRP Section 3.5.1.2, "Inte'rnally Generated Missiles (Inside Containment)." The review specifically excludes SRP Section 3.6.1, " Plant Design for Protectian Against Postulated Piping Failures in Fluid Systems Outside Containment," 3.6.2, " Determination of Break Locations and Dynamic Effects Associated with the Postulated Rupture of Piping," as well as those SRP sections. dealing with natural phenomena (including missiles generated by natural phenomen'a),
- oissil?s generated outside the facility, and turbine missiles.
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~ \\ \\ II. REVIEW CRITERIA The acceptability of the design of pr'otection for facility structures, systems, and components from internally generated missiles is based on meeting the following criteria: 1. General Design Criterion 4. " Environmental and Missile Design Bases" with respect to protecting structures, systems and components against the effects of internally generated missiles to maintain their essential safety functions, 2. Regulatory Guide 1.13. " Spent Fuel Storace Facility Design Basis" as related to the spent fuel pool systems and structures being capable of withstanding the effects of internally generated missiles, and preventing missiles from impacting stored fuel assemblies. 7 3. Regulatory Guide 1.27, " Ultimate Heat Sink for Nuclear Power Plants" as related to the ultimate heat sink being capable of withstanding the effects of internally generated miss'iles. III. RELATED SAFETY TOPICS AND INTERFACES Review Areas Outside the Scope of this Topic' As stated previously, this review specifically excludes the following: 1. SRP Section 3.6.1 " Plant Design for Protection Against Postulated Piping Failure in Fluid Systems Outside Containment" - This matter will be covered cnder Safety Topic III.S.B. " Piping Break Outside Containment."
- 2.. SRP Section 3.6.2. " Determination of Break Locations and Dynamic Effects Associated witir the Postulated Rupture of Piping" This matter will be covered under Safety Topic III-5.A. " Effects of Pipe Break on Structures.
Systess and Components Inside Containment.? j 1 1 2 :.:.:C. 30h.~.2L.22X?*"E.=E'.E?= F.3:.7... !?& - -= C~~=m-w m:231E2' DsM~.Ewx
j f ~ e ~ i l 3. Natural,Fhenomena - This matter will be covered under S afety Topics III-6, "Seis.aic Design Considerations" and III-4.A. " Tornado Missiles *. 4. Turbine Missil,es - This matter will be covered under S afety Topic III-4.B. "Turbin' Missiles." e Interfaces with Other SEP Safety Topics Satisfactory resolution of the. following safety topics will depend, at least in part, on the satisfactory resolution of this topic: 1. Topic VII-3, " Systems Required for Safe Shutd::wn" 2. Topic VII-4, " Effects 'of Failure in Non-Safety Related Systems On Selected Enginee ed Safety Features" 3. Topic IX-1 " Fuel Storage" 4 Tope IX-3 " Station Service and Cooling Water System" 5. Topic II-3.C " Safety-Related Water Supply (Ulti,= ate, Heat Sink)" IV. REVIEW GUIDELINES ~~~~~# '~ Systems and components needed to perfonn safety. functions were identified as , those listed in SRP Section 3.2.2, " Systems Quality Group Classification," 1. Systems needed to perform sinfety functions"(safe plant shutdown or accident sitigations) are; a. Primary Coolant System b. Emergency Core Cooling System c. Containment Emergency Cooling Systems l
