ML13330B304
| ML13330B304 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/03/1988 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| REF-GTECI-093, REF-GTECI-NI, TASK-093, TASK-93, TASK-OR GL-88-03, GL-88-3, TAC-67268, NUDOCS 8805090217 | |
| Download: ML13330B304 (9) | |
Text
Southem California Edison Company P. 0. BOX 8OO 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING (818) 302-1749 AND LICENSING May 3, 1988 U. S. Nuclear Regulatory Commission 10 CFR 50.54(f)
Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Generic Letter 88-03 Steam Binding of Auxiliary Feedwater Pumps San Onofre Nuclear Generating Station Unit 1 The subject generic letter provides the NRC staff's resolution of auxiliary feedwater pump steam binding, Generic Safety Issue 93.
The staff's resolution requires that SCE maintain procedural controls to preclude steam binding by monitoring fluid conditions of the auxiliary feedwater system each shift.
Additionally, procedures must be maintained for recognizing steam binding and restoring the auxiliary feedwater system to operable status, should steam binding occur. Accordingly the purpose of this letter is to confirm that these procedural controls are in place and will be maintained.
Provided for your information, as an enclosure to this letter, are copies of the appropriate procedures which cover monitoring of the auxiliary feedwater system for steam binding and mitigation should binding occur. Additionally, per your request the staff time to prepare this response including the requested confirmation is estimated to be 3 man-days.
If you have any questions regarding this information, please let me know.
Respectfully submitted, Subscrib d to and sworn before me OFFICIAL SEAL this 3 i day of 1988.
C Notary Public--Califonia LOS ANGELES COUNTY
,My Comm. Exp. Apr. 20, 1990 Notary Public i~and for the County M om x.Ar 019 of Los Angeles, State of California cc: J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 8905090217 880503Y PDR ADOCK 05000206 DCD
Enclosure Generic Letter 88-03 Steam Binding of the Auxiliary Feedwater System (Generic Safety Issue 93)
Response
San Onofre Nuclear Generating Station Unit 1
Generic Letter 88-03 San Onofre Nuclear Generating Station Unit 1 Introduction Generic Letter 88-03 requires that there be the procedural controls to prevent and mitigate steam binding of the Auxiliary Feedwater System. In particular, the generic letter requests that SCE confirm that the following procedural controls are in place and will be maintained:
- 1. Maintain procedures to monitor fluid conditions within the AFW system each shift during times when the system is required to be operable. This monitoring should ensure that fluid temperature at the AFW pump discharge is maintained at about ambient levels.
Section A, Step 7.0 of SONGS Procedure S0123-0-9, Routine Operations and Inspections, requires that a plant equipment operator inspect the auxiliary feedwater system for steam binding once per shift, specifically:
7.0 Auxiliary feedwater pumps. Check for oil leaks, check the valves for normal alignment, check the pump casings and discharge piping for greater than ambient temperatures which may indicate "backleakage" from the Main Feedwater System. This condition leads to steam binding or cavitation of the pumps. If backleakage is suspected, notify the Control Room Operator of the condition and take action to correct the condition per S01-7-3, "Auxiliary Feedwater System".
In addition to the above inspection, monitoring for backleakage is also performed per Operating Instructions S01-12.3-26 and S01-12.8-20 following the monthly and 18 month surveillance testing.
- 2. Maintain procedures for recognizing steam binding and for restoring the AFW system to operable status, should steam binding occur.
If backleakage is detected, Section F of Operating Instruction 501-7-3, restores the Auxiliary feedwater system to operational status. A copy of Section F of S01-7-3 is provided for your information.
NUCLEAR GENERATION SITE OPERATING INSTRUCTION SO1-7-3 UNIT I SECONDARY PLANT REVISION 3 PAGE 57 OF 72 TCN AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 1.0 OBJECTIVES, 1.1 To detail procedures to be followed if AFW Check Valve Backleakage is TCN defected during Plant Operation.
.1 1.2 To describe the method of monitoring and adding oil to the Steam Driven TCN AFW Pump turbine bearing.
3-.
1.3 To restore the Steam Driven AFW Pump Steam Supply Line to Service in XN Modes 1 through 3.
3
2.0 REFERENCES
2.1 Procedures 2.1.1 50123-VI-0.9, Documents - Author's Guide to the Preparation T0N of Site Orders, Procedures and Instructions 2.2 Other
?.2.1 Significant Operating Experience Report 84-3 dated April 17, 1984;
Subject:
Auxiliary Feedwater Pumps Disabled by Backleakage 3.0 PREREQUISITES 3.1 Prior to use of a user-controlled (pink) copy of this Site Document to perform work, verify that it is current by checking a controlled copy and any TCNs or by use of the method described in S0123-VI-0.9.
