ML17312A633
ML17312A633 | |
Person / Time | |
---|---|
Site: | Palo Verde ![]() |
Issue date: | 03/23/1996 |
From: | LEVINE J M ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
Shared Package | |
ML17312A634 | List: |
References | |
102-03631-JML-A, 102-3631-JML-A, NUDOCS 9604020036 | |
Download: ML17312A633 (27) | |
Text
CATEGORY j.9 REGULATO~INFORMATION DISTRIBUTION zSTEM (RIDS)AClESSION NBR:9604020036 DOC.DATE: 96/03/23 NOTAR ZED: YES DOCKET FACI!':STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH.NAME AUTHOR AFFILIATION LEVINE,J.M<
Arizona Public Service Co.(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Contro1 Branch (Document Control Drisk)
SUBJECT:
Application for amend to license NPF-5l,revising TS SR 4.8.2.l.e.,"DC Sources," to suspend provision of TS 4.0.1 4.0.4 for battery capacity testing requirements until entry into Mode 4 following sixth refueling outage.DZSTRZBUTZON CODE: ROOZD COPZES RECEZVED:LTR J ENCL J SZZE: I 5+I TITLE: OR Submittal:
General Distribution E NOTES:Standardized plant.05000529 RECIPIENT ID CODE/NAME PD4-2 LA THOMASzC INTERNAL: ACRS NRR/DE/EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT EXTERNAL: NOAC COPIES LTTR ENCL 1 1 1 1 6 6 1 1 1 1 1 1 1 1 RECIPIENT ID CODE/NAME PD4-2 PD~LE CENTS~&0 NRR/DRCH/HICB NRR/DSSA/SRXB OGC/HDS2 NRC PDR COPIES'TTR ENCL 1 1 1 1 1 1 1 1, 1 0 1.1 0 D U E N NOTE TO ALL"RIDS" RECIPIENTS:
PIEASE HELP US TO REDUCE WASTEl CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN SD-5(EXT.415-2083)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED)TOTAL NUMBER OF COPIES REQUIRED: LTTR 18 ENCL 17 t
Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O.BOX 52034~PHOENIX, ARIZONA 85072-2034 10 CFR 50.90 10 CFR 50.91 JAMES M.LEVINE VICE PRESIDENT NUCLEAR PRODUCTION 102-03631-JML/AKK/DRL March 23, 1996 U.S.Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-37 Washington, D.C.20555
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)Unit 2 Docket No.STN 50-529 Proposed Technical Specification Amendment to Specification 3/4.8.2, DC Sources, Under Emergency Circumstances Pursuant to 10 CFR 50.90 and 10 CFR 50.91(a)(5), Arizona Public Service Company (APS)submits herewith a request to amend Facility Operating License NPF-51 for Unit 2 of the PVNGS.The proposed amendment would revise Technical SpeciTication Surveillance Requirement 4.8.2.1.e,"DC Sources," to suspend provision of Technical Specifications 4.0.1 and 4.0.4 for battery capacity testing requirements until entry into Mode 4 following the sixth refueling outage.Approval to suspend the Technical Specification battery capacity surveillance requirement from now until entry into Mode 4 following the Unit 2 sixth refueling outage is necessary to allow plant operation and refueling activities until new batteries can be obtained and installed.
Provided in Enclosure 1 to this letter are the following sections which support the proposed Technical Specification amendment:
A.B.C.D.E.F.G.H.Explanation of the Emergency Circumstances Description of the Proposed Technical Specification Amendment Request Purpose of the Technical Specification Need for the Technical Specification Amendment Safety Analysis for the Proposed Technical Specification Amendment Request No Significant Hazards Consideration Determination Environmental Impact Consideration Determination Revised Technical Specification Page (gg~g AA'IIb0402003b'9b0323<
l PDR ADQCK 05000529 p PDR V CM J I I J I I Et U.S.Nuclear Regulatory Commission Attn: Document Control Desk Proposed TS Amendment to 3/4.8.2 Page 2 Enclosure 2 provides the marked-up Technical Specification pages to support the proposed amendment.