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. d. Chemical and Volume Control Systems e. Residual Heat Removal System f. Component Cooling k'ater System 9 Service Water System h. Cor. pressed Air System 1. Diesel Gcnerator Auxiliary Systens J. Diesel Fuel Oil System k. Main Steam System (portions of) 1. Feedwater and Condensate Systems (portions of) m. Auxiliary Feedwater System n. Ventilat'en System for Areas such as Control Room. 2. Systems whose failure may result in release of unacceptable amounts of radioactivity. a. Spent Fuel Pool Cooling and Cleanup System b. Sampling System c. Liquid Waste Processing System d. Gaseous. Waste Proc.essin.g, System e. Containment Purge System 3. Aco1tionally, electrical systems, which are necessary to support those fluid systems needed to perform safety functions are: a. Diesel Generators b. Station Batteries. c. 4160 Volt and 430 Switchgear and Relay Rooms d. Control Room e. Cable Spreading Room f. Containment Electrical Vault _i a ':] - J :.. CE.L.~.'Z: 2 D ; M'Q.L"'1";;& Yg --- _ -+ n --cwLv _u n-~ m _ -. - -
-l - s V. P.EVIEW AND EVALUATION 1. Systems Needed to Perform Safety Functions a. Primary Coolant System The primary coolant system serves as the pressure retaining boundary for the primary coolant a.nd, ris co.mprised of the reactor pressure yes'sel 1 and four parallel heat transfer loops. Each loop contains a circulating pump, two stop valves, a bypass line and a steam generator. The system also includes the pressurizer, pressurizer relief tank, the connecting piping, and instrumentation. The purpose of the pres-surizer is to maintain primary coolant pressure and to, compensate for coolant volume changes as the heat load changes. All components of the primary coolant system except the nitrogen pressure regulator and vent drain isolation valves for the pressurizer relief tank are located within the containment building. l 1 t The reactor vessel is a cylindrical vessel with a gasketed re..ovable. upper head. _The vessel, upper he,ad is held in' position by studs. It is unlikely that any of these studs will become a missile because they are not subjected to reactor pressure and, therefore, are not i exposed to sufficient pressure to create an accelerating force sufficient to cause them to become missiles. 6 .3 j 'i N ?$ ~~ ~ ~ ~
l 1 .6 The pressurizer relief valves have the potential for becoming missiles. All of the relief valves are mounted on top of the pressurizer. The position of the pressurizer above the loops is such that if any parts blow off the relief valves, they would strike above or to the side walls and are therefore, not likely to damage other components or piping of the primary coolant system. Control rod
- drive modules are mounted on top of the reactor vessel and are considered as an extension of the reactor vessel head.
Each module is bolted to a flange on the reactor vessel head and seal welded. The modules are all structurally tied together for seismic reasons and to provide lateral stability. Because of this design, we do not consider the modules as likely missiles for these reasons. Further, a 24" thick concrete cover is placed over the control rods during operation as further protection against potential missile damage to safety systems. Instrumentation generally requires some penetration into the reactor coolant systen. These penetrations are usually small and take the form of welded wells. The wells are not credible missiles but should one fail, that it will not cause serious damage to the reactor coolant system or compromise its safety due to their defuntation. The possibility that missiles may also result from destructive over-speeding of one of the primary coolant pumps in the event of a pipe 9 i e t 3 3._. . u g - _.z a m gw - m.n_ = -. = - _ - - _ ~ _ _ _- - = - --
~7-break in the pump discharge was also reviewed. potentially damaging impeller missile ejection from the broken pipe is minimized by a massive steel pump casing.
- 4e believe that the probability of missiles from overspeed of both the motor and impeller of a primary coolant pump that could result in damage to safety-related equipment is acceptably Icw to allow continued operation of this plant.
