ML20091M568
| ML20091M568 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/04/1984 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| NED-84-287, TAC-42505, TAC-42506, NUDOCS 8406110346 | |
| Download: ML20091M568 (141) | |
Text
y-g Q)c2gia Power Company 333 Pwximont Avenue Attanta, Georg'a 30308 Telephone 404 526 6526 Mailno Akhess:
Post othce Box 4545 Atlanta. Georgia 30%2 Georgia Power L T. Gucwa t% Southyn nrtrc system Manager Nuclear Enginecong am cNet Ndar Engine"'
NED-84-287 aine 4, 1984 Director of Maclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operatirg Reactors Branch No. 4 Division of Licensing U. S. M1 clear Regulatory Comnission Washiryton, D. C.
20555 NBC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EIMIN I. HA'ICH NUCLFAR PLANP UNI'IS 1, 2 RESPONSE 'IO REQUEST FOR ADDITIONAL INEORMATION ON ELEC'IRICAL EQUIPBENP QUALIFICATION Gentlenen:
By letter dated May 14, 1984, you reglested specific information concerning the Plant Hatch program for coinpliance with 10 CFR 50.49.
We following information constitutes the Georgia Power Conpany (GPC) response to that reglest. Note that the rumbering for each item below corresponds to the outline used in Encloalre 1 to the reglest letter:
1.. As is discussed in Enclosite 3 to the GPC eglipment gialification albnittal dated March 30, 1984 (NED-84-161),-the alstifications for Contirued Operation (JOOs) for Plant Hatch were developed usiry an approach which is consistent with the reglirements of 10 CFR 50.49(i).
GPC has carefully reviewed the function of each covered conponent and examined the individual failure modes. ' Based on this review we ' have demonstrated, for each eglipnent item not yet gialified, that failure of any one of these conponents will not prevent the mitigation of a design basis event or mislead the operator to the extent that he takes an action which is adverse to safety.
'Ihe reglested Joos are enclosed in Attachment 1 to this response.
2.
GPC certifies '. that in performirg the review of the methodology to identify eglipaent within the scope of 10 CFR 50.49(b) (2) the following steps were taken:
1.
The Plant Hatch electrical eglipment gialification list was developed usirq a methodology consistent with =10 CFR. 50.49(b) (1).
his is documented in Attachment 2 to this response.
8406110346 840604 i 4O PDR ADOCK 05000321 g
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GeorgiaPower A Director of Riclear Reactor Reg 11ation Attention: Mr. John F. Stolz, Chief aine 4, 1984 Page Two 2.
%e elementary wiring diagrams of the safety-related electrical estipment identified in item 2.1 above were reviewed to identify any alxiliary devices electrically connected directly into the control or power ciralitry of the safety-related eglipnert (e.g.,
altamatic trips) whose failure dLie to postulated envi orinental conditions could prevent req 11 red operation of the safety-related eglipment.
3.
A1xiliary eglipnent reglired to alpport accident mitiration is included in the Plant Hatch gialification eglipment list if it is located in a harsh environment.
%is is doalmented in Attachment 2 to this response.
4.
The GPC review of elementary diagrams inchided analysis of all circuitry electrically connected to the safety related conponents.
In each situation a review was made to enaire that the non-safety-related circuits were electrically isolated from the safety-related citalits by fuses or circuit breakers.
3.
%e Plant Hatch design meets the regtirements of 10 CFR 50.49 (e) (1),
namely that eglipment within the scope of 10 GR 50.49(b) is gialified to the most severe design basis accident citring or following which the estipnent is reg 11 red to remain functional.
All design basis events both inside and outside containment, including flooding, which could potentially reallt in a harsh envirorment have been identified and evaluated.
For areas altside contirment which may experience High Energy Line Breaks (HELBs), tenperature/presaire profiles that envelope the worst case conditions were developed using methods and asainptions that are doalmented in the Plant Hatch Final Safety Analysis Reports
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(FSARs).
For eglipment inside containnent, both Loss of Coolant Accidents (IDCAs) and HELBs were evaluated.
A plant specific analysis of the IOCA for each Hatch unit is doolmented in the FSARs, while the drywell HEIB analysis for each unit is contained in the General Electric Campany proprietary document, NSED-52-0583, which was enclosed in a aabnittal made to the NRC by GPC on Febntary 24, 1984 (NED-84-079).
Bglipment inside the drywell will be gialified to the temperature /presaire profiles for both types of accidents.
It should be noted that GPC has asalmed that the accident profiles and methodologies aabnitted on Febniary 24, 1984, will be found acceptable by the NRC staff.
Sincerely yours, O
L. T. G1 cwa L
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Director of 111 clear Reactor Regulation Attention: Mr. John F. Stolz, Chief June 4,1984 Page '1hree CBS Encloaires xc:
J. T. Beckham, Jr.
H. C. Nix, Jr.
J. P. O'heilly (NRC-Region II)
Senior Resident Inspector rwns s,
- - -_ _ - - ___ _ _ - -- - -_-_a
ATTACHMENT 1 i
E. I. HATCH PLANT UNIT 1 JUSTIFICATION FOR CONTINUED OPERATION BALANCE OF PLANT COMPONENTS EQUIPMENT BEING REPLACED DURING THE PRESENT OUTAGE t
GENERIC - LIMIT SWITCHES FOR INDICATION ON AIR OPERATED VALVES The limit switches'on the' valves are supplied to provide valve position indication only. They do not provide any control function. The valves, on to which they are mounted receive a signal and move to their safety position within the first few seconds of any event for which they are required to operate. The operator at this time is required to verify isolation and the switches will most likely indicate properly during the early stages of any postulated accident event.
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Once a valve is in its safety position, it is not credible to assume that a valve will shift position since the electrical cable, connections, switches, which are associated with energizing the solenoid are qualified.
In etc.
order for the valve to move to its non-safety position the solenoid must be energized to port air to the isolation valve which has been shown to be not credible.
Since qualification data to demonstrate complete acceptability of the limit switches has not been located to date, qualified replacement limit switches have been purchased.
Continued operation is justified since the probability of a LOCA or HELB outside containment occurring coupled with the failure of these switches and the associated solenoid valves prior to their replacement is very remote.
In addition, as indicated above, the switches are only for indication and provide no control.
GENERIC-PIL0T SOLEN 0ID OPERATORS T
The solenoid on these valves operate within the first few seconds of the postulated accident.
It is not credible to assume that the harsh environment has time to signf ficantly affect their operation before they receive their safety signal and move to their safety position which is de-energized.
Once the solenoid de-energizes, there is no need for them to be re-energized for any action pertaining to safety. The most probable failure of a solenoid valve is a loss of power due to either a short or open in the coil which will cause the solenoid to fail in its safety position.
Since qualification data has not been a7,'f found to date, replacement solenoids have been purchased.
Continued operation is justified until installation since the probability of the postulated LOCA or a HELB occurring coupled with a failure of these solenoid valves to function as designed for that event prior to the next refueling outage is extremely remote.
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E 2
B21-F019 Valve B21-F019 is a main steam line drain isolation valve.
It will receive a signal to close on a containment isolation due to a LOCA and on a Main Steam Line Break signal.
B21-F019 will only be subjected to a harsh environment due to radiation after a LOCA. This valve is assumed to be in its safety position, closed, since the only time it will open is during startup.
It is not credible to assume that a LOCA will occur concurrent with a plant startup. The time listed on the system component evaluation work sheet is fifteen (15) seconds which is consistent with the Plant Technical Specifications but the actual time could be "0".
If for some reason the valves were to be open at the onset of a LOCA, it will be closed within fifteen (15) seconds of the initiating signal. The time duration during which it must operate is short enough that it is not credible to assume that appreciable radiation damage will occur potentially rendering the valve inoperable prior to it reaching its fully closed position. Once in its safety position, there is no reason to assume that it will move since all its controls are fully qualified for their associated environment.
B21-F019 could experience a harsh environment due to temperature and steam in the unlikely event of a RCIC or Main Steam line break but the valve is assumed to go to its safety position, closed, if it is open. The basis for this rational is the same as is presented for the radiation case above, that is, the valve will be in its safety position prior to any significant degradation, due to the temperature and steam environment occurring.
In the unlikely case that B21-F019 does not function as required, valve B21-F016 receives the same signals to close. This valve is located inside the primary containment and has j
demonstrated complete qualification.
In addition, this valve will not experience the harsh environment for which it is being given a signal to close.
The valve is located inside the primary containment and has demonstrated complete qualification.
In addition, this valve will not experience the harsh environment for which it is being given a signal to close.
It is powered from a separate power source and as such is assumed to close.
Based on the above, continued operation is justified.
3
E11-MOV-F004D, E11-M0V-F075A The above listed motor operated valve operators, which previous to this revision were considered fully qualified, are now considered open items.
A recent field inspection revealed that the nameplates of the subject equipment were missing.
It is felt the lack of positive identification necessitates the replacement of these components in order that complete traceability exists.
However, justification for continued operation until the replacements can be implemented exists because no discrepancies between the as-tested and as-installed components were found.
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E11-F008 Valve E11-F008 is the outside primary containment shutdown cooling isolation j
valve for the RHR system.
It isolates the reactor from the RHR system shutdown cooling mode suction line.
E11-F008 will be subjected to a harsh environment due to radiation after a LOCA. The valve will always be closed during normal plant operation. The closed position is assured since there is a high pressure interlock which prevents valve opening when the primary pressure approaches the design rating of the system.
Since the valve is in its safety position, radiation damage will not prevent the valve from serving its safety function.
The valve may be called upon to operate later in the LOCA, to go into shutdown cooling, but if it downs not operate the alternate method of cooling which is described in section 6.2.6 of the " General Electric High Energy Line Break Evaluation for Edwin I. Hatch Nuclear Power Station" can be used.
Based on the above, continued operation is justified.
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E11-M0V-F009, E11-MOV-F021A, E11-M0V-F021B, E21-MOV-F004A, E21-M0V-F004B, i
E21-MOV-F005A, E21-MOV-F005B The above listed motor operated valve operators, which previous to this revision were considered fully qualified, are now considered as having an open item regarding the radiation qualification of the motor brake assemblies.
Recent information from the suppliers of the motor operated valve operators indicate their unwillingness to formally support the radiation qualification of their brake assemblies. However, note that brakes similar in design to the subject brakes have in fact successfully undergone both HELB/LC0A and radiation testing.
Reference to Limitorque test report 600376A (F-C3441 Appendix C) states that 8
the brake was radiated to over 2.04X10 rads with no apparent damage.
However, the same specimen which had been radiated did not undergo a HELB/LOCA test. For this reason, each of the above listed motor operated valve operators are being replaced with a design which precludes the necessity of brake assemblies.
Based on the successful-though limit-testing and the fact that the operating time requirements are minimal (3 minutes within 1st 25 days), operation until such time as fully qualified components can be installed is justified.
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E11-F022 Valve E11-F022 is the inside primary containment reactor head spray isolation valve for the RHR system.
It isolates the reactor from the RHR system in the event of a LOCA or if the primary system pressure approaches the design rating of the RHR system.
This valve has been tested but there is not adequate documentation to demonstrate complete acceptability of the motor brake mechanism when subjected to radiation.
E11-F022 will be subjected to a harsh environment due to radiation during a LOCA but it will be in its safety position, which is closed. This valve will never be open when the reactor is at pressure but still receives a containment isolation signal. All the associated controls for the valve are fully qualified; therefore, it is not credible to assume that during a LOCA, when it will be subjected to the adverse environment, it will open.
The failure of this valve will not create a condition which is adverse to safety.
Based on the above, continued operation is justified.
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E11-F028A,B The subject valves are required for the use of RHR in the suppression pool spray and/or cooling mode. The safety analysis does not take credit for the suppression pool spray mode.
The valves are qualified for the radiation but lack adequate data for the high energy line break environment.
During a LOCA the valves are subject to a harsh environment due to radiation.
Since the valves are qualified for the radiation dose they will perform their function during that accident.
Subsequent to a HELB outside the containment, the valves will see a harsh environment due to the temperature and steam.
If the subject valves fail to operate, when called upon for suppression pool cooling subsequent to a HELB, the drywell spray mode of the system can be initiated. This mode of operation takes suction from the suppression pool, sprays the drywell and the downcomers return the water to the suppression pool.
The above discussion provides justification for continued operability.
8
E11-N017B&D Static-0-Ring Pressure Switches These pressure switches provide a pressure available signal which permits the operation of valve E11-F068B. The function of valve E11-F068B is to control the RHR service water pressure such that it is greater than the RHR pressure.
The higher service water pressure insures that any leakage will be into the RHR System and not into Service Water System. The E11-N017B&D pressure switches prevent opening of the E11-F068B valve if the RHR Service Water System is not in operation. The switches will be subjected to a high temperature condition during a HPCI steam line rupture. The switches will experience a high temperature environment in excess of their qualification profile for less than three (3) minutes.
