ML17305B707
| ML17305B707 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 08/21/1991 |
| From: | Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17305B708 | List: |
| References | |
| 161-04124-WFC-D, 161-4124-WFC-D, NUDOCS 9109030186 | |
| Download: ML17305B707 (22) | |
Text
ACCELERATED DISTIUBUTION DEMONSTPWTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
CCESSION NBR:9109030186 DOC.DATE: 91/08/21 NOTARIZED: YES DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION CONWAY,W.F. Arizona Public Service Co. (formerly Arizona Nuclear Power R RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Application for amends to Licenses NPF-41,NPF-51 6 NPF-74, revising TS Surveillance Requirement 4.8.1.1 re ac sources D to change KW value of Train A HPSI pump from 696 KW to 771 KW 6 load sequencing for 24 h surveillance tests.
DISTRIBUTION CODE: AOOID TITLE: OR.
COPIES RECEIVED:LTR Submittal: General Distribution I ENCL L SIZE:
A NOTES:STANDARDIZED PLANT 05000528 Standardized plant. 05000529 D Standardized plant. 05000530 D
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 TRAMMELL,C 2 2 THOMPSON,M 2 2 INTERNAL: ACRS 6 6 NRR/DET/ECMB 7D 1 1 NRR/DET/ESGB 1 1 NRR/DOEA/OTSBll 1 1 NRR/DST 8E2 1 1 NRR/DST/SELB 7E 1 1 NRR/DST/SICB8H7 1 1 NRR/DST/SRXB 8E 1 1 NUDOCS-ABSTRACT 1 1 OC/DF2gL 1 0 OGC/HDS1 RES/DSIR/EIB 1
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~C< ".G ~ah 01 1 1 EXTERNAL: NRC PDR 1 1 NSIC NOTES: 1 1 D
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NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTEI CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
OTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL 25
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Arizona Public Service Company P.O. BOX 53999 ~ PHOENIX. ARIZONA85072-3999 WILLIAMF. CONWAY 161-04124-WFC/DAF EXECUTIVEVICEPRESIDENT NUCLEAR August 21, 1991 Docket Nos. STN 50-528/529/530 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station Pl-37 Washington, D. C. 20555
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3 Proposed Technical Specification Amendments to Specification 3/4.8.1, A. C. Sources File: 91-F-005-419.05; 91-056-026 Pursuant to 10 CFR 50.90, Arizona Public Service Company (APS) submits herewith a request to amend Facility Operating Licenses NPF-41, NPF-51, and NPF-74, for PVNGS Units 1, 2, and. 3, respectively. The proposed amendments would revise Technical Specification Surveillance Requirement 4.8.1.1., A.C. Sources, to 1) change the KW value of Train A HPSI pump from 696 KW to 771 KW and the KW value of Train B AFW pump from 839 KW to 903 KW, and 2) change the loading sequence for the 24 hour diesel generator surveillance tests.
The change in the KW value would reflect the actual (i.e., worst case) KW load of Train A HPSI pump motor M-SIA-P02 and Train B AFW pump motor M-AFB-P01, as determined by a revised diesel generator load calculation.
The change in loading sequence would reverse the order of the 100% and 110% load runs. The diesel generators are currently loaded to approximately 110% of full load for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> run, with the remaining 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> run at 100% of full load. The diesel manufacturer recommends an alternate loading sequence of 100% of full load for the first 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> and 110% of full load for the remaining 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> loaded surveillance test.
Provided in the attachment to this letter are the following sections which support the proposed Technical Specification amendments:
Description of the Proposed Technical Specification Amendment Request B. Purpose of the Technical Specification C. Need for the Technical Specification Amendment D. No Significant Hazards Consideration Determination E. Safety Analysis for the Proposed Technical Specification Amendment Request F. Environmental Impact Consideration Determination G. Marked-up Technical Specification Change Pages 9109030i86 9i0821 PDR 'DOCK 05000528' PDR
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161-04124-WFC/DAF August 21, 1991 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Page 2 l
Pursuant to 10 CFR 50.91(b)(1), and by copy of this letter and attachment, the Arizona Radiation Regulatory Agency is being notified of this Technical Specification amendment request.
f If you should have any questions, please call Michael E. Powell of my staff at (602) 340-4981.
Sincerely,
. WFC/DAF/pmm Attachment cc'. C.
B.
M.
