ML18029A280

Proposed Tech Specs Re Removal of Requirement for Initiation of Reactor Scram on Condensor Low Vacuum

ML18029A280
Person / Time
Site:	Browns Ferry
Issue date:	11/19/1984
From:	TENNESSEE VALLEY AUTHORITY
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ML18029A279	List: ML18029A278 ML18029A280
References
NUDOCS 8411270269
Download: ML18029A280 (40)

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{{#Wiki_filter:'Eg ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION REVISIONS BROMNS FERRY NUCLEAR PLANT (TVA BFNP TS 204)f 84ii2702b9 84iii9 PDR ADOCK 05000259 P PDR~ UNIT 1 PROPOSED SPECIFICATIONS

SAFETY LIMIT LIMITXNG SAFETY SYSTEM SETTING 1.1 FUEL CLADDING INTEGRITY 2.1 FUEL CLADDING INTEGRITY B Power Transient To ensure that the Safety Limits established in Specification 1.1.A are not exceeded,'ach required scram shall be initiated by its expected scram signal.The Safety Limit shall be assumed to be exceeded when scram is accomplished by means other than the expected scram signal.l.scram and isola-{PCIS groups 2,3,6)reactor low water level 2.Scram--turbine stop valve closure 3, Scram--turbine control valve fast closure or turbine trip, I 538 in.above vessel zero S 10 per-cent valve closure 550 psig 4.(Deleted)5.'Scram-main steam line isolation 5 10 per-cent, valve"losuro 6, Main steam isola-~825 psi" tion valve closure<<-nuclear system low pressure C.Reactor Vessel Water Level C.Water Level Tri Settin s Whenever there is irradiated .'fuel in the reactor vessel,~the water level shall.not be less than'7.7 in.above.the top of the normal active fuel zone.Core spray and LPCI actuation-- reactor loM water level HPCI and HCZC actuation-reac-tor low water.level I 378 in.above vessel zero 470 above vessel zero Main steam isola-tion valve clos ur e-r eactor'ow water level h 378 in.'bove Vessel zero P 2.1 BASES~I~t t~1~(DELETED)C.6 H.Hain Stags Line Is~wtion on LoBB Prcssure and Hain Steam Line Isolation Scracs The lov pressure isolation of the main steam lines at 825 psig vss provided to protect against rapid reactor depreasurization and the'esulting rapid cooldovn of the vessel.Advantage is taken of the scram feature that occurs vhen the main steam line isolation valves are closed, to provide for reactor ahutdovn ao that high povsr opera-tion at lov reactor preoeur does not occur, thus providing protection for the fuel cladding integrity safety limit.Operation of the reac-tor at pressures lover than g2>psig requires that the reactor cade~Mitch be in the STARTUP position, vheze protectfon of'the.fuel cladding'ntegrity safety limit is provided by the IRM and APRM high neutron flu'x acrams.Thus, the cotsbinstion of main steam line lov pressure isolation and isolation valve closure scram assures the availability of neutron flux scram protection over the entire range'of applicab'lity of the fuel cladding integrity safety liBBit.In addition, the isolation valve closure scram anticipates the pressure and flux transients that occur during normal or inadvertent isolation valve closure.With ths scrams~et at lO percent of valve closure, neutron flux does not increase, t TABLE 3 1nA REACTOR PROTECTION SYSTEM (SCRAM)INSTRUMENTATION REQUIRENEtIT Min.No.of Operable Ins't o Channels Per Trip o~snt n 1$(3)".Itto Innttton Tri Level=ettin Modes in Qhich Function Must Be 0 erable 8 hut-Startup/Hot =onn~nntntl I I".nntt I n n~ntio Main Steaa Line Isola-tion Valve Closure 5 10%Valve Closure X(3)(6)X{3)(6)X(6)1.A or 1.C Turbine Cont.Valve Past Closure or Turbine Trip Turbine Stop Valve Closure k 550 peis S 10S Valve Closure X(4)1 A or 1 D X(4)1 A or 1 D I 2.Turbine First Stage Pressure Permissive not 8154 psis X{18)X (18)X (18)(19)2.~Main Steam Line High Radiation (14)3X Normal Full Paver Background(20) X(9)X(9)X(9)1.A or 1.c 0 TABLE 4.I.A, REACTOR PROTECTIOH STSTEH (SCRAH)IH~iUHBfTATIO!l PUHCTIONAL TESTS HDiOSH FUHCTIOHAL TEST FkPPEHCIES POR SAP ETT IHSTR.AHD COHTRDL CIRCUITS%au Functional Teat Hfnfnun fre ueacy (3)Hode Svftch ia Shutdovn Haaual Scraa IRH High flux Place Hode SMitch in Shutdovn Each Refueliog Outage Trip Channel and Alake (4)Once Per Meek Durfag lefuelin and Before Each Startup A Trfp Channel and Alar>a Every 3 Hontha Inoperative-C.Trip Channel and Aiara (4)Oace Per Meek During kefuelin and Before Each Startup APRH High flux (1ST acraa)High Flux (Flow Biased)Hfgh tluz (Fixed Trip)Inoperat f ve Douna ca le Trip Output Relays (4)Trip Output Relays (4)Trip Output Relays (4J Trip Output kelaya (4)Trip Output Relaya (4)Before Each Startup and Meeki When Required to be Operable Once/ljeelc Once/Meek Once/Meek PIov Eiaa (6)(6)Rfgh Reactor Preaaure High Dryvoll Preeaure Reactor Lou Meter Level High Water Level in Scram Discharge.Tank.Float Skitches (LS-85-45C-F) High Water Level in Scram Discharge Tank'lectronic Level Switches (LS-85-45A; B, G, H)Trip Channel and Alarm Trip Channel and Alarm Trfp Channel aad Alara Once/Honth (1)Once/Honth (1)Dace/Hoath fl).Trip Channel and Alarm Once/Month Tr'ip Channel and Alarm (7)Once/Month Hain Steam Line.High Radiation B Trip Channel and Alarm'4')Once/3 months (8) TABLE, 4 1~B REACTOR" PROTECTION SISTEM (SCRAM)XNSTRVMENT CALIBRATXON MXNXMVM CALIBRATIOM FRE()azrs:IES FOR REAcroR PRoTECTzoN XNSTRVMENT CHANNELS Instrument Channel IRM High Flux Qroup (1)c calibration Compari,son to APRM on Control led startupa (6)Minimum Frequency (2)Note (4)APRM High Flux Output Signal Flow Bias Signal LPRM Signal High Reactor Pressure High Drywell Pressure Reactor Low Mater Level B B B Heat Balance Calibrate Flo<<Bias Signal (7)TZp System Traverse (8)Standard Pressure Source Standard Pressure Source Pressure Standard Once every 7 days Once/operating cycle~Every 1000 Effective~ Full Power Hours Every 3 Months Every 3 Months Every 3 Months High Water Lovel in Scram Discharge Volume Float S~itches (LS-85-45 C-F)High Water Level in Scram Discharge Volume Electronic Level britches (LS-85-45-A, B, G, H)B Calibrated Water Column (5)Ca 1 i br a to d W a t er Co 1 umn Note (5)Onco/Operating Cycle (9).Hain Steam Line Isolation Valve Closure'ain Steam Line High Badiation I 0 Turbine First Stage Pressure Permissive (PT-1-81A and B, Pl'-1-91A and B)Turbine Cont.Valve Fast Closure or.Turbine Trip Turbine Stop Valve Closure B Note (5)Standard Current Source (3)Standard Prcssure Source Standard Pressure Source Note (5)Note (5)Every 3 Honths Once/Operating Cycle (9)Once/Opera ti n8 Cyc 1 e Note (5) 3.i slsEE It modes.In the pover range the APLi system pzovidos requ tod protection. 4 Ref.Section 7.5.7 PSAR.Thus, the IRH System ie not required in the Run mode.The APRM's ond tho IRN's provida adequate covet>>go in the startup and intermediate range.The high reactor.pressure, high dryvell pressure, reactor lov vater level and scram discharge volume high level scrome are required for Startup and Run aedes of plant operation. They are, therefore, required to be opera-tional for these modes of'eactor operation. The requirement to have tho octan functions as indicated in Table 3.1..1'perable io the Refuel etode is to oeauze that shifting to the Refuel mode during reactor pnvcr operation does not diminish the need for the reactor protection syste~.Because of the APL'ovnscole limit of>3Z vhen in the Run mode and high level limit of<15I vhen in the Startup Hode, the transition betvoen tho Startup and Run Nodes must be made vith the APRH instrumentation indicating betveen 3I and 15I of rated paver or o control rod octan vill occuz.In addition, the IRf system must be indicating belov tho High Plux setting (120/125 of ocale)or a scram vill occur vhen in tho Startup Mod>>.Pot normal operating conditions, those limits provide assurance of ovet'lap botreen the IRH system and APLf system eo that thoro aze no"gape" in the paver lovel indicetione (i.e., the pover level ia continuously nanitorad from beginning of etartup to full povor and fton full pover to ehutdovn). 4hen povet ie being reduced, if a tran>>fez to the Startup mode ia tuLCo end th>>IL'l'e have not been fully inserted (a maloperationol but not Mpoeeiblo condition) a control rod block~odiatcly occurs so that reactivity meez-tion by control rod vlthdraval cannot occur.44 UNIT 2 PROPOSED SPECIFICATIONS 0 A~~SAFETY LIMIT t~~<<l..5'IMITING SAFETY SYSTEM SETTING l.1 FUEL CLADDING INTEGRITY P~-2.1 FUEL CLADDING INTEGRITY'ower Transient To ensure that the Safety Limits'stablished in Specification 1.1.A are not exceeded,*'each required scram shall be initiated by its expected scram signal.The Safety Limit shall be assumed to be exceeded.when scram is accomplished by means other than the expected scram signal.B.Power Transient Tri Settin s l., Scram and isola-h 538 in.tion (PCIS groups above 2,3,6)reactor low'essel , water level.zero 2.Scram-turbine 5 10 per-stop valve cent valve closure closure 3, Scram--turbine .,=550 psig control valve fast clo"ura or turbine trip 4 (Deleted)5, Scram-main.5 1,0 per-steam line.cent valve isolation'."losuro'I 6,'Main steam.isola-~825'sig 0ion valve closure-nuclear system low pressure C.Reactor Vessel 4'ater Level C.Water Level Tri Settin s whenever there is irradiated .fuel in the reactor vessel,~the water.level shall not be less than 17.7'in.above the top of the normal active fuel zone.Core spray and'pCI actuation-reactor lofti'water level HPCI and RCIC actuation-reac-tor low water,.level h 378 in.above vesaeT xero 470'bove vessel zero 3~Main steam isola-.tion valve closure--reactor low water level.~378 in'., above vessel zero R

