ML20062C432
| ML20062C432 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/28/1982 |
| From: | John Marshall ARKANSAS POWER & LIGHT CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20062C418 | List: |
| References | |
| REF-SSINS-6820 ICAN058214, ICAN58214, IEB-80-06, IEB-80-6, NUDOCS 8208050251 | |
| Download: ML20062C432 (14) | |
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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK ARKANSAS 72203 (501) 371-4000 May 28, 1982
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1CAN058214 JLN 21982 Mr. John T. Collins
!d Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011
Subject:
Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Reevaluation of Response to IEB 80-06 Gentlemen:
Our April 16, 1982, letter 2CAN048208 committed to a reevaluation of our Unit 1 IE Bulletin 80-06, " Engineered Safeguards Features (ESF)
Reset Controls," response.
We subsequently committed to accomplishing this task by May 30, 1982, in a telephone conversation with your staff on April 23, 1982.
The reevaluation of our previous Unit 1 response to IEB 80-06 was very similar to our Unit 2 reevaluation.
The actions completed on our reevaluation for Unit 1 are as follows:
A.
An Engineering review of all Unit 1 electrical schematics to identify all ES components has been conducted and a listing of all safety related components receiving ES signals compiled in the same manner and format as the Unit 2 reevaluation.
B.
The identification and listing of all ES components were examined to determine what categories these components would fit in.
(The categories are the same as those used in the April 16, 1982 letter.) Categories are as follows:
8208050251 820723 PDR ADOCK 05000313 G
PDR MEMBER MIDDLE SOUTH UTILITIES SYSTEM
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Safety Flyback Modification Modification Documented l l
Related Feature Required Complete Testing i
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l CATEGORY 1 Yes Yes Yes Yes Yes l
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l CATEGORY 2 Yes Yes No No No*
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l l CATEGORY 3 Yes No No No No*
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l l CATEGORY 4 Yes Yes Yes No No*
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I I CATEGORY 5 No NA NA NA Not l
l Required l l
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- Existing documentation does not provide reasonable assurance that l
l testing was performed.
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l is a listing of all Category 1 components.
These components were previously modified.
Existing documentation provides reasonable assurance that testing has been conducted to verify effective corrective action. is a listing of components that receive ES signals and were not tested as part of the original Unit 1 IEB 80-06 testing.
These components were identified as IEB 80-06 components, however, the testing of these components was not accomplished with the other IEB 80-06 components.
The testing of these components was credited to the Unit 1 Integrated ES Test, Procedure 1305.06.
Although there are no individual signoffs addressing "Flyback" in the Integrated ES Test, the test could not have been successfully completed had any of these components exhibited "Flyback" characteristics as an unacceptable station 480V blackout would have occurred.
Therefore, credit for testing for "Flyback" characteristics was taken for these components.
In order to provide a step by step procedure and specific documentation of the testing of these components, a permanent change (PC-8) to Procedure 1409.10 has been implemented and the testing performed during the current Unit 1 outage.
This current test confirmed that no "Flyback" characteristics were exhibited by these components.
Thus, these components are considered Category 1 items. is a listing of all Category 2 components followed by a component by component evaluation / justification for allowing these components to continue to flyback. is a listing of all Category 5 components.
These components are non-safety components which receive ES signals.
These components were identified during this reevaluation and are outside the scope of IE Bulletin 80-06.
No Category 3 or Category 4 items were identified on our reevaluation of IE 80-06 for Unit 1.
Safety evaluations have been completed on all Category.2 and Category 5 items and are attached.
No further testing or modifications are required for Unit 1 to meet the requirements of IE Bulletin 80-06.
