ML20202G799

Proposed Tech Specs Revising Description of Starting Logic for RB Recirculation Sys Fan Coolers to Ensure That Only One RB Fan Starts on Es RB Isolation & Cooling Signal

ML20202G799
Person / Time
Site:	Crystal River
Issue date:	12/05/1997
From:	FLORIDA POWER CORP.
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ML20202G797	List: 3F1297-11, Application for Amend to License DPR-72,revising Description of Starting Logic for RB Recirculation Sys Fan Coolers to Ensure That Only One RB Fan Starts on Es RB Isolation & Cooling Signal ML20202G799
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NUDOCS 9712100112
Download: ML20202G799 (12)

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FLORIDA 'OWER CORPORATION CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50-302/ LICENSE NUMBER DPR-72 LICENSE AMENDMENT REQUEST #224 REVISION 0 REACTOR BUILDING FAN STARTING LOGIC MODIFICATION ATTACHMENT E ITS BASES AND FSAR REVISIONS Strikeout / Shadow Changes Text being deleted Indicated-by-s-tt h eotrt l Text being added Indicated by bold italics

!u 228M" 8u88802 P PDR CRYSTAL RIVER ENERGY COMPLEX 15780W. L6 treet .C at Rwer, Florida 34428 6708 352) 795-6488

c. Tmdrgerd CUu mMCool6t Achdent Ont RB Cooltr skaB kave the cayhtllly to ream a minimum of so 110'BTulkrfrom the Ra Atmosphcre vfa cond(nsatt la lhe RB Sumf and hfAI (tar $f(T lo (kt SW Sp[fM. With a deCign fouling factor ef-0-0018 hr r f t!/Stu.160 x 10!-Btu /br removed from RB atmosphere,

, of ;-;hich 131 x 102-Stu/h- (65.5101 Btu /hr per c00ler) 1; rejected to

{

the SW System The remaining 16.5 x 10! Btu /n- for each c00ler remains y in the condensate ;;hich fall: to the RB sump (Ref 6').

L F ft%t With a cleaner heat exchanger (fouling factor of 0.0009 hr176 10. x 14! Stu/hr is re Btu /hr is rejected to the SW System No more than one D)" two (2) RB m .. fans ,,g wiH orm_ toMeso2_=W--d-fo%ub . ^ - ^^

d. Normal heating load (outside design air temperature of 25 F. inside design air temperature of 60 F full shutdown of plant): 615.000 Btu /hr.

e. Ventilation and exhaust rate (1.5 air changes per hour): 50.000 cfm.

At this rate, the system reduces the activity level in the building to doses defined by 10 CFR 20 for a 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> occupational work week which will allow accessibility within two hours after initiation of the purge systems, after establishing a Plant Operational Mode 5.

5.

5.2 DESCRIPTION

The Reactor Building Cooling Systems are subdivided into three major sets of components - Group A. Group B. and Grouc C. These are shown in the flow diagram Figure 5-27.

a. Groun A Group A components are those which filter (demister only) and recirculate air throughout the building under both normal and emergency conditions. Sensible and latent heat are removed as required. Included in this group are the reactor building fan assemblies and the auxiliary fan systems which deliver air to the operating floor, the reactor compartment, and the steam generator compartments. This group also includes the normal duty Industrial Cooling (Cl) system. featuring a water cooled chiller. two evaporative cooling towers, and miscellaneous supporting equipment. The CI System supplies cooling water to the RB Fan Assemblies and Cavity Coolers during normal plant operation.

b. Group B Group B components are those which supply filtered (85% efficient NBS) and electrically heated (tempering only) outside air to the building whenever required for purging, during Operational Modes 5 and 6.

Included in this group are the two 48 inch diameter butterfly valves which seal the building air supply port.

c. Groun C Group C components are those which exhaust air from the building during Operational Modes 5 and 6 aurging, pass it through roughing.

HEPA, and charcoal filters. and tien discharge it to the atmosphere I through the unit vent. Included in this group are the two 48 inch diameter butterfly valvet which seal the building air exhaust port.

