ML20155H627

Rev 36 to Procedure B.4, Plant Shutdown & Cooldown

ML20155H627
Person / Time
Site:	Rancho Seco, 05000000
Issue date:	12/18/1985
From:	SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:
Shared Package
ML20155H523	List: ML20155H518 ML20155H562 ML20155H585 ML20155H596 ML20155H625 ML20155H627 ML20155H636 ML20155H645 ML20155H654 ML20155H665 ML20155H686 ML20155H706 ML20155H720 ML20155H726 ML20155H742 ML20155H774 ML20155H798 ML20155H841 ML20155H894 ML20155H911
References
RTR-NUREG-1195 B.4, NUDOCS 8605160306
Download: ML20155H627 (22)

Text

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9. t EFFECTIVE DATE 12 _18 .85 SRey?36-j{

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. B.4 '

N PLANT SHUTDOWN AND COOLDOWN #

1.0 PURPOSE

~.

.1 To outline the steps by which the nuclear steam system is ' shutdown' from 15 percent power and cooled to the cold shutdown condition. , , ,

.1 Plant Shutdown, Section 4.0 - -' "

.2. Plant Cooldown, Section 5.0 > E' "'^'U'

.3 Natural Circulation Cooldown, Section 6.0 * .

.'* ,s) ,

9

2.0 REFERENCES

la ~- . I

I'~SMUD Rancho Seco Unit 1 FSA,R, Section 15 Technical Specifications -

.2 SMUD Rancho Seco Unit 1. Plant Process Standards

.. c. . ' :&. v.

C, >

.3 ,SMUD Rancho Seco Unit 1. Water Chemistry Manual. AP.306 2 ,/ t. . .

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.4 SMUD Rancho Seco Unit 1. Plant Operations Manual . . ,

, , i-3.0 LIMITATIONS AND PRECAUTIONS ' '

.1 Maintain RCS Pressure, temperature, and cooldown rate within the limits of Process Standards Curve 101-2a. 2  ?.a-l

.. m 1

.2 The pressurizer.cooldown rate shall not exceed 100*F/hr.

.3 Maximum allowable gT between the RCS cold let temperature and pressurizer l temperature is 410 F. s. -

.4 The secondary side of the OTSGs shall not be presgurized >200"psig if the temperature of the steam generator shell is < 130 F.  : mo'

.5 The feedwater temperature to the OTSG shall be no'more than'350*F'below OTSG downcomer outlet temperature. . < **

.6 Do not open valves connecting the decay heat removal system to"the' reactor  !

coolant system until reactor coolant pressure is.less than or equal to the maximum pressure shown in Process Standards Curves 101-30 through 101-3K, '

and/or 101-4, and until RCS tempera'ture is less than 290*F. o.

r.'.Y.. . .

2 Rev. 36

$605160306860306 DR ADOCK 0500 g,4 1 s

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i LIMITATIONS AND PRECAUTIONS (Continusd) 3.7 At all times during cooldown, the reactor shall be maintained at least one' 4 percent subcritical. If source range count rate increases abnomally,  %

discontinue cooldown until cause is identified and corrected.

l

.8. Maintain makeup and purification system and decay heat removal system boron concentrations equal to or greater than the boron concentration of the reactor coolant system such that the reactor coolant system is not diluted during cooldown. ,

C., l

.9 Observe allowable RCS pressure-temperature curves for simultaneous.

operation of RC pumps and Decay Heat System; see OP A.2.' -

t-

.10 Continue seal injection and component cooling water to RCS pumps until RCS temperature is <150*F.

I .

' 11 Before RCS temperature decreases to 500*F at least one RCS pump must be taken out of service.

t

.12 Close core flood tank isolation valves when RCS pressure decreases to <700 ,

but >600 psig.  !

.13 All subcritical boron changes shall be verified every estimated 30 ppm  !

change or hourly, whichever is more frequent.' .  ;

.14 Between 0 and 15 percent reactor power, maintain pressurizer level" l commensurate with, but not less than, Process Standards Curve 101-16. . ;

.15 Maximum allowable 4T between OTSG downcomer inlet temperature and RCS Tcold -

is 25 F. . .

.16. Maximum allowable RCS temperature change rate between 0 and 15 percent power is 150*F/hr. ~

1

.17 Maximum allowable AT between OTSG average shell temperature and RCS  !

temperature is 60*F (see OP A.6, Enclosure 8.6 for calculating 0TSG '

' Average Shell Temperature). .

ti . . .

.18 To prevent inadvertent actuation of the auxiliary feedwater system during cooldown, the automatic start controls for the pumps and valves-should be placed in manual prior to cooldown. .

.19 The auxiliary Q 8 inches level)feedwater system OISG when RCSshall be usedisfor>200 temperature fill,F.ing an empty .-

?. .

.20 If all RC pumps are lost during cooldown, continue RCS cooldown'via natural circulation per Section 6.0. S' .

J-

.21 The maximum allowable aT between RCSh T ot and cT old is 100*F.

