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| {{#Wiki_filter:DOCKET 05000528 05000529 05000530 | | {{#Wiki_filter:CATEGORY y |
| | REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) l~ |
| | ACCEbSION NBR:9801070174 DOC.DATE: 97/12/30 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 LEVINE,J.M. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk) |
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| ==SUBJECT:== | | ==SUBJECT:== |
| Provides APS 90 day response to NRC GL 97-04,"Assurance of Sufficient Net Positive Suction Head for ECC&.Containment Heat Removal Pumps." DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE: TITLE: OR Submittal: | | Provides APS 90 day response to NRC GL 97-04, "Assurance of Sufficient Net Positive Suction Head for ECC &. Containment Heat Removal Pumps." |
| Gen'eral Distribution y CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)l~ACCEbSION NBR:9801070174 DOC.DATE: 97/12/30 NOTARIZED: | | DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE: |
| YES FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi AUTH.NAME AUTHOR AFFILIATION LEVINE,J.M.
| | TITLE: OR Submittal: Gen'eral Distribution NOTES:STANDARDIZED PLANT 05000528@ |
| Arizona Public Service Co.(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)NOTES:STANDARDIZED PLANT Standardized plant.Standardized plant.05000528@'05000529 05000530()
| | Standardized plant. '05000529 Standardized plant. 05000530() |
| RECIPIENT ID CODE/NAME PD4-2 LA CLIFFORD,J COPIES LTTR ENCL 1 1 1 1 RECIPIENT ID CODE/NAME PD4-2 PD COPIES LTTR ENCL 1 1 INTERNAL: ACRS NRR/DE/ECGB/A NRR/DRCH/HICB NRR/DSSA/SRXB OGC/HDS2 EXTERNAL: NOAC 1 1 1 1 1 1 1 1 1 0 1 1 CENTER NRR/DE M B NRR/DSSA/SPLB NUDOCS-ABSTRACT NRC PDR 1 1 1 1 1 1 1 1 D U E N NOTE TO ALL"RIDS" RECIPIENTS: | | RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 LA 1 1 PD4-2 PD 1 1 CLIFFORD,J 1 1 INTERNAL: ACRS 1 1 CENTER 1 1 NRR/DE/ECGB/A 1 1 NRR/DE M B 1 1 NRR/DRCH/HICB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 D OGC/HDS2 1 0 EXTERNAL: NOAC 1 1 NRC PDR U |
| PLEASE HELP US TO REDUCE WASTE.TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL 13 Cammltment. | | E N |
| InnovattNL Energy.Pa'lo Verde Nuclear Generating Station James M.Levine Senior Vice President Nuclear TEL (602)393-5300 FAX (602)3934077 Mall Station 7602 P.O.Box 52034 Phoenix, AZ 65072-2034 102-04057-JMUAKK/JRP December 30, 1997 U.S.Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001 | | NOTE TO ALL "RIDS" RECIPIENTS: |
| | PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL 13 |
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| | Cammltment. InnovattNL Energy. |
| | James M. Levine TEL (602)393-5300 Mall Station 7602 Pa'lo Verde Nuclear Senior Vice President FAX (602)3934077 P.O. Box 52034 Generating Station Nuclear Phoenix, AZ 65072-2034 102-04057 JMUAKK/JRP December 30, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001 |
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| ==Subject:== | | ==Subject:== |
| Palo Verde Nuclear Generating Station (PVNGS)Units 1,2, and 3 Docket Nos.STN 60-628/629/630 Response to NRC Generic Letter 97-04 This letter provides Arizona Public Service Company's (APS), 90 day response to NRC Generic Letter 97-04,"Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps".The attached response addresses items 1-5 of the Requested Information Section of the Generic Letter.In addition to the response, APS is working with the Combustion Engineering Owners Group (GEOG)and other industry groups in addressing the issues associated with the referenced Generic Letter.Should you have any questions or concerns plea'se contact Scott A.Bauer at (602)393-5978.Sincerely, JMUAKK/JRP/rlh Attachment cc: E.W.Merschoff K.E.Perkins J.W.Clifford J.H.Moorman 9801070i74 971230 PDR ADGCK 05000528 P PDR | | Palo Verde Nuclear Generating Station (PVNGS) |
| | Units 1,2, and 3 Docket Nos. STN 60 - 628/629/630 Response to NRC Generic Letter 97-04 This letter provides Arizona Public Service Company's (APS), 90 day response to NRC Generic Letter 97-04, "Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps ". |
| | The attached response addresses items 1-5 of the Requested Information Section of the Generic Letter. In addition to the response, APS is working with the Combustion Engineering Owners Group (GEOG) and other industry groups in addressing the issues associated with the referenced Generic Letter. |
| | Should you have any questions or concerns plea'se contact Scott A. Bauer at (602) 393-5978. |
| | Sincerely, JMUAKK/JRP/rlh Attachment cc: E. W. Merschoff K. E. Perkins J. W. Clifford J. H. Moorman 9801070i74 971230 PDR ADGCK 05000528 P PDR |
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| | STATE OF ARIZONA ) |
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| | COUNTY OF MARICOPA ) |
| | I, J. M. Levine, represent that I am Senior Vice President - Nuclear, 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 Bc9(A Day Of , 1997. |
| | Notary Public orrcQL sQL My Commission Expires MORA E. MEADOR Wotan Pobtio - State of Arizona MARrtCOPA COUNTY My Contnt. Bp'es Apnt 6, 1999 |
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| | ATTACHMENT RESPONSE TO NRC GENERIC LETTER 97-04 ASSURANCE OF NET POSITIVE SUCTION HEAD FOR EMERGENCY CORE COOLING AND CONTAINMENTHEAT REMOVAL PUMPS The following is provided in response to NRC Generic Letter 97-04, Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps, dated October 7, 1997 for Palo Verde Nuclear Generating Station. |
| | SYSTEMS OVERVIEW Palo Verde is a three unit Combustion Engineering System 80 pressurized water reactor facility with an Emergency Core Cooling System (ECCS) and a Containment Spray System (CSS) which function to provide cooling flow to the core and to reduce containment pressure, respectively, following certain design basis accidents. The ECCS is comprised of two independent trains each with one high pressure safety injection (HPSI) system and one low pressure safety injection (LPSI) system. The train related HPSI, LPSI and CSS pump suctions are aligned in parallel to the respective train containment sump following depletion of the borated water inventory in the Refueling Water Tank. These are the only pumps which take suction from the recirculation sump during accident conditions. Figure 1 illustrates the Palo Verde configuration. |