5-96 (Sev. 23)

5.5.3.2 Emeroency 00eration When an emergency occurs which actuates Reactor Building isolation and Cooling, the Group A components (fan assemblies) assume their emergency mode of operation as follows:

a. Motors are supplied by emergency power.

b. The two nyrc ;;++:r;-7 tripped from fast speed.

The t'c'e ont fS selested motor 11 start and run at low speed.

d. The cooling water supply from the CI System will be isolated and the cooling water from the SW system will be admitted to the reactor building fan cooling units. The isolation and admittance of these flows is accomplished with automatic valves.

5-98a (Rev. 23)

6.3 REACTOR BUILDING EMERGENCY C001.ING SYSTEM 6.3.1 DESIGN BASES Reactcr Building emergency cooling is provided to limit post-accident ambient pressures and temperatures to design values.

Reactor Buildini air recirculatic" cnd cooling units, backed up by the Reactor Building S] ray System (BS; described in Section 6.2 are used during emergency cooling periods.

T1e systems are designed so that the heat removal capability required during theJolt_

accident period can be attained by operating Reactor Building Spray Systems erctor Building air recirculation cooling units in the emergency mode. There a f w e threr combinations possible for configuring the systems:

Soray Systems Coolina Units g p w ns One-twc Two a

=c -_-_-_ u A h rv (None _: -- .. ,,ThreJe These 4wst hree combinations are acceptable for limiting the Reactor Building below -

~

trie design pressure of 55 psig and the design temperature of 281 F after a Design Basis LOCA.

The Design Basis LOCA evaluation described in Section 14.2.2.5 assumes the worst case single failure is a loss of one train of emergency power due to failure of an Emergency Diesel Generator to start. Consequently, only one RB spray train and one RB cooling unit are assumed to be available for post-accident reduction of containment pressure and airborne lodine.- _,,r t n listed above assumes the failure of one BS trai but two second first

^^

with a cooling units we railable. - m f- _

The secod comknation is win the Reactor sulldig codig ad syay systens oyrates with out a fallure.

The third combination recognizes that two trains of the BS System will actuate if a single failure makes the entire RB cooling system unavailable. No single active failure can disable a train of the BS System and both trains of RB coop The Reactor Building Emergency Cooling System is not single failure proof. This cundition is acceptable since adequate Reactor Building pressure, temperature, and iodine red.uction can be accomplished with two BS trains and no RB coolers. -- ,, , -

cWouith [05binat5 thr7RB c00leNniti and no BS train . require; multip'h failure in the BS System. as Well 20. Operator action; and 10 therefore, not

> Gees 4dered credible. It 1: included to identify it as a combination considered for i pfessure and temperature control However due to Sh' System thermal and hydraulic

? restraints, this c0 & nation is not acceptable for d::ign bas 4 accident nitigation A-m4rimur of One train of BS System and One tradr Of 98 Emergenc' C001%g is required to provide long ter"' containment heat removal and iodinc removd -

(Rev. 23) 6-26

6.

3.2 DESCRIPTION

The schematic flow diagram of the Reactor Building Emergency Cooling System with associated instrumentation is shown in Figure 5-27.

Emergency cooling of the reactor building is performed using the same equipment which provides normal heat removal as described in Section 9.7. Each unit contains a moisture separator a cooling coil and a two-speed fan. Under post-accident emergency coolug conditions, the units will operate at a reduced speed with the heat being rejected to the Nuclear Services Closed Cycle Cooling System (SW).

The SW System is pressurized continuously so that a minimum of 54.75 psig is maintained in the three reactor building cooling coils and piping systems. Provisions for detecting and isolating leakage in reactor building cooling coils and piping are described in Section 9.7.

Figure 6-12 shows the heat exchange characteristics versus building ambient pressure conditions for these units. A failure aaalysis is shown in Table 6-9. The design data for the cooling units are shown in Table 6-10. Normal operation of these units is described in Section 9.7.