It is not credible to assume that the switches will reach an equilibrium temperature in excess of 200 F within this three (3) minute period. The switches have been qualified at 200 F for six (6) hours. Thus, the system has a high probability to operate as designed.
Based on the above, continued operation is justified.
9
E41-F001 Valve E41-F001 is the steam inlet valve to the HPCI turbine. The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar envi onment.
E41-F001 will only be subjected to a harsh environment due to radiation after a LOCA. The valve will receive its signal and move to its safety position in the first few minutes of an event.
The time duration during which it must operate is short enough that it is not credible to assume that appreciable radiation damage will occur potentially rendering the valve inoperable prior to it reaching its full open position.
E41-F001 could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break.
No credit is taken for the operation of this valve after a HPCI steam line break.
Based on the above, continued operation is justified.
10
E41-F003 E41-F003 isolates the HPCI System from the reactor.
Tnis valve has not been tested; however, the manufacturer is in the process of developing qualification information based on similarties with other valve motors which have undergone qualification testing. The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
E41-F003 will only be subjected to a harsh environment due to radiation after a LOCA. The valve is a normally open valve and does not have to move.
It is not credible to assume the valve will inadvertently close rendering the HPCI system incooperable since all associated controls for the valves are fully qualified.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break but the valve will receive a signal to close on a HPCI steam line break early enough in the transient that there is a high degree of assurance that the valve will reach a fully closed position prior to experiencing significant degradation due to the environment.
In addition, E41-F007 will also receive a signal to close. This valve is located inside the primary containment. This will not be subjected to the adverse environment created by this break.
It is powered from a separate power source and as such is assumed to close.
Based on the above, continued operation is justified.
11
E41-F006 E41-F006 isolates the HPCI system from the feedwater system.
The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
E41-F006 will only be subjected to a harsh environment due to radiation after a LOCA.
The valve will receive its signal and move to its safety position in the first few minutes of an event.
The time duration during which it must operate is short enough that it is not credible to assume that appreciable radiation damage will occur potentially rendering the valve inoperable prior to it reaching its full open position.
The subject valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI, RCIC, or Main Steam line break.
HPCI can and in all probability will function as designed for a RCIC and Main Steam line rupture and is not required for a HPCI line break.
The basis for this rationale is the same as is presented for the radiation case above, that is, the valve will be in its safety position prior to any significant degradation, due to the temperature and steam environment, occurring.
Based on the above, continued operation is justified.
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E41-F007 Valve E41-F007 is the discharge isolation valve for the HPCI pump. Adequate documentation has not been located to adequately demonstrate the complete acceptability of the motor brake mechanism.
The normal and accident position of the subject valve is open. The only time the valve would be closed is during maintenance operations on the HPCI system ana it is not credible to assume a HELB or a LOCA during that time.
No identified motor operator failure mechanism exists that could cause the valve to close during HPCI system operation since all the controls for the valve have documentation to demonstrate their complete qualification.
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E41-F041 Valve E41-F041 is the suction from the suppression chamber isolation valves for the HPCI pump. The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break but no credit is taken for the system in the event of this break.
Valve E41-F041 will only be subjected to a harsh environment due to radiation after a LOCA.
The valve is required to open when the suppression chamber reaches the high level alarm. The valve will not be subjected to a high temperature and steam envircnment concurrent with the high radiation environment; therefore; there is a high degree of assurance that it will function as designed.
In the unlikely event that valve E41-F041 does not open, the control room operator can manually operate the ADS system and use the low pressure ECCS systems to assure core cooling.
Based on the above, continued operation is justified.
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E51-F008 E51-F008 isolates the RCIC System from the reactor. The valve motor has been identified as having Class H insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
E51-F008 will only be subjected to a harsh environment due to radiation after a LOCA.
The valve is a normally open valve and does not have to move.
if for some reason the valve closes, it does not affect safety since no credit is taken for the RCIC system to mitigate the consequences of a LOCA.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a RCIC or Main Steam line break but the valve will receive a signal to close on a d(IC line break early enough in the transient that there is a high degree of assurance that the valve will reach a fully closed position prior to experier.cing significant degradation due to the environment. The valve is not required to operate on a Main Steam line break.
In addition, E51-F007 will also receive a sigr.al to close.
This valve is located inside the primary containment and has demonstrated complete qualification.
In addition, this valve will not experience the harsh environment for which it is being given a signal to close.
it is powered from a separate power source and as such is assumed to close.
Based on the above, continued operation is justified.
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E51-F031 Valve E51-F031 is the suction from the suppression chamber isolation valve for the RCIC pump. The valve motors have been identified as having Class B insulation which have been shown to be acceptable for other components which have been subjected to a similar environment.
E51-F031 will only be subjected to a harsh environment due to a radiation after a LOCA. The valve is required to open when the suppression chamber reaches the high level alarm and the operator manually signals it to open.
The valve will not be subjected to a high temperature and steam environment concurrent with the high radiation environment; therefore, there is a high degree of assurance that it will function as designed.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a RCIC line break.
In the unlikely event that the valve does not function as designed, it does not affect safety since no credit is taken for the RCIC system in the accident analysis.
Based on the above, continued operation is justified.
1 16
G31-F001 Valve G31-F001 isolates the RWCU system from the reactor. Adequate documentation has not been located to adequately demonstrate the complete acceptability of the motor brake mechanism.
The valve must close on a LOCA or a HELB in the RWCU system.
It will be subjected to a harsh environment due to radiation, temperature and pressure in the event of a LOCA.
In the unlikely event of a LOCA the valve will receive a signal and move to its' safety position within thirty (30) seconds of the event. There is a high degree of assurance that the valve will reach its fully closed position prior to experiencing significant degration due to the environment.
In addition, valve G31-F004 will not experience the LOCA environment and is assumed to close.
Valve G31-F001 does not experience a harsh environment during a line break in the RWCU system outside the drywell and is assumed to close.
Based on the above, continued operation is justified.
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i G31-F004 G31-F004 isolates the RWCU System from the reactor.
The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
Valve G31-F004 is a containment isolation valve which must operate to isolate containment on a LOCA and to isolate the RWCU system from the Reactor on a break in that system.
The valve will only be subjected to a harsh environment due to radiation after a LOCA.
Being a containment isolation valve, it will receive a signal and move to its safety position in the first few minutes of an event.
The time duration during which it must operate is short enough that it is not credible to assume that appreciable radiation damage will occur potentially rendering the valve inoperable prior to it reaching its full open position.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a RWCU line break but it will receive a signal to close on a RWCU line break early enough in the transient that there is a high degree of assurance that the valve will reach a fully closed position prior to experiencing significant degradation due to the environment.
in addition, G31 F001 will also receive a signal to close. This valve is located inside the primary containment and will not be subjected to a harsh environment when required to close and as such is assumed to close.
Based on the above, continued operation is justified.
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-T41-FS N002A,B T41-FS 'i4003A,B T41-FS N004A,8 T41-FS N005A,B T41-FS N011A,B P'etz Flow Switches The present cooler logic requires the control switch for one unit to be on
" Auto" and the redundant unit on " Standby". Subsequent to ECCS pump initiation
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the cooler on " Auto" comes on and in case of a malfunction the standby cooler comes on based on low flow for lead cooler, p
The system operating procedure is being changed to require the control switches for both coolers to be placed in " Auto". _ This justifies continued operation since both coolers will come on and stay on upon system. initiation.
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L T41-N019A&B, T41-N020A&B, T41-N021A&B, T41-N022A&B j
The present cooler logic requires the control switch for one unit to be on
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" Auto" and the redundant unit on " Standby". Subsequent to ECCS pump initiation the cooler on " Auto" comes on and in case of a malfunction the standby cooler comes on based on compartment high temperature or low flow for the lead cooler.
The system operating procedure requires the control switches for both coolers to be placed in " Auto". This justifies continued operability since both cooler will come on and stay on upon system initiation
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P52-N021 Pressure switch PS2-N021 monitors the pressure in the normal supply to the non-interruptable air system and sends a signal on low pressure to open valve P52-F875. A failure or misoperation of the instrument is not adverse to s.lety since the misoperation of valve P52-F875, as has been previously demonstrated, does not create condition which is adverse to safety.
Based'on the above, continued operation is justified.
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21-4
T46-N005B&C These instruments monitor the zip between the reactor building and atmospheric pressure. The instrument provides the control room operator with an indication that the standby gas treatment system is in operation and the reactor building is being maintained at a negative pressure.
This instrument serves no control function, it just provides the operator with confirmatory information as to the operation of the SGTS.
The operator has available to him many other indication which will provide him with the desired indication such as damper position, fan running indication, and refueling floor to outside atmosphere lip indication. Therefore, a failure of the subject instruments will not mislead the operator. The only action which the operator may take based on the information provided by this instrument is to start the SGTS system which, in all cases, is the correct action and will not cause a condition which is adverse to safety.
Based on the above, continued operation is justified.
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T47-N003 and T47-N009 These instruments are RTDs which monitor the drywell temperature in the area of the reference legs on the RPV water level instruments. The instruments are used by the operators to density compensate the level instruments based on drywell temperatures.
The level instruments do not require the density compensation in order for all automatic system actuations to take place to assure plant safety.
The temperature instruments in conjunction with the level instrument will be used by the operator to confirm proper injection system operations.
The maximum expected error in the level instruments is 25 inches which corresponds to a drywell temperature of 340 F.
The operator is very aware of this error and if in the doubt will apply the maximum error in the safe direction.
If the instrument provided an incorrect reading the operator could be misled but the automatic system actuations which occur on high and low RPV level will protect the core and will alert the operator tc the fact that he is being misled by the temperature elements. Therefore, plant safety is assured.
Based on the above, continued operation is justified.
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T48-K001 & T48-N001 These instruments provide the control room operator with an indication that the nitrogen system is available for use for CAD or as an alternate supply to the drywell pneumatic system.
The instruments serve no automatic function and are backed up by local pressure and level indication at the tanks which are outside the secondary containment.
If the operator suspects an anomaly in his indication he can have it locally verified. The operator will take no improper action based on a false indication from these instruments.
CAD system operation will be required days after a DBA and the SRVs have backup N accumulators to assure their short term operability; therefore, there is no 2
urgent need for operator action on nitrogen system logs.
Based on the above, continued operation is justified.
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T48-N009A-D These instruments are RTDs and are used to monitor the water temperature in the suppression chamber. They do not provide any automatic initiation signals.
In the event of a LOCA, the instruments may be subjected to a harsh environment due to radiation. The plant is operated within the technical specifications which requires that the temperature be monitored and corrective actions be taken at various temperatures. The accident analysis has shown that during a LOCA condition a sufficient heat sink is provided by the suppression chamber volume to assure plant cafety regardless of the temperature monitoring capabilities.
The temperature elements could be subjected to a high temperature and pressure environment in the event of an HELB in the torus room.
If due to the HELB, a plant cocidown is required which uses the suppression chamber as a heat sink the operator, due to his experience and training, kr.ows that the suppression pool cooling mode of operation is required. He will place the RHR system in the cooling mode regardless of the temperature indication if it is erratic or ambiguous.
In the event of major flooding in the torus, if the suppression chamber is used as a heat sink, the suppression pool cooling mode of the RHR system is required and will be initiated by the operator regardless of the operation of the temperature elements.
Based on the above, continued operation is justified.
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T48-FIT-N014A&B, T48-F112A&B, and T48-E/S-K001A&B The subject flow indicating transmitter, power supply and associated valve are required for recording and modulation of the nitrogen flow. Nitrogen provides containment atmosphere dilution subsequent to a postulated LOCA to maintain containment hydrogen concentrations less than 4%.
While it is important to measure flow and have flow control capability for hydrogen control, interim plant operation can be justified by the following:
1.
If the postulated failure of the flow transmitter / power supply disables flow measurement capability, the control valve can be placed in the manual mode and hydrogen control capability is still provided.
Containment hydrogen concentrations and pressures can be read in the Control Room.
2.
If the postulated failure of the flow transmitter disables the control valve, alternate nitrogen injection capability is provided by the nitrogen inerting system. The flow controller for the nitrogen inerting can be placed in the manual mode and flow control valve throttled to the lowest flow. Containment hydrogen concentrations and pressures can be read in the Control Room.
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T48-N210 and N211 The differential pressure switches open air operated isolation valves upstream of the suppression chamber to the secondary containment vacuum breakers. The vacuum breakers are provided to protect the suppression chamber against negative pressures.
The operability of the differential pressure switches is required for a LOCA in the containment or for a HELB in the torus compartment.
Interim plant operability can be justified by the following:
1.
The post LOCA pressure profile as shown in FSAR figures 14.4.10a,b (copy in section C.3 of this report) indicates that the pressure in the torus will never be negative.
2.
The HELB analysis for the torus chamber roon gives a peak pressure of 16.7 psia. AS indicated in FSAR section N.5.3.1.2 and referenced on the instrument data sheet, the torus has been evaluated for this external pressure with acceptable results.
