ML13302A167
| ML13302A167 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/04/1981 |
| From: | Southern California Edison Co |
| To: | |
| Shared Package | |
| ML13302A166 | List: |
| References | |
| SO23-3-5.30, NUDOCS 8102090153 | |
| Download: ML13302A167 (13) | |
Text
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 1 of 13
- Revision I LOSS OFrFEE&DWATERT~ ' C 1.0 SYMPTOMS NOT FOR)C; 1 .1 Alarms 1.1 .1 FWCS No. 1 SG E089(N) Level Hi/LO 1.1.2 FWCS No. 2 SG E088(S) Level Hi/Lo 1.1.3 MFWP Lo NPSH Trip 1.1.4 MFWP P062 (P063) Disch Press Lo 1.1.5 MFWP P062 (P063) Flow Lo 1.1.6 MFWP K005(N) (K006-S) Trip 1.1.7 Condensate Pump OC/GRD 1.1.8 Condensate Pump Flow Lo 1.1.9 'Heater Drain Tank Pump OC/GRD 1.1.10 Heater Drain TK Pump P058(S) (P059-N) Disch Flow Lo 1.1.11 Loop 1(2) Cold Leg Temp Hi (on total loss of flow) 1.2 Indications 1.2.1 Decreasing steam generator water levels.
1.2.2 Low feedpump suction pressure, discharge pressure or flow (possible high flow for a feedwater line break).
1.2.3 Low condensate pump discharge pressure.
1.2.4 Possible increase in containment pressure and humidity (for feedwater line break inside containment).
1.2.5 Reactor power decreasing slowly prior to trip, then sharply decreasing with trip.
1.2.6 Reactor Coolant System Tavg inital increase, then decrease with reactor trip followed by an increasing trend.
1.2.7 Pressurizer pressure initial increase, then decrease with reactor trip followed by an increasing trend.
1.2.8 Pressurizer level increases before reactor trip, then decreases and stabilizes.
0 8 102090 l
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION 023-3-5.30 UNITS 2 and 3 EMERGENCY Page 2 of 13 Revision 1 1.0 SYMPTOMS (Continued) 1.2.9 Steam generator pressure increasing prior to trip, then sharp increase immediately following trip, then decrease.
2.0 AUTOMATIC ACTIONS (some or all of the following may occur)
NOTE: The time delay for initiation of these events varies considerably depending on the size of steam flow/feedwater flow mismatch and/or the size of the feedwater line break.
2.1 Actions related to a partial loss of feedwater.
2.1.1 With decreasing steam generator levels, the FWCS generates a signal opening the Main Feedwater Regulating Valves, Main Feed water Regulating Bypass Valves and increases Main Feedwater pump speed.
2.2 Actions related to a complete loss of feedwater.
2.2.1 Reactor trip on low steam generator level (23% narrow range level).
2.2.2 Turbine trip (initiated by reactor tripped signal).
2.2.3 Emergency Feedwater Actuation Signal (EFAS) actuates the emergency feedwater system at 23% narrow range steam generator level.
2.2.4 Feedwater Control System reactor tripped override closes the main feedwater valves FCV-1111 and FCV-1121, and positions the main feedwater bypass valves HV-1105 and HV-1106 for 5% flow
(% 25% open).
2.3 Actions related to a feedwater line break inside containment.
2.3.1 If containment pressure rises above 2.95 psig, a CIAS, SIAS and CCAS will be generated.
NOTE: A CIAS closes the Main Steam Isolation Valves (MSIVs) and the Main.Feedwater Isolation Valves (MFIVs).
3.0 IMMEDIATE OPERATOR ACTIONS 3.1 Without a reactor trip condition reached and no reactor trip:
3.1.1 Reduce steam flow demand and increase feedwater flow until they match.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 3 of 13 Revision 1 3.0 IMMEDIATE OPERATOR ACTION (Continued) 3.1.2' If feedwater flow cannot be matched with steam flow, or if steam generator level continues to decrease with indicated feedwater flow in excess of steam flow, trip the reactor.
3.2 With a reactor trip condition-reached or a reactor trip:
3.2.1 Verify all reactor trip breakers indicate open and reactor power is decreasing.
.3.2.2 Carry out immediate and subsequent post trip actions per Emergency Operating Instruction S023 3-5.1, "Emergency Plant Shutdown".