Seismic, pressure, and temperatm ' : tors as well as radiation, chemical, and degradation factors pertinent to th ,aication have been accounted for in the design of this system. In addition, component performance and prototype tests of components under simulated emergency conditions have been run. Prototype component tests under simulated emergency conditions include the cooling coil, motor insulation, moisture separator, aearings, motor heat exchanger pressure relief valves, gaskets and seals.

motor terminal lead spiice, and motor unit.

The duct system and fan plenum were designed to withstand a dif'orential pressure of two pounds per square inch. The system was analyzed to determu that the duct sizes and outlet locations are such that two pounds differential is not exceeded during the transient period. The emergency cooling air handling unit was designed to withstand two pounds pressure differential.

6.3.3 ACTUATION Receipt of the reactor building isolation and cooling signal automatically switches the Reactor Building Emergency Cooling System to the emergency mode. This includes:

a. De-energizing the high speed portion of the starters for the operating recirculating air handling units. ,rWOv

b. Energizing the slow speed ~h.J A starters for the twc ou recirculating air handlin unit 3 :c'ected for E!] crvis je

c. Automatic isolation of the cooling water supply from the industrial cooler and automatic opening of the cooling water supply from the SW System.

6-27 (Rev. 23)

TABLE 6-9 Single Failure Analysis - Reactor Building Emeroency Coolina System Malfunction Comments Component

1. One of the Fails to start When any of the air handling units are not operating they are emergency air or fails to automatically isolated from the system by gravity dampers. This handling start at low unit is not required for safety. The remaining unit will operate.

and in combination with the spray system. provide heat removal units speed capability in accordance with the schedule.

2. Cooling water Rupture If a rupture or major leak is detected through indication of inlet supply and and outlet flow differer.ce, the coil and lines can be isolated from the contr h ( Vr rp yw_

return lines Th+ remairing unit "4" operate and da combi"ation ith +-be ray

3. Power Fails closed operated sy < providey--~"a -MJity jn arcerdanctwin . e supply or schedule.

return valve

4. Cooling water Fails to start Two 100% capacity pumps in parallei have been provided.

pump

5. Diesel power Diesel fails to In order to prevent overloading the Emergency Diesel Generator to emergency start during certain accident conditions. only one air handling unit is j air handling acceptable for loading on a single Emergency Diesel Generator.

unit Therefore. if one Emergency Diesel Generator is inoperative. power will be available to only one air handling unit.. The Design Basis LOCA in Section 14.2.2.5 assumes this worst case power loss of a single train of emergency power.

6. Cooling water a. Fails to The cooling water supply is procedurally isolated to the non-discharge close due to o>erating air handling unit, preventing an increase in SW flow to valve on malfunction tle air handling units.

third specific to non-operating valve air handling unit- b. Fails to close due to loss of DC power without a LDOP t" -

o-49 (Rev. 23)

TABLE 6- '

i

! Reactor Buildina Coolina tinit Performance and Eau 1pment Data (Capacities are on a per air handling unit basis)

Duty

. Performance Data Emergency Normal No. Installed 3 No. Required 0 21* 2 Type Coil Finned Tube Finned lube Design Heat Load. Btu /h 80.000.000* 2.150.000 Fan Capacity. cfm 54.000 108.000 Reactor Building Atmosphere Inlet Conditions Temperature. F 281 110 Steam Partial Pressure, psia 49.99 ---

Air Partial Pressure, psia 18.31 ---

Total Pressure, psia 68.30 Atmospheric Cooling Water Flow, gpm 1.780 10 Cooling Water Inlet Temperature. F M (c)

Cooling Water Outlet Temperature. F 183 93.1 f' two (2) y ow TrauT

_y.-- --

ins fans operates 'llowing imme.llately receipt (a) No more t' of an ES . .nal(ran Igle parnf5 two fans fn,,4 cyrraffy at the same (far). m

