ML17216A324

Proposed Tech Specs Supporting Installation of safety-grade Automatic Feedwater Sys During Upcoming Refueling Outage

ML17216A324
Person / Time
Site:	Saint Lucie
Issue date:	10/22/1985
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17216A323	List: ML17216A322 ML17216A324
References
NUDOCS 8510290314
Download: ML17216A324 (28)

Text

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TAIILE 3. 3-3+Continued ENGINEEREO SAFETY FEATURE ACTUATION SYSTEtl IIISTRU%NTATION C

HllllllN TOTAL NO. CHANNELS - CIIANNELS APPLICASLE FUNCTIONAL UNIT OF CIIANNCLS TO TRIP OPERAGLE NGES ACllON C S. CONTAl INEIIT SINP REC IR<ULATION (RAS)

a. IL)nual RAS (Trip Guttons) 1,2,3,1 8

b. Refueling Mater Tank--

Los 1,2,3 6.. LOSS OF POMER

~. i.l6 kv Ewergency bus Undervoltage (Loss of Voltage)>> 2/Gus 2/bus I/bus 1,.2, 3 12

b. 1.16 kv ENergency bus Under-vol tage (Degraded Vol tage)

(1) Undervol tage Device 'll* 2/Bus 2/bus I/bus 1. 2, 3 12 (2) Undervol tage Device l2>> 2/bus 2/bus 1/bus 1, 2, 3 12

c. 180 V Ejwergency bus Under-voltage (Degraded Voltage)>> 2/bus 2/bus 1/bus 1,2,3

7. AUXILIARY FEENATE1 AUTONTIC START Steaa Generator (SG)

Level lnstrments 1/SG 2/SGV 2/SG 1, 2, 3

%4 Jl 2/SG for either stem generator Will start one train of AFM.

TIIis specification ~ill be effective pr or to Cycle 7 restart.

/DE'5 7MlL 3,g g ANlLIARYFEENATER (AFAS)

a. Hanual (Trfp Buttons) 4/SG 2/SG 4/SG

b. Automatic Actuatfon

• I.opfc 4/SG 2/SG 3/SG SG Level (fh/fb) - t.mt 4/SG 2/SG 3/SG 13 , 14

8. AUXILIARY FEEDMATER ISOLATION

a. SG fA-SG fB Offferentfal Pressure 4/SG 2/SG 3/SG Feaster Header SG LA - SG 18 Dff-fer en' al .Pressure 4/SG 2/SG 3/SG

ea Cs t

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TABLE 3.3-3 Continued TABLE NOTATION ACTION 1O- Nth the nurrber of OPERABLE channels one less than the Total Number of Channels, operation may proceed provfded the inoperable channel fs placed fn thc bypassed condition.

-and the Mfnfmum Channels OPERABLE requirement fs demonstrated wfthfn 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; one additional channel may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Sepciffca-tfon 4.3.2.1.1.

ACTION 11- Instrument operability requirements are contained fn the Reactor Protection System requirements for Reactor Trip on Steam Generator Level. If an Automatic Star t channel fs fnoperablc. operation may continue provided that the affected pump is verified to be OPERABLE per Specification 4.7.1.2.a within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and at least once per 7 days thereafter; and the Automatic Start channel shall be rcstorcd to OPERABLE status within 30 days or the reactor s all be fn at least HOT SHUTDOWN within thc next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

ACTION 12- fifth the number of OPERABLE Channels one less than the Total Number of Channels operation may proceed until performance of the next required CHANNEL FUNCTIONAL TEST provided the fnoperable channel fs placed fn the tHpped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

ACTION 1i- With the number of OPERABLE channels one less than the Total Number of Channels, restore the inoperable channels to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

ACTION 13- With the number of'channels OPERABLE one less than the Total Number of Channels, STARTUP and/or POWER OPERATION may continue provided the inoperable channel f s placed fn the bypassed or tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. If the inoperable channel is bypassed, the desirability of maintaining this channel in the bypassed condition shall be reviewed in accordance with Specification 6.5.1.6m. The channel shall be returned to OPERABLE status no later than during the next COLD SHUTDOWN.

ACTION 14- Mith the number of channels OPERABLE one less than the Minimum Channels OPERABLE, STARTUP and/or POMER OPERATION may continue provided that one o'f the inoperable channels has been bypassed and the other inoperable channel has been placed in the tripped condition within I hour.