Very truly yours, Q,L 2 WA OL John R. Marshall JRM/jp
- Attachments l
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ATTACHMENT 1 CATEGORY 1 COMP 0NENT DESCRIPTION CV2214 Letdown Coolers Isolation Valve CV6203 Reactor Building Chilled Water Isolation Valve CV1065 Quench Tank Condensate Isolation Valve CV1667 Nitrogen System Isolation Valve CV6202 Chilled Water Isolation Valve CV2100 Penetration Room Isolation Valve CV2101 Penetration Room Isolation Valve CV2102 Penetration Room Isolation Valve CV2103 Penetration Room Isolation Valve CV2104 Penetration Room Isolation Valve CV2105 Penetration Room Isolation Valve CV2106 Penetration Room Isolation Valve CV2107 Penetration Room Isolation Valve CV2108 Penetration Room Isolation Valve CV2111 Penetration Room Isolation Valve CV2112 Penetration Room Isolation Valve CV2113 Penetration Room Isolation Valve CV2114 Penetration Room Isolation Valve CV2115 Penetration Room Isolation Valve CV2116 Penetration Room Isolation Valve CV7446 Post Accident Sampling System Gas Isolation Valve SV7510 PASS Sample Valve SV7512 PASS Sample Valve SV7454 PASS Sample Valve SV7456 PASS Sample Valve i
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i A301 B5 Feeder Breaker A310 A3 to A4 Bus Tie A401 B6 Feeder Breaker i
'A410 A4 to A3 Bus Tie B512 B5 Main Breaker
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B513 B5 to B6 Bus Tie 1
B612 B6 Main Breaker l
B613 B6 to B5 Bus Tie i
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ATTACHMENT 3 CATEGORY 2 COMP 0NENT DESCRIPTION P34A Decay Heat Flow Low Alarm P34B Decay Heat Flow Low Alarm P36A Lube Oil Pressure Auto Control P36B Lube Oil Pressure Auto Control P36C Lube Oil Pressure Auto Control P35A Pump Failed On ES Alarm P35B Pump Failed On ES Alarm CRM023 Load Disconnecting Control DG #1 Relay CRM024 Load Disconnecting Control DG #2 Relay l
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I COMPONENTS P34A Low Flow Alarm P34B Low Flow Alarm ES Channels 3 and 4 COMP 0NENT FUNCTION Contacts close on ES #3 and ES #4 to permit a low decay heat removal flow alarm on Loop A and Loop B on the computer to come in if needed.
QF:
Yes CATEGORY:
2 SAFETY IMPLICATION These alarms are designed to flyback upon reset of the ES signal.
Decay heat removal flow is not in 'peration during normal operation.
Only when in the shutdown cooling mode or the ES mode is decay heat removal required.
If the alarms did not flyback, a continuous low flow alarm would come in when decay heat removal was not in operation. The only effect of alarm flyback failure would be an unnecessary alarm.
CONCLUSION No reduction in the margin of safety as it relates to the public health and a
safety is involved.
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3 COMP 0NENTS P36A P36B j
P36C ES Channels 1 and 2 COMP 0NENT FUNCTION
. q, P36A Primary Makeup Pump Lube Oil Pressure Auto Control P36B Primary Makeup Pump Lube Oil Pressure Auto Control P36C Primary Makeup Pump Lube Oil Pressure Auto Control QF:
Yes CATEGCRY:
2 SAFETY IMPLICATION The lube oil pressure control is provided to prevent damage to the makeup pumps in the event of low lube oil pressure.
Upon ES actuation the low pressure control is bypassed.
7 Upon reset of an ES signal, the pressure control is reinstated.
However, the makeup pumps would continue to run provided low lube oil pressure did not exist.
Reinstatement of the low pressure control would not impair operator response to the initiating event.
CONCLUSION No reduction in the margin of safety as it relates to the public health and safety is involved.
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3 COMPONENTS P35A Failed on ES Alarm P35B Failed on ES Alarm j
ES Channels 7 and 8 i
COMP 0NENT FUNCTION Provide an alarm on failure of pump start.
QF:
Yes CATEGORY:
2 SAFETY IMPL CATION The realtor, building spray pumps receive a start signal on ES, and if the pumps fail to star,t,' after a time delay, the " failed on ES" alarm will come in.
On reset of an 65 signal, the alarm would clear if it had come ip.
- However, the operator would have already verified that at ',-t one spray pump was running or tried/to start the failed pump.
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- ps were started by the operjitor, the alarms would clear before the E5 s.,ai was reset.
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r Clearin'g of the alarms, on reset of, ES,*would not' impair operator respense to4-i the initiating event.
f CONCLUSION No reduction in the margin of safety as it relates to the public health and safety is involved.