It is requested that this Technical Specification change be issued by March 24, 1996, in order to prevent further delay for Unit 2 core offload.Should issuance of this change not be possible by that date, it is requested that consideration be given to issuance of a Notice of Enforcement Discretion in accordance with Section VII.C of Appendix C, General Statement of Policy and Procedure for NRC Enforcement Actions, to 10 CFR Part 2, Rules of Practice for Domestic Licensing Proceedings and Issuance of Orders.By copy of this letter and its enclosures,.the Arizona Radiation Regulatory Agency is being notified of this Technical Specification amendment request pursuant to 10 CFR 50.91(b)(1).
Should you have any questions, please contact Scott A.Bauer of my staff at (602)393-5978.Sincerely, JML/AKK/DRL/pv Enclosures (all w/enclosures) cc: L.J.Callan K.E.Perkins C.R.Thomas K.E.Johnston A.V.Godwin (ARRA)
I t II STATE OF ARIZONA))ss.COUNTY OF MARICOPA)I, J.M.Levine, represent that I am Vice President-Nuclear Production, Arizona Public Service Company (APS), that the foregoing document has been signed by me on behalf of APS with full authority to do so, and that to the best of my knowledge and belief, the statements made therein are true and correct.J.M.Levine Sworn To Before Me This~Day Of~1996.Notary Public My Commission Expires IJIy CommL6SlonExplres Jun812,1997
'L V gN'~r""
ENCLOSURE 1 PROPOSED AMENDMENT TO TECHNICAL SPECIFICATION SECTION 3/4.8.2 DC SOURCES I 14 tw~eg 4I I j I I b I I I ENCLOSURE I A.EXPLANATION OF THE EMERGENCY CIRCUMSTANCES During the current Unit 2 sixth refueling outage, APS performed capacity testing on the Class 1E batteries.
Battery banks A and C were capacity discharge tested on March 20, 1996 and March 22, 1996, respectively, to satisfy the requirement of IEEE Standard 450-1980 to capacity test new batteries within the first two years of service.The test results of Channel C did not meet Technical Specification Surveillance Requirement (SR)4.8.2.1.e.
On March 23, 1996, the D battery bank was declared inoperable because the predicted capacity was less than the required 90%capacity stated in SR 4.8.2.1.e.
This predicted capacity was derived from the results of the Channel A and C testing.The emergency circumstances exist because the two Class 1E batteries (Channel C and D)do not meet the 90%requirement of SR 4.8.2.1.e; therefore, PVNGS Unit 2 must comply with TS 3.8.2.2 Action a which causes the suspension of fuel movement.The emergency circumstances could not be avoided because the degradation in battery capacity was unexpected.
The batteries were installed in Unit 2 in February 1995 as-replacement cells for the previously installed ATBT batteries which contained a manufacturing defect.This request, under emergency circumstances, provides the justification to allow PVNGS Unit 2 to continue fuel movement with battery capacities less than required in Specification 4.8.2.1.e, until the battery bank capacities are returned to above 90%.B.DESCRIPTION OF AMENDMENT REQUEST APS proposes to modify Technical Specification 4.8.2.1.e, DC Sources-Operating, to specify that the provisions of Technical Specifications 4.0.1 and 4.0.4 are not applicable to the battery capacity requirements until entry into Mode 4 coming out of the sixth refueling outage or u'pon any deep discharge cycle of the battery.This change will allow APS to declare the Unit 2 batteries operable based upon the current capacities of the batteries without having to satisfy the surveillance requirement of Technical Specification 4.8.2.1.e.
The justification for this change is described below.C.PURPOSE OF THE TECHNICAL SPECIFICATION Technical Specification 3.8.2.1,"DC Sources-Operating," requires the operability of two trains of DC power sources to ensure that sufficient power will be available to supply the safety-related equipment required for 1)the safe shutdown of the facility and 2)the mitigation and control of accident conditions within the facility.The initial conditions of the Design Basis Accident and transient analyses in the Updated FSAR, Chapter 6 and Chapter-15, assumes that Engineered Safety Feature systems are.operable.The DC electric power system provides normal and emergency DC electrical V Page 1 of 6 k'1 I 1~E, Pw 1 P I+I I 11'l 1 t power for the Emergency Diesel Generators, emergency auxiliaries, and control and switching during all modes of operation.