( ) Only 6fMt BTU /h rejected to SW System. Remaining 11 x 10!- BTU /br is condensate to RS semp. With a c'eaner heat exchanger ' fouling facter of . l 0.0009 hr F ftf/ Btu). 72 " 102 Stu/b" is rejected to the SW System and the %*

remaining 16 x 10! But/hr is condensate to the RB su~p. One Rs Cooitr shall havt }

the cayability to remove a mfxImum of so t so'sTulkrfrom the na Atmayhere sta ecdensatt to the as sump f anel krat traxfer to the sw system. j i i (c) ^ c00 ling water inlet temperaturc of 10B"F correspond; to an W System j q temperature of approx = tely 05 F4 Inlet temperatere and temperature i differential are a function of seasonal s'."ings in RW-Systen temperature.

@ (c) i6noomni6 neG outside ambient air temperature down to 65 F within system limits.

6-50 (Rev. 23)

The EFW Block timer is a conditional logic specifically for the EFW motor driven pump EFP-1 of the ES 'A' train to provide for anticipatory start of the EFP 1 pump in 5 seconds in the event of a LOOP event without ES actuation and to provide sequence loading 5 seconds after Block 3 should an ES condition be present. This is accomplished by the auxiliary relay contact of timer 2 which is normally closed. The Block 1 relay contact is normally open and the auxiliary relay contact for LOOP is a normally deenergized closed contact.

Hence, for a LOOP event without HPI initiation, the EFW Block timer times out in 5 seconds. For an ES HPl initiation without a LOOP event, the EFW Block timer times out 5 seconds after Block 3 (timer 2) or 15 seconds after the EDG is loaded. For a LOOP event after a ES HPl conditnn the EFW timer and associated timer 2 are reset such that EFW will again time out 5 seconds after Block 3 (timer 2). For an ES HPl initiation after a LOOP event, the EFW timer will again time out in 5 seconds after Block 3 (timer). A logic circuit of relay contacts from Block 1. Block 3. LOOP auxiliary relay and 500 psig RC pressure trips the EFW pump EFP-1 when a LOOP event is followed by an ES HPl initiation or a 500 psig RC pressure as shown of Figure 7-5.

The interlocks with the undervoltage scheme is such that, in case of a blackout, block 2. 3. 4. 5. 6. and EFW are kept in their reset status as long as there is no voltage on the related engineered safeguards bus. As soon as the emergency diesel generator is connected on the bus, auxiliary contacts from the diesel generator circuit-breaker are used to defeat the action of the undervoltage relay scheme irrespective of the voltage on the bus thus preventing erratic loading or simultaneous energization of load blocks 2. 3. 4. 5. 6. and EFW. The emergency diesel generator is connected automatically on the bus only when correct voltage and frequency are reached.

De-energizing output relays of block 1.2.3.4.5.6. and FFW in two of the three channels will start, in sequence, the following equipment.

Block 1 HPI pumps Injection and nuclear service valves Inverters, ghting, misc. panels, batterv charger s Block 2 Reactor building cool fans c lov speed" Emergency nuclear serv _ ater pu .

Flush water pumps  !

Block 3 Emergency nuclear services closed cycle cooling water pumps Decay heat pump air handling units g Block 4 LPI pump (for which minimum flow recirculation is provided) or Start Permit EFW Block Motor driven emergency feedwater pump Block 5 Decay heat service seawater pumps Blork 6 Reactor buildina sprav o!ao_ start-permit _ -

e a &w h eajcn:LoJTny m wp w ? "

(a) ody one nr, ran wtB cpate at a time (ra Igic frevents two fas from e)sratly at tk same time). If the lead ja falls to start a second ja wl8 start 4.5 sccends latir. = -'

^ " " - -' ^ -

(Rev. 15)

3. Turbine Building Switchgear Rooms, two 100% capacity Filter and Cooling Supply Systems (AHF-16A AHF-168).

4. Miscellaneous support buildings.

9.7.2.1 Modes of Operation Emergency and normal modes of operation of the Plant Ventilation Systems are as follows:

a. In the Reactor Building, during normal operation 1 or 2 Reactor Building Recirculation System fans operate continuously at 1.800 rpm.