The four steam generators have manways held in position by studs on the primary and secondary sides of the shell. These studs are not subjected to sufficient stress to result in a significant missile scurce. 'de therefore do not consider the steam generators as likely missile generating sources. In summary, in considering the primary cobla'nt system, because of its equipment design features and component arrangement (i.e., separation), it is our judgement that this system's function will not be detrimentally affected considering internally genera'ted missile sources from the reactor coolant system as identified above. However, should a missile create a break in the primary coolant system, the emergency core cooling -4 system will keep the core cooled. i
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[ 1. _ b. Emergency Core Cooling System The amergency core cooling system (ECCS) serves as the means of injecting water for core protection in the event of reactor coolant system water loss. The ECCS is comprised ~ of the high pressure safety injection (HpSI) system, the low pressure safety injection (LpSI)systemandchargingsystems.IThehigh-headsystemconsists of two pumps, each rated at 1750 gpm, the low-head systems consists of two pumps, each rated at 5500 gpm, and the charging system con-sists of two motor driven centrifugal charging pumps each rated at 360 gpm. These pumps are located in separate cubicles in the primary auxiliary building. A missile caused by failure of any high energy line in this system could not affect more than one of these pumps due to their compartmentalization. The failure of the suction of discharge lines of any one pump could eliminate that pump only and would leave the other pumps unaffected. The initial source of water for the high-head and low head pumps is the Refueling Water Storage Tank (RWST). This tank is located outside, north of the containment building. The associated piping is buried. The location of the tank would tend to make the tank safe from internally generated missile other than those which might originate from turbine generator (See Safety To'pic III-4.B " Turbine Missiles"). The tank is not tornado missile protected (See Topic III.4.A " Tornado Missiles..). 3
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In summary, in considering the ECCS, because of its functional design, redundant features,' separation and equipment design features, it is our judgement that this system will be capable of performing its design function considering internally generated missile sources as discussed above. ,c. Containment Emeroency Cooling System The containment emergency cooling systems consists of two independent systems - an air recirculating system and the containment spray system. The containment air recirculation system consists of four fan cooled coil units and a system of distribution duct work, instrumentation and controls. The units and controls are located at quarter points in the annulus between the crane support wall and the reactor con-tair.mant wall at elevation 22-feet and 5 inches. Therefore, because of separation it is unlikely that a single missile could fai.1 more than one of these units. Cooling water for the air circulat' ion system is provided by the service water system. The service water system is-not a high energy line and therefore is not i likely can-didate to produce missiles. The containment spray system utilizes the residual heat pumps, the residual heat exchangers 'and a spray header ring at elevation 110 feet to distribute water throughout the containment. Power to the residual pumps is normally available from the station service system. The spray nozzles are located high inside containment. It is unlikely that any missile could reach these components. Should a missile-strike this system it will still be capable of performing its design function considering internally generated sources as discussed abov'e. t a k .?
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-j .. _. _ 7 In sum:ary, in considering the containment emergency cooling systems, the air recirculating system and the containment spray system, should a missile strike either of these systems and results in its failure, the other system will be available to perform its design function considering internally generated missile sources as discussed above. 9 d. Chemical and Volume Control System (CVCd) ~.a CVCS controls and maintains reactor coolant system inventory and parity through the process of makeup and letdown. The system con-sists of a regenerative heat exchanger and letdown heat exchanger to cool the excess coolant taken from the primary system during plant heat up and plant operation. The coolant is reduced in ]-- - temperature and pressure and passed to purification and deborating demineralizers where corrosion and fission products are re.oved. The coolant is then returned to the volume control tank. The charging pumps return the coolant to the crimary system from the volume con-trol tank. Additional wate'r or b'oric acid is supplied from the ~ charging pumps as necessary. a The regenerative heat exchanger, the drain cooler, and the charging and letdown line isolation valves are located in the reactor con-ta inment. The mixed bed demineralizers, the spent fuel pit deminera- ~ lizer, and the rear. tor coolant prefilter and post-fi1ters are ^ ~ gygg,2m mgwm j "..,.,.J'