The operability of the DC sources is consistent with the initial assumptions-of the accident analyses and is based upon meeting the design basis of the unit.This includes maintaining the DC sources operable during accident conditions in the event of 1)an assumed loss of all offsite AC power or all onsite AC power';and 2)a worst case single failure.D.NEED FOR THE TECHNICAL SPECIFICATION AMENDMENT Palo Verde Nuclear Generating Station Units 1, 2, 8 3 have AT8T LINEAGE 2000 Round Cell batteries installed in the safety-related 125VDC battery banks.To date.Units 1 and 3 have experienced the expected capacity from these batteries.
The batteries installed in the Unit 2 125VDC battery, however, are experiencing degraded capacity.Capacity discharge tests run in March 1996 indicate capacities of 88%for bank C and using that data, a projected capacity of 88%for bank D.Banks C and D are below the 90%limit of Specification 4.8.2.1.e.
Both banks have currently been declared inoperable.
The proposed change to the Technical Specification is necessary to allow the Unit to continue fuel movement.Replacement cells, which when installed will restore capacity above 90%, are not due onsite until April 8, 1996.E.SAFETY ANALYSIS OF THE PROPOSED AMENDMENT REQUEST Back round The proposed Technical Specification Amendment would allow operation of the Unit 2 safety-related 125VDC battery banks at less than the required capacity in Specification 4.8.2.1.e.
Four Class 1E Direct Current (DC)power banks designated A, B, C, and D are provided in each unit.The DC banks A and B provide control power for Alternating Current (AC)load groups 1 and 2, respectively.
These banks also provide vital instrumentation and control power for channels A and B, respectively, of the reactor protection and Engineered Safety Features (ESF)systems and diesel generators A and B, respectively.
The DC banks C and D provide vital instrumentation and control power for channels C and D, respectively, for the reactor protection and ESF systems, and other safety-related loads as referenced in Table 8.3-'6, Class 1E DC System Loads, of the Updated Final Safety Analysis Report (FSAR).Each Class 1E DC power bank consists of one 125VDC battery, one battery charger, one distribution, panel, and is supplied with 480VAC power from a different Motor Control Center (MCC).Four'nverters, supplied from the DC banks, provide four independent 120VAC vital instrumentation and control power supplies for the banks of reactor protection and ESF systems.(See Figures 1 and 2.)During normal operation, the normal battery charger supplies DC power to the control center at a float voltage of 135VDC.In addition to carrying the loads on the DC control center, the normal battery charger provides a float (trickle)charge to the battery to keep the battery fully charged.The battery is available as a standby DC source to carry the control center load automatically in case of loss of the charger.In case of complete loss of AC power, each DC control center will be fed by its battery for at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.Upon Page 2 of 6
~{~I 4 j i, Wv restoration of AC power, the battery charger is operated in the equalize mode to supply all the steady state loads and the charging current required to restore the battery from.the design minimum charge state to the fully-charged state within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.In case of loss of AC power to the normal battery charger or non-availability of the normal battery charger due to maintenance or testing, the backup battery charger is manually connected to the control center to supply control center loads and trickle charge the battery.Each train of the Class 1E battery has sufficient capacity to independently supply the required loads as shown in Table 8.3-6 of the Updated FSAR for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.The sizing of the batteries is based on a minimum temperature of 60'in the battery room for the , 2-hour service period.The PVNGS design exceeds the IEEE Standard 450-1980 requirement for 25%design margin in that battery banks (C and D)have a design capacity of 344%and 667%, respectively, of the required end-of-life capacity.The Technical Specification references capacity to the"manufacturer's rating." A 100%-manufacturer's rating for battery bank C is, therefore, a 29%design capacity.The safety margin is based o'n the safety-related functions requiring 29%of the manufacturer's rating for battery bank C.The current Technical Specification requires the as-found capacity to equal or exceed 90%of manufacturer's rated capacity and was conservatively selected based upon the expectation that the ATBT LINEAGE 2000 Round Cell battery capacity would increase for the rest of plant life.The AT8T LINEAGE 2000 Round Cell battery, although relatively new in nuclear applications, has been available for almost twenty years, and there are more than 500,000 in service today.The Round Cell battery is similar in design to other lead-acid batteries in that it uses a conventional pasted plate construction.
