ML19320D117
| ML19320D117 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/19/1980 |
| From: | Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-06, IEB-80-6, NUDOCS 8007180589 | |
| Download: ML19320D117 (6) | |
Text
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o Jersey Central Power & Light Company
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Madison Avenue at Punch Bowl Road Momstown, New Jersey 07960 (201)455-8200 June 19, 1980 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Dear Mr. Grier:
SUBJECT:
Oyster Creek Nuclear Generating Station Docket No. 50-219 I E Bulletin No. 80-06 The purpose of this letter is to respond to the directives set forth in I E Bulletin No. 80-06 which is concerned with safety-related equipment moving out ot its emergency mode upon reset of Engineered Safety Features Actuation signals. Our response to each item is addressed below.
ITEM 1 Review the drawings for all systems serving safety-related functions at the schematic level to determine whether or not upon the reset of an ESF actuation signal, all associated safety-related equipment remains in its emergency mode.
RESPONSE
The following systems serving safety-related functions at Oyster Creek were reviewed on a schematic level to determine whether or nct safety-related equipment remains in its emergency mode upon the reset of its ESF (Engineered Safety Feature) actuation signal.
Drywell Isolation Main Steam Isolation Core Spray System Containment Spray System Standby Gas Treatment System Auto Depressurization System Isolation Condenser System Drywell Isolation The Drywell Isolation auto initiation signals are the same as those which initiate Core Spray.
That is EITHER Low Low Water Level (7'2" above the top of the active fuel regica) 1R High Drywell pressure (2 PSIG).
Drywell isolation may only be reset if the initiating signals have cleared and the "Drywell Isolation Reset" pushbutton is operated.
Upon reset of Dryw-ll Isola-tion the following valves and/or equipment, depending upon the psition at their control switches, will revert automatically to other than their emergency mode position.
8007180 W Jersey Central Power & Ligh: Company is a Member of the General Public Uteties System
I E Bulletin No. 80-06 Page 2 June 19,1980 These valves are; all drywell and torus vent and purge valves, oxygen sample valves, drywell equipment drain tank isolation valves, drywell floor drain sump isolation valves, shutdown cooling inlet and outlet isolation valves, cleanup system isolation valves, standby gas treatment system fan and inlet, outlet and recirculation dampers, and traversing incore probe isolation valves.
The Reactor Building Closed Cooling Water (RBCCW) to the drywell isolates on triple low water lever OR a combination of Low Low Water Level AND High Drywell Pressure. Reactor Building Closed Cooling Water isolation may only be reset after the isolation signals have cleared. Upon reset of the isolation signals the RBCCW isolation valves will revert to other than their emergency mode position.
Main Steam Isolation The Main Steam Isolation auto initiation signals are Main Steam Line High Radiation OR Low Low Water Level OR Low flain Steam Line Pressure OR Steam Line Break (High Steam Tunnel Temp or High Steam Line Flow).
Main Steam Isolation may only be reset if the initiating signals have cleared and the " Main Steam Isolation Reset" pushbutton is operated.
Upon reset of Main Steam Isolation the following valves, depending upon the position of their control switches, will revert automatically to other than their emergency mode position.
These valves are; the four (4) main steam isolation valves, four (4) main steam line drain valves, four (4) isolation condenser vent isolation valves, two (2) reactor coolant sample line isolation valves and one (1) control air isolation valve to drywell.
Core Spray System The Core Spray System auto initiation signals are Low Low Reactor Water Level OR_ High Drywell Pressure. Once received the initiating signals are locked in and cannot be reset until the actuating signals have cleared.
Upon reset of the initiating signals the Core Spray Systems parallel isolation valves will shut down automatically to their Standby Position.
If the initiating signals return the systems parallel isolation valves will respond as required.
The Emergency Diesel Generators also auto start upon Core Spray System auto initiation signals and if power to an emergency bus is lost the respective Diesel Generator will fast start and pickup load.
If there is no loss of power to an emergency bus the Diesel Generators wilI continue to idle until the Core Spray Logic is reset. After reset the Diesel Generators will continue to idle for 11.5 minutes then shut down automatically to a standby mode.
Standby Gas Treatment System The Standby Gas Treatment auto initiation signals are; High Radiation Level on Refueling Floor OR High Radiation in Reactor Building ventilation system, OR Low Low Reactor Water Level OR High Drywell Pressure. Once received the initTa~ ting signals are locked in and cannot be reset until the actuating
I E Bulletin No. 80-06 Page 3 June 19,1980 signals have cleared. Upon reset of the initiating signals the Standby Gas Treatment S3 stem will shut down automatically to its Standby Position.
If initiating signals return the system will respond as required.
Acto Depresserization System The Auto Depressurization System initiation signals are a combiration of the following; Triple Low Reactor Water Level, High Drywell Pressure and Core Spray Booster Pump Discharge Pressure. Once received the initiating signals are locked in and a two (2) minute timer delay circuit is energized.
Manual Reset of the initiating signals will cause the electromatic relief valves to close if open, and if initiating signals are still present will restart the timer delay circuit at zero.
If initiating signals are no 1cnger present, operating the reset pushbutton will shut down the system and place it in a Standby Position.
If initiating signals return the system will respond as required.
Containment Spray System The Containment Spray System auto initiation signals are a combination of Reactor Low Low Level AND High Drywell Pressure. There are no reset features associated with the actuating signals of the Containment Spray System. Once received the initiating signals are locked in and the system will continue to run until drywell,Jressure is 1 PSIG and decreasing, or until the system is manually shut down.
If the system shuts down automatically on drywell pressure 1 PSIG and decre:Ising the system will return to its standby position and will be available if called upcn to return to service.
