ML13308B794
| ML13308B794 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/06/1980 |
| From: | Curran J, Morgan H Southern California Edison Co |
| To: | |
| Shared Package | |
| ML13308B793 | List: |
| References | |
| SO23-3-5.6, NUDOCS 8011250471 | |
| Download: ML13308B794 (11) | |
Text
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 1 NEW LOSS OF COOLANT ACCIDENT 1.0 SYMPTOMS 1.1 Alarms 1.1.1 Pressurizer Level Error Lo 1.1.2 Pressurizer Level Lo-Lo 1.1.3 Pressurizer Press Deviation Hi/Lo 1.1.4 Pressurizer Press Hi/Lo Fkt it.
1.1.5 Containment Pressure Hi E/
1.1.6 Containment Temperature Hi 1.1.7 Containment Atmosphere Humidity Hi 184 1.1.8 Containment Sump Level Hi-Hi 1.1.9 SIAS Actuation Train A(B) 1.1.10 CIAS Actuation Train A(B) 1.1.11 CCAS Actuation Train A(B) 1.1.12 CSAS Actuation Train A(B)
EDisoN 1.1.13 Pressurizer Safety Valves Open ASIE 1.1.14 Quench Tank Level Hi/Lo 1.1.15 Quench Tank Temp Hi 1.1.16 Quench Tank Press Hi 1.2 Indications 1.2.1 Decreasing pressurizer pressure 1.2.2 Decreasing or increasing pressurizer level NOTE:
Pressurizer level may not always be a true indicator of RCS fluid inventory. Pressurizer steam space ruptures, void formation elsewhere in RCS, reference leg flashing and reference leg failures may cause indications which are contrary to true RCS fluid inventory conditions.
1.2.3 Increasing containment pressure
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 2 NEW NO'/
6 1980 1.0 SYMPTOMS (Continued) 1.2 Indications (Continued) 1.2.4 Increasing containment temperature 1.2.5 Increasing containment humidity 1.2.6 Containment atmosphere and/or radwaste area ventilation radiation monitor alarms 1.2.7 Pressurizer safety valve open position indication 1.2.8 Increasing quench tank level 1.2.9 Increasing quench tank temperature 1.2.10 Increasing quench tank pressure 1.2.11 Sudden decrease in RCS subooling noted by the subcooling margin monitor 1.2.12 Decreasing RCP motor current or erratic RCP pressure differential 1.2.13 RCP seal AP indicator abormal-no pressure drop between seal stages 1.2.14 Letdown flow decrease or total loss of letdown flow 1.2.15 Charging line break 1.2.16 Sample line break 1.2.17 Steam generator tube rupture NOTE:
Many of the above systems could result from a steam supply line rupture, steam generator tube rupture or CVCS malfunction. Careful evaluation is re quired in order to determine which emergency is in progress.
(See Figure 1 and 2 attached).
2.0 AUTOMATIC ACTION 2.1 CPC generated reactor trip 2.2 If pressurizer pressure drops below 1806 psia or containment pressure rises above 2.95 psig, a SIAS, CIAS and CCAS may be generated.
2.3 If containment pressure rises above 8.14 psig, a CSAS may be generated and the Containment Spray System will be put into operation (= 45 sec.
fully operational)
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 3 NEW 2.0 AUTOMATIC ACTION (Continued) 2.4 Possible EFAS initiation to either or both steam generators.
NOTE:
The time delay for initiation of these events varies con siderably depending on the size of the break.
3.0 IMMEDIATE OPERATOR ACTION 3.1 Verify the reactor tripped and reactor power is decreasing. If not, manually trip the reactor.
3.2 Verify the turbine tripped. If not, manually trip the turbine.
3.3 Verify the unit output breakers are open. If not, manually trip the unit output breakers.
Verify turbine speed is decreasing.
3.4 Verify the unit auxiliaries have transfered to the reserve auxiliary transformers. If not, manually transfer to reserve auxiliary transformers.
3.5 Verify the SIAS, CIAS and CCAS have properly activated. If not, manually initiate them.
3.6 After a SIAS due to low pressurizer pressure, and as soon as possible after it has been verified that all CEA's have been fully inserted for at lease five (5) seconds, stop all operating reactor coolant pumps.
3.7 Verify activated or actuate EFAS-1 and/or EFAS-2 and check auxiliary feedwater flow is established on FI-4720 and FI-4725.
3.8 Use the atmospheric steam dump valves to control steam generator pressure at 1000 psig.
3.9 If containment pressure is above 8.19 psig, verify CSAS has been properly activated. If not, manually establish -, 1750 gpm spray flow and a 15 gpm NaOH flow.