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27
- f PVC CABLE Although the specific cables in the subject systems have not been tested to the standards required by the D0R guidelines which are an attachment to I. E.
Bulletin 79-01B, justification for continued plant operation until replacement on or before June 30, 1982 is principally based on IEEE paper entitled" Insulation and Jackets for Control and Power Cables in Thermal Reactor Nuclear Generating Stations, (IEEE Transactions on Power Apparatus and Systems Vo.
Pag-88, No. 5, May 1969)."
A key consideration in the evaluation of this report relative to the acceptability of the cable installed at HNP-1 is that under no circumstances will the accident dose of radiation occur concurrent with the harsh environment created by a high energy line break since all the subject cables are located exterior to the drywell. With this in mind radiation can be evaluated independently of the high energy line break.
The IEEE paper in Table XI concludes that PVC has an "Overall threshold of 5
damage" of 5 X 10 Rads. Were it not for the failure of the test cable in a 6
simulated steam environment after being irradiated to 5 X 10 Rads the overall 6
threshold of damage would have been 5 X 10 Rads.
Since we are not considering 6
- a. steam environment concurrent with the maximum radiation, the 5 X 10 Rads threshold of damage compares favorably with the highest actual accident dose of 6
1.86 X 10 Rads in the area of the NE and SE corner rooms.
The IEEE paper in Table II indicates that the useful life of PVC cable in terms of elongation loss is greater than 115 years even after being irradiated to 5 X 6
10 Rads. Although further evaluations of cable life are possible, these evaluations are not necessary because the cable is being replaced.
28
The maximum accident temperature-of 214 F presents no significant problem because PVC cable, as pointed out in the IEEE paper on page 534, has a useful life of 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> at'136*C (276"F). Additionally, a steam environment presents no significant problem because PVC cable, as pointed out in the IEEE paper on page 534 and Table IX, was found suitable in a steam environment greater than 9 days.
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B-GP-12263 ATTACHMENT 1 EDWIN I. HATCH NUCLEAR PLANT UNIT 1
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N JUSTIFICATION FOR CONTINUED OPERATION NUCLEAR STEAM SUPPLY SYSTEM COMPONENTS EQUIPMENT BEING REPLACED DURING THE PRESENT OUTAGE GENERIC-LIMIT-SWITCHES FOR INDICATION ON AIR OPERATED VALVES The limit switches on the valves are supplied to provide valve position indication only. They do not provide any control function. The valves on to which they are mounted receive a signal and move to their safety position within the first few seconds of any event for which they are required to operate. The
-[operatoratthistimeisrequiredtoverifyisolationandtheswitcheswillmost likely indicate properly during the early stages of any postulated accident event.
/
Once a valve is in its safety position, it is highly unlikely that a valve will shift position since the electrical cable, connections, switches, etc. which are associated with energizing the solenoid are qualified and in order for the valve to' move to.its non-safety position the solenoid must be energized to port air to
~
Y-1the isolation valve.
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l Since qualification data to demonstrate complete acceptability of the limit switches has not been located to date, qualified replacement limit switches have been purchased.
Continued operation is justified since the probability of a LOCA or HELB outside containment occurring coupled with the failure of these switches and the associated solenoid valves prior to their replacement is very remote.
In addition, as indicated above, the switches are only for indication and provide no control.
GENERIC-S0LEN0ID OPERATORS The solenoid on these valves operates within the first few seconds of the postulated accident.
It is highly unlikely that the harsh environment has time to significantly affect their operation before they receive their safety signal and move to their safety position, which is de-energized. Once the solenoid is de-energized, there is no need for them to be re-energized for any action pertaining to safety. The most probable failure of a solenoid valve is a loss of power due to either a short or open in the coil which will cause the solenoid to fail in its safety position.
Since qualification data has not been found to date, replacement solenoids ~ have been purchased.
Continued operation is justified until installation since the probability of the postulated LOCA or a HELB occurring coupled with a failure of these solenoid valves to function as designed for that event prior to their replacement is extremely remote.
2 g
B21-N006A-D, B21-N007A&B, B21-N008A-D and B21-N009A-D The switches sense high flow in the main steam lines and cause an isolation in the event of a main steam line break. On a break, they will sense the flow and isolate the steam lines within ten (10) seconds. The temperature to which they will be subjected is less than the temperature to which test experience is available. There is a high degree of probability that the switches will operate as designed and initiate an isolation signal.
If for some reason they do not operate the high ambient temperature switches will cause the MSIVs to close terminating the event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
1 e
3
B21-tiO10A-D, B21-N011A-D, B21-N012A-D, B21-N0013A-D These instruments are temperature switches which are designed to detect high ambient temperature and initiate an isolation of the main steam lines on high temperature. The instruments are randomly spaced in the main steam tunnel in order to assure that they will detect a break. Test data is available to show that the switches will operate at temperatures equal to their set point temperature. The data provides assurance that the switches will operate and cause the required main steam line isolation.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
4 w
w wr "a
821-N017A-D Switches B21-N017A-D sense a low RPV level to provide scram initiation and trip the HPCI and RCIC turbines on high RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have served their function, to scram the reactor, prior to any significant irradiation of the device. On a HELB outside the drywell the instruments will be subjected to a harsh environment due to temperature. The instruments have test data to demonstrate that they will operate at temperatures up to the accident temperature. The test experience has shown that the effect of the adverse environment is to decrease the accuracy of the instrument. The decrease in accuracy could cause the switch setpoint error to be approximately two (2) inches. The effect of this error is insignificant with respect to assuring adequate core cooling.
In addition, the racks on which these instruments are mounted are widely separate, therefore, there is a high degree of assurance they will operate mitigating the consequences of the event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
l 5
B21-N021A-F i
Switches B21-N021A-F sense RPV pressure and provide the low RPV pressure permissive signal for the low pressure ECCS systems.
These switches are redundant, diverse, separated and there is test documentation which provides a high degree of assurance that they will function. The test experience has demonstrated that the effect of the adverse environment is to decrease the accuracy of the instruments. This decrease in accuracy could cause a setpoint error to be no more than 28 psi. The effect of this potential error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
6
B21-N024A&B, B21-N025A&B These instruments provide the signal which causes the isolation of the MSIVs on low RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have served their safety function prior to any significant irradiation. On a HELB outside the drywell the instrument will be subjected to a harsh environment due to high temperature. There is a high degree of assurance that they will operate to serve their safety function since they have test data to show they will operate at the accident temperature. The test experience has shown that the potential affect of the adverse environment is to decrease the accuracy of the instrument. This decrease could cause the setpoint error to be no more than six (6) inches.
The effect of this error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
7
B21-N026A&B B21-N026A& B Level Indication Transmitter Switch (LITS) provides control room indication of reactor vessel level.
Transmitters A&B provide indication readout on level instruments B21-R604A&B on panel H11-P603. These transmitters are Yarway model 4418CE.
Transmitters C&D provide level recorder inputs to recorders B21-R623A&B on panel H11-P601.
These transmitters are Barton 760 level indicating transmitter switches. 1 The transmitters are located on racks H21-P004 and H21-P005 which could be affected by a RWCU HELB resulting in an ambient temperature transient peak of approximately 210 F.
They also could be affected by a LOCA event which may result in a total radiation exposure of 12 X 6
10 rads.
Even though the transmitter function of the Yarway 4418CE was not evaluated during temperature test, it may be assumed from the test data that the transmitter function would survive the harsh environment and would provide an indication of vessel water level, albeit somewhat degraded, during and subsequent to the accident event. This engineering judgement is based upon the operating principle of the Yarway 4418CE LITS which uses a reliable magnetically actuated armature assembly and transmitting coil (LVDT) to provide a driving signal to a remote LVDT slave device. The same signal drives the local indicator and the remote indicator and test data indicated that the local indicator read out properly during the test. THe non-metallic materials used in the Yarway LITS have been reviewed and it appears that the minimum threshold of 6
damage in the radiation environment is approximately 10 rads.
In addition to the Yarway remote level indicators, the B21-N026A& B transmitters drive a remote recorder in the control room. These transmitters are Barton 760 devices for which no test data could be formed.
Since the Yarway transmitters driving the control room level indicators are expected to survive the harsh environment and since the Barton transmitters driving the control room level recorders are diverse instruments, the probability of having a water level indication in the control room thrcughout the accident event is high.
8
B21-N026A&B (Continued)
-This piece of equipment has been used during normal operation in plants similar to' Hatch I for.the past eleven (11) years. To date, no age related common mode failures have.been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
9 c.
B21-N027 This instrument measures the RPV level from the botton of the dryer skirt to the top of the RPV head.
This instrument is only required to recover from the alternate shutdown cooling mode of plant operation. The instrument will be measuring on scale when in this mode of operation; therefore, the operator will know if the instrument is operating properly.
If the operator expects that the instrument has been degraded, the instrument will be replaced before the recovery operation is started. While the reactor is being cooled in this mode it is in a safe and stable condition; therefore, the replacement method is considered acceptable.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
10
B21-N031A-D These switches provide a signal which starts the high and low pressure ECCS systems on low RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have served their safety function prior to any significant irradiation. On a HELB outside the drywell the instrument will be subjected to a harsh environment due to high temperature. There is a high degree of assurance that they will cperate to serve their safety function since they have test data to show they will operate at the accident temperature.
The test experience has shown that the potential effect of the adverse environment is to decrease the accuracy of the instrument. This decrease could cause the setpoint error to be no more than six (6) inches. The effect of this error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
11
B21-N036, B21-N037 These instruments provide a containment spray pernissive signal and provide shroud water level indication.
The accident analysis does not take credit for the containment spray function of the RHR system, therefore, the containment spray permissive function of the instruments is not required to assure plant safety.
The indication function of the instrument could be affected by the high radiation condition post LOCA.
If the indication becomes erratic or ambiguous, the operator will-turn on all of the low pressure ECCS systems thus filling the RPV and open one or more SRVs to allow the ECCS flow to spill out the relief valves to the suppression chamber. This operation assures adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limitec' service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
12
B21-N042A&B These instruments provide an ADS permissive signal on low RpV water level which is only required post LOCA. They will be subjected to a harsh environment due to radiation but will have served its safety function prior to any significant irradiation.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
13 L
B31-F031A, 831-F031B The above listed motor operated valve operators, which previous to this revision were considered fully qualified, are now considered as having an open item regarding the radiation qualification of the motor brake assemblies.
Recent information from the suppliers of the motor operated valve operators indicate their unwillingness to formally support the radiation qualification of their brake assemblies. However, note that brakes similar in design to the subject brakes have in fact successfully undergone both HELB/LOCA and radiation testing.
Reference to Limitorque Test Report 600376A Appendix B (F-C3441 Appendix C) 8 states that the brake was radiated to over 2.04 X 10 rads with no apparent damage. However, the same specimen which had been radiated did not undergo a HELB/LOCA test. For this reason, each of the above listed motor operated valve operators are being replaced with a design which precludes the necessity of brake assemblies.
Based on the successful-though limited-testing and the fact the operating time requirements are minimal (30 seconds within the first 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />), operation until such time as fully qualified components can be installed is justified.
14
C32-N005A&B This instrument measures RPV pressure and is provided to give the operator additional information regarding plant performance.
No operator actions can be taken solely as a result of the information provided by this instrument which will affect the automatic operation of the ECCS systems and, therefore, reactor safety.
Test data is available for these devices to show that they will function properly in an environment with temperatures up to 150"F. The maximum expected accident temperature in the area of these transmitters is 210 F due to a RWCU line break.
Since, no improper operator action that can affect reactor safety will result from an incorrect vessel pressure indication, continued plant operation is justified.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
9 15
.C71-N002A-D These instruments monitor drywell pressure and provide a SCRAM signal on high drywell pressure.
These switches could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will sense high pressure and actuate very early in a LOCA event prior to.any high radiation being present and will not have to function again. The safety function of these switches is there satisfied.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported.
These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified, i
16
E11-N002A&B These instruments measure the P across the RHR Heat Exchanger and provide a signal to the RHR Service Water Outlet Valve E11-F068A&B to regulate such that
-service water pressure is always greater than RHR System Pressure.
The instrument may be subjected to a harsh environment due to temperature in the event of a HELB in the corner rooms where they are located but no credit is taken for the system operation in that compartment after a HELB.
The instrument could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. There is a high degree of assurance that the instrument will function as designed in this case since the instrument has test data to show that which it will be subjected to afte-this event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
17
E11-N010A-D These instruments monitor drywell pressure and provide an ADS permissive signal on high drywell pressure.
These switches could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will sense a high pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of these switches is therefore satisfied.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years.
To date, no age related common mode failures have been reported. inese devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
9 18
)
E11-N011A-D l
These-instruments monitor drywell pressure and provide a signal to initiate the ECCS Systems on high drywell pressure.
These switches could be subjected to a harsh environnent due to radiation in the unlikely event of a LOCA. The switches will sense a high pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of these switches is therefore satisfied.