The drywell recirculation fans will also shut down upon receiving Containment Spray actuating signals, however no automatic action will occur upon loss of Containment Spray initiating signals.
The drywell recirculation fans require manual startup.
Isolation Condenser System The Isolativr. Condenser System auto initiation signals are High Reactor Pressure OR Low Low Reactor Wsts. Level.
Once received, the initiating signals are locked in and cannot be reset until the actuating signals have cleared.
Upon reset of the initiating signals the Isolation Condenser System will shut down automatically to its Standby Position.
If initiating signals return the system will respond as required.
The Isolation Condenser System also has an automatic isolation feature which will isolate the affected condenser upon a line break (high flow on steam outlet or condensate return) in that associated loop.
If auto initiation signals are present and the system has isolated due to a line break, operation of '.in reset pushbutton will allow the system to return to service.
Present plant procedures require placing the control switches of the affected isolation valves from the " auto" position to the " closed" posit n thus preventing the reopening of the isolation valves upon inadvertant operation of " Isolation Condenser Reset" pushbutton.
I E Bulletin.No. 80-06 Page 4
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- June 19,1980 ITEM 2' Verify the actual installed instrumentation and controls at the facility are consistent with the schematics reviewed in Item 1 abo!e by conducting a test to demonstrate that all equipment rc: sins in its emergency made upon removal of the actuating signal and/or manual resetting of the i
various isolating or actuation signals.
Provide a schedule for the performance of the testing in your response to this Bulletin.
j
RESPONSE
The actual installed instrumentation and controls at Oyster Creek have been verified as being consistent with the schematics reviewed for i
Item 1 through the performance of nornal plant surveillance testing with the following exceptions:
Main Steam Isolation - Upon removal of actuating signals (Main Steam Line Low Pressure, HSL High Flow or MSL High Temperature) all equipment i
will remain in its emergency mode.
Containment Spray System - Upon removal of Low Low Level signal, system will remain in its emergency mode.
Isolation Condenser System Upon removal of initiating signals (High Reactor Pressure or Low Low Reactor Water Level) system will remain in its emergency mode.
i.
.The above exceptions shall be verified by including temporary changes to existing surveillance procedures to demonstrate upon rcmoval of initiating signals equipment will not move out of its emergency mode. The completion of such testing shall be accomplished within a period of 45 dayt after startup from l
' the.1980 Refueling Outase.
If the above testing reveals discrepar.cies associated with the schematics
. reviewed, a supplemental response to Item 2 shall be written to the coamission within a period of 30 days.
ITEM 3 If any safety-related equipment does not remain in its emergency mode upon reset of an ESF signal at your facility, describe proposed system modification, design change, or other corrective action planned to resolve.the problem.
RESPONSE
' Safety-related equion.ent.that does not remain in its emergency mcde upon reset of an ESF signal, and the corrective action taken ari proposed to resolve the problems are described below:
Drywell Isolation Corrective action taken was the revision of all plant' procedures-i (Emergency and Operating), which require or instruct operation of the "Drywell
-Isolation Reset" pushbutton, to reference a new procedure which requires all position switches to be placed in their appropriate emergency mcde position prior to resetting the isolatten signals.
a I E Bulletin No. 80-06 Page 5 June 19, 1980 Proposed long term solution is the replacenent of two psition switches with three position spring return to neutral switches which,ould require no operator action prior to resetting the isolatiag signals. This replacement is scheduled to take place during the 1981 Refueling Outage.
Procedures addressing the reset of Reactor Building Closed Cooling Water Isolation have been revised to caution the operator, that upon reset, the isolation valves will revert automatically to their open position unless the control switches are moved to the " Closed" position.
Main Steam Isolation Corrective action taken was the revision of all plant procedures (Emergency and Operating) which require or instruct operation of the " Main Steam Isclation Reset" pushbutton to reference a new procedure which requires all position switches to be placed in their appropriate emergency mode position prior to resetting the isolation signals.
Proposed long term solution is the replacement of two position switches with three position spring return to neutral switches which would require no operator action prior to resetting the isolating signals.
This replacement is scheduled to take place during the 1981 Refueling Outage.
Core Spray System No action has been taken or proposed for the Core Spray System.
The
-reset functicn allows the system to be shut down to a standby position when the initiating signals no longer exist.
Standby Gas Treatment System Corrective action taken was the revision oi.n plant procedures (Emergency and Operating) which require resetting of the Standby Gas Treatment System auto initiating signals to caution the operator that upon reset of the initiating signals the Standby Gas Treatment System will shut down to its standby mode unless placed into manual operation.
No further action is proposed for the Standby Gas Treatment System as the reset feature allows the system to te shut down to a Standby Position when the initiating signals no longer exist.
Auto Depressurization System No corrective action has been taken or proposed for the Auto Depressuriza-tion System. The reset function allows the system to be returned to its Standby Position in the event that actuating signals clear before the timer relay is energized. The reset function also allows the system to be snot down i.6 its standby mode upon completion of its intended function.
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I E Bulletin No. 80-06 Page 6 June 19,1980 1 solation Condenser System No action has been taken or proposed for the Isolation Condenser System. The reset function allows the system to be shut down to a Standby Position when the initiating signals no longer exist.
Emergency procedure.s concerning the isolation of an Isolation Condenser due to a pipe break have been revised to place the control switches for the isclation valves to the " Closed" position prior to operation of the " Isolation Condenser Reset" pushbutton.
Very truly yours,
'b WA-Donald A. Ross, Manager Generating Stations-Nuclear DAR:dh cc:
NRC Office of Inspection and Enforcement Div. of Reactor Operations Inspecticn Washington, D. C.
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