.22 When cooling the RCS with one OTSG in a dry condition, that'0TSGs Average -

Shell Temperature must be within 100*F of the RCS temperature and maximum Thot and Tcold across that OTSG is 10*F g i Rev. 36

. B.4-2 O e

LIMITATIONS AND PRECAUTIONS (Continued) ~ W '# d 3.23 For loss of OTSG. feed or decay heat removal system, see Emergency BN' h-

• Procedure C.10 or C.12, respectively. . ML u

.24 Control rod safety group 1 shall be fully withdrawn whenever positive reactivity is being added to the reactor by either xenon,' boron,-

temperature, or m6 tion of part length control rods. The following exceptions may be applied. L. 7 , _

.1 The reactor coolant system has been borated to at least the hot, xenon free boron concentration and is being maintained at hot shutdown.

.2 The reactor coolant system has been borated to the cold shutdown boron concentration and the plant is being cooled down.

.25 If 02 Analyzer is out of service, notify Chem-Rad to sample within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of start of plant cooldown.

..?2 c.:

.26' If there exists a .kriown primary to secondary leak, and the Hogging Air Ejector, the Auxiliary Feed Pump Terry Turbine, or any of the Atmospheric Dump Valves, the Main Steam Relief Valves, or the Auxiliary Steam Relief Valves operates, the information requested in Enclosure 8.2 must be recorded and given to Chem-Rad as soon as is practical. Also, ensure roof area is clear of personnel prior to hogger operations under these circumstances.

4.0 'PLANY SHUTDOWN . INITIAL

• H

. Initial Conditions ,

t: :4 ;

.1 Unit is -15 percent power. --

a .

v. n v n v,

.2' Unit Tave is controlling at 582*F and Reactor Coolant Pressure is controlling at ~2155 psig.  :

e & n'- in p .. -

g g a .r o ,

.3 Two main feedwater pumps and one condensate pump operating N, (Preferably one main feedwater pump in auto and the other in r- -

manual at minimum speed).  :.1 e m m.

.4 At 1 east two circulating water pumps in operation.

9

.5 An auxiliary boiler is hot and pressurized per OP A.39 Section 4.0.

.6 RCS shutdown boron concentration has been determined for hot shutdown and/or cold shutdown per OP 8.6 and calculations made per B.9 to insure > one percent shutdown margin during all stages of plant shutdown ~and/or cooldown.

.7

..3 7

Pressurizer level control in " Auto" and controlling at 200 inches.

Rev. 36 B.4 .3 I

• _.L..-_._. .. . . _ . . _ . . _ _ . _ . _ _ _ . _ . _ . _ _ _ . _ . _ , _ _ . . . _ _ _ _ . . . . . _ . . . , _ _ _ _ _ , _ _ . . . . _ .

PLANT SNUTDOWN (Continued) -

' # ~NITIAL I

4.8 Plant loads transferred from unit auxiliary transfonners No. l'ind' W No. 2 to startup transformer, per OP A.58. '>

.9 - If the RCS is to be cooled down, RCS degassification is in progkess' per OP A.15 and/or OP A.3.

Procedure NOTE:

Consunicate witT5RUD dispatcher prior to switching power supplies, large equipment such as RC pumps or anything that would affect power transmissions.

^ ^

CAUTION:

If 0TSG is isolated due to tube leak, do not ,.

)  ; n. m open blowdown or drain to condenser. ,

.10 Place reactor steam generator, feedwater loops A and B and reactor

-: ;rdenand in hand and decrease feedwater demand to zero. Establish ,

OTSG blowdown per OP A.6.

1 NOTE:

o' " it This insures th'aFI)TSG is being controlled

.. . at minimum level.

.11 Place 'the EHC in " Operator Auto." ,

T'.12 Set speed-load reference setter at 50 MW. -

.13 Set load rate setter to five percent per minute or less.. ~

J .

.14.. Depress EHC "Go" pushbutton. As load decreases, observe t'u'rbine bypass valve maintains steam header pressure at setpoint (885 psig).

.15 At -10 percent turbine generator load, take the reheaters out of service in accordance with OP A.46.

.16 When load decreases to -50 MW, trip the OCBs and remove main generator excitation per OP A.64, Section 6.1. Observe turbine-bypass valves are controlling header pressure at 885 psig.

N* .

36H CAUTION:

Tripping the Turbine at a reactor power level -

-3.

greater than 18 percent will result in an RPS '

Anticipatory Reactor Trip. (- -

.17 Trip the turbine and observe that AC bearing oil pump starts on decreasing oil pressure. Start the bearing lift pump.

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e Rev. 36 ,

8.4-4 G

9 9

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. r ??.TI PLANT SHUTDOWN (Continued) INITIAL l .,, 3/ cl SS..

4.18 Follow OP A.46, Section 6.0, for steps to completely place the j unit on turning gear. - -

. 4 I.

i

.. ~.m l

.19 Gradually reduce reactor power to 8 percent while monitoring and '

plotting cooldown rate (maximum of 150*F per hour between 0 and i 15 percent power).

NOTE:

Between 0 and ITpercent reactor power '. ,

adjust pressurizer level setpoint to decrease pressurizer level to 90-115 ' l inches. Maintain pressurizer level decrease commensurate with but not less than Process Standards Curve 101-16.

i

.20 Between 8 and 5 percent reactor power, place the CRD panel in manual and gradually reduce power to <2 percent, by inserting the t regulating group.

I NOTE: . ,

Makeup to the makeup tank, as required i to maintain makeup tank level between

~

60 and 80 inches. If going to cold I

.tshutdown, add concentrated boric acid as -

l

.A ---

calculated per B.9 for boration during l cooldown.

• I L '

.21 The plant is now at hot standby:  ; .

