ML17299B251
| ML17299B251 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 05/21/1986 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| ANPP-36654-EEVB, TAC-62800, TAC-62801, NUDOCS 8605270362 | |
| Download: ML17299B251 (8) | |
Text
C" REQUL Y INFORNATION DISTRIBUTI SYSTEN
( R IDS)
J ACCESS IQN NBR: 8605270362 DOC. DATE: 86/05/21 NOTARIZED:
NQ DOCNET 0 FAC IL".STN-50-529 Palo Verde Nuc 1 ear Stat ion>
Unit 2.
Ari z ona Pub 1i 05000529 AUTH. NANE AUTHOR AFFILIATIQN VAN BRUNT'. E.
Arizona. 'Nu c Iear Popover Pro g ec t
( formel 1 Q Arl z ona Pub Ii c Serv RECIP. NANE RECIPIENT AFFILIATION NINGTON, G. M.
PMR Pro g ec t Direc t orate 7
SUBJECT:
Responds to NRC 860403 request for add 1 info on Tech Spec s re number of reactor or shutdown coolant 1 oop 5 that must be operable in Nodes 3
8c 4 5 control element assemb 1 g withdrawal. Tech Specs correct 0
c onsi stent to/STS.
DISTRIBUTION CODE:
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Arizona Nuclear Power Project P.O. BOX 52034
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PHOENIX, ARIZONA85072-2034 May 21, 1986 ANPP-36654-EEVB/BJA/98.05 Director of Nuclear Reactor Regulation Attention.'r.
George W. Knighton, Project Director PWR Project Directorate
//7 Division of Pressurized Water Reactor Licensing B
U. S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Unit 2 Docket No.
STN 50-529 (License No. NPP-51)
Additional Information Concerning PVNGS Unit 2 Technical Specifications 3.4.1.2 and 3.4.1.3 Pile:
86-P-056-026
Reference:
Letter from E.
A. Licitra,
- NRC, to E.
E.
Van Brunt, Jr.,
- ANPP, dated April 3, 1986.
Subject:
Request for Additional Information Palo Verde Unit 2 Technical Specifications.
Dear Mr. Knighton:
The referenced letter requested ANPP to provide the NRC staff with additional information concerning PVNGS Unit 2
Technical Specifications 3.4.1.2 and 3.4.1.3.
These Technical Specifications are concerned with the number of reactor coolant loops and/or shutdown cooling loops that must be operable in Modes 3 and 4.
The concern, which is identified in the request from the NRC staff, is that the bases associated with these two Technical Specifications appear to require two Reactor Coolant Pumps (RCP's) in each loop to be operable in order to consider a reactor coolant loop operable.
'Jhe NRC staff believes that this is not consistent with the Limiting Conditions for Operation (LCO's) of these Technical Specifications which only require one RCP in a reactor coolant loop to be operable in order to consider -the reactor coolant loop operable.
The NRC has requested ANPP to explain this inconsistency and to include a reference to the relevant FSAR safety analysis.
ANPP believes that ICO's 3.4.1.2 and 3.4.1.3 are correct and that the associated bases section does support these LCO's.
Additionally, these Technical Specifications and bases section are consistent with the Standard Technical 'pecifications for Combustion Engineering PWR's (refer to NUREG&212).
The bases section correctly states
- that, for Mode 3
or 4
operation, a
single reactor coolant loop provides sufficient heat removal 8b052703b2 Sb0521 PDR ADQCH, 05'000529' roaM
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Mr. George M. Knighton Additional Information Concerning PVNGS Unit 2 Technical Specifications 3.4.1.2 and 3.4.1.3 ANPP-36654 Page Two capability for removing decay heat.
LCO's 3.4.1.2 and 3.4.1.3 contain the definition of the required components for a
reactor coolant loop to be considered operable.
This definition includes the reactor coolant loop, the associated steam generator, and at least one associated reactor coolant pump.
The NRC has also requested ANPP to identify the relevant safety analyses.
The safety analyses were reviewed for any limiting condition not recognized previously.
A particular concern of the NRC was the PVNGS Control Element Assembly (CEA) withdrawal analysis.
The CEA withdrawal
- analysis, which appears in CESSAR Section 15.4.1, was performed at essentially zero power in Mode 2
and credited a variable overpower trip at 17X power.
Pour reactor coolant pumps were assumed to be operating.
The analysis reported a
maximum power of 43.5X and a maximum core average heat 'flux of 16.9X.
lti If a CEA withdrawal event, initiated from Mode 3,'ere to result in achieving criticality, the event would be terminated by either a
Core Protection Calculator (CPC) trip or >by a,high log power level trip.
The high log power level reactor trip is specifically'rovided for protection from reactivity addition events in the shutdown modes.
The PVNGS Technical Specifications require this trip to be in operation in Modes 3, 4, and 5 with a maximum trip setgoint of 0.895X power.
The high log power level trip may be bypassed above 10 X
power but this requires a
positive operator action to bypass the trip.
Additionally, with less than four reactor coolant pumps in operation, a
CPC trip signal would be continuously generated.
The CPC bypass, which would allow closing of the reactor trip breakers even with a trip signal present, is automatically removed at 1X reactor power.
Therefore, even with the high log power level trip bypassed, a reactor trip would still occur at a very low power level.
The normal operating procedures for a reactor startup would also minimize the potential for having an accidental withdrawal of CEA's while in a
shutdown mode.
The reactor startup procedure requires that all four reactor coolant pumps be in operation prior to closing the reactor trip breakers.
Additionally, if the reactor coolant system low flow trip is not purposely bypassed, it will prevent the closing of the reactor trip breakers with less than one reactor coolant pump in each loop in operation.
These administrative and design controls greatly reduce the possibility of having an accidental withdrawal of CEA's while in a shutdown mode.
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Mr. George W. Knighton Additional Information Concerning PVNGS Unit 2 Technical Specifications 3.4.1.2 and 3.4.1.3 ANPP-36654 Page Three Based upon the previously listed justification, ANPP is convinced that the existing Technical Specifications are conservative.
If you have any additional quests.ons on this matter, please contact Mr.
W.
P.
Quinn of my staff.
Very truly yours, cul~ n~
E. E. Van Brunt, Jr.
Executive Vice President Prospect Director EEVB/BJA/dim cc:
E. A. Licitra R. P.
Zimmerman A. C. Gehr C. Y. Liang
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