ML13308B796
| ML13308B796 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/06/1980 |
| From: | Curran J, Norgan H Southern California Edison Co |
| To: | |
| Shared Package | |
| ML13308B793 | List: |
| References | |
| SO23-3-5.30, NUDOCS 8011250494 | |
| Download: ML13308B796 (7) | |
Text
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING PROCEDURE S023-3-5.30 UNITS 2 AND 3 EMERGENCY NEW NT/
6 1980 LOSS OF FEEDWATER OR STEAM GENERATOR LEVEL 1.0 SYMPTOMS 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 RECEpIED 1.1.5 MFWP P062 (P063) Flow Lo My 7 1.1.6 MFWP K005(N) (K006-S) Trip EDM-SITE 1.1.7 Condensate Pump OC/GRD 1.1.8 Condensate Pump Flow Lo 1.1.9 Heater Drain Tank Pump OC/GRD iss 1.1.10 Heater Drain TK Pump P058(S) (PO59-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 feed pump 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 Pressurizer pressure initial increase, then decrease with reactor trip followed by an increasing trend.
1.2.7 Pressurizer level increases before reactor trip, then decreases and stabilizes..
U0112 5 0 idn
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 2 NEW 1.0 SYMPTOMS (Continued) 1.2.8 RCS Thot constant or increasing prior to trip then decrease.
1.2.9 Steam generator pressure increasing prior to trip, then sharp increase immediately following trip, then decrease.
NOTE:
A feedwater line break downstream of the feedwater line check valve causes a steam line break type of RCS cooldown and depressurization as well as containment high pressure. A feedwater line break upstream of the feedwater line check valve is not expected to cause a RCS cooldown transient, but does cause high containment pressure if the break is in containment.
2.0 AUTOMATIC ACTIONS (some or all of the following may occur) 2.1 Reactor trip on steam generator low level.
2.2 Turbine trip on reactor trip.
2.3 Unit auxiliaries transfer to the reserve auxiliary transformer.
2.4 Unit CB's open.
2.5 Steam Bypass Control System operates to dump steam to condenser.
2.6 Emergency Feedwater System actuates (EFAS) at 235 level in the steam generators.
2.7 With a reactor trip, FCV-1111 and FCV-1121, main feedwater valves close; HV-1105 and HV-1106, bypass valves open to 5% flow position.
2.8 CVCS is restoring pressurizer level.
2.9 Pressurizer Pressure Control System restoring RCS pressure.
3.0 IMMEDIATE OPERATOR ACTION 3.1 Without a reactor trip condition reached and no reactor trip:
3.1.1 Reduce steam flow demand and reactor power to match available feedwater flow.
3.1.2 Verify that reactor power is matched with turbine power (Tavg = Tref).
3.1.3 If it is evident steam generator levels cannot be maintained, trip the reactor to preserve adequate heat removal capability.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION 5023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 3 NEW 3.0 IMMEDIATE OPERATOR ACTION (Continued) 3.2 With a reactor trip condition reached and a reactor trip:
3.2.1 Verify the reactor is tripped and reactor power is decreasing.
If not, manually trip the reactor.
Verify all CEA bottom lights are on.
If more than one CEA has not inserted fully, initiate emergency boration.
3.2.2 Verify the turbine tripped.
If not, manually trip the turbine.
3.2.3 Verify turbine stop valves are closed. If not, manually close MSIVs.
3.2.4 Verify unit output breakers are open.
If not, manually trip the unit output breakers.
Verify turbine speed is decreasing.
3.2.5 Verify unit auxiliaries have transferred to the reserve aux iliary transformners.
If not, manually transfer to reserve auxiliary transformers.
3.2.6 Verify SBCS is controlling steam generator pressure at 1000 psig.
If condenser vacuum is lost or if MSIVs closed, use atmospheric dump valves to control steam generator pressure.
3.2.7 Verify main feedwater flow is decreasing to or is at approxi mately 5'. flow on FR-loll and FR-1021.
3.2.8 If the main feedwater pumps have tripped or other conditions If~~~~~~ not maulyfrpthlec or.Veif allat CEAS botto prevent establishing at least 3% flw6cut FSlado EFAS-2 and check that auxiliary feedwater flow is established on FI-4720 and/or FI-4725.
3.2.9 If a SIAS/CIAS has been actuated and after it has been veri fied that Ems have been fully inserted for five (5) seconds, stop all operating RCPs.
.1 Verify SIAS, CIAS and lCAS have properly actuated.
If not, manually initiate.
3.2.10 If a major rupture has occurred 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.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 4 NEW 4.0 SUBSEQUENT OPERATOR ACTION 4.1 Without a reactor trip condition reached and no reactor trip:
4.1.1 After insuring the plant is in stable condition, determine and correct the cause of the loss of feedwater. Return to normal power operation.
4.2 With reactor trip:
4.2.1 Monitor auxiliary feedwater flow to each steam generator. When steam generator levels have been stabilizied at 23% by the emergency feedwater system, take manual control of the emergency feedwater system. Refer to Operating Instruction S023-2-4, "Auxiliary Feedwater Pump Operation".
4.2.2 If all main feedwater flow is lost, coordinate the dumping of steam to the condenser and the addition of auxiliary feedwater to restore steam generator level to u 68% and TAVG to - 5443F.
If condenser is unavailable, use the atmospheric steam dump valves.
CAUTION: Avoid overfeeding the steam generators to prevent excessive cooldown of the RCS. Maintain a steam generator level which will allow a controlled rate of heat removal.
.1 Stop one RCP in each loop to minimize heat input to RCS, if feedwater cannot be restored immediately.