The switches could be subjected to a harsh environment due to temperature after a HELB but are nct required to assure plant safety after that event.
l This piece of equipment has been used during normal operation in plants similar l
to Hatch I for past eleven (11) years. To date, no age related common mode failures have been reported.
These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for five (5) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
19
?
E11-N016A-D These instruments monitor the discharge pressure of the LPCI pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI System will receive its' signal and start prior to any core uncovered. Once the switch has operated it does not have to function again to serve its safety function.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relative limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
i 20
l E11-N020A-D These instruments monitor the discharge pressure of the LPCI pumps to provide a signal to the ADS logic.
This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI system will receive its' signal and start prior to any core uncovery. Once the switch has operated it does not have to function again to serve its' safety function.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
'Jesed on the above, continued operation is justified.
21
E11-N021A&B These instruments monitor LPCI flow and provide the signal to close the LPCI minimum flow valves, E11-F007A&B, when system flow is tigh enough to protect the pumps.
The instruments could be subjected to a harsh environment due to radiation after a LOCA. However, generally, the LPCI pumps are in operation before core damage would be predicted to occur. Further, for large breaks where total LPCI flow is significant to establishing reflooding time, the minimum flow valves would be closed before any potential radiation damage. Although analyses have not been performed it is expected this would also be true for small breaks.
Further for small breaks, total LPCI (or low pressure ECCS flow) is not significant in the reflooding calculation so that failure of the minimum flow bypass valve to close would not significantly affect core reflooding time. Therefore, the instruments are expected to function sufficiently to assure adequate core cooling.
In the event of a HELB in the area where the instruments are located, no credit is taken for the systems in that compartment; therefore, the instruments are not required.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
22 J
E21-N003A&B These instruments provide the operator with confirmatory information to assure that the core spray system is operating as designed.
No credit is taken for operation operation of these systems in the event of a line break which creates a harsh environment in the area where the instrument is located. Therefore, the instruments are not required after a HELB.
In the event of a LOCA, the instruments will be subjected to a harsh environment due to radiation. The instruments do not have any data to demonstrate their qualification in the high radiation environment but the operator will be able to verify proper automatic system operation prior to significant radiation degradation to the instruments.
In the event of erratic instrument behavior, the operator will not take an action which will compromise safety based on this indication.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch I as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
t 23
E21-N006A&B These instruments monitor core spray system flow and provide the signal to close the core spray pump minimum flow valves, E21-F031A8B, when system flow is high enough to protect the pumps.
The instruments could be subjected to a harsh environment due to radiation after a LOCA. However, generally the core spray pumps are in operation before core damage would be predicted to occur.
Further, for large breaks where core spray flow may be significant to the core heatup calculation or reflooding time, the minimum flow valves would be closed before any potential radiation damage.
Although analyses have not been performed it is expected this would also be true for small breaks.
Further for small breaks, total core spray flow (or low pressure ECCS flow) is not significant in the reflooding calculation so that failure of the minimum flow bypass valve to close would not significantly affect core reflooding time.
Therefore, the instruments are expected to function sufficiently to assure adequate core cooling.
In the event of an HELB in the area where the instruments are located, no credit is taken for the systems in that compartment; therefore, the instruments are not required.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
24
E21-N008A&B These instruments monitor the discharge pressure of the core spray pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will have operated to serve their This is based on the safety function prior to any high radiation being present.
fact that the LPCI System will receive its' signal and start prior to any core Once the switch has operated, it does not have to function again to uncovery.
serve its' safety function.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five With this limited service, this equipment is not expected to fail (5) years.
before replacement.
Based on the above, continued operation is justified.
25
E21-N009A&B These instruments monitor.the discharge pressure of the core spray pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI System will receive its' signal and start prior to any core uncover. Once the switch has operated it does not have to function again to serve its' safety function.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
26
E21-N015A&B These instruments provide the operator with confirmatory information to assure that the LPCI system is operating as designed.
No credit is taken for operator operation of these systems in the event of a line break which creates a harsh environment in the area where the instrument is located. Therefore, the instruments are not required after a HELB.
In the event of a LOCA, the instruments will be sebjected to a harsh environment due to radiation. The instruments do not have any data to demonstrate their qualification in the high radiation environment but the operator will be able to verify proper automatic system operation prior to significant radiation degradation to the instruments.
In the event of erratic instrument behavior, the operator will not take an action which will corapromise safety based on this indication.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
i 27
t E41-F012 Valve E41-F012 is the minimum flow valve for the HPCI pump.
3 In the event of a LOCA, the valve could be subjected to a harsh environment due to radiation. The minimum flow valve could be called upon to open at the time of system initiation on a large LOCA. The valve will not have been subjected to irradiation at that time and will operate as designed.
If the valve does not
'close the level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
In the event of a small break, the subject valve could be required to cycle on subsequent starts of the HPCI system.
If the HPCI system is required to cycle the break is small enough that the flow out the break is less than'the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damage. Therefore, the source of the high radiation will not be present.
\\
e In the event of a HELB, the valve could be subjected to a harsh environment due to temperatere and pressure, but the source of the harsh environment will be a HPCI steam,line break and no credit is taken for the operation of the HPCI syst in a'f t$r etnat event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement. '
Based on the above, continued operation is justified.
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28
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1 E41-N001A-D, E41-N004, E41-N005 These instruments monitor HPCI steam line pressure and flow, they provide an isolation signal on low pressure and/or high flow in the event of a HPCI steam line break.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. Yhe accident analysis takes no credit for the operation of these instruments for the mitigation of a LOCA.
The instruments could be subjected to a harsh environment due to temperature in the event of a HELB.
There is a high degree of confidence the switches will operate since there is test experience to demonstrate that the instruments will operate up to a temperature of 212'F which is only 2*F below the peak predicted temperature for the area where the switches are located. The subject switches will also operate prior to reaching that peak temperature and once they have operated, they will ha e se'ved their safety function and will not have to operate again.
In addition, these switches are backed up by high temperature elements which will also cause an isolation signal to be generated.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only fiva (5) years. With this limited service, this equipment is not expected to fail before replacement.
6ased on the above, continued operation is justified.
29
J E41-N006 E41-N006 is the flow instrument which provides the signal which operates the minimum flow valve, E41-F012.
In the event of a LOCA, the instrument could be subjected to a harsh environment due to radiation.
The instrument could be called upon to operate at the time of system initiation on a large LOCA. The instrument will not have been subjected to irradiation at that time and will operate as designed.
If the instrument does not operate the RPV level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
In the event of a small break, the subject instrument could be required to cycle on subsequent starts of the HPCI system.
If the HPCI system is required to cycle the break is small enough that the flow out the break is less than the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damage. Therefore, the source of the high radiation will not be present.
In the event of a HELB the instrument could be subjected to a harsh environment due to temperature and pressure but the source of the harsh environment would be a HPCI steam line break and no credit is taken for the operation of the HPCI system after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years.
With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
30
l i
E41-N008 This is a transmitter that provides control of the HPCI Turbine Control Valve position to maintain design rated HPCI flow.
It also provides the control room with indication of HPCI pump flow.
The transmitter is not subjected to a harsh environment for any HELB except the HPCI System Steam Line Break, and no credit for the HPCI system is taken for this break.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV level, the transmitter may be subjected to high radiation. However, in this case, the HPCI system is not required since the RPV will be depressurized by the break and/or actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
31
E41-N010 This instrument monitors HPCI pump suction pressure and initiates a pump trip on low suction pressure.
The instrument is not subjected to a harsh environment for any HELB except the HPCI system steam line break, and no credit for the HPCI system is taken for this break.
In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To (ate, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
32
E41-N012A-D These instruments monitor the pressure between the rupture disks off the turbine exhaust line and initiate a turbine trip if the inboard disk fails. The purpose of the instrument is to trip the turbine if the exhaust line becomes blocked.
Such a blockage is extremely unlikely so the switch should never be required to function.
In the highly unlikely event of such a blockage, line overpressurization would occur very early in the operation of the turbine, before the occurrence of a harsh environment from any LOCA or HELB.
Therefore, the switch would be expected to function.
The possibility of inadvertent actuation exists due to high radiation associated with a large LOCA for which HPCI cannot maintain RPV level.
In this case HPCI is not required since the reactor would be depressurized by the break and/or ADS and core cooling will be provided by the low pressure ECCS systems.
This piece of equipme, has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
9
~33 l
E41-N015A&B These instruments are level switches and monitor the suppression chamber level and provide a signal to the HPCI suction valves, E41-F042, E41-F041 and E41-F004 to switch the HPCI suction source from the condensate storage tank to the suppression chamber.
In the event of a LOCA, the instruments will be subjected to a harsh environment due to radiation. However, for any event for which the HPCI suction transfer is required, the transfer will be completed prior to the occurrence of any fuel damage. Therefore, the subsequent occurrence of high radiation is not a concern and the instrument is expected to function as required.
In the event of a HELB, the instruments will be subjected to a harsh environment due to temperature.
These instruments are widely used throughout the industry for boiler level control at temperatures far in excess of those to which it will be subjected during the postulated HELB. Therefore, there is a high degree of assurance that they will function as required.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years.
With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
34
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E41-N017A&B These instruments monitor the HPCI turbine exhaust pressure and initiate a trip signal on high pressure.
The instruments are not subjected to a harsh environment or any HELB except the HPCI system steam line break, and no credit for the HPCI system is taken for this break.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV level, the instruments may be subjected to high radiation. However, in this case the HPCI system is not required since the RPV will be depressurized by the break and/or actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacemer.t.
Based on the above, continued operation is justified.
E 35
E41-N027 E41-N027 is a pressure switch which senses HPCI pump operation and permits the minimum flow valve, E41-F012, to open if the system is operating and the flow is low.
In the event of a LOCA the instrument could be subjected to a harsh environment due to radiation. The instrument could be called upon to operate at the time of system initiation on a large LOCA. The instrument will not have been subjected to irradiation at that time and will operate as designed.
If the instrument does not operate, the RPV level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
In the event of a small break the subject instrument could be required to cycle on subsequent starts of the HPCI system.
If the HPCI system is required to cycle the break k small enough that the flow out the break is less than the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damages. Therefore, the source of the high radiation will not be present.
In the event of a HELB the instrument could be subjected to a harsh environment due to temperature and pressure but the source of the harsh environment will be a HPCI steam line break and no credit is taken for the operation of the HPCI system after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
36
E41-N030A&B, E41-N046A&B, E51-N025C&D, E51-N026C&D, E51-N027C&D These instruments are temperature sensors which monitor temperatures in areas where the HPCI steam line is located and initiate an isolation-signal in the event of a steam leak in the HPCI steam line.
The instruments could be subjected to a haish environment due to radiation in the unlikely event of a LOCA. No credit is taken in the accident analysis for the operation of these switches for the mitigation of a LOCA.
If the swit:hes misoperated due to a high radiation failure the HPCI system could be unnecessarily isolated. This does not cause a condition which compromises plant safety since the ADS system in conjunction with the low pressure ECCS systems will provide adequate core cooling.
In the event of a HELB the instruments could be subjected to a harsh environment due to temperature and pressure. A high degree of confidence exists that the instruments will operate to isolate the HPCI steam line break since test experience shows that the switches will operate up to a test temperature of 212*F. The setpoint of these switches is 170"F which is wall below the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch I for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
37 l
E51-N012A-D These instruments monitor the pressure between the rupture disks off the turbine exhaust line and initiate a turbine trip if the inboard rupture disk fails. The pJrpose of the instrument is to trip the turbine if the exhaust line becomes blocked. Such a blockage is extremely unlikely so the switch shsuld never be required to function.
In the highly unlikely event of such a blockage, line over-pressurization would occur very early in the operation of the turbine, before the occurrence of a harsh environnent from any LOCA or HELB. Therefore, the sw tch would be i
expected to function.
The possibility of inadvertent actuation causing a RCIC System isolation exists but no credit is taken for the operation of the RCIC system in the accident analysis.
This piece of equipment has been used during normal operation in plants similar i
to Hatch I for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in-Hatch 1 as they have been used during normal operation for only five (5) years.
With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
l 38
E51-N019A-D, E51-N017, E51-N018 These instruments monitor RCIC steam line pressure and flow, they provide an isolation signal on low pressure and/or high flow in the event of a RCIC steam line break.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The accident analysis takes no credit for the operation of the RCIC System for the mitigation of a LOCA.
The instruments could be subjected to a harsh environment due to temperature in the event of a HELB. There is a high degree of confidence the switches will operate up to a temperature of 212*F which is only 2 F below the peak predicted temperature for the area where the switches are located.
The subject switches will also operate prior to reaching that peak temperature and once they have operated they will have served their safety function and will not have to operate again.