.1 Reactor is critical at <2 percent pow'er'. "

.2 RCS pressure is being controlled at -2'155 psig.

.3 RCS Ta ve >525*F.

-a

.4 Startup feedwater valves in auto. i

.5 Main steam pressure being controlled at -885 psig by the turbine bypass valves. )

.6 One (1) condensate pump and two (2) main feedwater pumps '

in operation (one main feed pump in auto, and the other in manual at minimum speed).

Rev. 36

• 8.4-5 '

6 .

PLANT SHUTDOWN (Continued) fNITIA'L n.<

4.22 To take the plant to hot shutdown, complete the following:

f

, p. . . t. -q

.1, inse With reducethe CRDpower reactor paneltoin10-manuag, while amps,rt the regulating monitoring and groups' to plotting RCS cooldown rate.

.2 At 10-8 amps and steady, record reactivity balance infonnation as required below:

.1 Rod Configuration

.2 RCS Baron Concentration

.3 RCS P'ressure Temperature -

.4 Date/ lime

.~~. . . <,-

.3 Further Neduce reactor power to -5x10-Il amps by inserting i the regulating group. . 1 j

NOTE: l Observe that source range instrumentation 1 is energized at approximately 5x10-10 amps. '

.4 At -5x10-Il amps, verify source range instgumentation is on scale and indicating no greate,r than 5x10-3 CPS.

CAUTION: -

I

~ If the source range instrumentation does' not '" ' l indicate <5x105 CPS when the intermediate i range is at 5x10-ll' amps, the required one i  !

decade overlap does not exd1 t. Reactor power shall be maintained >5x10- amps until at-least one source range channel is operable.

t

.5 Fully insert the regulating groups.

NOTE:

If the plant is to be cooled down for refueling, group 8 may be inserted at this-time, if reactivity addition due to inserting group 8 will not decrease shutdown margin to 1 1percent shutdown. ,

,4,

g .'

Rev." 36 E B.4-6 -

. . - s.  ;

PLANT SHUTDOWN (Continued) '#

INITIAL q- 4.22 .6 When it has been confirmed that >l percent shutdown margin' '3-will exist, per B.6 calculations all safety groups may be" g". .

inserted. ~D NOTE: '

For cooldown' safety group 1 shall be withdrawn. -

NOTE:

If desired, for cooldown, the RCS may be ~

borated at this time to the cold shutdown ' ,? -

boron concentration. Since it is desirable

• M to batch borate for cooldown, the pressuri-

.- zer level may be increased to 290 inches -

during batch boration.

• See b.9 for boration ' -

. - - .during cooldown. 't U

~

37 . Open MCM-165 and MCM i66, feedwater loop A/B startup ' ".'"

recirculation valves to the condenser, to establish condensate recirculation flow. Throttle open FWS-129 and FWS-130 to provide continuous minimum feedwater flow to each OTSG.

.8 The plant is now at hot shutdown.

.1 Reactor 11 percent shutdown. ,

.2 RCS Tave 1525'F.

.3 RCS pressure being controlled at approximately 2155 psig.

.4 Main steam p'ressure.bein[ controlled at approximately 885 psig with .the turbine bypass valves in automatic.

. .5 OTSGs on low level control (30 inches), e ;-# .

. .  ;.b, . : .

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.6 One (1) condensate pump and two (2) main feedwater pumps runnin (one main feed pump in auto and the other in manual . ~

5.0 PLANT COOLDOWN Initial Conditions

.1 Reactor is in a hot shutdown condition. ~ R'

.2 Safety Rod Grup 1 fully withdrawn. h '

.3 RC Makeup aligned per OP A.15, for feed to makeup tank from demin.

RC Storage Tank and from concentrated boric acid tank.

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, Rev. 36 -

l 8.4-7 cm .

• . , . - - - . - - , . - - - , - - . , - ., ,- , ,.--.-,.,---,m...,,. ,,, ,.n.- - . , - - - ,

PLANT C00LDOWN (Continued) W INITIAL 5.4 Boron concentration / addition requirements determined per B.6 and , .s-calculated per OP 8.9 for cold shutdown or for refueling Q concentration. .

.5 RCS degassing completed per OP A.15 and/or OP A.3.

.6 Stop one main feedwater pump in accordance with OP A.50.. Verify the '

remaining feedwater pump is in automatic and verify MCM-165 and MCM-166 are open with condensate flow to condenser. j

.7 Place the automatic start signals for the emergency feedwater system  !

in manual (pumps and valves). ,

)

.8 Close the . letdown isolation valve SFV-22009. Monitor MU tank level and feed at the required boron concentration as necessary during i cooldown to saintain the MU tank between 60 and 80 inches.

.9 With OCB-220 and OCB-230 open, have Electrical Technician complete EM.174 with System Dispatcher's authorization.

. ' 'm -

Verify the RCS boron concentration every estimated 30 ppm change. Sample the pressurizer water space for boron concen-l tration and periodically increase spray

~

flow as required to keep the pressurizer boron concentration greater than RCS boron "

concentration minus 50 ppmB. _,

. , a-CAUTION:

If OTSG is isolated due to tube leak, do not

_ open blowdown or drain to condenser.' '

.10 Estatilish a drain path from the OTSGs to the HP condenser in accordance with OP A.6 Section 6.0. Follow OP A.6 for steps to control OTSG levels during cooldown. ,- .