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The letdown orifices are located in the pipe tunnel im.ediately out- ) side the reactor containment. All other system equipment is located 1 in the primary auxiliary building. The evaluation of this system did not identify any potential sources of missiles which might, endanger the CVCS. The charging and letdown lines are high energy systems;- however, a single missile could damage the redundant charging and letdown trains. Should that event occur the plant could still be shut dcwn' safely in a normal manner using the auxiliary feedwater system and the residual heat removal system. We therefore, conclude that the possibility of internal missile damage to the CVCS is very low. Further, such an event will not result in an unacceptable release of radioactivity or endanger the safe shutdewn of the plant. ~ e. Residual Heat Re oval System (RHR) [ Normal functions of the RHR system are: (1) to remove residual heat from the reactor core and reduce the temperature of the reactor coolant system (RCS) during plant cooldown; and (2) to transfer water from the refueling cavity back to the refueling water storage tank after a refueling operation. Additional functions of the RHR system after a loss of coolant incident are to cool ar.d circulate spilled water from the reactor containment sump, through the residual heat exchangers and back to the RCS, or to the suction of the high pressure safety injection (ht'SI) pumps and/or the charging pumps. 4 M 1 .. { i f *7.*.. ['[. k. '. [' k. $.h .b.k'. [ hY Nb h.Ib[Mdefk 5 dfMTOes?ihhRmM
,a While the RHR system is not redundant, the isolation characteristics of its components are such that the probability of missiles striking the system is low and should a missile strike the system, the auxiliary feed.iater system can maintain the plant in hot condition until the FHR system is repaired. Therefore, in our opinion the plant can be safely shutd'cwn considering that a missile strikes the system piping or components. f. Commonent Cooling System The component cooling water system is a closed system with three centrifugal pumps each rates at 2750 gpm and two heat exchangers. All c:rpor.snts in this system are located in the primary auxiliary -{ - building (PAB). The component cooling water (CCW) system removes heat from the shutdcwn cooling heat exchangers, seal water heat exchangers, the charging pump oil coolers, the residual heat removal p:r p seals, the reactor coolant pumps, and the neutron sh uld tank ccolars. The water is'circElated through these heat sources, heat ~ is transferred to the component cooling water which in turn is cooled ~~ by the river water. We conclude that this system would be an unlikely source of missiles due to its low operating temperature and pressure. Further, potential missile sources such as pumps are discussed in Section V.l.e of this SER. J] = i! i ,z..y,.
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~ However, if a missile strike occurred, and the CCW system is damaged it may be isolated from RHR heat exchangers by remote manual valves and service water could be substituted for CCW, (See also SEp Topic IX-3, " Station Service and Cooling Water Systems") until repairs to the CCW system could be made. We conclude that the ccmponent cooling water system is adequately protected from internally generated missiles. 9 Service Water System The service water system (SWS) consists of four two-stage vertical centrifugal pumps each rated at 6000 gpm located in the screenwell ~ ~ - ' house. The SWS provides a supply of cooling water to both the primary and secondary plants. It also provides the water required for cleaning the traveling water screens and the motive force' for infecting hypochlorite into circulating water system. The pump intake columns are submerged in' the pump well of the' screenwell house. Each pump is' driven through a solid coupling by a 250 HP vertical, solid shaft, induction motor having an open drip-proof enclosure. The system piping is routed underground from the screen-house to the other buildings. i I = t I .w. .7,.q, ~ rafn.. - c. - w r_rj t e-f i M m -7 52Y.Hn "a- ' " " " =
- l 1 Fewer for all the service water pumps is included in the capacity of the emergency diesel generators. Upon the loss of all normal alterr.ating current power and after the emergency power supply is l established, one service water pump will be started automatically on each diesel generator. If the first service water pump does not start, the power supply is automatically transferred to the second pump on that diesel generator bus. j These service water pumps are unlikely missile generators because their enclosure (casing) and submergence in the intake structure and their low operating speed (1185 rpm) and low operating pressure 1 i would not endanger the service water system piping in the intake structure and there are no potantial sources of missiles that could pose a threat to the service water system. However, if one of the pumps became a missile source,the orientation of the other three pumps is such as to provide reasor.able assurance that not all four pumps will be lost. Therefore, we conclude that the service water system - meets the requirements of protection against internally generated missiles. h. Ccmpressed Air System The compressed air system is designed to supply oil-free air to both l the instrument air and service air systems. Three full capacity ( l non-lubricated compressors are provided with separate after coolers, air receiversand air intake filter. The receivers are interconnected. Two air headers leave the air receivers, one to supply instruirent air after filtering and drying, the other to supply the service air systete. Both headers have branch lines routed to the various buildings 1 I t t 9 ,n . 3.5. y m b W '. M 9 ' C " M = "