However, the Round Cell battery is unique in that the positive grid is of pure lead and is of circular construction which creates a slow, uniform growth rate of=2%over 70 years compared with a growth rate of=4%over 15 years in conventional rectangular lead calcium batteries.
Because each concentric ring of the positive grid in the Round Cell grows at the same rate, good contact with the active material (or paste)is maintained over the life of the battery.Unit 2 Testin and De radation Predictions-During the current refueling outage, APS is conducting capacity testing of the Class 1E batteries to satisfy the requirement of IEEE Standard 450-1980 to capacity test new batteries within the first two years in service.The test revealed that the battery capacities for the C battery bank was less than the 90%capacity required by Technical Specification 4.8.2.1.e (i.e., 88%)while Bank A was 107%.These results indicated degradation that was unexpected.
APS has performed an analysis of the predicted capacity of battery bank D and is estimating a capacity of 88%.The projections for battery capacity from this evaluation indicated that battery bank D in Unit 2 is inoperable.
Cell degradation predictions for Channel D are based upon an analysis of the Channel A and C test results.Pre-test specific gravities were compared to post-test specific gravities and correlated with capacity loss during the test.This predictive model was Page 3 of 6 I
applied to Channel D and estimates the current capacity as 88%and for Channel B, capacity of approximately 104%.Com ensato Actions PVNGS will also initiate the following additional compensatory actions for each Unit 2 battery below 90%: 1.Maintenance limitations for important equipment PVNGS will protect the 125VDC system(s)required to be operable in the mode Unit 2 is in.PRA will review corrective/preventative maintenance in the 125VDC train(s)required to be operable in the mode Unit 2 is in.2.Controls.for electrical supply integrity:
PVNGS will issue a night order to the Unit 1 Control Room stating that the offsite power supplies required by Technical Specifications for the mode of operation Unit 2 is in and associated 13.8 kV buses will be protected.
Access to Unit 2 required equipment in the switchyard will be limited.AII switchyard work will be reviewed by the Unit 1 Shift Supervisor.
Increase the following battery testing to every other week for all cells in Channels C and D.Testing will be staggered between trains.Parameter'loat Voltage Float Current Limits/Allowable
>2.18Volts
<2 amps Avg of all,connected cells>1.290 Specific Gravity>1.280'ctions to be Taken if Outside Limits Battery Inoperable Battery Inoperable
.Restore within limits within 7 days Restore within limits within 7 days Not more than 0.020 below average of all connected cells Battery Inoperable Avg of all connected cells>1.280 Battery Inoperable 4.PVNGS will discharge test Channels B and=D only when fuel is in the fuel pool.Page 4 of 6 A~l lI F.NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION The Commission has provided standards for determining whether a significant hazards consideration exists as stated in 10 CFR 50.92.A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with a proposed amendment would'not:
Involve a significant increase in the probability or consequences of an accident previously evaluated; 2.Create the possibility of a new or different kind of accident from any previously evaluated; or 3.Involve a significant reduction in a margin of safety.A discussion of these standards as they relate to this amendment request follows: Standard 1: Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
The DC power sources are required to ensure that sufficient power is available to supply safety-related equipment required for safe plant shutdown and the mitigation and control of accident conditions.
Therefore, a change in battery capacity requirements does not involve a significant increase in on the probability of an accident previously evaluated.