.11 Establish one RC pump running in each loop Ipreferably B and D).

NOTE: .

Sequence for stopping RCPs during '

cooldown is: C, A, B, and D. .

.12 Initiate and control RCS cooldown with the. turbine bypass valves.

Monitor and plot RCS cooldown rate. Turn pressurizer heaters OFF and spray the pessurizer as required to ' stay within Process Standards Figure 101-2a. o] .

J

. l 2 l Rev. 36 B.4-8 E '

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l 1 _ . . , . .-

PLANT C00LDOWN (Continued) ' INITIAL l

D' s

5.12 (Continued)

NOTE:

N', - j i

Should it be necessary to close either the pressurizer spray isolation valve (HV-21510) or the EMOV isolation valve (HV-21505) while the plant is hot and the reason for closure , .

would not prevent further valve operation, the valve should be cycled every 100*F as the' -

plant is cooled down to prevent valve wedge seizure due to contraction or the valve body.. l

... j

.13 Vent the pressurizer to the PRT in 'accordance with OP A.3. Follow '

OP A.3, Section 6.0 for pressurizer cooldown. Vent the MU tank as,

- " '~

-4 necessary. '

. .1 c

.14 When RC system pressure decreases to between 1950 psig and 2000'psig, terminate depressurization and cooldown. "

1 i

.15 Drive all safety rod groups to the full "In" position as per N OP A.74.

• N

. . _ , NOTE:

• If cooldown is for refueling and group 6 ..' j has not been inserted, it may be fully 1 inserted at this time (prior to inserting

~

y-safet;y groups). Insartion of group 8 will , l

, , add positive reactivity, therefore, monitor -

v neutron count rate closely and verify '

... >1 percent shutdown margin -

.16 Trip the reactor and continue to depressurize to 1750 psig,

' terminate depressurization.

NOTE:

Adjust turbine bypass valve setpoint as required to maintain RCS temperature steady.-

t-

.17 Initiate Reactor Protection System shutdown bypass per OP A.69, Section 5.2.

- - .s _

.18 Notify the I and C Department to reset the high flux trips to

<5 percent per OP A.69, Section 5.2, (In accordance with I-104.).

Till out a Work Request fom. ,

I and C Technician to sign off this step when completed with Step 5.2.8 of A.69.

. Licensed Operator to sign off this step when the Reactor Protection System is in shutdown bypass.

.19 Withdraw safety rod group 1 to the full "Out" position.

g .

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". Rev. 36 B.4-9 l B

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PLANT C00LDOWN (Continued) -

INITIAL 5.20 Initiate safety features RC System low pressure hypass between - -

<??

1750 psig and 1650 psig. ',

CAUTION:

TRIP is at 1600 psig.

.21 Continue with depressurization and cooldown. Monitor and plot temperature-pressure to stay within Process Standards Figure 101-2a.

NOTE:

Establish letdown and purification for RC System as necessary. , , 73

.22 When main steam pressure falls to approximately 650 psig, hypass the main steam line failure logic. Place the main feedwater control and 2, block valves in~~m anual and closed. Leave the startup feedwater .

. valves in auto. . ,

1

.23 At approximately 500 psig main steam pressure, bypass the running -

main feedwater pump hy opening MCM-154. With the main feedwater pump at minimum speed, place it in. manual and secure it in accordance with OP A.50.

.24 When the RCS pressure is below 400 psig, verify the low range RCS l pressure transmitter is in service.

.25 At 675-700 psig RC System pressure, close the core flood isolation

valves (HV-26513 and 26514). Open AC supply switches at MCC-5202 .

s_,

and tag, in accordance with OP A.4..

l

.26 When the RCS temperature decreases to approximately 350*F adjust 1 pressurizer level controller setpoint to 90-115 inches, per OP. A.3, '

Section 6.0.

.27 When RCS temperature reaches 350*F, initiate the OTSG Hot Soak procedure if required by Section 7.6 of OP A.6. A temperature hold is needed on the RCS between 350*F and 300*F until the Hot Soak is completed. - --

.28 Close HV-23801; open HV-23802 and J0G open SFV-23810 to provide HPI spray to the pressurizer. Observe OP A.3, Section .  ;;

6.0, for pressurizer cooldown. -

.29 When RCS temperature reaches 350*F establish RCS overpressure protection as follows:

.1 Caution tag the electromatic relief block valve HV-21505 to remain open when RCS < 350*F. .

O Rev. 36 B.4-10 6

L .t _. . . . . . . _ , . . . . . . _ _ _ .

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o j

PLANT C00LDOWN (Continutd) " a W OINITIAL O

C-5.29 .2 Place the EMOV key lock selector switch, on Control Room console H1RC, in the low position. (Key is nomally left '

in the switch.) Ensure RCS pressure <470 psig prior to l performing this step.

.3 Close and place clearance on HV-23801, SFV-23809, SFV-23811 and SFV-23812.

.4 Place clearance on breakers for HPI pumps P-238A and P-2388.

NOTE: e-HV-23801, SFV-23EU9, SFV-23811, and/or -

i SFV-23812 may be opened as required for 'n ' l maintenance or Surveillance Testing if an '

~

in-series valve in their respective HPI- / rl . i line is closed and placed under clearance. .