ST. LUCIE - UNIT 1 3/4 3-13 Amendment No. A5, N1l. $ g

TABLE 3.3-4 ~CnntlnunA E INE ED SAFETV FEATURE ACTUATION STSTEII IHSTRNIENTATION TRIP VALUES ALL%ABLE IONAL UNIT TRIP VALUE VALUES

6. LOSS OF POIN

a. (1) 4.16 kv baergency Bus Undervoltage i Si 29second (Loss of Yo'Itage)>> 2900 volts elth a 2900 t 29 volts srith a 1 tiae delay l + .5 second tIae delay

b. i.l6 kv Ejsergeocy tus Uhdervoltage (Oegr aded Vol tage) 3615 i 36 volts with (1) Uodervol ta5e Device il>>

7 i iminute 3675 1

36 volts with a tiae delay . 7 i slate tiae delay 1

a (2) Uadervoltage Device l2>> 3592 4 36 volts.iith a 3592 4 36 volts ~ith a lb i X sec@ad t$ ae delay 18 ~ X second tlae delay

c. 1N volts beritacy Sus Undervoltage (Degraded- Vol taie)>> i29 i 5-0 volts stth a i2% ~ 5 -0 volts with a 7 + 1 secoad t$ ae delay 7 + 1 second tiae delay

7. NXILINVFEEQNTEI i %5 level i 3l5 level dpa waar pace This syecificatioI sill be effective prior to Cycle 7 restart.

7. AUNILIARZ FEEDWLTER (AFAS) e.. Hanua) (Trip Suttons) i Not Appl cable

b. Not Applicable Autoaotic Actuation Logic Not =Appl icabl ~ Not Applicable

c. SG lhtlS Level La> > 2,8,0X

. ~ 28$ 7r

8. AUXILIARY FEEONTER ISOLATION Steaw Generator hP-High

< 27$ -': psid < gwg psid

b. Feedrater Header High AP < 150.0 psid < F7.5 psid

I TABLE 3.3-5 ENGINEERED SAFETY FEATURES RESPONSE TINES INITIATING SIGNAL AND FUNCTION RESPONSE TINE IN SECONDS

1. Nanucl

a. SIAS

, . Safety Irgectfon (ECCS) Not Applicable Conta<eatnt Fan Coolers Not Applfcabl e Feedwater Isolation Not Applicable Conta)naent Isol ation Not Applkcabl e

b. CSAS Contaf nnent Spray Not Appl )cable

c. 'IS Contafeaent Isolation Not Appl kcable Shield Sufldfng Vent)latfon Sys~ Not Applicable

d. RAS Contafrment Sump Reckrculatkon Not Applicable

e. NSIS Nafn Steam Isolat)on Not Appl fcable Feechatar IsoIatton Not Appl fcable

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2. Pressurizer Pressure-Los

a. Safety Infect) on (ECCS) c 30./19.5~

b. Conta)nugent Isolation wee c 30.5a/20

, c. Containment Fan Coolers ~ 30.0~/17.~'

d. Fiedwater Isolat)on 60.0 ST. UlCIE - lJNIT 1 3/4 3-15 Peendoent No. Pl> g7, l9

f. AFAS 1 fary Feedwater Actuat)on

'ux) got Appl fcabl e

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~ TABLE 3.3-5 Cnntfnven' ENGINEERED SAFETY FEATURES RESP~'; = TIMES INITIATING SIGNAL AND FUNCTION RESPONSE TINE IN SECONOS Conta5nment Pressure-kf h Safety lrgect5on (ECCS) c 30.g fl9.5~

b." Conta5nment Isolat5on~ 30.5~/20.5~

c . Sh5eld Su5ld5ng Vent51at5on System ~ $ 0.0 /14.0

4. Conta5mcnt Fan Coolers ~ 30..0 /17.0

e. Feedwater Isolat5on 4 60.0 Containment Pressure--Hf h-Hf h

a. Conta5rment Spray c 30.0 fle.s Containment Rad5at5on-N h

a. 'onta5nment Isolat5on~ c 30.5~f20.5~

'h5eld Su5ld5ng Vent5lat5on Systen c 30.0 fl4.0

6. Steam Generator Pressure-Low

a. Na5n Steam Isolat5on

b. Feedwater Isolat5on c 60.0 Refuel5n Mater Storage Tank-Lmv

a. Conta5nment Sump c 91.5 Rec5rculat5on'team

8. Generator'evel Lo~

a. Aux515ary Feedwatar >ROSi + 600" r

TABLE STATION 8/Av 4 Kd )

D5esel generator stirt5ng and sequence load5n", delays fncluded.