associated with.the reactor facility. The nonnal air supply system functions at about 100 psig. The air is supplied to the plant through a double piping system originating at each of the two air receivers. The air distribution headers are protected from missiles by routing the piping.through protected structures until they reach their tenninal point. The main potential missile generator in this system is the air receivers but these ASME Code vessels are protected by relief valves set well below the air receiver rupture pressure. Our assessment of this system is that it is unlikely to produce missiles. However should a missile strike the compressors, the accumulators will provide enough air to shutdown the plant safely. Therefore, we cen- ~ T~ ' clude that this system will be capable of performing its design function considerine internalmissiles as discussed above. i. Diesel Gar.arators Auxiliary Systems. The two emergency diesel generators and their corresponding switch-gear are located within the diesel generator building which con-sists of a reinforced concrete roof and walls. The system consists of two 2850 KW 0.8 pf. 4160 volt, 4-phase 60 HZ, 900 rpm diesel engine driven synchronous generators and-two 4160 volt metal clad switchgear sections constituting the two emergency buses 8 and 9. l l j l l .c .na ~m.. wa =.+ w= ======m== "*'*^~""
. In addition to being housed 'in a reinforced concrete building the two diesel generators, their control cabinets, and the corresponding e ergency buses 8 and 9 are separated from the other unit by a 12" thick concrete wall. Further, except for the diesel generators them-selves, there are no potential missile sources located within these. cubicles. Dce to independence and separation of the diesels and their asso-ciated auxiliary systems, we conclude that the diesel generator auxiliary systons will be capable of performing their function con-sidering internal missiles.
- j. Diesel Fuel Oil System
]' The two diesel fuel oil tanks are housed in separate underground reinforced concrete structures. The piping is routed ur.dergrcund to the diesel generators. Due to indepdndence and separation of the tanks and piping, we conclude that the diesel fuel oil system will be capable of performing its function considering internal missiles. ~ k. Main Steam System (portions of) The main steam system consists of four steam generators and four 24" steam lines which exit the containment building through contain-ment penetrations into the main steam nonreturn valve area (unenclosed). From the main steam nonreturn valve area the four lines run across the plant yard, to the turbine building, through the heater bay area, j and to t.be turbine stop valves. I 4
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A missile frem any of the 'nonreturn valves could result in the loss of both the auxiliary feedwater pumps.which are located directly below the r.ain steam valves. Plant shutdown with loss of both auxiliary feedwater pumps is discussed below under Section V.l.m of this SER. No potential internally generated missile sources which pose a threat to the main steam lines exists between the nonreturn valve area and the turbine stop valves and therefore, this portion of the main steam system has been determined to be unaffected by potential missile sources. Further, this portion of the systea does nnt contain ~ credible sources of missiles. 'a'e conclude from our review of the main steam system that this system (except for the nonreturn valves) will not produce missiles due to its heavy walled design and constructioni Should a missile from other sources damage the system downstream of the main steam isolation valve, the plant could be safely sh'ut'own b;v closing'the isolation valve. d Should the missile damage occur upstream of the valve or at the valve itself the plant can be safely shutdown as one of the design basis accidents. (refer to SEP Topit XV-2). ~ - s. In summary, in considering the main steam system, its features, and the protected afforded from internally generated missiles due to plant layout, and available accider.t mitigation ecuipment, it is our judgment that this system will be capable c/ perfoming its design function considering internally generated missiles as described above. I, h .y.... ~.. e 1 .. a..IJ.id W AAWdNM*N"' ~~
. 1. Feedwater and Condensate Sys' tem (portions of) The main feedwater system consists of two motor driven pumps which punp water to the four steam generators during normal system operation. The cor.densate system transfers condensate and low pressure heater drain from the condenser hot well through five stages of feedwater - heating to the suctions of the main feedwater system pumps. Two half size condensate pumps take suction through 30 inch lines from the bottom of the condenser hot well. The puqs discharge into a comon header which carried the condensate through two steam jet air ejector c:ndensers arranged in parallel and through gland steam condenser. A missile generated from this system would have no effect on the equip-ment which is vital for safe shutdown. The only area of concern for this system is that portion between main feedwater isolation valves and the steam generators if the system were damaged in this area.that the steam generator would probably blow'down. Due to the protection afforded by surrcunding equipment, we conclude that missile damage to this portien of the fee Ater system is unlikely. Further if the system were damaged in this area, the use of the charging and safety infection pumps would be available for safe shutdown. m. Auxiliary Feedwater System The auxiliary feedwater system (AFS) consists of two turbine driven pumps. Both pumps are rated at 450 gpm. The demineralized water storace tank serves as a water source through a buried pipe to the pumps which inject it into the four steam generators. The pumps -li\\ l' 1 v,. n _ n._ =, -.n. e_,. =.,. n.