I or the RV head is removed. High pressure .

l

,; injection lines may be lined up as required ' - '

for the perfomance of SP 203.01A or B SFAS Digital Channel 1A or 18 Refueling Test, i without in-line valves tagged or the RV head ,

t being removed.

.30 When the RCS temperature reaches 300*F and the OTSG Hot Soak

. procedure in OP A.6 has been completed, initiate Section 6.0 of.-

OP A.47, to establish condensate and feedwater system chemistry for

{. ,layup. Change valve lineup to route condenser pit sump pump 3 discharge to the polisher sump. (0 pen CDS-494; Close CDS-493.)

NOTE:

Layup chemistry is not required if shutdown

. . is for short duration <48 hours and condesser vacuum is not to be broken.

.31 When main steam pressure has decreased to -200 pNg, verify Ehat the auxiliary boiler has picked up the auxiliary steam load.

~

.32 Before the RCS pressure / temperature relationship falls ~below the minimum, per Process Standards Curve 101-14; verify RCS boron concentration is > the cold shutdown boron concentration;.and, that.

>l percent shutdown margin exists; then, insert all safety groups and makeup at RCS boron concentration.

NOTE:

Rack out and clear LT5 Ereakers A and B. Supervisor, -

2 Nuclear Operatons Division, pemission required prior to re-energiz,ing CRDs.

.33 Initiate Work Request to have N2 spool pieces installed in. -

. pressurizer and OTSG lines, y

Rev. 36 B.4-11

- - - . e, em - - - , - - _ , * - . , - - -. - - - -,,.--.---__,,..-,-.,.,,,._,,,,c,.,,,_.-..,._,.,,-,.y---.,,.. ,.v, -----,---,.---n,w-p.,,

PLANT C00LDOWN (Continued) *IINITIAL 5.34 When the RCS temperature decreases to -300*F and the OTSG Hot Soak- O procedure has been completed, begin increasing the OTSG 1evels  %.

l to -85 percent on the operating range .in accordance with OP A.6, .

t Section 6.0.

NOTE: -

t Sample the RCS and verify chemistry is.

I within specification prior to reaching '

200*F RCS temperature.

4

.35 When RCS temperature approaches 300*F, place the NSRW system in service as per OP A.25 and the NSCW system in service as per OP A.24.

.36 When RCS temperg_ture/ pressure is <200*F/300 psig, place the following equipment under clearance CLOSED ~ with the applicable breaker Racked Out: SFV-29107/42-2A144 (Closed), SFV-29108/42-23153 (Closed), HV-26105/42-2A142 (Closed) HV-26106/42-28151 (Cicsed),

HV-20003/42-2A179 (Closed) P-291A/52-3A09, P-291B/52-3809.

NOTE:-

Breakers may be racked in as required for testing.

i

.37 Establish RCS' pressure and temperature for simultaneous operation of i RC pumps and decay heat system'; then, place the decay heat removal )

1 .

system in service per OP A.8, Sectiorr 4.3. '

- l

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• 38 When'the decay heat system is in service and RCS'<200*F rack out

. v and tag the auxiliary feedwater system in accordance with CP A.51, Section 6.0. ,

.39 Follow OP A.8,' Section 4.3, for cooldown with the decay heat system. ,

, Continue the cooldown with simultaneous operation of RCPs'and '

decay heat system in accordance with RCS operating pressure curves to <150*F. - -

. t'

.40 Follow OP A.3, Section 6.0 to control RCS pressure and pressurizer cooldown.

.41 When the RCS temperature decreases to ~230*F the OTSGs should be at -85 percent on the operate range. Follow OP A.6 Section 6.0 to

! secure OTSG feed, maintain wet layup, and place a nitrogen blanket i on'the OTSGs if condenser vacuum is broken.,

i

.42 When OTSG feed is terminated, close MCM-165 and MCM-166, and place the condensate and feedwater system in cleanup recirculation to the condenser, per OP A.47, Section 6.0.

.43 When the RCS is less than 200*F, verify RCS boron concentration and -

chemistry.

. 42 Rev. 36 D' l B.4;12 i

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PLANT C00LDOWN (Continued) ,

, _ ,, , . y y ,. ,

l S.44 Secure last RCP when RCS temperature is <150*F as read on wide - -

O L'

range Tc. (This will prevent RCS hot leg and upper head area " ' ..

temperature stratification.) ,

.45 If cond'nser e vacuum is to be broken, shut 'down the condensate and feedwater system per OP A.47, Section 6.0. l l

NOTE:

{

If condenser vacuum is to be broken for longer than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, place the feedwater heaters and ]

reheaters in layup, per OP A.53, Section 6.0.

.46 When the RCS is cooled down to approximately 13S*F,' initiate further cooldown of the pressurizer in accordance with OP A.3, Section 6.0.

.47 When the RCS temperature is 135*F, and the pressurizer' cooldown is completed, and a nitrogen blanket has been established in the pressurizer;' the makeup sy' stem may be secured in accordance with

-OP A.15, Section 6.0.

.48 When the decay heat cooler outlet temperature is <13'S*F and the MU pump stopped, the decay heat purification mode may be placed in I service per OP A.8, Section 4.5.

4

.49 At 140*F the cooldown is considered complete; however, it is 2

recommended to further reduce coolant temperature for personnel

- comfort and safety if RC systems are to be opened.