~(((A ((t~~1 RLSES.~X((44(~~(~,~~(4~, ((l'('l..a ('(~~(DELETED)~>>'C.4 H.lhin Staaa Line Is~ation on Lov Pressure and Rain Stepan Line Isolation Scran'fhe lov pressure isolation of the mein stean lines at 8Z5 psig veN-provided to protect esainet rapid reactor depressuri,zation and the resulting rapid cooldovn of the vessel.Advantage is taken of.the icr(aa feature that occurs vhen the aain stean)ine iso)ation valves are closed,<<o provide for reactor ahutdova so that high pover.opera-ciern at lov reactor proosur does not occur, thus providing protection for the tuel cladding integrity safety limit.Operation of the reac-<<or at pressures lover'han 8Z>poig requires that the reactor code avitch ba in the.STAR'LVP position, vhere protection of the fuel cladding integrity safety)Snit ia provided by'the IRM and APRH high neutron flux~oczans.Thus, the conbination of nein utean line lov pressure.isolation and isolation valve closure acracl assures the availability of neutron Flux acraa protection over the entire range of applicability of the fuel cladding integrity safety limit.In addition, the isolation valve closure ecraa anticipatea the pressure and flux transients that occur durini noaaal or inadvertent isolation valve closure.Mith the scree oet ot 1Q percent of valve closure, neutron i'lux does not increase.