If the SW System (emergency duty pump in operation) is used to cool the RB during normal operation, only 2 of 3 fans may be placed into service (limited due to EDG loading). The Cl System has the capacity to supply all three (3) fans while in the " free" cooling mode (only cooling tower in operation), but only 2 fans may be supplied due to post -LOCA EDG loading. If the Cl System is used to cool the RB in the

" mechanical" mode (chiller in operation). only 2 RB Fans can be placed in service (maximum evaporator flow is 1473 gpm). The RB fans are operated from the control rocm. ,

b. In the Reactor Building. during e .

tion, o rM Reactor Building Recirculation Syst{n: ans operates _ ,7r antinuou M W rpm. Water to the cooling coils ddWaiis operating mode is

" ' ~ ,...n w -,~ reumusW.,L Jrmg a syi-Toprvent overfelig the sw system durig ruergacy oferalfon, the Rtatfor rafldfgfa Igic w!H f rrvent the cyration of more the onefan. On a Es attution styal, the leadfa wtB start in slow sped or swilth to slow sytd ad the remainly fas are yrvcntedfrom startly. Startig a additionalfa ca occur after Es is Iryfaned. If the lead fa faffs to start or trifs while in service, a backuf fa w!H start.

+

=__.

• . a _ & m m -

c. In the Reactor Building, during normai operation, booster fans supplying air to the operating floors, steam generator compartments, and reactor compartment operate continuously. Units are operated from the control room. The Reactor Building booster fans are not required during an emergency.

d. For the Reactor Building Mein Cooling Systems, motor trip. excessive fan or motor vibration, and indication of loss of air flow are alarmed in the control room.

e. The Reactor Building Purge System consists of: (1) the Purge Supply System (AHF-6A and AHF-6B) and (2) the Purge Exhaust System (AHF-7A and AHF-7B). The Reactor Building Purge System operates as required during Operational Modes 5 and 6 with components indicated in Section 9.7.2.b.

Controls have beer provided to stop fans AHF-6A and AHF-6B and provide alarms in the control room on: (1) high temperature. (2) detection of combustible vapors, or (3) detection of smoke in the common discharge duct. Alarm indicators are also provided in the control room for low flow in the common discharge duct and for loss of fan operation.

9-53 (Rev. 23)

Reactor Building Spray and Containment Cooling Systems B 3.6.6 BASES BACKGROUND Containment Coolina System (continued)

Upon receipt of a high reactor building pressure ES signal (4 psig). the two operating c p h ef u nz m ing at high pC d M P M W ; W The two ioling unit fans l~ automatically restart

>u s connected

" to

" the ES buses h lormal or emergency power is available. In r^;+ r 9 nt operation following ar

. . a the or j itainment Cooling Sys designed to wtH s m 2" v u @ n h s ea [if th f trf , a sucdfa}

} or is not already running. If fle ledfa fafh to start or wtB atomatka2y start In slow spi A The fans-sr-ef% a la W "+ 7 moc wnumons to prevent motor overload from the higher density atmosphere. The automatic changeover valves operate to provi r w imi mem u osed Cycle Cooling (SW) System flow to e e sperating codly u its and isolate the CI System flow.

APPLICABLE The RB Spray System and Containment Cooling System limit the SAFETY ANALYSES tem)erature and pressure that could be experienced following a 03A. The limiting DBAs considered are the loss of coolant accident (LOCA) and the steam line break. The postulated DBAs are analyzed, with regard to containment ES systems, assuming the loss of one ES bus. This is the worst-case single active failure, resulting in one train of the RB Spray System and one train of the Containment Cooling System being inoperable.

The analysis and evaluation show that, under the worst-case scenario, the highest Jeak containment pressure is 54.2 psig (ex)erienced during a _0CA). The analysis shows that the peac containment temperature is 278.4 F (experienced during a LOCA). Both results are less than the design values.