Martin Trammell (all w/attachment)
S. R. Peterson D. H. Coe C. F. Tedford A. C. Gehr A. H. Gutterman
161-04124-WFC/DAF August 21, 1991 STATE OF ARIZONA )
) ss.
COUNTY OF MARICOPA )
I, W. F. Conway, represent that I am Executive Vice President Nuclear, 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 and correct.
W. F. Conway t
Sworn To Before Me This co( I Day Of 1991.
Nt~tary Public My Commission Expires
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161-04124-WFC/DAF August 21, 1991 ATTACHMENT The proposed Technical Specification amendments would reflect the actual (i.e., worst case).KW load of Train A HPSI pump motor M-SIA-P02 and Train B AFW pump motor M-AFB-P01, as determined by the revised diesel generator load calculation, 13-EC-DG-200, Revision 6.
The KW load of Train A HPSI pump motor M-SIA-P02 will be revised from 696 to 771 KW while the KW load for Train B AFW pump motor M-AFB-P01 will be revised from 839 to 903 KW. This surveillance requirement (4.8.1.1.2.d.2) will read as follows:
Verifying the generator capability to reject a single largest load of greater than or equal to 903 KW (Train B AFW pump) for emergency diesel generator B or 771 KW for emergency diesel generator A (Train A HPSI pump) while maintaining voltage at 4160 + 420 volts and frequency at 60 + 1.2 Hz.
The second item of the proposed Technical Specification amendments would revise Section 4.8.1.1.2.d.7; A. C. Sources, to reverse the loading sequence for the 24-hour diesel generator surveillance test.
The diesel generator manufacture, Cooper Bessemer, has recommended a reversed loading sequence for the 24-hour engine surveillance testing.
The diesels are currently loaded to approximately 110% of full load for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the 24-hour surveillance test. Cooper Bessemer recommends that the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />'overload run be performed during the last 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the 24-hour loaded surveillance test.
I Specifically, this surveillance requirement (4.8.1.1.2.d.7) will read as follows:
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Verifying the diesel generator operates+ for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. During the first 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of this test, the
. diesel, generator shall be loaded to an indicated 5200-5400 KW~ and during the remaining 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of this test, the diesel generator shall be loaded to an indicated 5800-6000 KW~> ~ Within 5 minutes after completing this 24-hour test, perform Surveillance Requirement 4.8.1.1.2.d.6,b).>~
(Note: The asterisks refer to footnotes in the Technical Specifications, and are not affected by this change.)
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161-04124-WFC/DAF August 21, 1991 PURPOSE OF THE TECHNICAL SPECIFICATION
,I The operability of the A. C. power sources and associated distribution systems ensures that sufficient power will be available to supply the safety-related equipment required for the safe shutdown of the facility and the mitigation and control of accident conditions" within the facility. The operability of the minimum specified A.C. power sources and associated distribution systems during shutdown and refueling ensures that the facility can be maintained in the shutdown or refueling condition for extended time periods with sufficient instrumentation and control capability available for monitoring and maintaining the unit status.
NEED FOR THE TECHNICAL SPECIFICATION AMENDMENT The PVNGS UFSAR states, in Section 1.2.4.E, that "each diesel generator is sized to meet the maximum demand of its engineered safety features (ESF) load group." Table 8.3-3 in the UFSAR, Load Bases for Class 1E Buses, lists the individual equipment loads on the diesel, including the single largest load for each diesel train.
Accordingly, the maximum demand of the single largest loads on Train A and Train B was recently calculated by PVNGS calculation 13-E-DG-200, revision 6 (approved 4/91). This calculation is based on using vendor data coupled with the worst case PVNGS pump demand to determine the actual (i.e., worst case) KW loads on the motors.
Therefore, the revision of Technical Specification KW load values on the Train A HPSI pump motor and Train B AFW pump motor is needed in order to reflect this new calculation.
In the second change item of the proposed Technical Specification amendments, the diesels are currently loaded to approximately 110%
of full load for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of a 24-hour run (required once each 18 months). However, the diesel manufacturer recommends that the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> overload run be performed during the last 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the 24-hour run, advising that the existing loading sequence does not allow for optimal stabilization of engine component temperatures.
This practice can accelerate wear rates in the structural and running gear members, which can, in the long term, reduce the engine capabilities to accept and recover from stress. Thus, these Technical Specification amendments are needed to revise the current diesel loading sequence.
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 a no significant hazards consideration if operation of the facility
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161-04124-WFC/DAF August 21, 1991 in accordance with a proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. A discussion of these standards as they relate to the amendment request follows:
Standard 1 - Involve a significant increase in the probability or consequences of an accident previously evaluated.