In addition, these switches are backed up by high temperature elements which will also cause an isolation signal to be generated.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
'39 1
1 E51-N021A&B, E51-N022A&B, E51-N023A&B, E51-N026A&B, E51-N025A&B, E51-N027&B These instruments are temperature sensors which monitor temperatures in areas where the RCIC steam line is located and initiate an isolation signal in the event of a steam leak in the RCIC steam line.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. No credit is taken in the accident analysis for the operation of these switches for the mitigation of a LOCA.
In the event of a HELB the instruments could be subjected to a harsh environment due to temperature and pressure. A high degree of confidence exists that the instruments will operate to isolate the HPCI steam line break since test experience shows that the switches will operate up to a test temperature of 212 F.
The set point of these switches is 170 F which is well below the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch I as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
40
G31-N016A-F, G31-N022A-F, G31-N023A-F These instruments are temperature sensors which monitor temperature in areas where the RWCU piping is located and initiate an isolation signal in the event of a leak.
These instruments could be subjected to a harsh environment due to radiation in the event of a LOCA. No credit is taken for the operation of these switches for the mitigation of a LOCA.
In the event of a HELB the instruments could be subjected to a harsh environment due to temperature and pressure. A high degree of confidence exists that the instruments will operate to isolate the RWCU line since test experience shows that the switches will operate up to a test temperature of 212 F.
The set point of these switches is substantially less than the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch I as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified, i
41
+
G31-N036, G31-N012, G31-N041 These instruments measure the flow for the FWCU system.
These instruments will be subjected to a to sh environment due to high temperature on a break in the RWCU system.
'% instruments will sense the break flow condition prior to being subjected to a temperature in excess of that for which we have test experience. Therefore, *.here is a high degree of confidence that they will function as intended and seid a signal which isolates the break.
Once the signal is initiated, the instrumeni, has served its safety function.
In addition, the temperature in each room is monitored by temperature sensors which will cause an isolation signal to be generated on high teinperature.
In the event of a LOCA these instruments are not required for accident mitigation.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 1 as they have been used during normal operation for only five (5) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
0 42 l
Unknown Internal Panel Wire It is not known if this wire is part of the circuit for any safety equipment. A walkdown of Unit 2 panels where unidentified internal panel wire was, showed that no safety equipment circuits included this wire.
As this wire was supplied in panels manufactured by the same vendor (as the Unit 2 panels' vendor), it is assumed the same situation exists. A similar walkdown of Unit 1 panels is planned for the next unit refueling shutdown to verify this fact.
Based on the above, continued operation is justified.
e 43
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t B-GP-12263 ATTACHMENT 1 E. I. HATCH PLANT UNIT 2 JUSTIFICATION FOR CONTINUED OPERATION BALANCE OF PLANT EQUIPMENT NOT REPLACED DURING THE PRESENT OUTAGE t
0
2E11-F021B Valve 2E11-F021B is required if the drywell spray mode of operation of the RHR system is desired. Adequate documentation has not been found to assure acceptability of the subject valve.
Subsequent to a LOCA or HELB the operation of the valve is not required since the accident analysis takes no credit for the d.ywell spray mode of operation to assure plant safety.
if, however, drywell spray operation is desired, the opposite train of spray could be used.
Based on the above, continued operation is justified.
1
2E11-M0V-F016A, 2E11-MOV-F021A The above listed motor operated valve operators, which previous to this revision were considered fully qualified, are now considered as having an open item regarding the radiation qualification of the motor brake assemblies.
Recent information from the suppliers of the motor operated valve operators indicate their unwillingness to formally support the radiation qualification of their brake assemblies. However, note that brakes similar in design to the subject brakes have in fact successfully undergone both HELB/LC0A and radiation testing.
Reference to Limitorque Test Report 600376A Appendix D (F-C3441 Appendix C) 8 states that the brake was radiated to over 2.04X10 rads with no apparent damage. However, the same specimen which had been radiated did not undergo an HELB/LC0A test.
For this reason, each of the above listed motor operated valve operators are being replaced with a design which precludes the necessity of brake assemblies.
Based on the successful-though limited-testing and the fact the operating time requirements are minimal (worst case 3 minutes with 1st 25 days), operation until such time as fully qualified components can be installed is justified.
2
B-GP-12263 ATTACHMENT 1 RESPONSE TO NRC IE BULLETIN 79-01B E. I. HATCH PLANT UNIT 2 JUSTIFICATION FOR CONTINUED OPERATION BALANCE OF PLANT COMPONENTS EQUIPMENT BEING REPLACED DURING THE PRESENT OUTAGE Generic - LIMIT SWITCHES FOR INDICATION ON AIR OPERATED VALVES The limit switches on the valves are supplied to provide. valve position indication only. They do not provide any control function.
The vaives, onto which they are mounted receive a signal and move to their safety position l
i within the' first few seconds of any event for which they are required to operate.- The operator at this time is required to verify isolation and the switches will most likely indicate properly during the early stages of any postulated accident event.
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Once a valve is in its safety position, it is not credible to assume that a valve will shift position since the electrical cable, connections, switches, etc. which are associated with energizing the solenoid are qualified.
In order for the valve to move to its non-safety position the solenoid must be energized to port air to the isolation valve which has been shown to be not credible.
Since qualification data to demonstrate complete acceptability of the limit switches has not been located to date, qualified replacement limit switches have been purchased.
Continued operation is justified since the probability of a LOCA or HELB outside containment occurring coupled with the failure of these switches and the associated solenoid valves prior to their replacement is very remote.
In addition, as indicated above, the switches are only for indication and provide no control.
GENERIC-PILOT SOLEN 0ID OPERATORS The solenoid on these valves operate within the first few seconds of the postulated accident.
It is not credible to assume that the harsh environnent has time to significantly affect their operation before they receive their safety signal and move to their safety position, which is de-energized. Once the solenoid de-energizes, there is no need for them to be re-energized for any action pertaining to safety. The most probable failure of a solenoid valve is a loss of power due to either a short or open in the coil which will cause the solenoid to fail in its safety position.
Since qualification data has not been found to date, replacement solenoids have been purchased.
Continued operation is justified until installation since the probability of the postulated LOCA or a HELB occurring coupled with a failure of these solenoid valves to function as designed for that event prior to the next refueling outage is extremely remote.
2 l
1
2E11-F003A Valve 2E11-F003 is a RHR heat exchance isolation valve. The motor on the subject valve has been replaced with a motor which has been rewound with Class F insulation. Class F insulation has better properties in all applicable areas than the Class B insulation which was on the original motors but test information to demonstrate complete acceptability of the motors has not been located to date.
The normal and accident position of the subject valves is open.
Since the valve is in its safety position, no identified motor operator failure mechanism exists which will cause the valve to shift position during an accident since the electrical cable, connections, switches, etc. which are associated with energizing the motors are fully qualified.
Further, the motor will only be subjected to a harsh environment due to radiation after a LOCA and test data is available to demonstrate acceptability 8
of the motor after a radiation dose of 2 x 10 rads which is far in excess of the dose which they could receive after a LOCA. The motor will not be subjected to a harsh environment due to temperature or pressure since no high energy lines are located in the corner rooms where the motors are located.
Based on the above, continued operation is justified.
3 4
'2E11-F008 2E11-F008 will be subjected to a harsh environment due to radiation after a LOCA. The valve will always be closed during normal plant operation. THe closed position is assured since there is a high pressure interlock which prevents the valve from opening when the primary pressure approaches the design rating of the system.
Since the valve is in its safety position, radiation damage will not prevent the valve from serving its safety function.
The valve may be called upon to operate later in a LOCA, to go into shutdown cooling, but if it does not operate the alternate method of cooling which is described in section 6.2.6 of the General Electric High Energy line break evaluation for Edwin I. Hatch Nuclear Power Station can be used.
The subject valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break but, due to the high pressure interlock, 2E11-F008 will be closed. As discussed above, if the valve cannot be opened after the transient to initiate shutdown cooling the alternate method of cooling can be used.
Based on the above, continued operation is justified.
4 l
'2E11-F027A l
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Valve 2E11-F027-is required if the torus spray mode of operation of the RHR system-is desired. Adequate documentation has not been found to assure acceptability of the subject valve.
Subsequent to.a LOCA or HELB the operation of the valve is not required since the accident analysis does not take credit for the suppression pool spray mode of operation to assure plant safety.
If, however, suppression pool spray is
. desired the opposite train of spray could be used.
4 Based on the above. continued cperation is justified.
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r 2E11-F028A,B The subject valves are required for the use of RHR in tne suppression pool spray and/or cooling mode. The safety analysis does not take credit for the suppression pool spray mode.
The valves are qualified for the radiation but lack adequate data for the high energy line break environment.
During a LOCA the valves are subject to a harsh environment due to radiation.
Since the valves are qualified for the radiation dose they will perform their function during that accident.
Subsequent to a HELB outside the containment, the valves will see a harsh environment due to the temperature and steam.
If the subject valves fail to operate, when called upon for suppression pool cooling subsequent to a HELB, the drywell spray mode of the system can be initiated. This mode of operation takes suction from the suppression pool, sprays the drywell and the downcomers return the water to the suppression pool.
The above discussion provides justification for continued operability.
O 6
l 1
S0LELN01D VALVES WHICH CONTROL THE OPERATION OF VALVES 2E11-F041A-D (2E11-F213 Through 2E11-F220)
The valves provide isolation capabilities for instruments 2E11-N0101A-D and 2E11-N011A-D. These instruments monitor drywell pressure and provide an ADS permissive signal on high drywell pressure.
The valves could be subjected to a harsh environment due to radiation in the event of a LOCA.
The switches which the valves service will sense a high drywell pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of the switches will be satisfied and the potential failure of the isolation valves will have no adverse impact on plant safety.
If one or more of the 2E11-F041A-D valves are' closed for any reason only a failure of the solenoid could cause the isolation valve to open but the chances of the valves being closed concurrent with a LOCA are remote. The instruments in question must be operable or the plant is in a LCO condition.
These valves could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after t. hat event.
Based on the above, continued operation is justified.
l 7
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2E11-M0V F075B Valve 2E11-F075B is the RHR service water inlet valve to the RHR System. The motor on the subject valve has been replaced with a motor which has been rewound with Class F insulation.
Test information to demonstrate complete acceptability of the motor has not been located to date.
Valve 2E11-F075B is normally closed and will only be opened in the very unlikely event that both trains of the LPCI system in addition to the core spray system fail to operate after a LOCA. The valve is backed up by valva 2E11-F073B which is fully qualified to assure that RHR service water is not inadvertently injected into the LPCI System.
Since the valve is only required to operate after a LOCA with concurrent failure of both trains of LPCI there is a high degree of confidence that operation of the valve will not be required.
If service water injection is required the "A" loop can be used to inject service water into the reactor.
Based on the above, continued operation is justified.
8
2E41-F004 Valve 2E41-F004 is the suction from the condensate storage tank isolation valve Tt.e valve motor has been identified as having Class 8 for the HPCI pump.
insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
m The valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break but no credit is taken for the system in the event of this break.
Valve 2E41-F004 will only be subjected to a harsh environment due to radiation The valve is required to remain open until the suppression
'after a LOCA.
chamber reaches the high level alarm then close. The valve will not be subjected to a high temperature and steam environment concurrent wit the high radiation environment; therefore, there is a high degree of assurance that it will function as designed.
In the unlikely event that valve 2E41-F004 does not close and the suppression chamber level exceeds the Technical Specification limit, the control room operator can manually stop the HPCI pump and actuate the ADS system and use the
low pressure ECCS systems to assure core cooling.
Based on the above, continued operation is justified.
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2E41-F006 isolated the HPCI system from the feedwater system. The valve motor hasbeenidentifiedashavingClasIsBinsulationwhichhasbeenshowntobe acceptable for other' Mmponents whh:h h' ave been subjected to a similar Anvironment.
i 2E41-F006c iV only be subjected to a harsh environment due to radiation after w
a LOCA. The>: give will receive. fits singal and move to its safety position in the first few'mintites of an event. ' The' time' duration during which it must s 1
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operate is s,hort e.nwgh "that it,.isris.ot credible to assume that appreciable w
radiation dama% w.ill occur potentially rendering the valve ;ipoperable prior to 4g it reachiiig is; full open pos'f tiork l
r, The' subject valve could experience'a harsh environment due to temperature and
[ team in the unlikely event of a HPCI, RCIC, or Main Steam line break.
HPCI can and/h all probability will function % designed for a RCIC and Main Steam lina 'rfqture' and is not required for a HEI' lini break. The basis for this 4
rationallis hhe sane as is presented for th,e radiation case above, that is, the valve.will be in.its safety;oosition prior to;.any significant degradation, due jf - s q
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to'thh-}tweraivreandsteamenvironment,'occerring.
If the valve does fail, however ADS concurrent with the low pressure systems may be used.
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Based on the above, continued operation is jus'ttf,M.
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2E41-F008 Valve 2E41-F008 is the HPCI test valve to the condensate storage tank.
