ML17305A329

Application for Amends to Licenses NPF-41,NPF-51 & NPF-74, Changing Flow Specs for HPSI Pump Simultaneous Hot Leg & Cold Leg Injection Flow Balancing

ML17305A329
Person / Time
Site:	Palo Verde
Issue date:	10/25/1989
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17305A330	List: ML17305A329
References
161-02522-WFC-R, 161-2522-WFC-R, NUDOCS 8911020024
Download: ML17305A329 (17)

Text

ACCELERATED IIISIBUTION DEMONSTRA ON SYSI'EM REGULATORY INFORMATION DISTRIBUTION TEM (RIDS)

ACCESSION NBR:8911020024'OC.DATE: 89/10/25 NOTARIZED: NO DOCKET FACIL:STW-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 ST4-50-529 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 RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Application for amends to Licenses NPF-41,,NPF-51 & NPF-74, changing flow specs for high pressure safety injection pump.

DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR I ENCL / SIZE:

TITLE: OR Submittal: General Distribution S

NOTES:

Standardized plant.

Standardized plant.

05000528 05000529 05000530

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RECIPIENT COPIES RECIPIENT COPIES

.ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1

'CHAN,T 5 5 DAVIS,M. 5 5 INTERNAL: ACRS 6 6 NRR/DEST/ADS 7E 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/RSB 8E 1 1

'NRR/DOEA/TSB 11 1 1 NUDOCS-ABSTRACT 1 1 OC 1 0 OGC/HDS1 1 0 G F 01  :

1 1 RES/DSIR/EIB 1 1 EXTERNAL: LPDR 1 1 NRC PDR 1 1 NSIC 1 1 NOTES: 1 1 D

h TOTAL NUMBER OF COPIES REQUIRED: LTTR 33 ENCL 31

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Arizona Public Service Company P.O. BOX 53999 ~ PHOENIX, ARIZONA 850724999 WILLIAMF. CONWAY 161-02522 WFC/RAB/JRP EXECUTIVEVICE PRESIDENT NUCLEAR October 25, 1989 Docket Nos. STN 50-528/529/530 Document Control Desk U. S. Nuclear Regulatory Commission Mail Station Pl-37 Washington, D. C. 20555

Dear Sirs:

Subj ect: Palo Verde Nuclear Generating Station (PVNGS)

(Units 1, 2, and 3)

Emergency Technical Specification Amendment Request Sections 3/4.5.2.h File: 89-F-005-419.05; 89-056-026 This letter requests an emergency amendment to PVNGS 1, 2, and 3 Technical Specification Surveillance Requirement-4.5.2.h. The proposed change would modify the flow specifications for high pressure safety inj ectioTI (HPSI) pump simultaneous hot leg and cold leg injection flow balancing. This change is needed to allow the startup of Unit 2 which is currently in Mode 3 (hot standby) awaiting approval of this request. Due to an error in,.the original installation of the flow measuring orifices (orifices provide flow indication only and do not provide a flow control function) in the A train HPSI pump hot leg injection lines, the surveillance requirement cannot be met. The orifices installed in the A train HPSI pump hot leg injection lines in Units 1, 2, and 3 were discovered on October 20, 1989, to be approximately 40 thousandths of an inch larger diameter than specified in the instrument calibration data sheets . This resulted in the HPSI hot leg injection flow indicators reading less than the actual flow during the performance of the simultaneous hot leg and cold leg injection testing required by Surveillance Requirement 4.5.2.h. The flow specification is 545 +20 gallons per minute (GPM) flow to both the hot and cold leg injection points. Since this test was performed with hot leg flow indicators reading lower than actual flow the results were a higher actual flow than the current Technical Specification allowable. The corrected value of the flow from the previous tests shows that the actual flows were approximately 30 GPM higher than the hot leg injection flow indication.

Reperformance of the testing is not required since the errors in the original tests are determinable and the actual flow rates known. An analysis by Combustion Engineering and PVNGS Nuclear Engineering Department has determined that the actual flow rates achieved during the original testing are acceptable from a safety analysis standpoint and will meet all the original design requirements. Furthermore, there would be a significant schedule and economic impact if this amendment is not processed in a timely manner..

o~l 89ii020024 89i025 Ill PDR ADOCK 05000528 P PNU

161-02522 WFC/RAB/JRP October 25, 1989 Enclosed with this amendment request are:

A. Description of Amendment Request B. Purpose of the Technical Specification, C. Need for the Technical Specification Change D. Basis for No Significant Hazards Consideration E. Safety Analysis'f the Proposed Change Request F. Environmental Impact Consideration Determination G. Revised Technical Specification Change Pages Pursuant to 10 CFR 50.91(b)(1) a copy of this request has been forwarded to the Arizona Radiation Regulatory Agency.