The diesel generators at PVNGS are manufactured by Cooper Bessemer with a maximum rated load of 5500 KW for each diesel. During a postulated accident condition, the total load on each diesel is 4991 KW (Train A) and 5222 KW (Train B). Accordingly, this leaves a margin on each diesel of 509 KW (Train A) and 278 KW (Train B). The addition of the incremental KW loads on Train A and B is still within the capacity of the diesels rated load as demonstrated in PVNGS calculation 13-EC-DG-200, revision 6, and therefore would not cause diesel generator failure by overload. A significant margin of KW for each diesel train remains after incorporating this change.
As such, this change will not impact previously analyzed accidents.
Also, previous load rejection tests of the diesel generator have confirmed that this change would not impact the capability of the diesel to maintain the remaining safety-related loads which may be required to mitigate the consequences of an accident.
The reversed engine loading sequence is equivalent to the existing surveillance test and is not disallowed by Regulatory Guide 1.108 which states, in part, "Demonstrate full load carrying capabilities for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of which 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> should be at a load equivalent to the continuous rating of the diesel generator and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a load equivalent to the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> rating of the diesel generator." 'hus, the reversed sequence can be considered functionally~identical to the current method used for the 24-hour loading test.
Based o'n the discussion of both items above, the proposed Technical Specification amendments will not involve a significant increase in the probability or consequences of an accident previously evaluated.
'tandard 2 -'reate the possibility of a new or different kind of accident from any accident previously evaluated.
The revised ratings of the Train A HPSI pump motor M-SIA-P02 and Train B AFW pump motor M-AFB-POl do not impact the existing analysis of an accident. The proposed change will reflect the actual (i.e.,
worst case) load based on calculation 13-EC-DG-200, revision 6. The change will not impact 1) the capability of the diesel generator to supply power as required, and 2) the load rejection capability of the diesel generator to reject the single largest load while
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161-04124-WFC/DAF August 21, 1991 maintaining voltage and frequency as required. No safety-related equipment supplied by the diesel generator is affected by the proposed component KW revisions.
In addition, the nameplate rated loads for each pump motor will still envelope the revised actual KW values as the nameplate rated
'load for the Train A HPSI pump motor is 787 KW while the revised actual load is 771 KW and the rated load for the Train B AFW pump motor is 982 KW while the revised actual load is 903 KW. It should also be noted that previous surveillance tests 73ST-XDG01, Class 1E Diesel Generator and Integrated Safeguards Surveillance Test-Train A, and 73ST-XDG02, Class 1E Diesel Generator and Integrated Safeguards Surveillance Test:-Train B, have successfully shed loads in excess of those proposed in this amendment request.
Specifically, the most recent unit test results are as follows:
Diesel Cencrator Train h hl hest load re ected Train B hl hest load re ected Unit 1 975 KW 1200 KW Unit 2 750 KW 900 KW Unit 3 800 KW 1000 KW As such, no new failure modes will be introduced by the AFW and HPSI pump motor load revisions.
The reversed diesel loading sequence is functionally equivalent to the existing sequence in testing the capabilities of the diesel generator to operate at the rated overload conditions.
Additionally, the reversed sequence has been recommended by the diesel generator manufacturer as beneficial in lessening engine component wear rates.
Neither of the two amendment items described above modify the design or operation of plant equipment. Based on the discussions above, therefore, the proposed amendments will not create the possibility of a new or different, type of accident from any accident previously evaluated.
Standard 3 - Involve a significant reduction in a margin of safety.
While the KW revisions sought in these amendments represent an increase to the individual HPSI and AFW pump motor loads, it should be noted that the refinements within revision 6 to calculation 13-EC-DG-200 (i.e., the use of vendor test data along with verification of equipment rated load vs. the connected load) have resulted in an increased margin from that currently stated in UFSAR Table 8.3-3.
Approval of revision 6 to 13EC-DG-200 has resulted in a net increase in KW margin for each diesel of 147 KW for Train A and 130 KW for Train B.
The reversed loading sequence and the KW revisions do not impact any equipment important to safety with respect to its availability and
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161-04124-WFC/DAF August 21, 1991 ability to perform its intended safety function. The proposed reversed loading sequence meets the guidance of Regulatory Guide 1.108, revision 1. Therefore, the proposed Technical Specification amendments do not involve a significant reduction in a margin of safety.