D5esel generator start5ng and sequence loidfng delays not Dffs5ta power ava5lable. 5ncluded.

Not aool4cable to conta5nment 5solat5on valve I-Nf-18-1.

n 3/I 3-17 AnttnenBBB Bo. ff: P. g

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'ADLE ~ .3-2 (Cn~nllnund ENGIIIEEREO SAFETY FEhTURE ACTUATlON SYSTE4 IHSTRNENThTlON SURVElLLAIICE RE IRENEIITS NOOKS lN NIICII CINIIIIEL CIIAIIIIEL FUNCTlONL SUAVE lLLAIICE FUIICT NNL UNlT CIICCK CAL IDDAllOD TEST E IIIlb b

6. LOSS OF PNEk

a. I;16 kv Gaergeacy Bus Under-voltage {Loss oD. Voltage)>> S 1.2.3

h. 1.1C Rv Eaergency Ws thder-voltage tOegradad Voltage)

(1) Uadervoltage Oevice ]1>> 1, 2. 3 (2) Uadervol tage Oevice /2>> N 1.2. 3

h. 18O V Eaargancy Ws Under- N 1,2,3 vol tage (Oegraded Vol tage)~

7. AUXlLlNYFEENNKR

a. Auto Star t --------(See Survei 1 1 aace 1.7.1.2.h)-----

b.

Aud ~ex7 ~

Stoaa Generator

• This specification will be effective prior tq Cycle 7

{See RES Table restart.

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7. AUXILIARY FEEDNTER (AFAS)

a. Nanual (Trip Buttons) N.A. N.A. 1,2,3

b. SG Level (A/8) - Low 1,2,3

c. Autowmatic Actuation Logic N.A. N.A. 1,2,3

8. AUXILIARY FEEDNTER ISOlATION

a. SG Level (A/B) - Low and N.A.

SG Differential Pressure 1,2,3 (BtoA/AtoB) - High

b. SG Level (A/B) - Low and Feedwater Header N.A. 1,2,3 Differential Pressure .

(Btoh/AtoB) - High

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ST. LUCIE UNIT NO. I AUTOMATIC AUXILIARYFEEDWATER ACTUATION SYSTEM SAFETY EVALUATION/NOSIGNIFICANT HAZARDS CONSIDERATIONS DETERMINATION This is a request to revise Technical Specification 3/4.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation, of the Technical Specifications for St. Lucie Unit 1.

1.0 Descri tion of Technical S ecification Chan e The proposed change contains those technical specifications needed to support the installation of the safety grade automatic auxiliary feedwater actuation system (AFAS), which will be installed to satisfy a requirement in NUREG-073V, Item II.E.1.2. The proposed change revises Table 3.3-3 (ESFAS Instrumentation), Table 3.3-4 (ESFAS Instrumentation Trip Values),

Table 3.3-5 (Engineered Safety Features Response Times), and Table 4.3-2 (ESFAS Instrumentation SurveiQance Requuements), and lists an additional responsibility for the Facility Review Group (FRG) in Technical Specification 6.5.1.6.

The change to Table 3.3-3 revises item V,.Auxiliary Feedwater, to include manual trip buttons, automatic actuation logic, and steam generator level as inputs to the AFAS. Item 8, Auxiliary Feedwater Isolation, was added to account for the systems ability to isolate a faulted steam generator based on high differential pressure between the steam generators and/or the feedwater header s. ACTION STATEMENTS were added to describe required action when the AFAS does not satisfy the channel requirements listed in Table 3.3-3.

The change to Table 3.3-4 revises item 7 and adds Item 8 to include all the inputs listed above with their applicable trip values and allowable values.

Note that the change to the AFAS steam generator low level setpoint is based solely on the addition of new level transmitters with less instrument uncertainty than those presently installed. The input to safety analyses is unaffected.

The change to Table 3.3-5 adds item 1.f to include a manual AFAS initiating signal and revises item 8, Steam Generator Level, to reflect the new Auxiliary Feedwater (AFW) system response time based solely on new equipment instrument uncertainty as stated by the vendor (+25 sec).

The change to Table 4.3-2 revises item 7 and adds item 8 to include the inputs to the AFAS, as listed above, and lists the associated surveillance requirements for each input.

The change to Technical Specification 6.5.1.6 adds paragraph 6.5.1.6.m to the list of responsibilities of the Facility Review Group (FRG). It requires the FRG to review and document the judgement concerning prolonged operation in an abnormal configuration as allowed in ACTION STATEMENT 13 of Table 3.3-3.