Adequate documentation has not been found to assure acceptability of the motor brake mechanism.
s a
The normal and accident position of the subject valve is closed.
The only time the valve would be open is during a HPCI system test and it is not credible to assume a HELB or LOCA during that time. No identified motor operator failure mechanism exists that could cause the valve to open during HPCI operation since all the controls for the valve have documentation to demonstrate their complete qualification.
Based on the above, continued operation is justified.
E I
11
Valve 2E41-F042 is the suction from the suppression chamber isolation valve for the HPCI pump. The valve motors have been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
The valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI steam line break but no credit is taken for the system in the event of this break.
The valve 2E41-F042 will anly be subjected to a harsh environment due to radiation after a LOCA. The valve is required to open when the suppression chamber reaches the high level alarm. The valve will not be subjected to a high temperature and s+aam environment concurrent with the high radiation environment; therefore; there is a high degree of assurance that it will fur.ction as designed.
In the unlikely event that valve 2E41-F042 does not open, the control room operator can manually operate the' ADS system and use the low pressure ECCS systems to assure core cooling.
Based on the above, continued operation is justified.
12 U.
2E51-F013 2E51-F013 isolates the RCIC System from the feedwater system. The valve motor has been identified as having Class B insulation which has been shown to be acceptable for other components which have been subjected to a similar environment.
2E51-F013 will only be sub.iected to a harsh environment due to a radiation after a LOCA. The valve will receive its signal and move to its safety postion in the first few minutes of an event. The time duration during which it must operate is short enough that it is not credible to assume that appreciable radiation damage will occur potentially rendering the valve inoperable prior to it reaching its full open position.
If the valve fails, however, it is not adverse to safety since no credit is taken for the system after a LOCA.
The subject valve could experience a harsh env.ironment due to temperature and steam in the unlikely event of a HPCI, RCIC, or Main Steam line break.
Although no credit is taken for the RCIC System within the accident analysis, RCIC can and in all probability will function as designed for a HPCI and Main Steam line rupture and is not required for a RCIC line break. The basis for this rational is the same as is presented for the radiation case above, that is, the valve will be in its safety position prior to any significant degradation, due to the temperature and steam environment, occurring.
Based on the above, continued operation is justified.
13
2E51-F031 Valve 2E51-F031 is the suction from the suppression chamber isolation valve for the RCIC. pump. The valve motors have been identified as having Class B insulation which have been shown to be acceptable for other components which have been subjected to a similar environment.
2E51-F031 will only be subjected to a harsh environment due to a radiation after a LOCA.
The valve is required to open when the suppression chamber reaches the high level alarm and the operatcr manually signals it to open. The valve will not be subjected to a high temperature and steam environment concurrent with the high radiation environment; therefore, there is a high degree of assurance that it will function as designed.
i The valve could experience a harsh environment due to temperature and steam in the unlikely event of a HPCI, RCIC, or Main Steam line break.
In the unlikely event that the valve does not function as designed, it does not affect safety since no credit is taken for the RCIC system in the accident ant., sis and it is not required to function for a HPCI or Main Steam line break.
Based on the above, continued operation is justified.
14
-2P33-F016 and 2P33-F017
'These valves provide the capability to select any available sample location for either of the H -0 analyzers.
The normal and accident condition of the valves 2 2
.is-de-energized. With no operation of the switching valves each analyzer has the capability to sample the drywell and the torus for H and 0.
If the 2
2 switching valve were to inadvertently energize there is a potential that an
. analyzer could be damaged due to low flow but this is very unlikely since without specific operator action the solenoid can not be energized. All controls and asscciated cables for the valves are fully qualified.
Continued operation is justified based on the fact that H and 0 sampling 2
2 cabilities exist for the torus and the drywell with the loss of switching capability.
1 i
i 4
9 a
15 bi-
~ Pressure. switch 2PS2-N002 monitors the pressure in the nonnal supply to the
.non-interruptable air system and sends a signal on low pressure to open valve A failure or misoperation of the instrument is not adverse to 2P52-F565.
. safety since the misoperation of valve 2P52-F565, as has been previously demonstrated, does not create a condition which is adverse to safety.
Based on the above, continued operation is justified.
F 4
1 d
t
.\\-
a 2
'16-mo
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R'
2T47-N003 and 2T47-N009 These instruments are RTDs which monitor the drywell temperature in the area of the reference legs on the RPV water level instruments. The instruments are used by the operators to density compensate the level instruments based on drywell temperatures.
The level instruments do not require the density compensation in order for all automatic system actuations to take place to assure plant safety. The temperature instruments in conjunction with the level instruments will be used by the operator to confirm proper injection system operations. The maximum expected error in the level instruments is 28 inches which corresponds to a drywell temperature of 340 F.
The operator is very aware of this error and if in the doubt will apply the maximum error in the safe direction.
If the instrument provided an incorrect reading the operator could be misled but the automatic system actuations which occur on high and low RPV level will protect the core and will alert the operator to the fact that he is being misled by the temperature elements. Therefore, plant safety is assured.
Based on the above, continued operation is justified.
i e
17
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2T48-F027 This valve is the redundant isolation valve for the Unit 2 nitrogen supply.
The nitrogen is used as a backup supply to the drywell pneumatic, and non-interruptable instrument air systems. The normal and accident position of the subject valve is open. No operation of the valve is required to mitigate the consequences of an HELB or a LOCA.
The valve will not move from its safety position as a result of the harsh environment since the electrical cables, connections, switches, etc., which are associated with energizing the motor are qualified and the motor must be energized in order for the valve to switch positions.
The only time the valve would be closed is during maintenance operations on the Unit 2 supply header or a rupture in the header which requires isolation.
It is not credible to assume that these events will occur concurrent with a LOCA coupled with a loss on the drywell pneumatic and non-interruptable instrument air system.
Based on the.above, continued operation is justified.
4 18 a
w m
2T48-N009A,B,C and 2T48-N075 These instruments are RTDs and are used to monitor the water temperature in the suppression chamber. They do not provide any automatic initiation signals.
In the vent of a LOCA, the instruments may be sub.iected to a harsh environment due tr radiation. The plant is operated within the technical specification which requires that the temperature be monitored and corrective actions taken at various temperatures. The accident analysis has shown that during a LOCA condition a sufficient heat sink is provided by the suppression chamber volume to assure plant safety regardless of the temperature monitoring capabilities.
The temperature elements could be subjected to a high temperature and pressure environment in the event of an HELB in the torus room.
If due to the HELB, a plant cooldown is required which uses the suppression chamber as a heat sink the operator, due to his experience and training, knows that the suppression pool cooling mode of operation is required.
He will place the RHR system in the cooling mode regardless of the temperature indication if it is erratic or ambiguous.
In the event of major flooding in the torus, if the suppression chamber is used as a heat sink, the suppression pool cooling mode of the RHR system is required and will be initiated by the operator regardless of the operation of the temperature elements.
Based on the above, continued operation is justified.
19
2T48-N210 and N211 The differential pressure switches open air operated isolation valves upstream of the suppression chamber to the secondary containment vacuum breakers. The vacuum breakers are provided to protect the suppressfor chamber against negative pressures.
The operability of the differential pressure switches is required for a LOCA in the containment or for a HELB in the torus compartnent.
Interim plant operability can be justified by the following:
1.-
The post LOCA pressure profile as shown in FSAR figure 6.2.5 (copy in section C.3 of this report) indicates that the pressure in the torus will never be negative.
2.
The HELB analysis for the torus chamber room gives a peak pressure of 17 psia. AS indicated in FSAR section 15.A.5.3.1 and referenced on the instrument data sheet, the torus has been evaluated for this external pressure with acceptable results.
20 1
B-GP-12263 ATTACHMENT 1 E. I. HATCH PLANT UNIT 2 JUSTIFICATION FOR CONTINUED OPERATION NUCLEAR STEAM SUPPLY SYSlEM COMPONENTS EQUIPMENT BEING REPLACED DURING THE PRESENT OUTAGE GENERIC-LIMIT-SWITCHES FOR INDICATION ON AIR OPERATED VALVES The limit cwitches on the valves are supplied to provide valve position indication only. They do not provide any control function. The valves on to which they are mounted receive a signal and move to their safety position within the first few seconds of any event for which they are required to operate. The operator at this time is required to verify isolation and the switches will most likely indicate properly during the early. stages of any postulated accident event.
Once a valve is in its safety position, it is highly unlikely that a valve will shift position since the electrical cable, connections, switches, etc. which are associated with energizing the solenoid are qualified and in order for the valve to move to its non-safety position the solenoid must be energized to port air to the isolation valve.
1
1 Since qualification data to demonstrate complete acceptability of the limit switches has not been located to date, qualified replacement limit switches have been purchased.
Continued operation is justified since the probability of a LOCA or HELB outside containment occurring coupled with the failure of these switches and the associated solenoid valves prior to their replacement is very remote.
In addition, as indicated above, the switches are only for indication and provide no control.
l GENERIC-SOLEN 0ID OPERATORS The solenoid on these valves operates within the first few seconds of the postulated accident.
It is highly unlikely that the harsh environment bas time to significantly affect their operation before they receive their safety signal and move to their safety position, which is de-energized. Once the solenoid is de-energized, there is no need for them to be re-energized for any action pertaining to safety. The most probable failure of a solenoid valve is a loss of power due to either a short or open in the coil which will cause the solenoid to fail in its safety positicn. Since qualification data has not been found to date, replacement solenoids have been purchased.
Continued operation is justified until installation since the probability of the postulated LOCA or a HELB occurring coupled with a failure of these solenoid valves to function as designed for that event prior to the next refueling outage is extremely remote.
2
2821-N006A-D, 2B21-N007A&B, 2B21-N008A-D and 2821-N009A-D The switches sense high flow in the main steam lines and cause an isolation in the event of a main steam line break. On a break, they will sense the flow and isolate the steam lines within 10 seconds. The temperature to which they will be subjected is less than the temperature to which test experience is available.
There is a high degree of probability that the switches will operate as designed and initiate an isclation signal.
If for some reason they do not operate the high ambient temperature switches will cause the MSIVs to close terminating the event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
3
2B21-N010A-D, 2821-N011A-D, 2B21-N012A-D, 2B21-N0013A-D These instruments are temperature switches which are designed to detect high ambient temperature and initiate an isolation of the main steam lines on high temperature. The instruments are randomly spaced in the main steam tunnel in order to assure that they will detect a break. Test data is available to show that the switches will operate at temperatures equal to their setpoint temperature. The data provides assurance that the switches will operate and cause the required main steam line isolation.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three(3) years. With this limited service this equipment is not expected to fail before replacement.
Baseo on the above, continued operation is justified.
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2B21-N017A-D Switches 2B21-N017A-D sense a low RPV level to provide scram initiation and trip the HPCI and RCIC turbines on high RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have serviced their function, to scram the reactor, prior to any significant irradiation of the device. On an HELB outside the drywell the instruments will be subjected to a harsh environment due to temperature. The instruments have test data to demonstrate that they will operate at temperatures up to the accident temperature.
The test experience has shown that the effect of the adverse environment is to decrease the accuracy of the instrument. The decrease in accuracy could cause the switch setpoint errcr to be approximately two (2) inches. The effect of this error is insignificant with respect to assuring adequate core cooling.
In addition, the racks on which these instruments are mounted are widely separate, therefore, there is a high degree of assurance they will operate mitigating the consequences of the event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.-
Based on.the above, continued operation is justified.
5
2821-N021A-F Switches 2B21-N021A-F sense RPV pressure and provide the low RPV pressure permissive signal for the low pressure ECCS systems.
These switches are redundant, diverse, separated and there is test documentation which provides a high degree of assurance that they will function. The test experience has demonstrated that the effect of the adverse environment is to decrease the accuracy of the instruments.
This decrea:e in accuracy could cause a setpoint error to be no more than 28 psi. The effect of this potential error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
I 6
1_-
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2B21-N024A&B, 2B21-N025A&B These instruments provide the signal which causes the isolation of the MSIVs on icw RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have served their safety function prior to any significant irradiation. On a HELB outside the drywell the instrument will be subjected to a harsh environment due to high temperature. There is a high degree of assurance that they will operate to serve their safety function since they have test data to show they will operate at the accident temperature. The test experience has shown that the potential affect of the adverse environment is to decrease the accuracy of the instrument. This decrease could cause the setpoint error to be no more than six (6) inches. The effect of this error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
7 j
i
2B21-N026A&B 2B21-N026A&B Level Indicating Transmitter Switch (LITS) provides control room indication of reactor vessel level.
Transmitters A&B provide indication readout on level instruments 2B21-R604A&B on panel H11-P603. These transmitters are Yarway model 4418CE. Transmitters C&D provide level recorder inputs to recorders 2B21-R623A&B on panel H11-P601. These transmitters are Barton 760 level indicating transmitter switches. The transmitters are located on racks H21-P004 and H21-P005 which could be affected by a RWCU HELB resulting in an ambient temperature transient peak of approximately 210 F.