If there are any questions concerning this request, please contact Mr. R. A. Bernier, Licensing Manager, at (602) 371-4295.

Sincerely, WFC/JST/)le Attachments cc: J. B. Martin (all w/a)

M. J. Davis G. W. Knighton T. L. Chan T. J. Polich C. F. Tedford

I Descri tio'n of Amendment Re est This amendment request proposes changes to Surveillance Requirement 4.5.2.h. The Surveillance Requirement is performed to verify that during HPSI pump simultaneous hot and cold leg injection, the flows to each leg are 545 +20 gpm. This surveillance test is required to be performed following completion of modifications to Emergency Core Cooling System (ECCS) subsystems that. alter the subsystem flow characteristics. The proposed amendment would revise this flowrate to a minimum value of 525 gpm per injection leg and a maximum total flow specification of 1200 gpm. The 525 gpm minimum value is consistent with the currently docketed analysis. The 1200 gpm total flow value is below the actual runout flow value of the pump.

The runout value of 1130 gpm, stated in the Updated Final Safety Analysis Report (UFSAR), was a minimum design specification and does not reflect the actual capability of the installed HPSI pumps.

The UFSAR will be changed to agree with Technical Specifications.

Also included as a change is a typographical error in Section 4.5.2.g.2, Low Pressures Safety Injection (LPSI) valves were incorrectly numbered SIA-UV-306 and SIB-UV-307. The correct valve numbers are SIA-HV-306 and SIB-HV-307.

B. Pur ose of the Technical S ecification The purpose of Surveillance Requirement 4.5.2.h is to verify long-term core cooling capability in the recirculation mode during the accident recovery period. This accomplishes three objectives: (1) prevents total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration, (2) prevents precipitation of boron in the reactor vessel during long-term cooling, and (3) provides sufficient flow to remove decay heat by boiloff without uncovering the core. The proposed amendment does not affect the currently docketed analysis for objectives (2) and (3) ~ The minimum flow of 525 gpm to the hot and cold leg injection 1

legs is not being changed. The maximum total flow of 1200 gpm (to prevent runout) is based on the installed capabilities of the HPSI pumps rather than the minimum design specification runout flow of 1130 gpm. The 1200 gpm flow has been reviewed by PVNGS Nuclear Engineering Department, Combustion Engineering, and Ingersol-Rand and determined to be within the capability of the pump. Thus the proposed amendment only involves raising the maximum total flow from its current Technical Specification value of 1130 gpm to 1200 gpm to reflect the capability of the installed pump.

C. Need for the Technical 8 ecification Chan e During a review of the HPSI pump simultaneous hot leg and cold leg injection flow balancing procedure in Unit 1 (Mode 6), it was discovered that the orifice installed in the A train HPSI pump hot leg injection line was incorrect in that it was 0.040 of an inch larger than specified in the instrument calibration data sheets.

After this discovery on October 20, 1989 in Unit 1, Units 2 and 3 were visually inspected and found to be in the same configuration.

An Emergency Technical Specification Amendment is necessary in order for Unit 2 to resume power operation and for Unit 3 to enter Mode 3 in early November 1989 after its present refueling outage.

The emergency circumstances do not apply to Unit 1, however we request that the Emergency Technical Specification Amendment include Unit 1.

The only alternative available to an Emergency Technical Specification Amendment would be to reperform'low balancing which would require Unit 2 to enter Mode 5 (cold shutdown) and operate in a reduced inventory condition in order to perform the retest.

Unit 3 (in Mode 5) would have to operate in a reduced inventory condition in order to perform the flow balance. After consideration, of~ this option, it was concluded that an Emergency l

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Technical Specification Amendment is the only alternative available.

In conclusion, this situation was recently discovered and every effort has been taken to avoid requesting an Emergency Technical Specification Amendment. However, based on our review, an Emergency Technical Specification Amendment is the only practical solution to restore the Units to operation in a timely and safe manner.

D. Basis for No Si nificant Hazards Consideration 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: (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, follows:

Standard 1 Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed amendment increases the maximum allowable flow from the HPSI pump during simultaneous hot and cold leg injection. The HPSI pump minimum runout flow was originally specified at 1130 gpm in both the Combustion Engineering Standard Safety Analysis Report System 80 (CESSAR) and to the pump vendor, Ingersol-Rand.

Ingersol-Rand has verified that the pumps that are capable of flows greater than 1200 gpm. This amendment utilizes the measured

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capability of the pump to increase the operational flexibility in the hot and cold leg simultaneous injection flow balancing. The assumptions in the safety analysis are not affected as the minimum flow values to both the hot and cold legs are maintained. The increased maximum flow value will increase the margin of safety in the analysis by allowing increased flushing flow to the vessel while maintaining the HPSI pump below its runout flowrate.