Descri tion of Chan e to the AFW S stem The present AFW system includes automatic actuation of auxiliary feedwater on low steam generator level, after the expiration of a preset time delay. This system represents FPL's short-term commitment to NUREG-0737, Item II.E.1.2 The new AFAS which is to be installed prior to

J start-up of Cycle 7, also includes automatic actuation of the AFW system on low steam generator level and an adjustable time delay. However, the AFAS also includes logic that will automatically isolate a faulted steam generator on low SG level coincident with high steam generator and/or high feedwater header differential pressure signals. Provisions are incorporated in the AFAS so that the actuation signal can be manually initiated.

The new AFAS will be as described and approved in the NRC's Safety Evaluation of the Auxiliary Feedwater System, Florida Power 4 Light Company, St. Lucie Plant, Unit No. 1, transmitted via NRC letter dated September 10> 1982 (R.A. Clark to R.E. Uhrig), except that a time delay has been added which will delay the actuation of the Auxiliary Feedwater (AFW) System for some pre-selected period of time (205 to 600 seconds) after receiving an initiation signal (low steam generator level setpoint).

If, however, the:. initiation signal is removed (due to increasing steam generator level above the bistable reset point) before the expiration of the time delay, the time delay is reset to zero. This stops the process and actuation of the AFW system will not occur unless the initiation signal is received again and the time delay expires before the initiation signal is removed.

The primary function of the time delay is to reduce challenges on the AFW system under the condition of reactor trip with offsite power and main feedwater available. The time delay also provides more favorable results for the'team Line Break analysis by delaying the actuation of the AFW system.

The installation of the safety grade automatic auxiliary feedwater actuation system (AFAS) is being done, in part, to satisfy a requirement in NUREG-0737, Item ILE.1.2. An NRC safety evaluation of the AFAS (NRC letter to FPL, R. A. Clarke to R.E. Uhrig, dated September 10, 1982) stated that the electrical, instrumentation, and control aspects of the AFAS were reviewed by the NRC and that the NRC concluded that the St.

Lucie, Unit No. 1 auxiliary feedwater automatic initiation system complies with the staff's long term safety grade requirements, and therefore, is acceptable. The safety evaluation recommended the addition of technical specifications addressing the surveillance testing of the AFAS automatic actuation logic. This proposed technical specification change package complies with those recommendations.

Automatic control of the Auxiliary Feedwater Actuation System will be modified to incorporate a time delay as described in Section 1.1, Description of Change to the AFW System. Two classes of events, increased heat removal and decreased heat removal, were re-evaluated to

'determine if they were affected by this change. The specific FSAR events re-evaluated, because the addition of the AFAS has .the most impact of them, were the Loss of Feedwater event and the Steam Line Break post-trip Return-to-Criticality event. The existing analyses for the Loss of Feedwater event and the Steam Line Break post-trip Return-to-Criticality event are still valid, as described below.

2.1 Steam Line Break Post-Tri Return-to Criticalit The Steam Line Break post-trip Return-to-Criticality Analysis can be affected by changes in the assumptions for the auxiliary feedwater flow rate and the time and duration of delivery. More flow, delivered sooner, could adversely affect the results. The effects of the AFAS on the Steam

Line Break post-trip Return-to Criticality analysis was evaluated by Combustion Engineering, the designer of the AFAS by comparing the Cycle 5 analysis results with those obtained after changing only those assumptions impacted by'AFAS.

These assumptions are listed in the table below. A comparison between the new values and the reference values shows that the reference analysis js conservative, in that it assumes the same auxiliary feedwater flow, the same AFAS actuation setpoint, and the same minimum delay time. The only difference is that the new AFAS has the ability to automatically isolate the ruptured steam generator on high differential pressure ensuring that no additional water is admitted to the ruptured steam generator. This feature of the AFAS makes the Cycle 5 Steam Line Break analysis conservative.

Ref. Analysis New Analysis Parameter Without AFAS With AFAS Comment S/G Water Level 62.596 (Normal 62.596 (Normal No Difference AFW Actuation Water Leve9 Water Leve9 Setpoint Minimum AFAS 180 seconds 180 seconds No Difference Delay Time Maximum AFW 1280 gpm 1280 gpm No Difference Flow Rate Maximum High SG N/A 530 psid+ For HZP case-No P AFW Isolation impact. For Full Setpoint Power Case Isolates AFW flow to ruptured S/G prior to AFAS U

actuation.

+ Note that the '530 psid isolation setpoint represents the Technical Sp~if ication value plus instrument uncer tainties in the conservative direction.