They also could be affected by a LOCA event which may result in a total radiation exposure of 1.2 x 6
10 rads.
Even though the transmitter function of the Yarway 4418CE was not evaluated during temperature test, it may be assumed from the test data that the transmitter function would survive the harsh environment ano would provide an indication of vessel water level, albeit somewhat degraded, during and subsequent to the accident event. This engineering judgement is based upon the operating principle of the Yarway 4418CE LITS which uses a reliable magnetically actuated armature assembly and transmitting coil (LVDT) to provide a driving signal to a remote LVDT slave device. The same signal drives the local indicator read out properly during the test. The non-metallic materials used in the Yarway LITS have been reviewed and it appears that the minimum threshold of 6
damage in the radiation environment is approximately 10 rads.
In addition to the Yarway remote level indicators, the 2B21-N026A&B transmitters drive a remote recorder in the control room. These transmitters are Barton 760 devices for which no test data could be formed.
Since the Yarway transmitters driving the control room level indicators are expected to survive the harsh environment and since the Barton transmitters driving the control room level recorders are diverse instruments, the probability of having a water level indication in the control room throughout the accident event is high.
8
This piece of equipment has bcen used during normal operation in plants similar to1 Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three
_(3) years. With this limited service this equipment is not expected to fail
- before replacement.
Based on the above, continued operation'is justified.
t O
d 9
2B21-N027 This instrument measures the RPV level from the bottom of the dryer skirt to the top of the RPV head.
This instrument is only required to recover from the alternate shutdown cooling mode of plant operation. The instrument will be measuring on scale when in this mode of operation; therefore, the operator will know if the instrument is operating properly.
If the operator expects that the instrument has been degraded, the instrument will be replaced before, the recovery operation is started. While the reactor is being cooled in this mode it is in a safe and stable condition; therefore, the replacement method is considered acceptable.
1 1
[
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
0 10
2821-N031A-D These switches provide a signal which starts the high and low pressure ECCS systems on low RPV level.
In the unlikely event of a LOCA the instruments will be subjected to a harsh environment due to radiation but will have served their safety function prior to any significant irradiation. On a HELB outside the drywell the instrument will be subjected to a harsh environment due to high temperature. There is a high degree of assurance that they will operate to serve their safety function since they have test data to show they will operate at the accident temperature.
The test experience has shown that the potential effect of the adverse environment is to decrease the accuracy of the instrument. This decrease could cause the setpoint error to be no more than six (6) inches.
The effect of this error is insignificant with respect to assuring adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 1 for the past eleven (11) years. To date, no age related common mode failures have oeen reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
11
2B21-N036, 2B21-N037 These instruments provide a containment spray permissive signal and provide shroud water level indication. The accident analysis does not take credit for the containment spray function of the RHR system, therefore, the containment spray permissive function of the instruments is not required to assure plant safety.
The indication function of the instrument could be affected by the high radiation condition post LOCA.
If the indication becomes erratic or ambiguous, the operator will turn on all of the low pressure ECCS systems thus filiing the RPV and open one or more SRVs to allow the ECCS flow to spill out the relief valves to the suppression chamber. This operation assures adequate core cooling.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three(3) years.
With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
12 4
n 2821-N042A&B These instruments provide an ADS permissive signal on low RPV water level which is only required post LOCA. They will be subjected to a harsh environment due to radiation but will have served its safety function prior to any significant irradiation.
This piece of equipment has been used during normal operation in plants similar
- to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipnent is not expected to fail before replacement.
Based on the above, continued operation is justified.
13 I
m._
2B21-N051A&B This instrument measures RPV pressure, and is provided to give the operator additional information regarding plant performance.
No operator actions can be taken solely as a result of the information provided by this instrument which will effect the automatic operation of the ECCS systems and, therefore, reactor safety.
Test data is available for these devices to show that they will function properly in an environment with temperatures up to 150 F.
The maximum expected accident temperature in the area of these transmitters is 210'F due to a RWCU line break.
Since no improper operator action that can affect reactor safety will result from an incorrect vessel pressure indication, continued plant operation is justified.
This piece of equipment has been used during normal operation in plants similar 1
to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
e 14
2C71-N002A-D These instruments monitor drywell pressure and provide a scram signal on high I
drywell pressure.
These switches could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will sense a high pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of these switches is therefore satisfied.
'The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been sued during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
15.
e
2E11-N002A&B These instruments measure the P across the RHR Heat exchanger and provide a signal to the RHR service water outlet valve 2E11-F068A&B to regulate such that service water pressure is always greater than RHR system pressure.
The instrument may be subjected to a harsh environment due to temperature in the event of a HELB in the corner rooms where they are located but no credit is taken for the system operation in that compartment after a HELB.
The instrument could be subjected to a harsh envirc.nment due to radiation in the unlikely event of a LOCA. There is a high degree of assurance that the instrument will function as designed in this case since since the instrument has test data to show that it has operated as designed after being irradiated to a dose in excess of that which it will be subjected to after this event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
16
=
-t These instruments monitor drywell pressure and provide an ADS permissive signal on high drywell pressure.
These switches could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will sense a high pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of these switches is therefore satisfied.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacemen'..
Based on the above, continued operation is justified.
9 17
2 Ell-N011 A-D These instruments monitor drywell pressure and provide a signal to initiate the ECCS systems on high drywell pressure.
These switches could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will sense a high pressure and actuate very early in a LOCA event prior to any high radiation being present and will not have to function again. The safety function of these switches is therefore satisfied.
The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for past eleven (11) years. To date, no age related common mode failures have been reported.
These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
i 18
2E11-N015A&B These instruments provide the operator with confirmatory information to assure that the LPCI system is operating as designed.
No credit is taken for operator operation of these systems in the event of a line break which creates a harsh environment in the area where the instrument is located. Therefore, the instruments are not required after an HELB.
In the event of a LOCA, the instruments will be subjected to a harsh environment due to radiation. The instruments do not have any data to demonstrate their qualification in the high radiation environment but the operator will be able to verify proper automatic system operation prior to significant radiation degradation to the instruments.
In the event of erratic instrument behaviour, the operator will not take an action which will compromise safety based on this indication.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during nornal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above, continued is justified.
19
These instruments monitor the discharge pressure of the LPCI pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI system will receive its signal and start prior to any core uncovered. Once the switch has operated it does not have to function again to serve its safety function.
The switches could be subjected to a harsh environment due to temperature after a HELB but are nct required to assure plant safety after that event.
This piece of equipment has been used durir.g normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relative limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
20 b
2E11-N020A-D These instruments monitor the discharge pressure of the LPCI pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI system will receive its signal and start prior to any core uncovery. Once the switch has operated it does not have to function again to serve its' safety function.
4 The switches could be subjected to a harsh environment due to temperature after a HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
21
2E11-N021A&B These instruments monitor LPCI flow and provide the signal to close the LPCI minimum flow valves, 2E11-F007A&B, when system flow is high enough to protect the pumps.
The instruments could be subjected to a harsh environment due to radiation after a LOCA. However, generally, the LPCI pumps are in operation before core damage would be predicted to occur.
Further, for large breaks where total LPCI flow is significant to establishing reflooding time, the minimum flow valves would be closed before any potential radiation damage. Although analyses have not been performed it is expected this would also be true for small breaks.
Further for small breaks, total LPCI (or low pressure ECCS flow) is not significant in the reflooding calculation so that failure of the minimum flow bypass valve to close would not significantly affect core reflooding time.
Therefore, the instruments are expected to function sufficiently to assure adequate core cooling.
In the event of a HELB in the area where the instruments are located, no credit is taken for the systems in that compartment; therefore, the instruments are not required.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
22
2E21-N003A&B These. instruments provide the operator with confirmatory information to assure that the core spray system is operating as designed.
No credit is taken for operator operation of these systems in the event of a line break which creates a harsh environment in the area where the instrument is located. Therefore, the instruments are not required after an HELB.
In the event of a LOCA, the instruments will be subjected to a harsh environment due to radiation. The instruments do not have any data to demonstrate their qualification in the high radiation environnent but the operator will be able to verify proper automatic system operation prior to significant radiation degradation to the instruments.
In the event of erratic instrument behavior, the operator will not take an action which will compromise safety based on this indication.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service this equipment is not expected to fail before replacement.
Based on the above continued operation is justified.
i l
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23
2E21-N006A&B These instruments monitor core spray system flew and provide the signal to close the core spray pump minimum flow valves, 2E21-F031A&B, when system flow is high enough to protect the pumps.
The instruments could be subjected to a harsh environment due to radiation after a LOCA. However, generally the core spray pumps are in operation before core damage would be predicted to occur. Further, for large breaks where core spray flow may be significant to the core heatup calculation or reflooding time, the minimum flow valves would be closed before any. potential radiation damage.
Although analyses have not been performed it is expected this would also be true for small breaks. Further for small breaks, total core spray flow (or low pressure ECCS flow) is not significant in the reflooding calculation so that failure of the minimum flow bypass valve to close would not significantly affect core reflooding time. Therefore, the instruments are expected to function sufficiently to assure adequate core cooling.
In the event of an HELB in the area where the instruments are located, no credit is taken for the systems in that compartment; therefore, the instruments are not required.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
24
)
2E21-N008A&B These instruments monitor the discharge pressure of the core spray pumps to provide a signal to the ADS logic. This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI system will receive its signal and start prior to any core uncovery. Once the switch has operated, it does not have to function again to serve its safety function.
The switches could be subjected to a harsh environment due to temperature after an HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common made failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
25
2E21-N009A&B These instruments monitor the discharge pressure of the core spray pumps to provide a signal to the ADS logic.
This signal tells the ADS logic that a low pressure ECCS pump is running.
The instruments could be subjected to a harsh environment due ta radiation in the unlikely event of a LOCA. The switches will have operated to serve their safety function prior to any high radiation being present. This is based on the fact that the LPCI system will receive its signal and start prior to any core uncovery. Once the switch has operated it does not have to function again to serve its safety function.
The switches could be subjected to a harsh environment due to temperature after an HELB but are not required to assure plant safety after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related comon mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
26
2E41-C002 2E41-C002 is the HPCI turbine. The HFCI turbine could be subjected to a harsh environment due to temperature after a HPCI steam line break but no credit is taken for the operation of the HPCI turbine following a rupture of its steam supply line.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV level, the turbine may be subjected to hign radiation.
However, in this case the HPCI system is not required since the RPV will be depressurized by the break and/or the actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
e 27
2E41-C002-1, 2E41-C002-2, 2E41-C002-3 These components are HPCI turbine auxiliaries. The HPCI turbine auxiliaries could be subjectr' to a harsh environment due to temperature af ter a HPCI steam line break but no credit is taken for the operation of the HPCI turbine following a rupture of its steam supply line.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV level, the turbine may be subjected to high radiation.
However, in this case the HPCI system is not required since the RPV will be depressurized by the break and/or the actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
28 l
1
2E41-F012 Valve 2E41-F012 is the minimum flow valve for the HPCI pump.
In the event of a LOCA, the valve could be subjected to a harsh environment due to radiation. The minimum flow valve could be called upon to open at the time of system initiation on a large LOCA. The valve will not have been subjected to irradiation at that time and will operate as designed.
If the valve does not close the level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
In the event of a small break, the subject valve could be required to cycle on subsequent starts of the HPCI system.
If the HPCI system is required to cycle the break is small enough that the flow out the break is less than the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damage. Therefore, the source of the high radiation will not be present.
In the event of a HELB, the valve could be subjected to a harsh environment due to temperature and pressure, out the source of the harsh environment will be a HPCI steam line break and no credit is taken for the operation of the HPCI system af ter that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not e(pected to fail before replacement.
Based on the above, continued operation is justified.
29
2E41-N001A-D, 2E41-N004, 2E41-N005 These instruments monitor HPCI steam line pressure and flow. They provide an isolation signal on low pressure aad/or high flow in the event of a HPCI steam line break.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The accident analysis takes no credit for the operation of these instruments for the mitigation of a LOCA.
The instruments could be subjected to a harsh environment due to temperature in the event of an HELB. There is a high degree of confidence the switches will operate since there is test experience to demonstrate that the instruments will operate up to a temperature of 212*F which is only 2 F below the peak predicted temperature for the area where the switches are located. The subject switches will also operate prior to reaching that peak temperature and once they have operated, they will have served their safety function and will not have to operate again.
In addition, these switches are backed up by high temperature elements which will also cause an isolatirn signal to be generated.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
30
i 2E41-N006 2E41-N006 is the flow instrument which provides the singal which operates the minimum flow valve, 2E41-F012.
In the event of a LOCA, the instrument could be subjected to a harsh environment due to radiation. The instrument could be called upon to operate at the time of system initiation on a large LOCA. The instrument will not have been subjected to irradiation at that time and will operate as designed.
If the instrument does not operate the RPV level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
IN the event of a small break, the subject instrument could be required to cycle on subsequent starts of the HPCI system.