- 1 9-discharge into a common header which branches into two parallel paths to the main steam generator feed system. A failure of one of the main steam return valves could result in the loss of both auxiliary feedwater pumps (refer to Section Vol.K of this SER), since the pumps are located in the enclosure directly below the main steam valves. The licensee also concludes that another source of missiles would be the pumps thenselves. The AFS can continue to perform its design function in the event of a single active component failure. However, the system is susceptible to single passive failures which could dis-able both auxiliary feedwater suction line from the demineralized water storage tank (DWST) the common feedwater discharge header, or the decay i heat removal header providing steam to the AFP turbines. In addition, passive failure of the condensate supply line from the DWST to several non-essential systems could divert condensate away from the AFPs since the AFP suction line connects directly to the non-essential service header from the DWST. Should it be determined during the integrated as-sessment that loss of both auxiliary feedwater pumps is unlikely, the balance of the auxiliary feedwater system and the condensate supply line need to be examined for susceptability to internally generated missiles. The licensee has described an alternate method for removing core decay heat if the AFS were disabled by one of the above passive failures. The " feed-and-bleed" method consists of blowing down the RCS to the primary containment via the pressure power-operated relief valves and injecting coolant with the safety injection systems. Long-term cooling would be accomplished by either ECCS recirculation or by the RHR system. Contain-ment cooling would be provided by the containment recirculation fan coolers. The use of the " feed-and-bleed" method should be addressed during the SEP integrated assessment.
s \\ Ventilation System for the Control Room n. This system supplies 3000 cfm of recirculated air and 1500 cfm of cutside air. The outside air is required to replace the filtered 'whsust air frnm the toilets and kitchnette to the corridor and tur-bine building. A portion of the air is passed through the main' con ~ trol board before returning to the suction of the air conditioning system. The rer.aining air is returned to the air conditioning unit through ceiling relief grills, a ceiling plenum, and a concrete streaming shield. An alternatie air intake is provided by a dampered intake register located in P supply duct in an adjoining enrridor. Our review did not reveal any potential missile genarators associated with the ventilation system for the control room. k'hile duct work can be penetrated by missiles, the total cooling capability will not be lost and time is available for action.to restore adequate ventila-tion. Additionally, all of the ventilation ecuipment is in a room ssparate from the centrol roca and no damaging missile sources are in the vicinity. In summary, in considering the ventilation systems for the control room, it is our judgment that this ~ system will be capable of performing itsdesignfunctionconsiderinointernallygeneratedmissjles. i \\ t i a i i 4
2. Systeas 'a' hose Failure May Result in Release of the Unacceptable Amounts - of Radioactivity a. Spent Fuel Pool Cooling and Cleanup System The spent fuel pool cooling system removes residual heat from the spent fuel stored in the pool. The spent fuel pool' cooling system is designed to remove the residual heat produced by the stored spent o fuel elements while maintaining the pool water temperature at 106 F o during nor.a1 refueling and 139 F during the full core offload condi-tion. The spent fuel pool cooling system consists of two cooling pumps and two heat exchangers. The spent fuel pool pu a draws water from the pool, circulates it through the heat exchangers, and returns it to the pool. Service water cools the spent fuel pool heat exchangers. The spent fuel cooling system is a low energy system, therefore it is unlikely to generate missiles. The pucps and heat'exchangers are pro-tected from missiles due to their compartmentalization. Should the ecuipment become inoperable due to that missile damage, there is sufficient time to effect r'epair or" arrange for alternate cooling such as fire hoses. In our judgment, this system will be capable of performing its function considering internally generated missiles as discussed above. ~ t 4 ..X& ' m ' ":r::::.;-r:wt- -c2;_z.s ae.i:.95,g5gy_,.m u,
