ML17298B600
| ML17298B600 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 12/07/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| ANPP-31366-EEVB, NUDOCS 8412110036 | |
| Download: ML17298B600 (20) | |
Text
REGULATOR INFORM'/ATION DISTRIBUTION TEM (R IDS)
ACCESSION NBR o 8012110036 DOC ~ DATE: 84/12/07 NOTARI'ZED:
YES FACIL:STN-50-528 Palo Verde Nuclear Station~
Unit ii Arizona Publi STN 50-529 Palo Verde Nuclear Stations Unit 2i Ar izona Publi STN 50-530 Palo Verde Nuclear Stationr Unit 3~
Ar izona Publi AUTH BYNAME AUTHOR AFFILIATION VAN BRUNTiE ~ E, Arizona Public Ser vice Co ~
RECIP ~ NAME RECIPIENT AFFILIATION KNIGHTONgGeW, Licensing Branch 3
SIZE:
/
DISTRIBUTION CODE:
B002D COPIES RECEIVED:LTR ENCL TITLE: Licensing Submittal: Fire Protection NOTES:Standardized plant.
Standardized plant.
Standardized plant
~
SUBJECT:
Forwards response to 841113 request for addi info re App R
supr ious actuation evaluation,Fol lowing reactor tr ip~at leaast 8
h of charging w/unbor ated water can occur w/o loss of subcritical conditions'OCKET 05000528 05000529 05000530 05000528 05000529 05000530 RECIPIENT ID CODE/NAME NRR LB3 BC COPIES LTTR ENCL 1
1 RECIPIENT ID CODE/NAME LICITRAg E 01 COPIES LTTR ENCL:
1 1
INTERNAL: ACRS ELD/HDS3 NRR HEG FILE EXTERNAL: LPDR NSIC 10 B
06 0Q 03 05 6
6 1
0 2
2 1
1 1
1 1
1 ADM/LFMB IE F ILE NRR/DSI/ASB RGN5 NRC PDR NTIS 07 02 0
1 1
1 1
1 1
1 1
1 1
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL 18
p P
I
Arizona Public Service Company D
ANPP-31366-EEVB/WFQ/KLM December 7,
1984 Director of Nuclear Reactor Regulation Attention: Mr. George W. Knighton, Chief Licensing Branch No.
3 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2 and 3
Docket Nos. STN-50-528/529/530
- 10CFR50, Appendix R Spurious Actuation Analysis File:
84-056-026; G.1.01.10
Reference:
(.1) Letter to G.W. Knighton, NRC, from E.E.
Van Brunt, Jr.,
APS, dated November 13, 1984;
Subject:
- 10CFR50, Appendix R, Spurious Actuation Analysis.
(2) Letter to E.E. Van Brunt, Jr., APS,from G.W. Knighton, NRC, dated December 4, 1984;
Subject:
Request for Additional Information - Palo Verde Spurious Actuation Evaluation.
Dear Mr. Ynighton:
Reference (2) requested additional information on the PVNGS Spurious Actuation Evaluation.
Attached are the responses to your questions.
It is our understanding that these responses will satisfy your concerns and thus close this issue.
If you should have any questions, please contact Mr. William F. guinn of my staff.
Very truly yours, KZ.U~~(~
E. E.
Van Brunt, Jr.
FEVBJr/KLM/no Attachment cc:
E.A. Licitra w/a
'A.C. Gehr w/a R.P.
Zimmerman w/a g4$ Qff0036 84>~07 PDR ADOCK 05000528 PDR APS Vice President Nuclear Production ANPP Project Director p+
ANPP-31366 STATE OP ARIZONA
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) ss.
COUNTY OP kfARICOPA)
I, Donald B. Karner, represent that I am Assistant Vice President, Nuclear Production of Arizona Public Service
- Company, that the foregoing document has been signed by me on behalf of Arizona Public Service Company with full authority to do so, that I have read such document and know its
- contents, and that to the best of my knowledge and belief, the statements made therein are true.
Donald B. Karner Sworn to before me thfe~bk day of
~iobr, 1984.
Notary Public My Commission Expires:
My C lssion aqlres Ap ll 6 1987
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ENCLOSURE 1
RESPONSE
TO NRC REQUEST FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION UNITS 1, 2
AND 3 APPENDIX R SPURIOUS ACTUATION ANALYSIS NRC QUESTION 1
In Revision 1 to the Outside Control Room Fire Spurious Actuation Study, Fire Areas 1, 3a, 2, 38, and 68 have no findings reported and have been deleted from the report.
The original version of the report contained findings for these areas.
Provide the reasons for deleting these fire areas in Revision l.
RESPONSE
The only finding in Fire Zones 1, 2, 3A and 38 was "loss of CST volume due to spurious opening of the EC System makeup valve".
Evaluations have shown that if the.Essential Chilled (EC) expansion tank makeup valve were to spuriously open, the condensate transfer pump does not have sufficient head to lift the system relief valves.
Therefore, there is no loss of CST volume through this path.