APS has determined, through calculation
'and test, that the Channels C and D can continue to perform their safety-related function with its capacity reduced to 88%of the original installed capacity.Analysis shows that the projected capacities of the banks will provide greater than 50%margin above that required for the safety-related loads.The projected capacities are expected to be approximately 88%for each bank.As such, the battery banks have sufficient capacity for the safety-related loads following a design basis event.Should any deep discharge of any battery occur, the battery will be declared inoperable.
Therefore, the proposed change to the battery capacity requirement does not involve a significant reduction in the consequences of an accident previously evaluated.
Standard 2: Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Calculations and testing have demonstrated that the higher loaded battery bank (Bank C)will continue to perform its safety-related function with an installed margin greater than 50%.Therefore, the proposed change will not create the possibility of a new or different kind of accident from any previously evaluated.
Page 5 of 6 I
Standard 3: Does the proposed change involve a significant reduction in a margin of safety?Although battery capacity is less than required by Specification 4.8.2.1.e, sufficient capacity remains for the batteries to perform their intended function.The following graph demonstrates the margin in capacity based on projected capacity and actual capacities.
120 100 80 60 40 20 0 m x"=C D Kl Installed I Tested/Projected I Required U In the most limiting case, the C, battery still has greater than 50%margin between the projected and required capacities.
Therefore, the proposed change to battery capacity requirements does not involve a significant reduction in a margin of safety.G.ENVIRONMENTAL IMPACT CONSIDERATION DETERMINATION APS has determined that the requested Technical Specification Amendment involves no change in the amount or type of effluent that may be released offsite, and that there is no increase in individual or cumulative occupational radiation exposure.As such, operation of PVNGS Unit 2 in accordance with the proposed amendment, does not involve an unreviewed environmental safety question.H.REVISED TECHNICAL SPECIFICATION PAGE 3/4 8-10 Page 6 of 6 0 V II';L 4 duo 0 3 y, Z>>L Lt Z 0<<IJ 1 0 0 0 0~0 0LI Z ft 4~tt V L AZ v 4<<ov4 4~Aa>>a 00 I I I I I I<<1~I I I I X V 4vL A 4 V 0'E V X Z,~vuu L 0 0~lo 0~4 rvo O a 0 U SA Z Vu J~'0 V n 0 no UZ t Y;LZ o 0 0 It on OA U a 4 4 0 no 0 4 ruo 0 0 tl 0 0 C A 0>>~0 LI~~Z tt It~C~>>~<<SAL v vo/U 0~n<<oval Aa~a 00 I I I I I I LL~I I I V 0 J I on OA tl I I I~I Lt'4 L V E Z LI a Z 0 V L Z Ll It I a I V I 0 I I I A I I E-,~I I I tl a CZ 0 IJ tl V~c 4>>>>VL I~I I I 0 C'lv U>>aa OL<<lt~4 a JV VE Ot J 4 I t I I I Ia I ol u'L E L I 4 I 4 V I ltl 0 I Io I IU I 0 v~o L OA OE~A~~0~0 Hv SoYVU"-VO~>>V 40 4\~vt 1L at>>Z 0 CV 0 1 I~""9 oKY'u"-vo~I>>4 to tl~~0 la Al~'IL 0 IL E4 PZ lv I,'o I I II I V I IOI~I lo 0 4 0 I I IVI I------Iol I 0 I%~>>nO Z'0 v vva 4 v 0 0 F 41~~Ill 0 I~v~E Z I>>" Eua I Oat I Anz v gO pl I I II II II II P All vll II II II II I I I II L C LI Jl~~PZ~a CO 2 tQ U~R V)CJ V)Q~nI IJ 6 CO 0 ti 4 6 HO CO A CfJ C Lt JI I C 4 E z II II II vll gll II I 0 I I>>>>I 04~An I II II II II II~I II~L 0 0 0 0 g I E I UA 0 0 Ju viz IL Lt Ju V 0 It 0 0 n EA 0, 0 Jt vt Z~4 JV v 0 A I'I'
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ENCLOSURE 2 MARKED-UP TECHNICAL SPECIFICATION PAGE FOR PROPOSED AMENDMENT TO TECHNICAL SPECIFICATION SECTION 3/4.8.2 DC SOURCES