3.10 After any SIAS, operate the SIS until RCS hot and cold leg temperatures are at least 50*F below saturation temperature for the RCS pressure and a pressurizer level is indicated, unless the cause of the SIAS has been verified to be an inadvertent actuation. If 50'F subcooling cannot be maintained after the system has been stopped, the high pressure injection system must be restarted.
3.11 If conditions permit, attempt to locate and isolate the source of the leak, possible leak locations include, but are not limited to the pressurizer safety valves, RCP seals, letdown line, charging line, sample line, and steam generator tubes.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 4 NEW 4.0 SUBSEQUENT OPERATOR ACTION NOTE:
For anti-core melt safety function, observe all available in dications to determine conditions within the RCS. Use the Critical Functions Monitoring System, subcooled margin meter, RCS hot leg temperature, RCS cold leg temperature, incore thermocouple temperature, and RCS pressure to determine if the RCS is subcooled or saturated. An increase in temperature equal to or above the saturation temperature for the existing pressure is an indication of voiding in the RCS. If this occurs, the operator must ensure the RCP's are turned off, the SIS is providing makeup to the RCS, and the steam generators are removing heat from the RCS.
The operator may be assured a heat sink is available by observing steam generator feedflow and steamflow, by indications that steam generator levels and pres sures are being controlled, and by observing that operation of the steam generators is maintaining or decreasing RCS temper ature and pressure.
NOTE:
For containment integrity safety function, use the Critical Function Monitoring System to verify containment isolation, containment heat removal and containment pressure control.
4.1 Operate atmospheric steam dump valves to maintain or reduce plant temperature and reduce steam generator pressure below the steam generator relief valve setpoints. Begin a plant cooldown as soon as possible, and in any case, within one (1) hour post LOCA.
NOTE:
Monitor primary system temperature and pressure to avoid exceeding a 750F/hour cooldown rate. Override and open MSIV's and use the SBCS, if available.
4.1.1 Refer to Emergency Operation Instruction S023-3-5.1, "Emergency Plant Shudown", for emergency plant shutdown sequential actions.
4.1.2 Refer to Operating Instruction S023-3-2.31, "Natural Circulation Guidelines".
4.1.3 Refer to Operating Instruction S023-3-2.30, "Deter mination of Adequate Core Cooling", to verify adequate core cooling.
4.2 Take control of auxiliary feedwater flow by overriding and positioning HV-4712 and'HV-4713 as required to stabilize steam generator levels at -, 65%.
4.2.1 If excessive reactor cooldown is experienced and the steam driven auxiliary feedwater pump P140 is not required, secure P140. Refer to Operating Instruction S023-2-4, "Auxiliary Feedwater Pump Operation".
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 5 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.3 The Watch Engineer shall notify the "duty" Station Administrator and Shift Technical Advisor and discuss the situation. An assessment of plant status and safety shall be made and the event classified. If an emergency is declared (Alert, Site or General), the Emergency Plan will be actuated using the implementing Emergency Procedures.
If unable to contact any Station Administrator in the normal reporting chain within fifteen (15) minutes following the declared emergency, notify the NRC via the red phone.
4.3.1 Refer to the following Operating Instructions to verify proper system operation:
.1 S023-1-4.1, "Containment Emergency Cooling System";
.2 S023-3-2.27, "Control Room Isolation System";
.3 S023-3-2.7, "Safety Injection System Operation";
.4 S023-3-2.9, "Containment Spray System Operation".
4.3.2 For implementing the Radiological Emergency Plan, refer to Station Emergency Procedure S023-VIII-1.3, "Unit Emergency".
4.3.3 Notify the Systems Operating Supervisor concerning the nature of the emergency.
4.4 Have the Chemical Radiation Technician commence sampling the re actor coolant and containment atmosphere using the post accident sampling system within one (1) hour post LOCA.
4.5 If transient conditions have stabilized and ESF busses are being supplied from offsite power, stop the.emergency diesel generators per Operating Instruction S023-2-13.0, "Diesel Generator Operation".
4.6 Terminate RCS charging no sooner than 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> nor not later than 2.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> post LOCA.
4.6.1 Override and stop the charging pumps and the boric acid makeup pumps.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 6 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.7 When Refueling Water Storage Tank (RWST) drops below 23% of normal low level, check the appropriate actions taken by RAS occured:
4.7.1 Upon indication of transfer to RAS, verify the flow path from the containment emergency sump to suction of HPSI pumps is open:
HV-9302, HV-9304, HV-9303 and HV-9305.
4.7.2 Verify LPSI pumps stopped.
4.7.3 Verify the minimum flow recirculation line stop valves are closed in order to prevent depletion of containment sump inventory. The following valves should indicate closed:
HV-9306, HV-9307, HV-9347, and HV-9348.