TABIH'3.1~A REACTOR PROTECTION SYS EM (SCRAM)INSTRUMi8TATION REQUIREMENT Kin.No.of Operable Inst.Channels Per Trip Tri Level Settin Modes in Nhich Function Must Be 0 erable Shut-Startup/Hot dovn~Re.'uel 7 Stan~db RGll~IICt1Oll 1 Main Steam Line Isola-tion Valve Closure 5 10%Valve Closure X (3)(6)X (3)(6)X (6)1.A or 1.C Turbine Cont Valve Past Closure Or Turbiae Trip k 550 pais X(4)1.A or 1.D~~Turbine Stop Valve Closure 6 10S Valve Closure X(4)1.A or 1.D 2-Turbine First Stage Pressure Permissive nor F154 psi8 X (18)X(18)X(18)(19)2 Main Steajs Line High 3X Normal Full Power Radiation (14).Background (20)X(9)X(9)X(9)1.A or 1.C TABLE 4m 1.A REACTOR FROTRCTlOM STSTF8 (SCRAH)DlSTRUHWTATlOR FUNCTlONAL TESTS HfHOSH HSCTfONAL TEST FREQUENCIES FOR SAFETT lNSTR.AND CONTROL CIRCU?TS Mode'Svitch ta Shutdova Haaual Scran TRH High flux Inoperatfra QEn~g Functional Teat A Place Mode Suitch tn Shutdoua A Trtp Channel aod Alarm Trip Channel and Afana (4)Trip Channel and Alara (4)Hiataun Fr ueacy ($)Each Retuettag Outage Every 3 Hoatha Once Pcr Meat Durfog Refueltn aad gefote Each Startup Once Per Meek Duriag Rcfueltn aad gcfore Each Startup~'~Cy APRH High Flux (1$Z acraa)High Flux (Flow Biased)High Flux (Fixed Trip)lnoperatfre Dovaacale Flou gtaa fffgh Reactor Preaeure Ifgh Dryvell Preaaure Reactor Lov Mater Level B 5 Trip Output Relays (4)Trip Output Relays (4)Trip Output Relaya (4)Trtp Output Relaya (4)Trip Output Relaya (4)Trip Channel and Alara Trfp Channel and'lara Trip Chaaael'aad Alaa~*before Each Startup aad Mcekl Mhca Required to be Operable Once/Week Dace/Meek Once/Mech Oace/Meek Dace/Honth (1)Dace/Hoath (1)Once/Honth (1).High Mater Level f a Scree Dtacharge Tank Float Switches 3 Differential Pressure Switches A Trip Channel and Alarm Once/month B.-Trip Channel and Alarm" Once/month (7)Main Steam Line High Radiation Trip Channel and Alarm On'e/3 months (8)

TABLE 4 1~B REACTOR PROTECrloH sysTEH (SciAH)IHSTROMEHT CALIBRATIOH HIHIHUH CALIBRATIOH PREQOE)a IES FOR REACXOR PROTECTIOH IHSTROKEssr CHANNELS Instrument Channel IRH High Flux APRH High Flux Output Signal Flow Bias Signal LPRH Signal High Reactor Pressure Bigh Orywell Pressure ReaCtOr LOw Water LeVel High Water Level in Scrafa Oischarge Volumes Float Switches Differential Pressure Switches Croup (1)B B A B Calibration Comparison to APRH on Control-led scarcupN (6)Heat Balance Calibrate Flow Bias Signal (7)TIP System Traverse (8)Standard Pressure'Source Standard Pressure Source Pressure Standard Note (5)Calibrated Mater Column Minimum Frequency (2)Hots (4)Once every 7 days Once/operating cycle Every 1000 EI(ective Full Power Hours Every 3 Months Every 3 Months Every 3 Months Note (5)Once/Operating Cycle.Main Steam Line Isolation Valve Closure A Main Steam=Line High Radiation B Turbine First Stage Pressure Permissive A Note (5)Standard Current Source (3)Standard Pressure Source Note (5)Everv 3 Months Every 6 Months Turbine Stop Valve Closure Turbine Cont;Valve Fast Closure or ur n;A Turbine Trip No'te (5)a<<a<<p'ressure Sour Note (5)Once/operating cycle