ED SAFETY ANALYSIS OF THE PROPOSED TECHNICAL SPECIFICATION AMENDMENT RE VEST The purpose of calculation 13-EC-DG-200, Diesel Generator Load Calculation, is to verify the adequacy of PVNGS diesel generators with respect to nameplate rated capacity vs. the connected equipment loads. This calculation supersedes the previous calculation (13-EC-PE-110) on this subject, as performed by Bechtel Power Corporation for APS in the course of the original plant design. This superseded calculation did not wholly reflect the current as-built configuration of the units. Calculation 13-EC-DG-200 is performed in three steps as follows:
- 1. Determination of the total load contribution of motor-operated valves on the emergency power system.
- 2. Calculation of the total cabling and transformer losses the diesel generator must supply.
- 3. Using the above data along with the characteristic electrical data of the other emergency bus loads, the total (worst case) demand on the diesel generator is established.
This calculation uses the same methodology as the original. In addition, the following criteria and assumptions also apply:
The continuous nameplate rating shall exceed the maximum load required at all times; this guarantees continuous operation at high availability.
This calculation includes consideration of all potential loads which could be manually connected to the emergency buses during a forced shutdown or loss of coolant accident (LOCA) concurrent with a loss of off-site power (LOP).
The continuous rating of the diesel generator must be governed by the larger of the LOCA/LOP or FSD (forced shutdown) condition.
Actual pump loads on large motors are derived from APS Calculation 13-MC-DG-401 which establishes values for peak load and runout conditions for the driven pump. The worst case brake horsepower value (normal or runout and the worst plant unit) is used in this DG loading calculation.
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iH 161-04124-WFC/DAF August 21, 1991 The actual battery charger loads are based on their rated output KW demand divided by the efficiency and power factor, as provided by vendor test of the PVNGS chargers.
~ For conservatism, the calculation is based on the continuous loading of the unit's motor operated valves, whose duty cycle is intermittent only.
The revision of the KW ratings of the Train A HPSI pump motor M-SIA-P02 and Train B AFW pump motor M-AFB-P01 are within the capacity of the diesel generator as demonstrated in the PVNGS calculation 13-EC-DG-200, revision 6. Previous load rejection tests of the diesels have confirmed that this change will not impact the capability of the diesel generator to maintain 'the remaining safety-related loads which may be required to mitigate the consequences of an accident.
The proposed change to reflect the as-built, worst case KW load of Train A HPSI pump motor M-SIA-P02 and Train B AFW pump motor M-AFB-P01 will not, introduce additional failure modes to associated equipment. A review of motor test data for Train A HPSI pump motor and Train B AFW pump motor concluded that the nameplate motor ratings envelope the calculated worst case KW values. These changes are fully within the load capacity of the diesel generator and hence, will not cause diesel generator failure or impact any equipment important to safety with respect to its availability and ability to perform its intended safety function.
The reversed diesel loading sequence can be considered functionally identical to the current surveillance test method used for the 24-hour loading test. The reversed loading sequence will not affect the capabilities of the diesel generators to provide on-site emergency power during various postulated events as identified in Chapter 15 of the UFSAR.
The reversed diesel loading sequence will not affect plant operation nor will it adversely affect the ability of associated safety-related equipment, structures, systems, or components to perform their safety-related or important to safety functions. In addition, the
'roposed reversed engine loading sequence will not increase challenges to safety systems assumed to function in the accident analysis.
The discussion presented above demonstrates an adequate level of safety to support the requested amendments.
ENVIRONMENTAL IMPACT CONSIDERATION DETERMINATION The proposed amendments revise Technical Specification Surveillance Requirement 4.8.1.1, A. C. Sources to 1) change the KW value of Train A HPSI pump from 696 KW to 771 KW, and the KW value of Train B AFW
N 161-04124-WFC/DAF August 21, 1991 pump from 839 KW to 903 KW, and 2) reverse t:he loading sequence for the 24-hour diesel generator surveillance tests.
APS has determined that the proposed amendments involve no change in the amount or type of any effluent that may be released offsite, and that there is no increase in individual or cumulative occupational
'adiation exposure. 'As 'such, operation of PVNGS Units l, 2, and 3, in accordance with the proposed amendments, does not involve an unreviewed environmental safety question.
G. MARKED-UP TECHNICAL SPECIFICATION CHANGE PAGES See attached pages 3/4 8-4 and 3/4 8-5 for PVNGS Units l, 2, and 3, respectively.
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