4.7.4 Verify (later) % level on LI-9386-1 and LI-9389-2, contain ment emergency sumps.
4.7.5 Close HS-9300 and HS-9301, Refueling Water Storage Tank isolation valves. Monitor RWST level and HPSI pump flow rates to verify the shift from injection to recirculation mode has been accomplished.
CAUTION: With a RAS, ensure the HPSI pumps are not operating at less than 35 gpm per pump. If HPSI pumps are delivering less than 35 gpm per pump, turn off the charging pumps (if operating) one at a time and then the HPSI pumps one at a time until only one HPSI pump remains operating. If the RCS contains non-condensible gases and/or steam generator heat removal capability is degraded, all of the flow from the HPSI and charging pumps may be required to prevent core uncovery. It is therefore essential, after each pump is turned off, to verify that at least 50*F of subcooling remains in operation.
Restart pumps as necessary to maintain 50'F sub cooling. Utilize subcooling margin monitor with hot leg temperature and pressurizer pressure to determine margin to saturation.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 7 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.8 Notify Chemical Radiation Technician to sample the safety injection pump recircline as soon as possible after RAS. Continue sampling at one (1) hour intervals until boron concentration has stabilized.
4.8.1 If boron concentration is less than 1720 ppm restart charging pumps to increase RCS boron concentration to greater than 1720 ppm.
4.9 When containment pressure decreases to 8 psig, the containment spray pumps may be stopped provided RAS has not occured. Containment spray must be placed in service if RAS occurs to provide containment sump cooling.
(Only core heat sink available.)
CAUTION:
Simultaneous hot and cold leg injection should not be initiated before two (2) hours. High steam velocity in the hot legs may prevent injected water from reaching the core before two (2) hours.
4.10 At two (2) hours post LOCA realign the discharge of the HPSI pumps so the total injection flow is divided equally between the hot and cold legs by performing the following:
4.10.1 Verify closed or close HV-9339 and HV-9337, SOC inlet isolation.
4.10.2 Verify closed or close HV-9378 and HV-9377, SDC inlet isolation.
4.10.3 Throttle closed the cold leg high-pressure injection valves in one train to a (later) % position open then gradually open the corresponding hot leg injection valve. Repeat for the other train. When both trains are aligned, use the cold leg injection valves to balance the flow to 50/50 be tween the hot legs and the cold legs as indicated on flow indicators FI-0311-2, FI-0321-1, FI-0331-1, FI-0341-2, FI-9421-1 and FI-9435-2.
4.11 After six (6) hours post LOCA, perform either of the following:
4.11.1 If RCS pressure has remained or risen above 300 psia, then the RCS is filled and subcooling has occured. Verify by checking saturation pressure for the existing temperature.
Establish conditions for SDC mode by continuing to cool down utilizing the steam generator atmospheric dump valves or turbine bypass and auxiliary feedwater until RCS tem perature is less than 350aF. Throttle HPSI pumps until RCS pressure is reduced to 361 psia. Do not terminate HPSI pump injection for any prolonged period in order to avoid depleting the RCS inventory.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 8 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.11.1 (Continued)
CAUTION:
Minimum pressure - temperature (MPT) operating restrictions take precedence over requirements for operating of the high pressure injection or charging system to maintain a minimum of 50'F subcooling during operation of the shutdown cooling system. The system must remain sub cooled, but an amount less than 50*F is accept able if required to avoid violating the MPT limits.
CAUTION:
If there is a high radioactivity level in the RCS,.circulation of this fluid in SDC may result in high area radioactivity readings in the safety equipment building. The activity level of the RCS should be determined prior to initiat ing SOC flow.
.1 Align all HPSI flow to cold legs.
.1.1 Close HV-9420, hot leg injection isolation.
.1.2 Close HV-9434, hot leg injection isolation.
CAUTION:
Vent or isolate the SIT's to prevent their pressurizing and injecting nitrogen into the RCS prior to initiation of the shudown cooling system. Refer to Operating Instruction 5023-3-2.7, "Safety Injection System Operation".
.2 Place the SDC system in service. While placing in service, do not warmup the SDC system and do not open HV-9353 or HV-9359 the warmup bypass valves. Refer to Operating In struction S023-3-2.6, "Shutdown Cooling System Operation".
CAUTION: Avoid excessive or prolonged LPSI pump cavitation during post LOCA shutdown cooling operation which may occure due to LOCA conditions.
.3 Secure feed and bleed of the steam generators by securing auxiliary feedwater as per Operating Instruction 5023-2-4, "Auxiliary Feedwater Pump Operation", Step 6.5.5.