tional for th P The requirement to have the scram functions as indicated in Table 3.1.1 operable io the Refuel mode is to assure that shifting to the Refuel sade during reactor pover operatioa does not diminish the need for.the react'or protection systems modes.In the paver raRge the APRH system provides requ'rod'protection. Ref.Section 7.5.7 FSAR.Thus, the IRH System io noc required in the Run mode.The APRH'aad tho ILN'a provide adequate coverage,in the etartup and incermediate range.4.The high reactor-pressure, high dryuell pressure, reactor lov voter level hand scram discharge volume high level seroms are required for Stortup and Run sades of plant operation. They are, therefore, required to be.opera-es>>modes of'eactor o eration.I Because of the APRH dovnseolo, limit of i 3X vhea in the Run mode and high'evel limit of c15I uhen in the Startup Hode, che transi'cion betuoea the Startup and Run Hodes must be made vith the APRH instrumentatioa indicatiag betveen 3X and 15X of rated pover or o eon'trol rod scram vill occur.In~ddition, the IRH system must be indicating belov the High Plux setting (120/125 of scale)or a scram vill occur vhen'ia the Stsrtup Mode.For normal operating conditions, those limits provide assurance of over'lap betveon the IRH system and APRf system so that there are ao"gapa" ia the pouer level indieationo (i.e., the pouer level is continuously cmnitored!rom beginning of startup to full paver aad from Cull pover to shutdovn),hen pover is being reduced, if o transfer to ths Startup'mode ia made sad'he IRN'e have not been tully inserted (a maloperotioaol but'ot impossible condition) o control rod block~odiatcly occurs so that rsactiv'ty macr<<tion by control rod vithdraval esaaot occur. 0 UNIT 3 PROPOSED SPECIFICATIONS

~SAFETY LIMXT 0'LIMITING SAFETY SYSTEM SETTING 1.1 FUEL CLADDING XNTEGRXTY 2 1 FUEL CLADDING INTEGRITY Power Transiene B.Power Transient Tri Settin s To ensure that the Safety Limit s established in Specification 1.1.A are noe exceeded,'ach required scram shall be initiated by its expected scram signal.The Safety Limit shall be assumed to be exceeded when'scram is accomplished by means other than the expected scram signal.Scram and isola-tion (PCXS groups 2,3,6)reactor low water level 2.Scram-turbine stop valve closure Scram--turbine control valve~fast clo"ura or eurbino trip h 538 in above vessel zero 5.10 per-cent valve closure 550 psig 4.(Deleted)5.'cram--main steam line isolation Main steam isola-tion valve closure-nuclear system low pressure 5 1Q per-cent valve..closur~~825 psi", l I C.Reactor Vessel Mater Level C.Mater Level Tri Settings Mhenever there is irradiated .fuel in the reactor vessel,~the waeer level shall noe be less than'7.7 in.above the top of the normal aceive fuel zone.Core spray and LPCI actuation- 'reactor 1oii water level 2, HPCI and RCIC actuation-reac-tor low water level Main steam isola-tion valve closure--reactor low water level I 378 in.above vesaeT zero.470 above vessel zero I 378 in.above vessel zero" 13

~~.~iJ" oil pressure at.the main turbine control valve actuator disc dump valves~a, This loss of pressure is sensed'by pressure switches whose contacts form..;the one-out-of-two-twice.logic input to the reactor protection system.This trip setting,.a-nominally 50X greater closure time and a different valve'characteristic from that:.ef the turbine stop valve,,combine to produce transients very similar to that for.the stop valve.Relevant transient analyses are'=discussed in References 1 and 2.%This scram is bypassed when turbine steam flow is below 30/of rated, as measured ,bv the turbine first staae oressure.F (DELETED)G.6 H.Main Steam Line Isolation on Low Pressure and Main Steam Line Isolation Scram The low pressure isolation of the main steam lines at 850 psiq was provided to protect against rapid reactor'epressurization and the resulting rapid cooldown of the vessel.Advantaqe is taken of the scram feature that.occurs.when the main steam line isolation valves are closed, to provide for reactor shutdown so that high power operation at low reactor pressure does not occur, thus providing protection for the fuel cladding integrity safety limit.Operation of the reactor at pressures lower than 850 psig requires that the reactor mode switch be in the STARTUP.23 TABLE.3.1.A (cont'd)REACTOR PROTECTIOH STSTEH (SCRA'1)IHSTRIlHEHTATIOH REQUIREIKNT dfnictun Hunbcr sf Operable instru=ent

hannels Pcr 2 23 Trf Punctlon High Mater Level in East Scran Discharge Tank (LS-85-h5E-H)