3.3 Use the public address system to notify on-site personnel concerning the nature of the emergency.
4.0 SUBSEQUENT OPERATOR ACTIONS INITIALS
- NOTE: Anticipated Scenario Explanation:
Loss of Feedwater is characterized by a decreasing steam generator level concurrent with a gradual decrease or increase in steam generator pressure.
A feedwater line-break downstream of the feedwater line check valve causes a steam 1ine break type of RCS cool down and depressurization when steam generator level falls below the feed ring, as well as containment high pressure.
If a rapid decrease in steam generator pressure is occuring, go to Emergency Operating Instruction S023 3-5.9, "Steam Line Rupture". A feedwater line break upstream of the feedwater line check valve is not expected to cause a RCS cooldown transient, but does cause containment high pressure if the break is in containment.
CAUTION: Do not place systems in "manual" unless misoperation in "automatic" is apparent. Systems placed in "manual" must be checked frequently to ensure proper operation.
- The initial column is an optional operator aid and is intended to be used as follows Initial each completed action. Do not write N.A. Leave blank, items that are not applicable. Proceed through the instruction performing all applicable steps fre quently re-checkingthose steps passed over to ensure action is taken when applicabl
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 4 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.1 Verify that all immediate operator actions have been initiated as follows:
4.1.1 Without a reactor trip condition reached and no reactor trip:
4.1.1.1 Reduce steam flow demand and increase feedwater flow until they match.
4.1.1.1.1 Use the CVOL to reduce turbine load. Insert CEAs and borate as necessary to follow tur bine load down with reactor power. Vary the rate of reactor power reduction as necessary to maintain Tavg approximately 50 F above Tref.
4.1.1.1.2 If feedwater pressure exceeds steam gen erator pressure, transfer the Main Feed water Valve Controller to manual and open FCV-1111 and/or FCV-1121, to increase feedwater flow to the affected steam generator.
4.1.1.1.3 If feedwater pressure is equal to or less than steam generator pressure, verify running or start all available condensate pumps, and heater driven pumps and increase the main feedwater pump speed.
4.1.1.2 If the decrease in steam generator level has been stopped, proceed as follows:
4.1.1.2.1 If feedwater control was transferred to manual, slowly restore steam generator level to \ 65% narrow range level.
4.1.1.2.2 If turbine load/reactor power were lowered to reduce feedwater flow demand, notify the Systems Operating Supervisor.
4.1.1.2.3 Determine the cause of the loss of feed water and request equipment repair to correct the problem.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 5 of 13
. Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued)' INITIALS 4.1.11.2.4 After the cause of the loss of feedwater has been determined, restore all non affected controls to automatic.
4.1.1.2.5 After the cause of the loss of feedwater has been corrected, resume normal plant operations per Operating Instruction S023 5-1.7, "Power Operations" and terminate the use of this instruction.
4.1.1 .3 If feedwater flow cannot be matched with steam flow or steam generator level continues to de crease with indicated feedwater flow exceeding steam flow, trip the reactor to preserve ade quate heat removal capability.
4.1.2 With a reactor trip condition reached or a reactor trip:
4.1.2.1 Verify all reactor trip breakers indicate open and reactor power is decreasing.
4.1.2.2 With a reactor trip condition reached or a reactor trip, carry out immediate and subsequent post trip actions per Emergency Operating Instruc tion S023-3-5.1, "Emergency Plant Shutdown",
performing applicable steps concurrently with the steps in this instruction.
4.1.2.3 When steam flow is less than feedwater flow, verify steam generator levels are increasing.
NOTE: If steam generator level in one or both steam generators continues to decrease, a feedwater line break is indicated downstream of the feedwater flow sen sing orifice.
4.1 .2.3.1 If steam generator level continues to de crease, verify which steam generator has the greater feedflow in excess of steam flow mismatch, then close its main feedwater isolation valve.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 6 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.1.2.3.2 If steam generator pressure rapidly decays after closing the affected steam generator(s) main feedwater isolation valve(s), a steam line rupture is indicated. Immediately go to Emergency Operating Instruction S023 3-5.9, "Steam Line Rupture" and terminate use of this instruction.'