If the HPCI system is required to cycle the break is small enough that the flow out the break is less than the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damage. Therefore, the source of the high radiation will not be present.
In the event of an HELB the instrument could be subjected to a harsh environment due to temperature and pressure but the source of the harsh environment would be a HPCI steam line break and no credit is taken for the operation of the HPCI system after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
31
2E41-N008 This is a transmitter that provides control of the HPCI turbine control valve position to maintain design rated HPCI flow.
It also provides the control room with indication of HPCI pump flow.
The transmitter is not subjected to a harsh environment for any HELB except the HPCI system steam line break, and no credit for the HPCI system is taken for this break.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV level, the transmitter may be subjected to high radiation. However, in this case, the HPCI system is not required since the RPV will be depressurized by the break and/or actuation of the ADS system.
Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the radiation environment is not present.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
32
2E41-N010 This instrument monitors HPCI pump suction pressure and initiates a pump trip on low suction pressure.
The instrument is not subjected to a harsh environment for any HELB except the l
HPCI system steam line break, and no credit for the HPCI system is taken for this break, l
In the event cf a large break LOCA for which the HPCI system cannot maintain RPV level, the instrument may be subjected to high radiation.
However, in this case, the HPCI system is not requried since the RPV will be depressurized by the t
break and/or actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the I
radiation environment is not present.
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j This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fall before replacement.
Based on the above, continued operation is justified.
1 33
2E41-N012A-D These instruments monitor the pressure between the rupture disks off the turbine exhaust line and initiate a turbine trip if the inboard rupture disk fails. The purpose of the instrument is to trip the turbine if the exhaust line becomes blocked.
Such a blockage is extremely unlikely so the switch should never be req'uired to function.
In the highly unlikely event of such a blockage, line overpressurization would occur very early in the operation of the turbine, before the occurrence of a harsh e.vironment from any LOCA or HELB.
Therefore, the switch would be expected to function.
The. possibility of inadvertent actuation exists due to high radiation associated with a large LOCA for which HPCI cannot maintain RPV level.
In this case HPCI is not required since the reactor would be depressurized by the break and/or ADS l
and core cooling will be provided by the low pressure ECCS systems.
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l This piece of equipment has been used during normal operation in plants similar l
to Hatch 2 for the past eleven (11) years. To date, no age related coninon mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
i 34
2E41-N015A&B These instruments are level switches and monitor the suppression chamber level and provide a signal to the HPCI suction valves, 2E41-F042, 2f.41-F041 and 2E41-F004 to switch the HPCI suction source # rom the confer.! a te storage tank to the suppression chamber.
In the event of a LOCA, the instruments will be subjected to a harsh environment due to radiation. However, fnr any event Mr which the HPCI suction transfer is required, the transfer will be completed prior to the occurrence of any fuel damage. Therefore, the subsequent occurrence of high radiation is nct a concern and the instrument is expected to function as required.
i In the event of a HELB, the instruments will be subjected to a harsh environment due to temperature. These instruments are widely used throughout the industry for boiler level control at temperatures far in excess of those to which it will be subjected during the postulated HELB. Therefore, there is a high degree of assurance that they will function as required.
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This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode l
failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
35
2E41-N017A&B These instruments monitor the HPCI turbine exhaust pressure and initiate a trip signal on high pressure.
The instruments are not subjected to a harsh environment or any HELB except the HPCI system steam line break, and no credit for the HPCI system is taken for this break.
In the event of a large break LOCA for which the HPCI system cannot maintain RPV l
1evel, the instruments may be subjected to high radiation. However, in this case the HPCI system is not required since the RPV will be depressurized by the break and/or actuation of the ADS system. Adequate core cooling is then provided by the low pressure ECCS systems.
l In the event of a small break LOCA for which the HPCI system can maintain RPV level, the core never uncovers and hence core cooling is maintained and the l
radiation envircnment is not present.
l This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode j
failures have been reported. These devices have experienced relatively limited
(
service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
l Based on the above, continued operation is justified.
36 l
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-2E41-N027 2E41-N027 is a pressure switch which senses HPCI pump operation and permits the minimum flow valve, E41-F012, to open if the system is operating and the flow is low.
In the event of a LOCA the instrument could be subjected to a harsh environment due to radiation. The instrument could be called upon to operate at the time of system initiation on a large LCCA. The instrument will not have been subjected to irradiation at that time and will operate as designed.
if the instrument does not operate, the RPV level could drop but the ADS system concurrent with the low pressure ECCS systems will assure adequate core cooling.
In the event of a small break the subject instrument could be required to cycle the break is small enough that the flow out the break is less than the HPCI flow in which case the core will not have been uncovered.
If the core is not uncovered, it is not credible to assume core damage; therefore, the source of the high radiation
.will not. be present.
In the event of a HELB the instrument could be subjected to a harsh environment due'to temperature and pressure but the source of the harsh environment will be e HPCI steam line break and ne credit is taken for the operation of the HPCI system after that event.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years.
To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
37
2E41-NO30A&B, 2E41-N046A&B, 2E51-N025C&D, 2E51-N026C&D, 2E51-N027C&D These instruments are temperature sensors which monitor temperatures in areas where the HPCI steam line is located and initiate an isolation-signal in the event of a steam leak in the HPCI steam line.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. No credit is taken in the accident analysis for the operation of these switchc: for the mitigation of a LOCA.
If the switches misoperated due to a high radiation failure the HPCI system could be unnecessarily isolated. This does not cause a condition which compromises plant safety since the ADS system in conjunction with the low pressure ECCS systems will provide adequate core cooling.
In the event of a HELB the instruments could be subjected to a harsh environment due to temperature and pressure. A high degree of confidence exists that the instruments will operate to isolate the HPCI steam line break since test experience shows that the switches will operate up to a test temperature of 212*F. The setpoint of these switches is 170*F which is well below the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
38
2E51-N012A-D These instruments monitor the pressure between the rupture disks off the turbine exhaust line and initiate a turbine trip if the inboard rupture disk fails.
The purpose of the instrument is to trip tt'e turbine if the exhaust line becomes blocked. Such a blockage is extremely unlikely so the switch should never he required to function.
In the highly unlikely event of such a blockage, line over-pressurization would occur very early in the ope:'ation of the turbine, before the occurrence of a harsh environment from any LOCA or HELB. Therefore, the switch would be expected to function.
The possibility of inadvertent actuation causing a RCIC System isolation exists but.no credit is taken for the operation of the RCIC syste.o in the accident analysis.
This piece of equipment has been used during nornial operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
39
2E51-N019A-D, 2E51-N017, 2E51-N018 These instruments monitor RCIC steam line pressure and flow. They provide an isolation signal on low pressure and/or high flow in the event of a RCIC steam line break.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA. The accident analysis takes no credit for the operation of the RCIC System for the mitigation of a LOCA.
The instruments could be subjected to a harsh environment due to temperature in the event of a HELB. There is a high degree of confidence the switches will operate up to a temperature of 212*F which is only 2 F below the peak predicted temperature for the area where the switches are located.
The subject switches will also operate prior to reaching that peak temperature and once they have operated they will have served their safety fucction and will not have to operate again.
In addition, these switches are backed up by high temperature elements which will also cause an isolation signal to be generated.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
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2E51-N021A&B, 2E51-N022A&B, 2E51-N023A&B, 2E51-N025A&B, 2E51-N026A&B, 2E51-N0278B These instruments are temperature sensors which monitor temperatures in areas where the RCIC steam line is located and initiate an isolation signal in the event of a steam leak in the RCIC steam line.
The instruments could be subjected to a harsh environment due to radiation in the unlikely event of a LOCA.
No credit is taken in the accident analysis for the operation of these switches for the mitigation of a LOCA.
In the event of a HELB the instruments could be subjected to a harsh environment due to temperature and pressure. A high degree of confidence exists that the instruments will operate to isolate the HPCI steam line break since test experience shows that the switches will operate up to a test temperature of 212'F. The set point of these switches is 170*F which is well below the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related consnon mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail-before replacement.
Based on the above, continued operation is justified.
41
2G31-NO36, 2G31-N012, 2G31-N041 These instruments measure the flow for the RWCU system.
These instruments will be subjected to a harsh environment due to high tempeMture on a break in the RWCU system. The instruments will sense the break I
flow condition prior to being subjected to a temperature in excess of that for which we have test experience. Therefore, there is a high degree of confidence that they will function as intended and send a signal which isolates the break.
Once the signal is initiated, the instrument has served its safety function, in addition, the temperature in each room is monitored by temperature sensors which will cause an isolation signal to be generated on high temperature.
In the event of a LOCA these instruments are not required for accident mitigation.
This piece of equipment has been used during normal operation in plants similar l
to Hatch 2 for the past eleven (11) years. To date, no age related common mode l
failures have been reported. These devices have experienced relatively limited l
service in Hatch 2 as they have been used during normal operation for only three (3) years. With this limited service, this equipment is not expected to fail before replacement.
Based on the above, continued operation is justified.
l 42 i
i 2G31-N016A-F, 2G31-N022A-F, 2G31-l.023A-F i
These instruments are temperature sensors which monitor ternperature in areas
}
where the RWCU piping is located and initiate an isolation signal in the event j
I of a leak.
i These instruments could be subjected to a harsh environment due to radiation in the event of a LOCA. No credit it taken for the operation of these switches for the mitigation of a LOCA.
[
i In the event of a HELB the instruments could be subjected to a harsh environtrent due to temperature and pressure. A high degree of confidence exists that the I
instruments will operate to isolate the RWCU line since test experience shows 1
that the switches will operate up to a test temperature of 212'F. The set point of these switches is substantially less than the temperature for which test experience exists.
This piece of equipment has been used during normal operation in plants similar to Hatch 2 for the past eleven (11) years. To date, no age related common mode failures have been reported. These devices have experienced relatively limited service in Hatch 2 as they have been used during normal operation for only three l
(3) years. With this limited service, this equipment is not expected to fail l
before replacement.
l Based on the above, continued operation is justified.
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i 43 e
r ATTACHMENT 2 METHODOLOGY TO IDENTIFY EQUIPMENT WITHINTHESCOPEOF10CFR50.49(b) RULE FOR l
l E. 1. HATCH PLANT UNITS 1 & 2 l
10CFR 50.49(b) requires that equipment required to assure the integrity of the reactor coolant pressure boundary, assure the capability to shutdown the reactor and to mitigate the consequences of accidents which could result in potential offsite exposures comparable to the 10CFR Part 100 limits be considered as part of the environmental qualification program.
The rule further requires that support equipment and some post accident monitoring equipment be included within the scope of the quellfication effort.
Georgia Power has approached the qualification effort in a deliberate and l
systematic manner.
From the onset, the approach taken to identify equipment has met the requirements as outlined in 10CFR 50.49.
The various steps taken within the equipment identification process are outlined j
below:
1.
An engineering task force comprised of senior engineering personnel familiar with the operation of Plant Hatch reviewed all plant systems i
and identified which systems would be required to mitigate the consequences of HELB or LOCA events.
The location of the components as well as their safety status was not considered in the selection of the Master List of components.
In addition, support equipment for the Master List components was identified and included during the initial task force effort.
1
ATTACHMENT 2 Documents utilized for this review included the plant P& ids, appropriate plant operating and emergency procedures plant Technical Specifications, the FSAR and to some extent the proposed BWR emergency procedure guidelines.
2.
The Master List was reviewed by a third party organization which is familiar with the operation of Plant Hatch.
5.
To gain further assurance that the Master List was comprehensive, Georgia Power operations department reviewed and concurred with the list.
Upon completion of the above noted series of evaluations the Master List components were located to determine their inplant location.
Equipment located in a harsh environment and required to operate for the event which created the harsh environment was considered part of the qualification effort.
In addition, any component part of the equipment which is included in the master list and located in a harsh environment and required to function was included.
During this effort essential equipment was used to the maximum extent possible; however, the safety classification (safety related or not safety related) of equipment was not a prerequisite for selecting equipment.
If equipment was.
required it was listed as is required by 10CFR 50.49(b.2).
It can be easily seen by the above that equipment considered ir, the E. I. Hatch Nuclear Plant qualification effort fully meets the requirements of 10CFR 50.49.
It should be noted that the issuance of the 100FR 50.49 rule did not required that Georgia Power Company add any equipment to the qualification program.
-All design modifications to Plant Hatch are reviewed to determine if the qualification program is affected by the design modification.
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I_
'10CFR 50.49(b.3) requires that certain post-accident monitoring equipment be included in the qualification program.
Specifically Category 1 and 2 instruments.as defined in Reg. Guide 1.97 Rev. 2 are required to be qualified per NUREG-0588. Georgia Power Ccmpany recongnizes this requirement.
The Reg.
Guide'1.97 issue is being resolved under a separate schedule and, when i
. resol'ved, any additiona1' instrumentation will.be considered within the scope of
'the environmental qualification program.
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