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J CRM023 Load Distbn'n'ecting Control DG #1 Relay
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Channels 1 and 2 c.O,,
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These relays provide logic,to,the non essential loads for load shedding during f
loading of the diesel gene,rators,on Es ectuation.
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QF:
Yes CATEGORY:
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SAFETY IMPLICATION.
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These reiIys are norma 11s de-e.nergized'and become energized by an auxilia y relay frcy the diesel generator autt sta'rt, circuits. on aa ES actuation.
The diesel tenerator output breakers must clot,e to complete the load shedding. Upon reset o nan ES s'ignal, the relays'will f)yback to arm the' circuit for Lanother ES actuation.
Critical loadg yould'have'already see,benced onto_the FS buses at the t m' of ES reset.
Auto re-appi.:ation of non-ES loads at this' time would ie net result in Es bus voltage degradu ion!
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l CONCLUSION,
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iNo reduction in the margin of safety as it relates to the public health'and safety 'is i'r.volved.
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ATTACHMENT 4 CATEGORY 5 COMPONENT DESCRIPTION A112 Unit Auxiliary Al Feeder Breaker A212 Unit Auxiliary A2 Feeder Breaker C2A Instrument Air Compressor C2B Instrument Air Compressor P64A Primary M/V Pump Auxiliary Lube Oil Pump P648 Primary M/U Pump Auxiliary Lube Oil Pump P64C Primary M/V Pump Auxiliary Lube Oil Pump P40A Spent Fuel Pool Circ. Pump P40B Spent Fuel Pool Circ. Pump VCH2A Control Room Chiller VCH2B Control Room Chiller l
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h COMPONENTS A112 Unit Auxiliary Al Feeder Breaker A212 Unit Auxiliary A2 Feeder Breaker ES Channel 1 and 2 COMP 0NENT FUNCTION Interposing relays provide logic to the breakers for selective load shed on ES actuation in order to assure a high degree of integrity of off-site power sources, if available, to serve safeguards buses.
QF:
No CATEGORY:
5 SAFETY IMPLICATION Auto reset of the ES actuated relays in the non-class 1E breaker schemes on ES reset does not result in automatic re-application of the loads removed.
Loads would be re-applied as necessary by direct operator action.
Such manual re-application of non-ES loads would follow any ES bus load sequencing and therefore would not result in ES bus voltage degradation.
1 CONCLUSION Since no actual loads are re-applied following an ES reset from load shed relay flyback, no reduction in the margin of safety as it relates to the public health and safety is involved.
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r COMPONENTS VCH2A, VCH2B Control Room Chillers P64A, P648, P64C Makeup Pump Auxiliary Lube Oil Pump P40A, P40B Spent Fuel Pool Circ. Pump ES Channels 1 and 2 COMPONENT FUNCTION Interposing relays are actuated by ES to load shed selected loads to provide higher integrity of off-site power sources for feeding safeguards buses.
QF:
No CATEGORY:
5 SAFETY IMPLICATION Flyback of the interposing relays allows the loads shed to be re-applied by operator action.
Critical loads would have already sequenced onto the ES buses at the time of ES reset, and re-application of loads to off-site power sources are under direct operator control after situation assessment.
CONCLUSION Since none of these loads previously shed on ES will be automatically re-applied on ES reset, no reduction in the margin of safety as it relates to the public health and safety is involved.
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COMPONENTS C2A, C2B Instrument Air Compressor ES Channels 1 and 2 COMPONENT FUNCTION These compressors are normally running and are load shed on ES actuation to provide higher integrity for ES bus sequence loading.
QF:
No CATEGORY:
5 SAFETY IMPLICATION The compressors are powered from ES 480V buses and are load shed on ES actuation and diesel loading.
C2C instrument air compressor is powered from a non-ES bus and is not shed if off-site power is available.
C2A and C2B are designed to restart (flyback) on reset of an ES signal.
Critical loads would have already sequenced onto the ES buses at the time of ES reset, and automatic re-application of loads to ES buses would not result in ES bus voltage degrada-tion.
On loss of off-site power and loss of C2C, the operator would take manual control and start one or both compressors by direct operator actions.
CONCLUSION Since manual or automatic re-application would not result in ES bus voltage degradation, no reduction in the margin of safety as it relates to the public health and safety is involved.
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