Standard 2 Create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed amendment to the Technical Specification Surveillance Requirements does not alter the plant configuration or operation.

Credit is taken for the actual installed capability of the HPSI pumps. Increasing the maximum allowable flow beyond the minimum design specification of 1130 gpm can improve the plants performance during the long-term cooling phase of a loss of coolant accident.

The increased flow can provide a greater flushing action to prevent boron precipitation in the vessel and more water for decay heat removal during the long-term cooling phase of the accident.

Standard 3 Involve a significant reduction in a margin of safety.

As discussed in Standard 2, the proposed amendment can improve the margin of safety during the long-term cooling following a loss of I

coolant accident. The margin of safety during long-term cooling is determined by adequate flow to the vessel to match decay heat boiloff, prevent boron 'precipitation in the reactor vessel, and keep the HPSI pump flow b'elow runout. All thr'ee of these requirements will be satisfied by the proposed, amendment.

1 The increased allowable flow ,can provide. more margin to the flow required to the vessel to match the boiloff due to decay heat and prevent boron precipitation. The higher maximum allowable flow will also be below the runout condition of the HPSI pump. The PVNGS Nuclear Engineering Department also performed a review of the

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net positive Suction head (NPSH) requirements for the HPSI pump and the diesel generator loading during long-term cooling and found this change to be acceptable to both.

The proposed change does not, match any of the examples, given in 51 FR 7751 of amendments, that do not involve a significant hazards consideration. The proposed amendment is a change resulting from a review of the installed equipment capabilities versus the original specification. In this case the allowable flowrate value was provided by Combustion Engineering and Ingersol-Rand after a review of the HPSI pump performance. This review verified that the HPSI pump will perform in excess of the original minimum design specifications for runout and allows this proposed increase in operational flexibility during simultaneous hot and cold leg HPSI pump flow balancing.

E. Safet Anal sis of the Pro osed Chan e Re est Technical Specification Surveillance Requirements for the Emergency Core Cooling System (ECCS) are intended to ensure that the system performs acceptably with respect to the assumptions used in the safety analysis and that the system operability is maintained. The change to the surveillance requirements associated with this amendment relates to the operation of the High Pressure Safety Injection (HPSI) System in the simultaneous hot leg and cold leg injection mode.

The intent, of the subject requirement is to ensure that a minimum quantity of flow is delivered to the intact side of the reactor coolant system (RCS) following'a loss of coolant accident, to remove core decay heat and also to provide sufficient flow for core flushing. The current technical specification assures this by requiring an approximately equal distribution of a minimum flow to each side of the RCS.

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t However, because an equal distribution is not a specific requirement. of the analysis, the surveillance requirement is being restated via this amendment in order to gain operational flexibility. The amended requirement will maintain the existing individual hot and cold leg minimum flow rate limits but replaces the individual hot and cold leg maximum flow rate limits with a maximum combined flow rate. This limits total system flow to avoid pump runout conditions without unnecessary restrictions on the system flow balance. This gain in flexibility does not result in a reduction in the current margin of safety. The current minimum flow capabilities are unchanged.

The existing allowable maximum flow rate of the system will be increased. This is possible due to the existence of available margin to the pump runout condition. The existence of this margin has been confirmed with the pump vendor Ingersol-Rand. The existing maximum value of 1130 gpm is based upon the minimum specified design value of the System 80 standard design. The revised maximum value takes advantage of the actual performance capabilities of the HPSI pumps. Based upon the available pump data, the HPSI pumps can perform acceptably at flow rates of as much as 1300 gpm. This available data consists of individual pump performance curves for each of the HPSI pumps. These curves provide specific information on total developed head, minimum NPSH requirements, efficiency, and brake horsepower.

The proposed Surveillance Requirement will specify a maximum total flow rate of 1200 gpm. This value is conservatively chosen as a limit which is sufficiently less than 1300 gpm to account for instrumentation uncertainties yet greater than the current tested system flow rates.

P. Environmental Im act Consideration Determination

The proposed'hange request does not involve an unreviewed environmental question because operation of PVNGS Units 1, 2, and 3 in accordance with this change would not:

Result in a significant increase in any adverse environmental impact previously evaluated in the Final Environmental Statement (FES) as modified by the staff's testimony to the Atomic Safety and Licensing Board, Supplements to the FES, Environmental Impact Appraisals, or in any decisions of the Atomic Safety Licensing Board: or

2. Result in a significant change in effluents or

'ower levels; or

3. Result in matters not previously reviewed in the licensing basis for PVNGS which may have a significant environmental impact.

The proposed change does not affect offsite dose calculations or any other plant effluent.

G. Revised Technical S ecification Chan e Pa es See attached marked-up pages 3/4 5-6 and B 3/4 5-3.