ML17297B730
| ML17297B730 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 09/29/1982 |
| From: | Kerrigan J Office of Nuclear Reactor Regulation |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 8210210026 | |
| Download: ML17297B730 (7) | |
Text
Docket Nos. 50-528/529/530 Mf' 9 1982 DISTRI B UTION
, -Document Coiitrol PRC System NRC PDR L PDR NSIC Mr. E. E.
Van Brunt, Jr.
Vice President - Nuclear Projects Arizona Public Service Company Post Office Box 21666 Phoenix, Arizona 85036
Dear Mr. Van Brunt:
LB¹3 Reading MLicitra JKer rigan JLee OELD OISE ACRS(16)
Subject:
Probabil istic Risk Assessment - Spray 'Nozzles for Palo Verde Ultimate Heat Sink ODParr JWermiel RMattson LRubenstein TMNovak DGEisenhut LGHul.mam ISpick1er RLobel EMarkee RAbbey RES By letter dated March 25. 1982, you provided for our review a document entitled "Palo Verde Nuclear Generating Station, Probabilistic Risk Assessment of Tornado Missile Damage to the Station Ultimate Heat Sink, Bechtel Study No. 13-NS-108."
As a result of our review, the staff has identified the need for additional information as listed in Enclosure 1.
This matter has been discussed with Mr. Kent Jones of your staff.
In order that we may complete our review of the above document, we request that you submit, by October 15. 1982, the information requested in Enclosure 1.
Please advise us ifyou have any problem in meeting this date.
Ifyou have any questions regarding this request, contact E. Licitra, the Project Manager, on (301) 492-7200.
Sincerely, 82i02i002b 820929 PDR
- DOCK 05000528 A
.'P,DR
Enclosure:
As stated cc w/enclosure:
See next page Janis D. Kerrigan, Acting Chief Licensing Branch ¹3 Division of Licensing DL:LB¹3
'¹ OFFICEI SURNAME/ ELicitra:1b oooo'....9Jaf!8~..........9!g!82..
NRG FORM 318 OO-80) NRCM 0240
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OFFICIA'L RECORD COPY VSQPO: 1981~&980
tlh
,,Palo Verde Mr. E.
E.
Van Brunt, Jr.
Vice President - Nuclear Projects Arizona Public Service Company P. 0.
Box 21666
- Phoenix, Arizona 85036 Regional Administrator -Region V.
U.S. Nuclear Regulatory Commission 1450 Mari a Lane Suite 210 Walnut Creek, California 94596 CC:
Arthur C. Gehr, Esq.
Snell
& Wilmer 3100 Valley Center
- Phoenix, Arizona 85073 Charles S.
Pierson Assistant Attorney General
.200 State Capitol 1700 West Washington
- Phoenix, Arizona 85007 Charles R. Kocher, Esq., Assistant Counsel James A. Boeletto, Esq.
Southern California Edison Company P. 0.
Box 800
- Rosemead, California 91770 Margaret Walker Deputy Director of Energy Programs Economi c Pl arming and Development Office 1700 West Washington
- Phoenix, Arizona 85007 Mr.
Rand L. Greenfield Assistant Attorney General Bataan Memorial. Building Santa Fe, New Mexico 87503 Resident Inspector Palo Verde/NPS U;S. Nuclear Regulatory Comnission P.
0.
Box 21324
- Phoenix, Arizona 85001 Ms. Patricia Lee.Hourihan 6413 S. 26th Street
- Phoenix, Arizona Lynne A. Bernabei, Esq.
Harmon
& Weiss 1725 I Street, N.W.
Suite 506 Washington, DC 20006
e
~'ALO VERDE NUCLEAR GENERATING STATION, UNITS 1
5 2 REQUESTS FOR ADDITIONAL INFORMATION AUXILIARYSYSTEMS BRANCH In order to complete our review of the document entitled, "Palo Verde Nuclear Generating Station, Probabilistic.Risk Assessment of Tornado Missile Damage to the Station Ultimate Heat Sink, Bechtel Study No. 13-NS-108" provided by the applicant's letter dated March 25, 1982, the applicant should provide a response to the following requests for additional information:
'I 1.
Provide further justification for the assumption in the PRA study that automobiles can be excluded from consideration in the tornado missile analyses.
2.
The PRA study as currently presented may not provide sufficient evaluation of.the effects of existing site features on the installed spray pond.
Thi's analysis is required in order to assure that a complete assessment of potential tornado missile damage to the spray pond has been performed.
Therefore, provide the following additional information.
- a. It appears that only the SRP Section 3.5.1.4 missile spectrum was considered in determining the "standard" missile used in the PRA study.
As the study is an evaluation of an existing structure, it must be shown that the standard missile bounds all potential missile impacts against unprotected spray pond components.
Therefore, pro-vide justification and any necessary supporting calculations for excluding potential site missiles of less mass than the "standard" missile traveling at lesser velocity from the PRA evaluation.
b.
A response to part a.
above is not required ifit can be demonstrated that the actual design wind loading and impulse load due to tornado missiles for which the spray riser piping and nozzles have been designed is.adequate to assure that.unacceptable damage does not occur as a result of, impact from the realistic potential site missiles to be addressed in a. above.
3.
Identify the upper and lower bounds selected *for each of the conditional probabilities in the PRA study and justify the actual bounds selected.
4.
The probability of the tornado as derived and used in Appendix A of'the PRA study does not appear to be a total conditional probability, but a conditional probability of tornado severity occurrence given a path area.
Justify the acceptability. of this approach.
5.
Identify and justify all assumptions and assumed conditions utilized in determining the conditional probabilities associated with Appendices B, C; D and E.
The justification shall. discuss the significance. of each assumption and its effect (the sensitivity) on the final answer.
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6.
In Appendix A of the PRA study, an assumption is made of a constant tornado frequency per unit area to account for a non-u'niform geographic distribution of tornado characteristics.
Justify the approach of="
adjusting the tornado frequency per county based on population distribution and neglecting the meteorological and/or geographic variabi1ities of the site area.
7.
In Appendix B of 'the PRA study, it is stated that P (a) is the probability of any -tornado striking per year.
However, this quantity is actually the probability of tornadoes of path area "a."
Explain the effects on the results for smaller path area tornadoes as appears to often be the cafe with tornadoes near the site area.
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