(See the Bases for LC0 3.6.4. " Containment Pressure." and LCO 3.6.5. " Containment Air Temperature." for a detailed discussion.) The analyses and evaluations assume a power level of 2568 MWt. one RB spray train and one RB cooling train operating, and initial (pre-accident) conditions of 130 F and 17.7 psia. The analyses also assume a response time delayed initiation to provide conservative peak calculated containment pressure and temperature responses.

(continued)

Crystal River Unit 3 8 3.6-37 Revision No. 2

Reactor Building Spray and Containment tooling Systems B 3.6.6 f

h"ofm bOh BASES L

'Of 1 hd \/

SURVEILLANCE SR 3.6.6.4 (continued)

REQUIREMENTS normally supplied to them re-directed to the post-accident loads. The 24 month Frequency was also considered acceptable based upon the existence of other Technical Specification Surveillance Requirements. A degradation in cooling unit performance between performances of this SR would likely be seen as an increase in RB temperature (monitored once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in accordanc.e with SR 3.6.5.1).

SR 3.6.6.5 and SR 3.6.6.6 These SRs require verification that each automatic RB spray valve that is not locked, sealed, or otherwise secured in the correct position, actuates to its correct position and that each RB spray pump starts upon receipt of an actual or simulated actuation signal. The 24 month Frequency is b" ed on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillances when performed at the 24 month Frequency.

Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

The SR is modified by a note indicating the SR is not applicable in the identified MODE. This is necessary in order to make the requirements for automatic system response consistent with those for the actuation instrumentation.

SR 3.6.6.7 This SR requires verification that each required containment cooling train actuates upon receipt of an actual or simulated actuation signal. In the event of a LOCA, the air steam mixture density is much higher than normal air density. The units are not designed to handle the full flow rate at this condition. To operate the unit at ful! flow (motor at high speed) at this condition, will cause the motor to overload and trip. To guard the motor from overloading, the volumetric flow rate must be cut (continued)

Crystal River Unit 3 B 3.6-44 Revision No. 2

Reactor Building Spray and Containment Cooling Systems B 3.6.6 BASES SURVEILLANCE SR 3.6.6 7 (continued)

REQUIREMENTS Thuc tH: SR approximate ensures th{ine cJ 1v thG h W &})at low speed).torsautotaticallyh_itchch muly low speed upon rvun nprrty r'n;_ w ,wu-m- ~' 7 ' ,. , ,T w nrl ik Other nuly m0for trifs. 1o frnin!

titteky SW ksfj;n temycraturts, by haty two Ra fans la servftt, this SR Also enwres thAt OMf f DNt RB[4n wlE sfatt 05 An ES AftN4tjdN sh44!.

I*' U NE tr% . . .._ ^% and has been shown to be acce) table through operating experience. See SR 3.6.6.5 and S1 3.6.6.6. above, for further discussion of the basis for the 24 month Frequency. 3 The SR is modified by a note indicating the SR is not applicable ir, the identified MODE. This is necessary in order to make the requirements for automatic system response consirtent with those for the actuation instrumentation.

SR 3.6.6.8 With the containme.it spray header isolated and drained of any solution, low pressure air or smoke can be blown through test connections. Performance of this Surveillance demonstrates that each spray nozzle is unobstructed and provides assurance that spray coverage of the containment during an accident is not degraded. Due to the passive nature of the design of the nozzles, a test at 10 year intervals is considered adequate to Jetect obstruction of the spray nozzles, i

REFERENCES 1. FSAR, Section 1.4.

2. FSAR, Section 14.2.2.5.9.

3. FSAR, Section 6.3.

4. R3-2787 Requirement Outline. Reactor Building Fan Assemblies. Addendum B, February 19, 1971.

5. ASME, Boiler and Pressure Vessel Code,Section XI.

Crystal River Unit 3 B 3.6-45 Revision No. 2 i

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