.2 Do not add feedwater to a dry steam generator, as indicated by Tavg stabilizing or starting to increase. Re-establish feedwater to the steam generator that is not dry, as in dicated by a decreasing Tavg or level indication. If both steam generators are dry, refill only one steam generator to re-initiate core cooling.
.3 If the main feedwater pumps are not available and the aux iliary feedwater system cannct supply either steam generator, use the following methods to provide the anti core melt - RCS heat removal safety function.
.3.1 If a condensate pump and main feedwater piping system is available, use the SBCS, or atmospheric steam dump if SBCS is not available, to depressurize one steam generator until.
condensate pump delivery begins.
CAUTION: Avoid excessive RCS cooldown while re-establishing the heat sink.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 5 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.2.3 The Watch Engineer shall notify the "duty" Station Adminis trator 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 activated using the im plementing 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.
.1 Notify the Systems Operating Supervisor concerning the nature of the emergency.
.2 Refer to Operating Instruction S023-3-2.30, "Determination of Adequate Core Cooling", to verify adequate core cooling.
.3 For implementing the Radiological Emergency Plan, refer to Station Emergency Procedure 5023-VIII-1.3, "Unit Emergency".
4.2.4 If SIAS has occured, operate the SIS until RCS hot and cold leg temperatures are at least 50aF below saturation temper ature for the RCS pressure and a pressurizer level of at least 28% and increasing, 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.
.1 Refer to Operating Instruction S023-3-2.7, "Safety Injection System Operation".
.2 Override and open the MSIV and use the SBCS, if available, for cooling down.
.3 If inadvertent SIAS, refer to Emergency Operating Instruction 5023-3-5.15, "Recovery from Inadvertent Safety Injection".
4.2.5 If a SIAS was activated, terminate RCS charging within thirty (30) minutes.
.1 Override and stop the charging pumps and the boric acid make up pumps.
.2 When the SIAS is reset, and if offsite power is available, establish normal charging and letdown per Operating Instruction 5023-3-2.1, "CVCS Charging and Letdown" and S023-3-2.2, "Makeup Operation".
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING ISTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 6 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.2.5.3 If offsite power is not available, line up charging pump suction to gravity feed from the RWST to maintain pressurizer level.
.3.1 Open LV-0227C, gravity feed valve from RWST.
.3.2 Verify closed or close the following:
LV-0227B, VCT discharge HV-9247, BAMU pump discharge to charging pump suction, HV-9235 and HV-9240, BAMT gravity feed to charging pump suction.
4.2.6 If SIAS was actuated, then if RCS hot and cold leg temperatures are at least 50aF below saturation for the corresponding RCS pressure and a pressurizer level of at least 28% and increasing is indicated, reset SIAS.
.1 Reset SIAS at the Plant Protection Panels and Auxiliary Relay Cabinets.
.2 Stop LPSI, HPSI and containment spray pumps.
NOTE:
If 5OcF subcooling cannot be maintained, restart the high pressure safety injection pumps.
4.2.7 If all RCPs are stopped, verify that natural circulation has been established per Operating Instruction S023-3-2.31, "Natural Circulation Guidelines".
.1 Reactor Coolant Pumps may be restarted provided the following criteria are satisfied (refer to Operating Instruction S023-3-1.7, "RCP Operation"):
.1.1 A LOCA does not exist;
.1.2 RCS temperature and pressure conditions permit restart;
.1.3 RCP services are available.
4.2.8 Verify the pressurizer pressure control system is auto matically restoring RCS pressure. If not, transfer pressurizer pressure control to manual using heaters or spray to restore pressurizer pressure.
4.2.9 Verify the CVCS is functioning to restore proper pressurizer level.
If necessary, take manual control of the letdown throttle valve and operate backup charging pumps as re quired to restore pressurizer level.
SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S023-3-5.30 UNITS 2 AND 3 EMERGENCY Page 7 NEW 4.0 SUBSEQUENT OPERATOR ACTION (Continued) 4.2.10 Secure steam generator blowdown by closing HV-4053 and HV-4054 steam generator blowdown isolation valves, and HV-4058 and HV-4057 steam generator sample valves.
4.2.11 If extended shutdown is anticipated, refer to Operating Instruction S023-5-1.5, "Plant Shutdown from Hot Standby to Cold".
.1 Insure condensate storage tank T-121 inventory is maintained to allow for possible cooldown.
.2 If a cooldown is anticipated, line-up alternate source of water to condensate storage tank T-121.
.2.1 Place makeup demineralizer, if available,.in service per Operating Instruction S023-11-2, "Makeup Deminerlizer Operation",
and lineup to condensate storage tank T-121.
.2.2 If the makeup demineralizer is not available, then lineup con densate storage tank T-120 to gravity feed to T-121 by:
.2.2.1 Closing locked open valve S2(3)1305MU082 condensate tank cross-connect line drain valve.
.2.2.2 Opening S2(3)1305MU475 and S2(3)1414MU076, T-120 and T-121 cross-connect valves.
.2.3 If condensate storage tank T-120 is depleted or otherwise un available, lineup the Fire Protection System water by:
.1 Verify diesel driven fire pump running.
.2.3.2 Closing locked-open valve S2(3)1305MU082 condensate tank cross-connect line drain valve.
.2.3.3 Open locked close valve S2(3)1305MU474 fire water supply to T-121 4.2.13 If the emergency diesel generators are operating, then if the transient has stabilized and ESF busses are being supplied from offsite power, stop the emergency diesel generators.
Refer to Operating Instruction 5023-2-13.0, "Diesel Generator Operation".
H. E. MORGAN SUPERINTENDENT UNITS 2 & 3 APPROVED:
M.
CURRAN PLANT MANAGER MT/sa