CAUTION: Adverse containment environment may increase instrumentation in accuracies. Do not rely on single parameter indication to evaluate plant conditions. Utilize all indications and combination of indications available to verify plant status.
4.2 If containment pressure increases above 2.95 psig, verify completed or complete the following:
4.2.1 Verify Train A and Train B CIAS, SIAS and CCAS actuation alarms are received. If not, manually actuate CIAS, SIAS and CCAS.
4.2.1.1 If manual actuation from the control room is not successful, dispatch an operator to the Train A and Train B Auxilary Relay Cabinets and open the associated trip leg circuit breakers.
4.2.2 If SIAS is actuated due to containment high pressure, then when pressurizer pressure decreases to the SIAS low pressurizer pressure setpoint, stop all oper ating RCPs.
4.2.3 After any CIAS or SIAS, then within 30 minutes restore CCW to the RCPs per Emergency Operating Instruction S023-3-5.26.1, "Loss of Component Cooling Water to a RCP", performing applicable steps concurrently with the steps in this instruction.
4.2.4 Verify the electric driven auxiliary feedwater pumps restart 30 seconds after SIAS actuation due to load sequencing. If not, manually restart them.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 7 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.2.5 Verify aligned or align all CIAS, SIAS and CCAS affected components per the Actuated Alignment Check-Off List contained in Operating Instruction S023-3-2.7, "Safety Injection System Operation",
performing applicable steps concurrently with the steps in this instruction.
4.2.6 When pressurizer pressure decreases below the shutoff head (% 1450 psia) of the HPSI pumps, verify HPSI flow to the cold legs from at least one train.
4.3 If a major rupture has occured in the condensate pump system, verify tripped or trip both feed pumps, trip all four (4) condensate pumps and both heater drain pumps to minimize damage to secondary components.
4.4 If all RCPs are stopped, verify natural circu lation has been established per Operating Instruction S023-3 2.31, "Natural Circulation Guidelines", performing applicable steps concurrently with the steps in this instruction.
4.5 Use Operating Instruction S023-3-2.30, "Determination of Ade quate Core Cooling", to confirm conditions are not trending toward an inadequate core cooling event, performing applicable steps concurrently with the steps in this instruction.
4.6- Secure steam generator blowdown by closing HV-4053 and HV-4054, steam generator blowdown isolation valves, to conserve steam generator water inventory.
4.7 If all feedwater (main and auxiliary) is lost to one steam gen erator and feedwater flow cannot be restored prior to the wide range level dropping below 5%, do not feed the steam generator.
NOTE: Due to potential decalibration of the wide range indication, a level below 5% is assumed to indicate a dry steam generator. Feeding a dry steam generator may result in potential thermal shock-brittle frac ture which would induce a steam generator tube rupture or more serious failure of the tube sheet.
4.8 If all feedwater (main and auxiliary) is lost to both steam generators and feedwater cannot be restored to either before wide range level drops below 5%, perform the following:
4.8.1 If three or more RCPs are operating, reduce the number of operating RCPs to one per loop, to minimize heat input into the RCS.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 8 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.8.2 When feedwater becomes available, refill only one steam generator to re-establish a heat sink.
4.8.2.1 Refill the steam generator with the first avail able source. However, use main feedwater when it becomes available because it is potentially warmer water.
4.8.2.2 If both steam generators can be refilled, refill the steam generator with the highest secondary side pressure.
4.8.2.3 If both steam.generators can be refilled, and both steam generators are at the same pressure, refill steam generator #2. .
4.8.3 When refilling a dry steam generator monitor the following for indications of a steam generator tube rupture:
4.8.3.1 Main Steam Line Radiation Monitors RR-7874-1 &
RR-7875-1 on Pnl L-405, Main Steam Line Radiation Monitor.,
4.8.3.2 Steam Generator Blowdown Sample Radioactivity Monitor RR-6753 and RR-6759 on Pnl CR-62.
4.8.3.3 If a SGTR is indicated, carry out Emergency Operating. Instruction. S023-3-5.29, "Steam Generator Tube Rupture", performing applicable steps concurrently with the steps in this instruction.