, i L NOTE:

If the RCS is to be opened for maintenance ~or refueling, vent the RCS loop high points and the l CRD's in accordance with OP A.1, in preparation I

. for draining. l

. 1 6.0 RCS NATURAL CIRCULATION COOLING

.1 Reactor Coolant Pumps (RCP's) Tripped Initial Cor$ditions

.1 Reactor tripped.

~ 1 Procedure

.2 Verify conditions required for natural circulation.

.1 Verify Aux FWS auto start.

c. .

@~ .2 Verify both OTSG 1evels approaching >50 percent on the Operate Range (-135" Startup Range).

Rev. 36 B.4-13 l -

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l. ~,,.  ; .

NATURAL CIRCULATION COOLING (Continued)

?

6.1 .2 .3 Verify RCS >50*F subcooled and RCS AT is <100*F. ~ . ., n . E C

.4 If the previous three steps cannot be verified, cSre cooling must be provided by HPI flow. Perform E0P Procedure E.02.

1 9

.3 Yerify Natural Cfrtulation e e :. .

.1 Th and incore T/C's rise about 35'F above Te and comence to track Te in 15 to 30 mnutes. (These values are indicative of a fu1]_ power trip with both OTSGs operable.) ,

i 4

.2 Tc remains steady or decreases slightly and is at or slightly greater than saturate temperature for OTSG secondary pressure.

r .3 Tc tracks OTSG secondary side Tsat-

'. 4 Th and incore T/C's track changes in OTSG secondary side pressure.

, -.c. 5 Trend computer Group No.15 " Loss of X and/or Y." Compare trend points 1 and 2 (T h loop A and B) with trend points 3 and 4 (incore T/C's). They should be of similar value and trend.

~

j .6 If T h, loop. A or B, is off scale high,. refer. to E0P Procedures, Inadequate Core Cooling. -

,.  : ~

".7 If T h, loop A or B, is off scale low, verify RCS subcooling '

, utilizing the "Tsat meters (120*F - 920*F) and incore T/C's (0-2000 F).

s

.4 Maintain the Plant at Hot Shutdown

.1 If natural circulation has been verified, maintain thh RCS in hot shutdown condition by using TBVs (condenser available) or ADVs (condenser unavailable) for ~RCS temperature conrol, if a natural circulation cooldown to cold shutdown conditions is not imediately necessary. Refer to Step 6.1.7 for cooldown.

CAUTION:

Maintaining >50 F subcooling takes precedence over controlling pressurizer level.

Rev. 36 B.4-14 l

I

- . _ _ _ _ - . _ _ .___e, _ _ . _ _ _ _ _ _ - _ . - . . . , _ . . . , . . . - , . _ . - . . -

l NATURAL CIRCULATION COOLING (Continued) ., pg ,3 gg O 6.1 .4 .2 Control feedwater and/or RCS makeup flow rate as necessary3 to' h' maintain pressurizer level 150

• 50 inches. Ensure RCS is maintained >50*F but <100*F subcooled.

l

.5 RV Thermal Shock Considerations If RCS temperature dropped below 500*F and exceeded 100*F/hr, i OR If RCS temperature dropped below 500*F and RCPs are'o}f abd flow ]

exists through any HPI inject valve as indicated on the HPI l flowmeters 1 1

.1 Stabilize the plant temperature / pressure within the Thermal 1 Shock Operation Region of Enclosure 8.1 (>50*F subcooled but I 1100*F subcooled) and prevent any heatup or pressurization above the stabilized condition for at least THREE hours. l 1

.2 Notify the station management of the plant condition.  !

.6 Restart of RCPs (Requires Feed To At Least One OTSG.)

NOTE:

Prior to RCP restart, it is desirable to ensure the pressurizer is in a saturated

- condition to minimize the RCS pressure swing that occurs due to mixing of water of dif- I ferent temperatures. Also, just prior to i starting an RCP, it is advisable ~ to close any open TBV's or ADY's to minimize the cool-ing effect. The valves must be reopened to ,

continue the cooldown. l

.1 Observe the following precautions for each RCP that is to be restarted: )

.1 CCW flow is established.

.2 Seal injection flow is established.

3 Seal return is established.

.4 RCS pressure is 1 250 psig.

Rev. 36 B.4-15 ,

I

NATURAL CIRCULATION COOLING (Continued) r 6.1 .6 .2 Start one RCP IAW normal pump start procedure OP A.2',' RCP' hystem Li,"

(preferred RCP in operable OTSG loop, if applicable). Do not operate more than one RCP/ loop.

.3 If an RCP has been successfully restarted; continue RCS cooldown, if desired, IAW applicable portions of Section 5.0 of

this procedure.

.7 Monitor Natural Circulation Cooldown

.1' While on natural circulation, maintain a cooldown rate between 10*F/ttr and 50*F/hr to prevent reactor vessel head void formation.

.2 If the RCP's are unavailable and a natural circulation cooldown I is desired or necessary, monitor the cooldown using: -

.1 Process Standards Figure 101-2A if there is no flow through any HPI loop inject valve OR

.2 Enclosure 8.1 if there is flow through any HPI loop inject "

valve.

NOTE:

• During the natural circulation cooldown, it is advisable to cooldown/depressurize as slowly as plant conditions allow to minimize the possibility of void formation in the reactor vessel head region or hot legs. The depressurization should be in steps not to exceed 70-100 psi.

