Letter Sequence Other |
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Results
Other: 05000312/LER-1985-019, :on 851002,reactor Trip Occurred & RCS Temp Decreased to Approx 70 F.Caused by Excessive Steam Loads Due to Two Open Relief Valves on Feedwater Heater 4A.HPI Flow Manually Initiated to Maintain Pressure, 05000312/LER-1985-023, :on 851205,reactor Trip Occurred on High RCS Pressure.Caused by Underfeeding of Main Feedwater Sys During Flow Scaling Procedure.Integrated Control Sys Modules Examined & Refurbished, ML20134A837, ML20137H936, ML20138B213, ML20138R097, ML20138R929
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MONTHYEARML20138B2131985-10-0404 October 1985
Confirmatory Action Ltr Re 851004 Telcon Concerning Return of Facility to Power Operations After 851002 Reactor Trip. Util Must First Conduct Root Cause Analysis of Trip & Provide Briefing to NRC Before Return to Power
Project stage: Other
ML20133K5131985-10-11011 October 1985
Notification of Significant Meeting on 851016 W/Util Onsite to Discuss Root Cause Assessment & Readiness for Resumption of Power Operations Following 851002 Reactor Trip
Project stage: Meeting
ML20133K5891985-10-14014 October 1985
Forwards Action List Providing Util Plan to Resolve Concerns Stemming from 851002 Transient,Per 851010-11 Meetings.Listed Commitments Scheduled for Completion Prior to Restart. Schedule for long-term Items Will Be Submitted by 851118
Project stage: Meeting
ML20133K7191985-10-18018 October 1985
Forwards Supplemental Info Re 851002 Transient,Per NRC Request During 851016 Meeting.Info Includes Main Feed Pump Trip Determination,Hpi a Flow Anomaly,Cooldown of RCS, Cooldown Rate,Tech Specs & Revised Action List
Project stage: Supplement
ML20133P8511985-10-25025 October 1985
Forwards Summary & Supplemental Info Re 851002 Transient, Per 851025 Telcon.Items in Plan Include pre- & post-startup Actions to Determine Root Cause of Event & Initiation of Corrective Programs
Project stage: Supplement
05000312/LER-1985-019, :on 851002,reactor Trip Occurred & RCS Temp Decreased to Approx 70 F.Caused by Excessive Steam Loads Due to Two Open Relief Valves on Feedwater Heater 4A.HPI Flow Manually Initiated to Maintain Pressure1985-10-29029 October 1985
- on 851002,reactor Trip Occurred & RCS Temp Decreased to Approx 70 F.Caused by Excessive Steam Loads Due to Two Open Relief Valves on Feedwater Heater 4A.HPI Flow Manually Initiated to Maintain Pressure
Project stage: Other
ML20134A8371985-11-0101 November 1985
Forwards Addendum to Attachment 5,Part Ii,Rev 1 to Auxiliary Feedwater/Main Feedwater Failure Analysis Contained in
Project stage: Other
ML20138R0971985-11-13013 November 1985
Forwards Rev 2 to Attachment 2 & Addendum NRC-5150 Re HPI a Flow Anomoly,Rev 1 to Attachment 5,Parts I & II Re Auxiliary Feedwater/Main Feedwater Failure Analysis & Attachment 8 Re Oil Levels on safety-related Pumps
Project stage: Other
ML20138R9291985-11-15015 November 1985
Forwards Latest Rev to Action List,Describing Program Plan to Resolve Concerns Stemming from 851002 Transient.All Startup Required Items Completed.All Power Escalation Items Will Be Completed by Full Power Operation
Project stage: Other
ML20137H9361985-12-23023 December 1985
Responds to Violations Noted in Insp Rept 50-312/85-30. Corrective Actions:Instrumentation & Control Procedure I.103 Revised to Include Multiplier Link Change Instructions & Pegging Steam Pressure Controller Setpoints Reduced
Project stage: Other
05000312/LER-1985-023, :on 851205,reactor Trip Occurred on High RCS Pressure.Caused by Underfeeding of Main Feedwater Sys During Flow Scaling Procedure.Integrated Control Sys Modules Examined & Refurbished1986-01-0202 January 1986
- on 851205,reactor Trip Occurred on High RCS Pressure.Caused by Underfeeding of Main Feedwater Sys During Flow Scaling Procedure.Integrated Control Sys Modules Examined & Refurbished
Project stage: Other
1985-10-04
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g esuun SACRAMENTO MUNICIPAL UTILITY DISTRICT ' 6201 S Street, PO Boa 15830. Sacramento CA 958521830.19161 452 3211 AN ELECTHIC SYSTEM SERVING THE HE AHT OF CAllFOHNIA RJR 85-539 November 1, 1985 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTN HUGH L THOMPSON JR DIVISION OF LICENSING U S NUCLEAR REGULATORY COMMISSION WASHINGTON DC 20555 00CKET NO. 50-312 LICENSE fi0. OPR-54
SUMMARY
AND SUPPLEMENTAL INFORMATION FROM TRANSIENT OF OCTOBER 2, 1985 Enclosed is an addendum to Attachment 5, Part II, Revision 1 -
Auxiliary Feedwater/ Main Feedwater Failure Analysis contained in the District's letter of October 25, 1935 (RJR 85-531).
The addendum includes the items discussed with various members'of our staff (00 November 1,1985.
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4 LN R. J. P0 RICUEZ ASSISTANT GENERAL %4AGER, NUCLEAR Attachment 00 0511110045 R51101 i
PDH ADOCK 05000'112
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P PDR RANCHO SECO NUCLt AH OtNf HATING STATION 14440 Twin Citm Howl Ha'ahl. CA 0'in1fl 9117!),120'H 33^) 7916
~3 ADDENDUM TO ATTACHMENT 5, PART II AUXILIARY / MAIN FEE 0 WATER FAILURE ANALYSIS (REFERENCE RJR 85-531 7
There.are no single failures that will prevent manual initiation of AFW for any given plant conditions.
Therefore, feedwater - i.e. main or auxiliary - will always be available to mitigate any accident or transient.
The District has reviewed the impact of single failures on the ability to provide main and/or auxiliary feedwater, and the highlights of this review are sumarized below.
I: MAIN FEE 0 WATER CONTROL VALVE The District believes there is no single failure in the ICS that will cause all main feedwater valves to go closed.
It would take a number of component failures for the valves to close and cut off all feed-water.
Therefore, the likelihood of this event is very small and does not pose a problem to plant operation.
This evaluation is based on Integrated Control System Reliability System Analysis, BAW 1564 l
11: MAIN FEE 0 WATER PUMP CONTROL i
l Based on Integrated Control System Reliability System Analysis, BAW 1564, l
there is only one failure which could cause loss of all main feedwater I
following a reactor trip.
This failure would be in the main feed pump l
speed control circuitry and could reduce both main feed pump speeds to l
minimum speed. The speed reduction would reduce pump discharge pressure to less than OTSG pressure, thus interrupting main feedwater flow. At' min. speed, the District will verify there will be an auto initiate of AFW flow.
If required, the District will make,' prior to startup,-modif1-cations to assure this condition will not cause a loss of all feedwater.
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