}fain Stean Line Isolation Valve Closuro Turbino Control Valve Past Closure or Turbine Trip Trf Level Settin<50 gallons c 10 percent valve closure i 550 psig Hodcs in Mhich Function 1'.ust be 0 erable StartuplHot itllii ml~lt t 1 (~Sia dh X X(2)X'lu'Aetio 1 X 1.i X(6)1.A or 1.C X(h)1 A or 1.D Turbine Stop Valve Closure c 10X Valve Closure X(4)1.A or 1.0.Turbine First Stage Pres'sure Pcrnfssfvc not i 154 psig X(18)X(18)X(18)(19)Main Stean Line High Radfatiun (14)3X Homal Full Pouer Bac'kground (20)X(9)X(9)X(9)I.h or 1.C TABLE 4~1~A REACTOR PROTECTIOII SYSTEH (SCRAM)I HSTRUHEHTATIOH FUHCTIOHhL TESTS HIIILLIUH FUIICTIOIIAL TEST FREQUQICIES FOR SAFETY IIISTR AND COIITROL CIRCUITS P~Gro 2 Functional Test Hinigug Frequency (J)Hode Switch in Shutdown Hanual Scrag Place Hode suit,ch in Shutdown Each Refueling Outage Trip Channel and Alarg Every 3 Honths IRH lligh Flux Inoperative APRH Iligh Flux (15%.scrag) {l)(,h Flux (Flou I)iased)(Fixed Trip)w Inollerative Downscale Flow Blas Illgh Reactor Pressure High Dryuell Pressure Reactor Lou Mater Level lllgh Mater Level in Scrag Discharge Tank Float.S'uitchcs (I.S-II5-45C-I') fluctronlc Lovel Switches..(LS-85-45A, II, G, II)h B Trip Channel and Alarla{4)Trip Channel and Alarg{4)Trip Output Relays (4)<I"~Trip Output Reiays (4)Trip IxItput Relays (p)h Trip Output Relays (4)Trip Output Relays (4){6I Trip Channel and Aiarg Trip Channel and blare Trip Channel and Alarg Trip Channel and Alarg-I FIp Chnnnul In(I AI'Irm 0)Once Per Meek D ring Refueling and Before Each Startup once Per Meek Dur(ng Refueling and Before Each Startup Defore Each Startup and Meekly Mhen Required to he Operable OIIce/Meek Oncatuaap Once/Meek Once/Heck (6)Once/Honth (I)Onco/Honth (I)Once/Honth (1)Onci"lonlh Cnce/:AIuth

TABLE 4 1 B REACTOR PROTECTION SYSTEH (SCRAH)INSTRUHENT CALIBRATION HINIHUH CALIBRATION FREQUENCIES FOR REACTOR PROTECTION INSTRUHENT CHANNELS Instrument Channel IRH High Flux APRH High Flux Output signal Flow Bias Signal LPRH Signal Group (1)B B B I Calibration Compari.son to APRH on Control-).ed stsrtups (6)c Heat Balance Calibrate Flow Bias Signal (7)TIP System Traverse (8)Hinimum Frequency (2)C'tiote (4)Once every 7 days Once/opera);ing cycle Every 1000 Effective Full Power Hours High Reactor Pressure High Drywell Pressure Reactor Low Mater Level Standard Pressure Source Standard Pressure Source Pressure Standard Every 3 Honths.Every 3 Honths Every 3 Honths e High Mater Level ln Scraa Discharge Vo luce Float Switches (LS-85-45C-F) Electronic Level Sul'tches (LS-()5-4 l.8, 0, K)Calibrated Mater Coluon (5)Calibrated Mater Colucn)(ot e (5)Once/Oporsllng Cycle (9)Hain Steam Line Isolation Valve Closure Hai n Steam Line High Radi ation Turbine First Stage Pressure Permissive '(urh(ne Cont.Vilve Fast Closure or Turh(ne Trip Turbine Stop Valve Closure-'Note (5)standard Current Source (3)Standard Pressure Source Standard I'ressure Source Note (5)Note (5)Every 3 Honths Every 6 Honths Once(opal'at)ng cycle Note (5)