Note that the loss of CST volume is still a concern for spurious openings of the EW and DG makeup valves.
f Further detailed circuit evaluation in Fire Zone 68 eliminated the original finding as a concern.
NSSS ESFAS occurrence was eliminated, and the BOP ESFAS concern was determined acceptable (as defined by the updated assumption No.
17 of the Outside Control Room Spurious Actuation Study report).
1 k
ll
I
NRC QUESTION 2 For Fire Area 50-B in Table 3-1, the reader is advised to see the findings for this area;
- however, the body of the report does not contain any dis-cussion on Fire Area 50B.
Explain this discrepancy.
RESPONSE
The findings for Fire Zone 50B are located on page 89 of the Outside Control Room Fire Spurious Actuation Study report.
(See Enclosure 2).
( ~
'4 J
NRC QUESTION 3 Several Fire Zones in the initial report contain the essential chilled water expansion tank in the evaluation's findings as a system which can experience spurious operation, see fire zone llB as an example.
In Revision 1, this system has been removed from the findings.
Provide justification for removal of this system from the evaluation findings.
RESPONSE
See the response to NRC question 1.
NRC ()UESTION 4 On Page 56 of Revision 1, it is stated that "Interruption of SDC can be tolerated..."
How is SDC interrupted and for how long?
What are the consequences of the interruption and how are they rectified?
RESPONSE
Shutdown Cooling (SDC) interruption could be caused by a fire induced spurious Recirculation Actuation Signal (RAS).
RAS is a concern only if the plant is in SDC recirculation at the time of the fire.
The RAS stops the LPSI pump which terminates RCS heat removal until the system is realigned.
System realignment may only require overriding the RAS (via Control Room pushbutton) and restarting the LPSI pump or may, at the worst
- case, require starting of the redundant SDC loop (depending on the location of the fire and the Train of SDC in operation prior to the fire).
These actions are not expected to take an extensive period of time to perform (i.e., within 1/2 hour).
NRC QUESTION 5
Assumption 17 of the original report has been deleted and replaced with a new assumption.
This new assumption appears to be broader in scope than the original.
Provide the reason for this change.
RESPONSE
The Revision 0 Assumption No.
17 stated that control room panel "cross-talk circuitry" running in the cable spreading rooms did not require fire damage evaluation.
The basis for the original assumption validity was that, at worst, fire damage would result in ESFAS occurrence.
This was going to occur anyway because of other circuitry in the zones.
The control room panel "cross-talk circuitry" was, in actuality, evaluated for fire damage concerns which eliminated the need for the original assumption and lead to the "new" Assumption No. 17.
The new Assumption No.
17 is a modified version of the original concern, and is applicable to more than just the cable spreading room fires.
(See the response to NRC Question 1).
NRC (QUESTION 6 Definc the term degraded core cool ing.
RESPONSE
Degraded core cooling is defined as one third of the steam generator tubes covered and RCS heat removal capability reduced.
Comparatively, degraded core cooling occur s at approximately 13 minutes whereas core damage will occur within 59 minutes if feedwater flow is not established.
Note, the definition of degraded core cooling has remained consistent throughout the entire evaluation effort.
NRC QUESTION 7
In Revision 1 to the Control Room Fire Spurious Actuation Evaluation, Evaluation Finding 1, in Section 3.7 and 3. in Section 3.13 have been deleted.
Provide the rationale for these deletions.
RESPONSE
The reason for the deletion of Evaluation Finding 1 in Section 3.7, "Essential
.Chilled Water System" is explained in the response to NRC Question 1: Regarding the deletion of Evaluation Finding 3 in Section 3.13, "Main Steam System",
the original option to rely on fail open N2 accumulator solenoid valves to ensure a pneumatic energy source to the ADV's was based entirely on the knowledge that this proposed design change was in progress at the time of the evaluation.
The need for "fail open" valves was subsequently determined unnecessary since further investigation identified that the yard liquid nitrogen backup to the instrument air system is capable of supplying the necessary pneumatic
- energy, and this backup is not subject to damage, due to the Control Room fire, either directly or indirectly (spurious actuation).
ENCLOSURE 2
3.45 PIRE ZONE:
50B (Por a fire in this zone, use SSD Train A)
EVALUATION PINDING:
The ability to prevent inadvertent boron dilution may,not be possible due to inability to close VCT outlet valve J-CHN-UV-501 from the control room.
KEY MONITORABLE PARAMETERS:
(functional)
RCS temperature, pressurizer level and pressure.
TIME CONSTRAINTS:
Following a reactor trip, at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of charging with unborated.
water can occur without loss of subcritical conditions.
OPERATIONAL CONSIDERATIONS:
Isolate unborated. water sources to the charging pumps.
COMPENSATORY MEASURES:
To ensure the ability to prevent inadvertent boron dilution, local manu-ally close valve J-CHN-UV-501 after opening circuit breaker M7208 in MCC E-NHN-M72 or close manual CHV771.
(NOTE:
E-NHN-M72 is located in Fire Zone 52D.
Valve J-CHN-UV-501 is located. in Pire Zone 50B and valve CHV771 is located in the yard.)