~ f ~ (_._ ; 7 _ _ _. ~._ r s. p - ~ \\ ~ / v saa s y e ~: s ~ . s x ~ a h \\ ~.. 4 - p,,y b. ladpling Syste'm x ~ .- m 1 ., The seapling system provides fluid and gaseous samples for laboratory ar.alysis tr$ crder to evaluate and provide a basis for control of 1~ x 3 re6ctor Eco]dnt chemistry and radioche :istry. .il, [ + \\ s Most of the system equipc6nt is located in the sample and radioactive ~ valve ' rood'of the primary auxiliary building (PAB). A delay coil. x ~ capillary tube, and several sample lines with associated Yalves are 'i \\ Ilgeated in the reactoy contalnpent. Any release of radicactivity in ~ 3 i this portion of the system can be cr.nfined to containment. ~ All of the sanpling bperations are performed inside the sampling hood s. in the valve reqm in the PAS. It 1s hjghly unlik'ely that missiles from ary source will cause damage to this system. ' HowLver, if a missile m 'cid damase this system, the resulting release would not-result in '~ unacceptable conshuences since it could bA Dntained in this area and sufficient time is avgilabid to make repair;;. The, release would be controlled via an air' operated valve (A0V) inl the valve room and/or a s 3 i 3 valve in containment. \\ s c. Liquid 'Jaste Processing System Liquid wastes enter the liquid waste processing system from the vent and drain system and are collected in the aerated drain tanks. The liquid is subsequently pumped to the test tanks, via the aerated liquid waste ion exchanger and fitter, for either further treatment, evaporation, or discharge to the river. The Tiquid waste processing system is not a high energy line system and therefore it is unlikely that this system will produce a missiTe. Further, na pctential -l missile generators were Tocated within the vicinity of this system. a :.. g.;;. zw.m : %tE =&.Dit.'.a- '"L'2 ~ ' W!'W'""~ =* ~ " " ' ' ' '
... _ ~. _ _... . t Should a missile darage this system and if contents are drained, the resulting liquid release would be retained in the building long enough'to allow a clean up. d. Gaseous b'aste Processing System The hydrogen and radioactive fission product gases enter the gaseous waste system from the vent and drain system as off-gases frcm the boron recovery system and as gases evolved from liquid in the primary drain collecting tank and baron waste storage tanks. The licensee has stated that this system is protected from internally generated missiles from outside sources and the potential for internally generated missiles from the system itself was small. In the event of damage to the waste gas system, it would not pose any hazard to the public health and safety. Further, missile damage-to the system will not affect the safe shutdown of the facility. e. Contain: ent Purae System The containment purge system is provided to periodically purge the containment prior to entry. The system consists of two fans, a iodine ~ removal unit, ductwork, louvers, dampers, instrumentation and controls. The shielded iodine removal unit consists of a centrifugal fan, moisture separator, absolute filter and air activated charcoal fil ter. All of these components except por,tions of the ductwork and isolation valves are located in the primary auxiliary be:lding. From our review we conclude that the probability of this system producing missiTes or being damaged by a missiTe is very low ,al j jl s.w.w-www.+...n._wan.=wn - a__ _.-xm,
1 due to its low operating pressure. Should a missile damage this ~ system, there would be ample time to perform repairs. Therefore - ~ we conclude that the missile protection provided for this system is acceptable. 3. Electrical Systems k'hich Are Necessary to Suoport These Fluid Systems Needed to Perform Safety Functions a. Diesel Generators See Section V.:1.1. b. Station *atteries The 125 volt batteries supply power and control for operation of the turbine generator emergency auxiliaries, switchgear, motor cperated disconnect switches, annunciators,125 volt DC solenoid valves, vital bus inverters, and emergency lighting. Th'e principal equipment comprising the system are: two 60-cell lead acid-type batteries; two static battery chargers; and a two-section battery distribution switchboard. The batteries are located in a corner of the swite.hgear room along with the 430 volt switchgear (See 3c). A masonry wall separates '.; the two batteries.' However the batteries are not separated from other areas of the switchgear room which houses the two rod motors.