4.0 PRECAUTIONS TCN 4.1 In Modes 1-3 both Steam Generator Auxiliary Feedwater Pumps and TO associated flow paths shall be OPERABLE as follows:
4.1.1 One Auxiliary Feedwater Pump capable of being powered from an emergency electrical source, and 4.1.2 One Auxiliary Feedwater Pump capable of being powered from an OPERABLE steam supply system. (Tech. Spec. 3.4.3.A) 4.1.3 With one Auxiliary Feedwater Pump inoperable, restore both Auxiliary Feedwater Pumps (one capable of being powered from an emergency electrical power source and one capable of being powered by an OPERABLE steam supply system) to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
(Tech. Spec. 3.4.3.B)
NUCLEAR GENERATION SITE OPERATING INSTRUCTION S01-7-3 UNIT I SECONDARY PLANT REVISION 3 PAGE 58 OF 72 TCN AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 5.0 CHECKLISTS 5.1 None TON 3.1 6.0 INSTRUCTIONS NOTE:
Check valve backleakage is evidenced by increasing pipe temperatures. Temperatures should be checked on top of the pipes due to stratification that can occur under low flow conditions.
(Reference 2.2.1)
TCN 6.1 Determine the Extent of the Backleakaqe TGN 6.1.1 If check valve backleakage is detected, then check pipe temperatures with a contact pyrometer.
.1 Check temperature near each AFW header connection to main feed piping.
.2 Check temperature near each redundant header connection to main feed piping.
TO CAUTION Temperatures at an AFW Pump of 200'F or
==
above are indication of probable steam binding of that pump. A steam bound pump is considered inoperable.
.3 Check temperature at each AFW pump.
6.1.2 If backleakage is identified to the Motor Driven AFW Pump, then perform step 6.2.
6.1.3 If backleakage is identified to the Steam Driven AFW Pump, then perform step 6.3.
6.2 Flush the Motor Driven AFW Pump and Backleaking Header 6.2.1 Place "A" AFW System Mode switch in "Manual."
6.2.2 Document manual valve manipulations on SO(1) 431, Component Control Form.
NUCLEAR GENERATION SITE OPERATING INSTRUCTION S01-7-3 UNIT 1 SECONDARY PLANT REVISI N 3 PAGE 59 OF 72 TCN
- -f AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 6.0 INSTRUCTIONS (Continued) 6.2.3 Vent the Motor Driven AFW Pump using:
.1 AFW-429, Motor Driven AFW PP Vent.
.2 Instrument Drain between AFW-442, PT-2011 Root, and PT-2011.
6.2.4 When the Motor Driven AFW Pump is filled with ambient temperature water, then CLOSE vent and drain opened in step 6.2.3.
6.2.5 Perform step 6.2.6 or step 6.2.7 as applicable.
6.2.6 Flush backleaking redundant header to Motor Driven AFW Pump.
.1 CLOSE the Train "A" AFW Flow Control Isolation Valves:
.1.1 AFW-316, FCV-2300 Isolation Valve.
.1.2 AFW-314, FCV-2301 and FCV-3301 Isolation Valve.
.1.3 AFW-313, FCV-3300 Isolation Valve.
.2 START the Motor Driven AFW Pump.
.3 OPEN MOV-1202, AFW Pump G1OS Discharge.
.4 Observing precautions concerning current plant status, THROTTLE OPEN the AFW Flow Control Isolation Valve(s) to the redundant header line(s) with backleakage.
.5 When the pipe temperature(s) is(are) back to ambient, then STOP the Motor Driven AFW Pump.
.6 CLOSE MOV-1202.
.7 LOCK OPEN the Train "A" AFW Flow Control Isolation Valves:
.7.1 AFW-316, FCV-2300 Isolation Valve.
.7.2 AFW-314, FCV,2301 and FCV-3301 Isolation Valve.
.7.3 AFW-313, FCV-3300 Isolation Valve.
.8 Go to step 6.4.
NUCLEAR GENERATION SITE OPERATING INSTRUCTION SO1-7-3 UNIT 1 SECONDARY PLANT REVISION 3 PAGE 60 OF 72 TCN AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 6.0 INSTRUCTIONS (Continued) 6.2.7 Flush backleaking AFW header to Motor Driven AFW Pump.
.1 START the Motor Driven AFW Pump.