The high SG P AFW isolation setpoint was evaluated to determine if a hysteretic value was required to make the effects of re-initiating AFW flow to the ruptured steam generator acceptable. For this analysis the ruptured steam generator will be isolated when the SG P reaches 530 psid, and remains isolated until the feedwater header P falls below 200 psid.

Since the feedwater header P does not fall below 200 psid until well after the time of peak reactivity, re-initiation of AFW is not of concern; therefore, a hysteretic value for the SG P AFW isolation setpoint is not required..

Exxon Nuclear Co. has performed their safety evaluation based on the current AFAS and has found the Cycle 7 analysis to be bounding.

Feedwater line breaks were not analyzed for excessive heat removal because the steam line break is the limiting cooldown event as stated in the FSAR.

2.2 Loss of Feedwater/Feedwater Line Breaks Loss of Feedwater events, including Feedwater Line Breaks, were previously evaluated as a result of post TMI requirements (NUREG-0737,

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Item II.E.1.1). This evaluation showed that the Loss of Feedwater event was limiting for the AFW system. This evaluation was submitted to the NRC and app'roved in the NRC's SE, transmitted via NRC letter dated September 14, 1982 (R. A. Clark to R. E. Uhrig). This evaluation is presently reflected in Section 10.5 of the FSAR. A reevaluation of these events confirmed that the loss of main feedwater with loss off offsite power plus an active failure of the A or B battery and a high energy line break in the AFW system was the most limiting with regards to the AFW system requirements.

An evaluation of this event, plus the Loss of Feedwater analysis shown in Section 15.2.8 in the Final Safety Analysis Report (FSAR) demonstrates that, after the start of the events, at least ten minutes are available to verify auto-start or, if necessary to manually initiate auxiliary feedwater flow before steam generator dryout occurs. The new AFAS will actuate the AFW system automaticaQy well within the time frame demonstrated as acceptable in the FSAR. Based on the above, the existing Loss of Feedwater Analysis in the FSAR remains bounding and no additional analysis is required.

3.0 Si ificant Hazards Consideration On September 14, 1982, NRC approved the changes to the Auxiliary Feedwater (AFW) System at St. Lucie Unit 1, which were to be made to satisfy NUREG-073V,Section II.E.1.2. Because St. Lucie Unit 2 was being licensed at that time with the same auxiliary feedwater actuation system (AFAS) as what was approved for St. Lucie Unit 1, NRC allowed postponement of the implementation of AFAS on St. Lucie Unit 1 until the Fall 1985 refueling outage, in order to obtain operational experience with the system on Unit 2.

St. Lucie Unit 1 will be implementing the new AFAS during the upcoming refueling outage, scheduled to begin on October 20, 1985. The only difference between the system approved by NRC and the system being installed is the addition of a time delay. The addition of the time delay on

. the new system performs the same function as the currently installed time delay, i.e., it delays actuation of. the system for a pre-selected period of time after receiving an actuation signal (low steam generator level setpoin t).

The proposed changes to the technical specifications are necessary to meet NUREG-0737 technical specification recommendations in that additional surveillance requirements are now specified for the AFW system. This is similar to Example (ii) of the examples of amendments that are considered not likely to involve significant hazards considerations, contained in the Commission's guidance for determination of significant hazards considerations, in that the new surveillance requirements are changes that constitute additional limitations, restrictions, or controls not presently included in the technical specifications: for example, a more stringent surveillance r equirement.

The proposed change to the steam generator low level setpoint for AFW system initiation (Table 3.3-4 Item 7) is based solely on the addition of new level transmitters with less instrument uncertainty than those presently installed. The input to the safety analyses is unaffected.

~ ~

The proposed change to the Steam Generator Level-Low response time for AFW System initiation (Table 3.3-5 Item 8) is also based solely on the new equipment instrument uncertainty as stated by the vendor.

The proposed change to Technical Specification 6.5.1.6 adds paragraph 6.5.1.6.m under the Facility Review Group responsibilities to be consistent with the addition of new ACTION STATEMENT 13 of Table 3.3-3.

These last three changes are similar to Example (i) of the examples of amendments that are considered not likely to involve significant hazards considerations, in that they are administrative in nature to achieve consistency throughout the technical specifications and to change the technical specifications to be consistent with the installed instrumentation.

Based on the safety evaluation and discussions above, it has been determined that the proposed changes do not involve significant hazards considerations.

WP/DISCNB0000/Rev Tech Spec/0985/BL