CAUTION:

During the natural circulation cooldown, monitor pressurizer level and makeup tank level. A sudden-increase in either level while pressure is constant or decreasing could indicate voiding in the RCS.

In addition, unexpected pressurizer level changes during makeup or spray operations could also indicate voiding in the RCS. If voiding is suspected, stop any depressurization and repressurize to maximum pressure allowed by applicable cooldown curve and raise OTSG levels to' 95 percent on the Operate Range. Do not continue cooldown on natural circulation unless required by plant conditions. If continued cooldown is required, cooldown and depressurize as slowly as

, possible for current plant conditions. Monitor $ ,

, natural circulation closely during the cooldown.

Rev. 36 D

8.4-16 -

. e

~ ^ , , . - - - , , -

, ,-n v,----. , - . .

l

' i NATURAL CIRCULATION COOLING (Continued) l h

6.1 .7 .3 During natural circulation cool'down, maintain a coolbown rate greater than 10*F per hour, but less than or equal to 50*F per hour to prevent upper head voiding.. )

\

.4 During the natural circulation cooldown, monitor incore T/C's to determine RCS subcooling margin. If thessubcooling margin decreases to < 50*F or RCS AT approaches 100*F,, refer to E0P Procedure E.0'l. e.

CAUTION:

Using auxiliary pressurizer spray requires .,

isolating one HPI injection valve. Do. not -

use auxiliary pressurizer spray when criteria for throttling or stopping HPI is not met.  ;

(EOP Rule 2.2.)

.5 Establish pressurtizer spray flow with the' makeup' system in

' accordance with 5.36 of procedure B.4 as required to control RCS pressure in relation to RCS temperature. Maintain RCS subcooling y,50*F during cooldown. . -

' N"

.6. Continue plant cooldown with natural circulation until the Decay Heat System can be placed in service IAW OP A.8 or RCP flow can be established..

H .7 With Aux. FWP's supplying the OTSG's, break condenser vacuum when the CST reaches the Lo-Lo level alaru point (29'3"). With the Plant Cooling Water and Reservoir System in service IAW OP A.36, shift Aux. FWP's suction to site supply system when the CST level reaches the Lo-Lo-Lo level alarm point ~(3').,

P-318, Open PCW-076 - then close MCM-057 P-319, Open PCW-079 - then close MCM-058

\

l l

l l

l

.2 RCP's to be stopped by Operator Action with RCS subcooling" verified.

Initial Conditions

.1 At least one RCP operating.

.2 Reactor tripped for at least 10 minutes.

Procedure .

Q .3 Verify Aux FWS in operation and RCS parameters stable, d

Rev. 36 B.4-17 .

NATURAL CIRCULATION'C00 LING (Continued) .

g g,qq y 6.2 .4 Manually control Aux FWS flow to slowly raise the OTSG level to.50 6

percent on the Operate Range recorders. ,

Q.

. Control feedwater rate to insure pressurizer l'evel remains at 150

• 50 inches and RCS pressure remains steady.

.5 Verify RCS > 100*F and < 150*F subcooled (T-SAT meter, Th Tc and/or incore Tc'sT. Slowly adjust OTSG secondary level between 50 percent and 95 percent on the Operate Range as necessary to maintain this amount of subcooling BEFORE stopping the last RCP.

.6 When RCS pressure / temperature and pressurizer level are stable,- trip the RCP's in accordance with OP A.2.

Verify Th-and/or incore Tc's indicate a steady rise of about 35'F above Tc, then stabilize. Tc should remain steady or decrease slightly. .

.7 Verify RCS subcooling does not decrease below 50*F. Restart at least one RCP (preferably one/ loop) if at least this amount of subcooling ~

is not maintained, or provide' core cooling with HPI flow.

~

--.8 Refer to Section 6.1 through 6.1.4 for continued natural circulation operation.

7.0~ ABNORMAL OPERATIONS' ,

- .'1';SolidPlantOperation ,

Initial Conditions '

- .1 ' Reactor / Turbine tripped. E0P's E.02 in progress.

.2 The following plant conditions are established in accordance with E0P CP.105.

.1 HPI is providing core cooling.

.2 All 4 RCP's tripped.

.3 Aux. FWP(s) supplying feedwater to at least one OTSG .in automatic mode.

.4 "RCS is > 50*F subcooled. U

.3 Pressurizer indicated level is off scale high. (Verify at 'all available indicators.)

Rev. 36 -

B.4-18 9

6

. A

ABN0liMALOPERATIONS (Continued) s, m I ' '

Procedure N ,,

~,

w ' - .

7.1 .4 Establish a steady cooldown of the RQS of at least 20*F/hr takin manual control of"the TBV's (use ADV s if no condenser vacuum). g

.5 Verify natural circulation cooldown in accordance with OP B.4, Section 6.

.6 Adjust makeup /HPI flow to control RCS pressure. Ensure subcooling of

'at least 50*F. Utilize the Pressure / Temperature curve at. the.H1RC ~

1 l

and "T-SAT" fridicators. l

. g . c. r  :.

.7 Continue to adjust makeup / injection flow as necessary.)to offset RCS 1 pressure changes due to steaming of the OTSG(s).

