ML18192B173
| ML18192B173 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/07/1978 |
| From: | Van Brunt E Arizona Public Service Co |
| To: | Boyd R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML18192B173 (6) | |
Text
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REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
DISTRIBUTION FOR INCOMING MATERIAL 50-528/529/530 REC:
BOYD R S
ORG:
VAN BRUNT E E DOCDATE: 07/ 7/78 AZ PUB SVC DATE RCVD:
/12/78 DOCTYPE:
LETTER NOTARIZED:
YES
SUBJECT:
FORWARDING ADDL INFO AS REQUESTED BY NRC CONCERNING QUALIFICATION REVIEW FOR SUBJECT FACILITY ITEM 3. 32 POSITION 2 "INTERACTION OF ONSITE
<STANDBY)
PWR SOURCES WITH SHED FEATURF... NOTARIZED 07/07/78.
PLANT NAME: PALO VERDE UNIT 1
PALO VERDE UNIT 2 PALO VERDE UNIT 3 REVIEWER INITIAL:
XJM DISTRIBUTER INITIAL:~
DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS NOTES:
STANDARDIZED PLANT PSAR/FSAR AMDTS AND RELATED CORESPONDENCE (DISTRIBUTION CODE B001)
FOR ACTION:
INTERNAL:
EXTERNAL:
ASST DIR VASSALLO++LTR ONLY PROJ MGR ANGELO44W/ENCL EG FILE+4W/EN NCL OPERATOR LIC BR++W/ENCL QABu~W/ENCL MIPC++LTR ONLY MECH ENG BR+wW/ENCL MATERIAL ENG,BR++W/2 ENCL REACTOR SYSTEMS BR+4W/ENCL CORE PERFORMANCE BR+~W/ENCL AUXILIARYSYS BR++W/ENCL I 5 C SYSTEMS BR++W/ENCL AD FOR SITE TECH44W/4 ENCL ACCIDENT ANALYSIS++W/ENCL RAD ASSESSMENT BR++W/ENCL GEOSCIENCES BR+4W/ENCL LPDRiS PHOENIX'Z+4W/ENCL TERA>4W/ENCL NSIC+4W/ENCL ACRS CAT B+~W/ih ENCL BR CHIEF LWRNi BC4~LTR ONLY LIC ASST LWR81 LA~~LTR ONLY NRC PDR++W/ENCL OELD+4LTR ONLY EMERGENCY PLAN BR>>W/ENCL DIRECTOR NRR+%LTR ONLY AD FOR ENG++LTR ONLY STRUCTURAL ENG BR<<W/ENCL AD FOR REAC SFTY+>LTR ONLY ANALYSIS BR++W/ENCL AD FOR PLANT SYSTEMS~+LTR ONLY CONTAINMENT SYSTEMS44W/ENCL POWER SYS BR>+W/ENCL AD FOR SITE ANLYS~<LTR ONLY EFFLUENT TREAT SYS+>W/ENCL KIRKWOOD++W/ENCL DISTRIBUTION:
LTR 57 ENCL 47 SIZE:
1P+1P CONTROL NBR:
781930050
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II nr
P. O. BOX 2I666
'HOENIXs ARIZONA 85036 July 7, 1978 ANPP-11315-JMA/DBK s
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Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C.
20555 Attn:
Re:
Roger S. Boyd, Director Division of Project Management Palo Verde Nuclear Generating Station Units 1, 2
g 3 Docket Nos:
SBl-50-528/529/530
Dear Sir:
As requested by your staff, submitted herewith as Attachment 1 is additional information concerning the Qualification Review for Palo Verde Nuclear Generating Station Units 1, 2 5 3, Item 3.32, Position 2, "Interaction of Onsite (Standby)
Power Sources with Shed Feature."
Respectfully submitted, ARIZONA PUBLIC SERVICE CG~PANY BY:
Edwin E. Van Brunt, Jr.
Vice President Construction Projects On its own behalf and as agent for all other joint applicants STATE OF ARIZONA
)
) ss County of Maricopa )
Subscribed and sworn to before me this Z day of July, 1978.
Nota Public My Commission Expires:
781P300g0
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t Attachment 1
Additional Information Concernin PVNGS Qualification Review Item E.32 Position 2
Load shedding of the Class IE 4.16kv bus is initiated. by detection of undervoltage on this bus using a two-out-of-four coincidence logic of undervoltage relays.
Section 8.3.1.1.2.11.B of the PVNGS PSAR sum-marizes the design and setpoint criteria for these relays.
The load shed signal is a single one second pulse generated upon detection of an undervoltage occurrence.
This pulse acts to (1) shed all loads directly connected to the Class IE 4.16kv bus and (2) trip the Class IE 4.16kv bus preferred (oHsite) power supply breaker.
This second action isolates the Class IE onsite power system, including the undervoltage relays, from the offsite power system.
There is, therefore, no possibility of subsequent interaction between the load shed and the offsite power system.
The return of the Class IE 4.16kv bus to oHsite power must be done manually.
After load shed, tripping of the Class IE 4.16kv bus oHsite supply breaker and subsequent closing of diesel generator breaker to the Class IE'.16kv bus, the undervoltage relays monitor the standby (onsite) power supply for an undervoltage occurrence.
Should an undervoltage occur, the Class IE 4.16kv loads are shed and the loading sequence restarted.
As the undervoltage relays are transferred with the Class IE 4.16kv bus from oHsite (preferred) to onsite (standby) power on a loss of oHsite power, no by pass of these relays to prevent interaction of oHsite power with the shed feature. is required.
In addition, as stated in PSAR Section 8.3.1.1.2.11.9'.6, the technical specifications will include minimum and maximum trip setpoints for the undervoltage relays.
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