4.9 The Watch Engineer shall notify the "duty" Station Administrator and Shift Technical Advisor and. discuss the situation.
4.9.1 An assessment of the plant status and safety shall be made and the event classified per Table 4-1 of the SONGS 2 & 3 Emergency Plan.
4.9.2 If an emergency is declared (Alert, Site or General),
use the following Emergency Procedures to implement the SONGS 2 & 3 Emergency Plan:
4.9.2.1 Alert - S023 (later)
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 9 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.9.2.2 Site - S023 (later) 4.9.2.3' General - S023 (later) 4.9.3 If unable to contact any Station Administrator in the normal reporting chain within fifteen (15) minutes fol lowing the declared emergency, notify the NRC via the red phone.
4.9.4 Notify the Systems Operating Supervisor concerning the nature of the emergency.
4.10 When the following conditions are established, restt SIAS per Step 4.11 of this instruction.
4.10.1 RCS hot and cold leg temperatures are at least 500 F subcooled.
4.10.1.1 Use the Subcooled Margin Monitor indicators as the primary method of determining RCS subcooling.
4.10.1.2 Use pressurizer pressure and Thot, or incore thermocouples if indicating a higher temperature, as a backup method for determining subcooling.
4.10.2 Both pressurizer level safety channels indicate a level greater than 28% and levels are stable or increasing.
4.10.3 RCS cold leg temperatures are stable or decreasing.
4.10.4 Containment pressure less than 2.95 psig.
4.11 When all of the conditions in Step 4.10 of this instruction are satisfied, proceed as follows:
4.11.1 Lower the SIAS pressurizer pressure setpoint on all four safety channels below the existing pressurizer pressure using the "Low Pzr Press Setpoint Reset" on the PPS Remote Control Modules.
4.11.2- Unlock (arm) and depress the SIAS, CIAS and CCAS push buttons at the Plant Protection Panel.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 10 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.11.3 Depress the Train A SIAS, CIAS and CCAS reset push buttons and Train B SIAS, CIAS and CCAS reset push buttons at the ESFAS Auxiliary Relay Cabinets.
4.11.4 Stop the LPSI, HPSI and Containment Spray Pumps.
4.11.5 Restart the HPSI pumps as necessary to maintain a subcooled margin of 50'F.
4.12 If CIAS has occured (and has not been reset) and the SBCS is available, proceed as follows:
4.12.1 Override and open the MSIV bypass valve(s) associ ated with the intact (i.e., no SGTR or Steam/Feed water Line Break) steam generator(s).
4.12.2 Operate the SBCS per Operating Instruction S023 3-2.18, "Steam Bypass System Operation", to control steam generator pressure at 1000 psia, performing applicable steps concurrently with the steps in this instruction.
4.12.3 If the SBCS is not available, operate the atmospheric steam dump on the intact steam generator(s) to control steam generator pressure at 1000 psia.
4.13 If auxiliary feedwater has been lost to either steam generator, or if CIAS, SIAS and CCAS have been actuated, initiate a plant cooldown as follows:
4.13.1 If RCPs are running, cooldown per.
Operating Instruction S023-5-1.5, "Plant Shutdown from Hot Standby to Cold", performing applicable steps con currently with the steps in this instruction.
4.13.2 If RCPs are not running, cooldown per Operating Instruction S023-3-2.31, "Natural Circulation Guidelines", performing applicable steps concurrently with the steps in this instruction.
4.13.3 If RCS cooldown is not required, maintain Hot Standby conditions per Operating Instruction S023-5-1.3.1, "Plant Startup Hot Standby to Minimum Load", perfor ming applicable steps concurrently with the steps in this instruction.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY. Page 11 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.14 If SIS is operating, terminate emergency boration of the RCS within 30 minutes of the time that SIS initiated emergency boration as follows:
4.14.1 Override and stop the charging pumps and boric acid makeup pumps.
4.14.2 If pressurizer pressure is above the shutoff head of the HPSI pumps, return the charging pumps to service as follows:
4.14.2.1 Open LV-0277C, gravity feed valve from RWST.
4.14.2.2 Verify closed or close LV-0277B (VCT discharge).
4.14.2.3 If the RCS is subcooled, start and stop the char ging pumps as necessary to maintain pressurizer level between 28% and 57%. If the RCS is not subcooled, run all available charging pumps continuously until 500 F subcooling can be maintained.