~*,~ ,- ~ '. ,

NOTE:  :

Both steaming rates and HPI injection can '

cause dramatic pressure swing in RCS pres-sure. Ideally, the steaming rate should be stabilized (requires frequent operator atten- .

tion) and the RCS injection rate varied as necessary, to . stabilize RCS pressure. Any changes in flow rate (steam or injection) must be done slowly and one at a time. Allow plant conditions to become steady after each adjustment.

~

.8 Determine the pressurizer temperatura as indicated at the HIRC.

Using the Pressure / Temperature curve, determine saturation pressure for the pressurizer. .

.9 Place all available pressurizer heaters in service in accordance with OP A.3, to support establishing a steam bubble.

.10 Maintaining at least 50*F subcooling, permit the RCS pressure to decrease to saturate condition for the pressurizer.

CAUTION:

Verify natural circulation is not interrupted by this action, f.e., Tc rate of decrease and core AT should -

remain steady.

.11 When saturate conditions have been reached in the pressurizer, RCS pressure will stabilize as further RCS.cooldown takes place.

.12 With RCS pressure stabilized, slowly reduce makeup /injectio'n' flow to a minimum. Ideally, RCP seal supply flow will provide necessary makeup.

, l l

1"% -

1 V -

. Rev. 36 8.4-19

ABNORMAL OPERATIONS (Continued) e 19e .u1U P-

. 7.1 . 13 RCS shrinkage due to cooldown will establish a visable. level in the pressurizer (monitor all available pressurizer level indicators).

$[

W

.14 With an indicated pressurizer level of 150

• 50", adjust makeup / injection flow as necessary, to stabilize indicated level.  ;

.15 Continue plant cooldown in accordance with Section 6 of this procedure.

)

8.0 ENCLOSURE ,, l l

.1 Reactor Coolant System Interim Fracture Limit--No Forced Flcw And Thermal i Shock Operating Region. -

.2 Radiological ReTease Infomation u - >

, .a r

\*'

s 3 9

??

Rev. 36 I 8.4-20 e

A. A

'~-

. ENCLOSURE 8.1 FIGURE 1

(, ,.

REACTOR COOLANT SYSTEM INTERIM FRACTURE LIMIT NO FORCED FLOW AND THERMAL SHOCX OPERATING REGION i 3200' --

E' NOTE: Maintaining the reactor' 3000 - E coolant subcooled takes 5precedenceovertheInterim - ' - - - - -

E Brittle Fracture Curve NO FORCED FLOW

-5(B&W 74-1122501 page.6) OPERATING BAND 2800 -

d W/HPI 5IhttKIMBRITTLEFRACTURr 2600 -

E CURVE BREAX-POINTS VARIABLE 5

~

SU INTERIM BRITTLE 2400 -

! TEMPERATUREPRESSURE 5 FRACTURE CURVE m E

[Di E 303 250 'v 5 500 1500 --.

w 2200 --- .=- -

E f ,i

p 5-w ,  :: '

TED E 2000 - , f' REGION e' _':

e' C. . <g 3gon - -;'

d .,-,

8 y

T. S. CURVE 3.1.2-2 NOT LIMIT -

,e'

f.  !

y 1600 -

c x . -.. '.,e -

z_  ;:-

3 c:

1  ;

a 1400 -

.... . . . .. . .... -f . . .;

/-f W THERMAL SHOCK e' 5

- 1200 - OPERATING REGION- - e' e' e' g 1 -

z, -

e  ;

~'  :  ;:

5 INCORE TC'S TO MONITOR c i'-J e' 7 .'

1000 -

i ~

' 2 z' _ SATURATION ;:;

iPREFERRED ALTERNATE-

, f '1_ f- / ,j

CURVE g 800 -h 1) T9254 T9256

/ ' .-Y '

e' ,'

j2) T9258 T9260 e f ,-' r ,e E3) T9263 T9252

.fe7

/e' e' is / ,e 600 -l4) T9272 T9266 - ' e '-' ?Y ':'  :

3 5) T9286 .,

T9270 - ,/ / e' f ,-

RESTRICTED REGION EE 400 - -  :' '

l ,.-' , ' . . . ' '

- 1' .

l ,,"

--- - W-^ ;,Q .' .. % 5^^ T. -- ; .' ^;, ,; 2^ '..'" -

. ,f ', }'

200 -

7y / z '/

j u-

. y.

/

.7 y 0_ - . . v 0 100 260 3d0 400 500 600 70(

INDICATED RC TEMPERATURE--?F Rev. 36 B.4-21

ENCLOSURE 8.2 RADIOLOGICAL RELEASE INFORMATION 4%...

.1 Hogging Air Ejectors l

.1 How Many _ . .

.2 Condenser Vacuum "d

.3 Duration - ~ ..

.4 Date ' "- -

.2 Atmospheric Dump Valves '

>- . u: l

^*

. en-- l

.1 How Many .

.2 Duration ~ ~ '

~'  !

, l

.3 Date -

l

.3 - Main' Steam Code Relief Valves

~

((

.1 Which'Ones -

~.2

~~ ::

Duration of Each . --

..= .

- Q5_.3 _ Date -

El '-

- .= : . - ,

.~ 4 ~ Auxiliary Steam Relief V'al_ves .

.1 Duration

. 2 ' Date ,

~ ~

.1 .3 , Side Supplying Steam ' '

~

.5 Auxiliary Feed Pump (Terry Turbine) ,

.1 Duration - -

.1 Date -

l

. l Rev. 36

-END h

B.4-22 -

4 S ,