r which a scram would be required hut not be able to perform its function adequitely. A source range monitor-(SRN)sysrlbea is also provided to supply additional neutron level information during startup but has rio scram functions Ref Section 7 5.0 TSAR Thus~the IRM is required in the Refuel and Startup modes In.the pover range the APRM system pmvides xequired protection. Ref.Section 7~5~7 FsAR Thus~the IRN System is not required in the Run mode..The APRN~s and the IRM~s provide adequate coverage in the startup and intermediate range~The high reactor pressure, high drywell pressure, reactor lmt water level and scram discharge volume high level scrams are required for Startup and Run modes of plant operation. They are, therefore, required to be operational for these modes of reactor operation. The requirement to have the scram functions as indicated in Table 3.1.1 operable in the Refuel mode is to assure that shifting to., the Refuel mode during xeector poser operation does not diminish the need for the reactor protection systea.Because of the APRM downscale limit of h 35 when in the Run mode and high level limit of 5 15%when in the Startup Mode, the transition between the Startup and Run Modes must be made with the APRM instnmentation indicating between 3%and 15%o'f rated power or a control rod scram will o'er In addition, the IRN, system must be indicating below the High Plex setting (120/125 ofscale)or a scram vill occur when in the Startup Node For norial opexating conditions, these limits provide assurance of overlap between the IRN eystoaa and APRN system so that there are no"gape" in the power leve1 indications (i e, the power level is continuously monitored from beginning of startup to full pover and from full pover to shutdown). Shen power is being reduced, if a transfer to the Startup mode is made and the IRM~s have not been fu11y inserted (a maloperational but not impossible condition) a control rod block immediately occurs so that reactivity insertion by control rod withdrawal cannot occur.43

ENCLOSUE 2 DESCRIPTION AND JUSTIFICATION (TVA BFNP TS 204)Descri tion of Pro osed Chan es Units 1 and 2-pages 11, 24, 34, 37, 40, and 44 Unit 3-pages 13, 23, 33, 36, 39, and 43 The proposed revisions delete the requirement for initiation of a reactor scram on condenser low vacuum.Reason These revisions are being proposed to preclude plant der ating,during periods of high condenser back pressure.These conditions exist primarily during conditions of high river water temperatures. These'conditions have previously caused unit deratings. These proposed revisions, therefore, will allow an increased power output during conditions of higher than normal condenser back pressure.Additionally, these proposed revisions will reduce surveillance testing requirements and decrease the probability of an inadvertent scram.Justification and Safet Anal sis'The basis for the turbine condenser low vacuum scram is to provide"'an anticipatory scram to reduce the pressure increase of the reactor vessel caused~onl by a turbine trip on low condenser vacuum.At greater than 154 psig turbine first stage pressure, the turbine trip would also cause a scram.In the accident and transient analyses, no credit is taken for this anticipatory signal;"therefore,, there will be no decrease in safety margins caused by deletion of this scram.Additionaly, the BWR Standard Technical Specifications ,contain no requirement for this scram.

ENCLOSURE 3 BROWNS FERRY NUCLEAR PLANT PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION (TVA BFNP TS 204)The proposed change would delete the technical specification r equir ement in tables 3.1.A, 4.1.A, and 4.1.B for an automatic reactor pressure system initiation (scram)on turbine condenser low vacuum.Basis for Proposed No Significant Hazards Determination NRC has provided guidance concerning the application of standards by providing examples of actions that are not 11kely to involve a significant hazards considerations (48FR14870). One example of actions not likely to involve a significant hazards consideration is a change which either may result in some increase in the probability or consequences of a pieviously analyzed accident or may reduce in some way a safety margin, but where the results of the change are clearly within all acceptable criteria wi.th respect to the system or component specified in the Standard Review Plan.The proposed amendment does not involve a signif1cant increase in the probability or consequences of an accident or create the possibility of a new or different accident.The basis for the turbine condenser low vacuum scram is to provide an anticipatory scram to reduce peak pressure in the reactor vessel caused only by a turbine trip on low condenser vacuum.Without the anticipatory scram at 23 inches of mercury vacuum on decreasing condenser vacuum, the main turbine would receive a trip at 21."8 inches of mercury vacuum.This trip signal would cause the turbine stop valves and control valves to close initiating a scram in less than one second.While the reactor was scramm1ng, there would also be an increase in reactor.vessel pressure because of isolat1on of the main condenser, from the reactor.This pressure rise would normally be limi.ted by automatic open1ng of the turbine bypass valves.For the purposes of conservatively analyzing~tur bine trip transients, no credit was taken for either the condenser low vacuum scram or operation of the turbine bypass valves.Thus, deletion or nonoperation of the condenser low vacuum switches is conservatively bounded by the existing analyses and no decrease in safety margin is created.In addition, the Standard Technical Specificat1ons do not require this'nticipatory scram.Therefore, since the proposed amendment is encompassed by an example for which no sign1ficant hazards are likely to ex1st, TVA proposes to determine'that the proposed amendment does not involve a signifi.cant hazards consideration.}}