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T -25.. The rod drive motors are 150 HP motors located in the middle of the switchgear room. Evaluation o'f these motors show that the 150 HP motors are unlikely missile generators because of their low operating speed (1750 rpm) and : nick steel casing. However, if one of the motors did fail, both station batteries could be damaged. ^We recommen'd that the phys' cal proximity of the batteries with regard to rod drive motor missiles be evaluated during the plant's inte-grated assessment. c. 4180 Volt and a80 Volt Switchcear and Relay Rooms The engineered safeguards diesel generators and switchgear are separated into two redundant systems. These systems are located in the diesel generator building in separate rooms which are separated by a concrete wall. Due to separation, it is,not con-sidered credible for missiles to damage both power sources since a concrete wall separate them. The essential 480 volt station service system distributes and con-trols power for all 480 and 120 volt AC station smice demands. The 480 volt switchgears are located in the switchgear room. Within the room there are no barriers that separate redun_ dant 480 volt switchgear. The only potential missile sources in this room ' :.L..M.%sa 2&%M:'3 f&M'
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__.__ 7 _ . are the two rod drive motofs. The rod drive motors are 150 HP motors located in the middle of the room. Evaluation of these motors show that the 150 HP motors are unlikely missile generators because of their low operating speed (1750 RFM) and thick casings. McEever, should a missile be generated redundant 480 volt switch-gear could be damaged, causing loss of all 480 volt power. We conclude that the location of the essential 4160 volt switch-gear provide adequate protection from internally generated missiles. However, we cannot conclude that essential 480 volt switchgears are adequately protected. We recorr.end that the physical proximity of the 480 volt switchgear with regard to rod drive motor missiles T' be evaluated during the plant's integrated assessment. d. Control Room. The control room is located in the turbine building. There are no internally generated missiles which could damage the control roon.' The control room has a large plate glass for the visitors. The control room boundary is protected by a concrete wall which provides protection from internally generated missiles outside the control room. e. Cable Spreading Room The cable spreading room is a reinforced concrete room directly below the switchgear room. There are no high energy systems located in this arent therefore, the likelihood of any damaging missiles i oroduced from this room or impacting this area irr unlikeTy. I' s / 1 ,hK W:22 '.~i miaruk *
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y ' f. Containment Electrical Vault The containment electrical vault is a reinforced concrete structure outside of the containment building. This vault does not contain piping or other sources which might produce missiles. Due to its construction, it is unlikely that a missile would penetrate.the walls and do any dam. age to this structure. VI. ' Conclusions Based on our review of the systems and components needed to perform safety functions, we conclude that the design of protection from internally generated missiles meet the intent of the criteria listed in Section II - REVIEW CRITERIA with the exception of the following: 1. The essential 480 volt switchgear and the station batteries ~ are not adequately protected from the internally generated missiles. The need for additional protection in this area of the plant from the effects of internally generated missiles will be evaluated during theintegratedassessmentforHiddamNeck. In addition, the " Feed ~and Bleed"[meth6'd'propo, sed for pl. ant' shutdown by the licensee following missile events that damage redundant auxiliary feedwater 1 j trains should be evaluated during the integrated assessment. 0e -e e a e o e -O b 08 4 h 88 4 4 '}}