NOTE: In the above charging pump alignment, HV-9247 (BAMU pump discharge), HV-9235 and HV-9240 (BAMT gravity feed) remain open, for a backup supply. Since the RWST elevation head is greater than the BAMT elevation head, the Boric Acid line check valves will close.
4.15 If offsite power is available, establish normal charging and letdown as per Operating Instruction S023-3-2.1, "CVCS Char ging and Letdown" and Operating Instruction S023-3-2.2, "Makeup Operations", performing applicable steps concur rently with the steps in this instruction.
4.15.1 If offsite power is not available, line up charging pump suction to gravity feed from the RWST to main tain pressurizer level, as follows:
4.15.1.1 Open LV-0277C, gravity feed valve from RWST. _
4.15.1.2 Verify closed or close the following:
4.15.1.2.1 LV-0227B, VCT discharge valve;
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 and 3 EMERGENCY Page 12 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.15.1.2.2 HV-9247, BAMU pump discharge to the charging pump suction; 4.15.1.2.3 HV-9235 and HV-9240, BAMT gravity feed to the charging pump suction.
4.16 If the RCPs were stopped, restart the RCPs in the loops associated with the steam generators being used for heat removal as per Operating Instruction S023-3-2.7, "Reactor Coolant Pump Operation".
4.16.1 If a RCP is restarted, continue cooldown as per Oper ating Instruction 5023-5-1.5, "Plant Shutdown from Hot Standby to Cold", performing applicable steps concurrently with the steps in this instruction.
4.16.2 If the RCPs cannot be restarted, continue cooldown per Operating Instruction S023-3-2.31, "Natural Circu-.
lation Guidelines", performing applicable steps con currently with the steps in this instruction.
4.17 If the auxiliary feedwater system is in use, ensure that conden sate storage tank T-121 inventory is continuously replenished as follows:
4.17.1 Place makeup demineralizer, if available, in service per Operating Instruction S023-11-2, "Makeup Demin eralizer Operation", and lineup to condensate storage tank T-121 .
4.17.2 If the makeup demineralizer is not available, then lineup condensate storage tank T-120 to gravity feed to T-121 by:
4.17.1.1 Closing locked open valve S2(3)1305MU082 conden sate tank cross-connect line drain valve.
4.17.2.2 Opening S2(3)1305MU475 and S2(3)1414MU076, T-120 and T-121 cross-connect valves.
4.17.3 If condensate storage tank T-120 is depleted or other wise unavailable, lineup the Fire Protection System water by:
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.3U UNITS 2 and 3 EMERGENCY Page 13 of 13 Revision 1 4.0 SUBSEQUENT OPERATOR ACTIONS (Continued) INITIALS 4.17.3.1 Verifying diesel driven fire pump running.
4.17.3.1 .1 "Fire Pump P-220(E) Running" alarm on annunciator panel 2/3UA-61A window 11 in the control room will be annunciated.
4.17.3.1.1.1 If diesel driven fire pump is not running, then start from the con trol room.
4.17.3.2 Closing locked-open valve S2(3)1205MU082, con densate tank cross-connect line drain valve.
4.17.3.3 Open locked closed valve S2(3)1305MU474, fire water supply to T-121.
4.18 If the transient has stabilized and ESF Busses are being sup plied from offsite power, stop the emergency diesel generators within 30 minutes per Operating Instruction 5023-2-13, "Diesel Generator Operation".
4.18.1 If the diesels are providing power to the ESF Busses, then when offsite power becomes available transfer the ESF Busses to the reserve auxiliary transformers and stop the diesel per Operating Instruction S023-2-13, "Diesel Generator Operation".
4.19 If the SIAS and CCAS has been reset, return the safety injection system and containment cooling system to normal per Operating Instruction S023-3-2.7, "Safety Injection System Operation".
4.20 When the plant is cooled and depressurized to 350'F and 361 psig, initiate shutdown cooling per Operating Instruction S023-3-2.6, "Shutdown Cooling System Operation".
H. E. MORGAN Superintendent Units 2 and 3 APPROVED:
J. M. CURRAN Plant Manager VBF/sa