.2 Observing Precautions concerning current plant status, THROTTLE OPEN MOV-1204.
.3 When the pipe temperature is back to ambient, then STOP the Motor Driven AFW Pump.
.4 CLOSE MOV-1204.
.5 Go to step 6.4.
6.3 Flush the Steam Driven AFW Pump and Backleaking Header 6.3.1 Place "B" AFW System Mode' switch in "Manual."
6.3.2 Document manual valve manipulations on SO(1) 431, Component Control Form.
6.3.3 Vent the Steam Driven AFW Pump using:
.1 AFW-348, Steam Driven AFW PP Vent.
.2 AFW-345, AFW PP Discharge Line Drain.
.3 AFW-347, Steam Driven AFW PP Drain.
6.3.4 When the Steam Driven AFW Pump is filled with ambient temperature water, then CLOSE vent and drains opened in step 6.3.3.
6.3.5 Perform step 6.3.6 or step 6.3.7 as applicable.
6.3.6 Flush backleaking redundant header to Steam Driven AFW Pump.
.1 CLOSE the Train "B" AFW Flow Control Isolation Valves:
.1.1 AFW-305, FCV-2300 Isolation Valve;
.1.2 AFW-306, FCV-2301 and FCV-3301 Isolation Valve.
NUCLEAR GENERATION SITE OPERATING INSTRUCTION S01-7-3 UNIT 1 SECONDARY PLANT REVISION 3 PAGE 61 OF 72 TCN AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 6.0 INSTRUCTIONS (Continued) 6.3.6.1.3 AFW-308, FCV-3300 Isolation Valve.
.2 START the Steam Driven AFW Pump by.depressing the "Turbine Start" pushbutton.
.3 Observing precautions concerning current plant status, THROTTLE OPEN the AFW Flow Control Isolation Valve(s) to the redundant header line(s) with backleakage.
.4 When the pipe temperature(s) is(are) back to ambient, then STOP the Steam Driven AFW Pump.
TCN
.5 LOCK OPEN the Train "B" AFW Flow Control Isolation Valves.
.5.1 AFW-305, FCV-2300 Isolation Valve.
.5.2 AFW-306, FCV-2301 and FCV-3301 Isolation Valve.
.5.3 AFW-308, FCV-3300 Isolation Valve.
.6 Go to step 6.4.
6.3.7 Flush backleaking AFW header to Steam Driven AFW Pump.
.1 START the Steam Driven AFW Pump by depressing the "Turbine Start" pushbutton.
.2 CLOSE CV-3213, AFW Pump G10 Discharge.
.3 Observing precautions concerning current plant status, THROTTLE OPEN AFW-346, AFW to 1st Point Heater Inlet.
.4 When the pipe temperature(s) is(are) back to ambient, then STOP the Steam Driven AFW Pump.
.5 CLOSE and LOCK AFW-346.
.6 Go to step 6.4.
6.4 Restoration from Backleakage 6.4.1 Perform independent verification of valve position for TON manual valves manipulated per this instruction.
6.4.2 Ensure both AFW System Mode switches in "AUTO," in Modes 1 through 3.
NUCLEAR GENERATION SITE OPERATING INSTRUCTION SO1-7-3 UNIT 1 SECONDARY PLANT REVISION PAGE 62 OF 72 TCN AUXILIARY FEEDWATER SYSTEM F. MISCELLANEOUS AFW SYSTEM OPERATIONS 6.0 INSTRUCTIONS (Continued) 6.4.3 Perform Operability test on AFW Pumps per S01-12.8-20, 7CN Auxiliary Feedwater System Operability Test.
3 6.4.4 Monitor temperatures with a contact pyrometer every one-half hour until it is certain no backleakage exists.
.1 Monitor temperature at each redundant header connection to main feed piping.
.2 Monitor temperature at each AFW header connection to main TO feed piping.
CAUTION Temperatures at an AFW Pump of 200'F or above
=
are indication of probable steam binding of that pump. A steam bound pump is considered inoperable.
.3 Monitor temperature at each AFW pump.
6.5 Adding Oil to the Steam Driven AFW Pump Turbine Bearing NOTE:
The turbine bearing sight glass has been marked with "min" TCN and "max" level ranges.
6.5.1 When the oil level in the turbine bearing sight glass is approximately 1/4 of the acceptable range, then the bearing should be filled until the oil is at the "max" level mark as follows:
.1 Monitor the sight glass to ensure sight glass operation,
.2 Measure the amount of oil added within + 10 ml,
.3 Add the oil through the bearing cap plug,
.4 Document the oil addition on Attachment 2.