.4 Secure steaming steam generators by closing atmospheric steam dumps using controllers HIC-8419A1 and HIC-8421A2 or by closing steam bypass control valves using controllers HIC-8423, HIC-8424, HIC-8425 and HIC-8426.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION 5023-3-5.6 UNITS 2 AND 3 EMERGENCY Page 9 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.11.2 If RCS pressure has fallen or remained below 300 psia, the break may be too large for absolute assurance that proper suction is available for the SDC mode; however, in this event there is complete assurance that simultaneous hot leg/cold leg injection alone will both cool the core and flush the reactor vessel indefinitely.
.1 Secure steaming steam generators by closing HIC-8419A1 and HIC-8421A2 atmospheric steam dump controllers or by closing HIC-8423, HIC-8424, HIC-8425, and HIC-8426, steam bypass control valves.
4.12 Sample containment for H concentration. Place containment combust able gas control system Tn service prior to reaching a H2 concentra tion of 3.5 Vol. % as per Operating Instruction S023-3-2.28 "Contain ment Combustable Gas Control System".
5.0 ATTACHMENTS 5.1 Figure 1 - Accident Identification Small Breaks 5.2 Figure 2 - Accident Identification Large Breaks H. E. Morgan Superintendent Units 2 and 3 Approved:
(YM.
Curran Plant Manager MT/sa Attachments (2)
1 19ure I ACCIDENT IDENTIFICATION SHALL BREAK IPRESSURIZEIR PRESSURE AND LEVEL I a)DECHEASING AT A SLOW HAT E OBSERVE I -AVG AND HEACTOR POWER TAVG DECREASING AND HX POWER INCRlASING T-AVG AND REACTOR POWER CONSTANT OUSElVE TURBINE LOAD LOCA Oft S.G. TUBE RUPTURE CONSTANT OH DECHEASLD INCliLASED OIRVE CONTAINMENT PiESSIIE.
w TEMPERATURE. HUMIDITY. AND WECESSSTEAM EXCESSLOAD a-m
'C FLOW ACCIDENT ACCIDENT own
_______NORMAL INCREASING OBSERVE CONTAINMENT REDUCE TURBINE LOAD PRESSURE, TEMPERAT~lURE, WITH LOAD SET Oilft.
B IIUMIDITY, AND SUMP LEVEL LOAD LIMIT RUPTURE oR LOCA~ OUISD TRIP REACTOR INCREASING NORMAL IF UNALE TOLOADTSETM(il ANDTACEUATC REDUCE LOAD TRIP SAFETY SYSTEMS NEACTOLE j
UNDINE STEAM BREAK STEAM BREAK OBSERVE INSIDE OUTSIDE AIR EJECTOR I
RFER TO CONTAINMENT CONTAINMENT IEFERTOEP.
OR STEAM DUMP REACTOR TRIP MONITOR LOCA OR TURBINE TRIP PLANT AND BYPASS VALVE CLOSE MSIV'S OPEN It TO.P.
OBSERVE STEAM STEA DUMP & BYPASS LINE__UPTURE VALVE POSITION INDICA I ION 0 CJ
_CLOSED__A CoC~
OPENANACUT TRIP PLANT AND C
z CLOSE MSIVS MANUALLY)
PCLOENISV'SREFER TO REFERl TO E.P.
IF UNABLE TO F.P.
STEAM CLOSE TRIP PLANT S.G. TUE LNE RUPTURE AND CLOSE MSIVS RUI TIUEL
emFigure 2
ACCIDENT IDENTIFICATION LARGE BREAKS Dm
- 4J PHESSUIIIZEll PRESSURE AND I
LEVEL DECiREASING IIAPIDLY OUSERVE STEAM GENElRATOiR PRESSUlES Lo >
AUNORMALLY LOW IN ONE STEAM GENEHATOH PRESSURES w z OH 1OTH STEAM GENE RATORS NORMAL OR RISING STEAM LINE LOCA On RUPTUES.G.
TUbE RUPTURE OUSEllVE OUISEllVE CONTAINMENT PHESSUlRE CONTAINMENT PRESSURE REASIcitNORMAL INREASIN NORMAL STEAM IlEAK STEAM BRIEAI(
LOCA S. UETURE INSIDE OUTSIDE IUTR CONTAINMENT CONTAINMENT REFEli TO L9 E.P.
VERIFY HIGH LOCA RADIATION IRIP PLANT THIP PLANT 41R EJECTOR AND CLOSE AND CLOSE DISCHARGE MAIN SILAM MAIN STLAM ISOLA I ION ISOLA I ION VALVES VALVES C)cl HEFEH TO F
E.P.
z.-,S.G.
TUHIE R
REFER TO REFER TO RUPTURE E.P.
E.P.
STEAM LINE STEAM LINE HUPTIIIIE ItUP FUllE