| | GENERIC LETTER 97-04 RESPONSES |
| | : 1. Specify the general methodology used to calculate the head loss associated with the ECCS suction strainers (sump screens). |
| | The response to this question will conservatively encompass the total methodology used to quantify the available net positive suction head (NPSHA) to the ECCS pumps and the CSS Pumps, inclusive of the specific methodology for the calculation of the loss associated with the ECCS sump screens. The general methodology used at Palo Verde to calculate the NPSHA for the ECCS and CSS pumps is as follows: |
| | The basic equation for calculating NPSH is: |
| | NPSH h+ hyp+ + h3) hi8 where: |
| | h, = absolute pressure on the surface of the liquid supply level. |
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| | h, = head corresponding to the vapor pressure of the liquid at the temperature being pumped. |
| | h= static height that the liquid supply level is above or below the pump centerline or impeller eye. |
| | h= suction line losses including entrance losses and friction losses. |
| | Additional detail on each of the terms is provided below. |
| | h, - absolute pressure on the surface of the liquid supply level This term is the containment pressure above atmospheric pressure that is taken credit for in the analysis. Palo Verde, however, does not credit containment overpressure and conservatively assumes that the sump fluid is saturated at the containment pressure at all times. Hence, h, is assumed equal to the vapor pressure of the sump fluid at the pump suction, h. |
| | h- head corresponding to the vapor pressure of the liquid at the temperature being pumped As noted for the absolute pressure term, h the Palo Verde NPSHA analyses assume that the sump fluid is at saturated conditions. Since containment overpressure is not credited and therefore h, is equal to h, the sump fluid temperature is irrelevant and the available head reduces to the difference between the static water head and the suction losses defined below. |
| | h- static height that the liquid supply level is above or below the pump centerline or impeller eye This term is the minimum static height of fluid above the ECCS and CSS pump datum. The minimum water height in containment following a LOCA, for conditions which will result in transfer of the ECCS and CSS pump suction to the recirculation sump, has been calculated assuming minimum transfer volume from the RWT and other water sources. |
| | h- all suction line losses including entrance losses and friction losses Palo Verde has calculated the total suction line losses for the ECCS and CSS pumps using standard industry methodology. In |
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| | general, the calculated line losses are the sum of the losses for the total piping runs and the losses for the valves, fittings and components. Additional loss is applied for entrance and exit effects due to the sump screen. Loss due to the accumulation of fibrous debris. is also included in accordance with NRC Regulatory Guide 1.82, Revision 1, Sumps for Emergency Core Cooling and Containment Spray Systems. |
| | Piping losses are based on friction factors for clean stainless steel piping. No consideration of aging or increased pipe roughness is included due to the relative cleanliness of the water and minimum system operation time. |
| | Maximum (conservative) head loss is predicated on bounding system operation which maximizes the suction flow rate for each of the pumps and for the common suction flow paths. For Palo Verde, the suction piping head loss is calculated assuming concurrent operation of the train related ECCS and CSS pumps at their respective vendor specified run-out flow rates during the limiting mode of operation. No credit for variable ECCS or CSS flow rate, as a function of containment pressure, is assumed. |
| | The limiting mode of operation considered in the evaluation of NPSHA is recirculation following injection for a large break or certain small break LOCAs. No other design basis accidents, such as the Main Steam Line Break event, result in sufficient depletion of the Refueling Water Tank which would initiate the transfer of the ECCS and CSS pump suction to the recirculation sump. No other mode of operation requires a suction flow path from the recirculation sump for which NPSH must be evaluated. |
| | The Palo Verde recirculation sump screen design is described in the PVNGS UFSAR, Section 6.2.2.2. The screen is composed of an outer trash rack, a medium coarse screen, and a fine inner screen. Head loss for the clean composite screen is calculated by summing the losses across the rack and each screen. The calculated losses are predicated on maximum flow conditions corresponding to concurrent operation of the train related ECCS and CSS pumps at design runout flow rate. The resultant head losses are based on published empirical correlations and have been determined to be negligible. This conclusion is supported by initial sump design testing by the Architect - Engineer. |
| | The head loss across the sump screen associated with fibrous debris accumulation has been incorporated in accordance with |
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| | NRC Regulatory Guide 1.82, Revision 1. The head loss correlation published in NUREG-0897, Containment Emeergency Sump Performance, has been applied to quantify the loss conservatively assuming equal debris loading on the available flow area of the sump screen. The available flow area considers the fraction of screen area blocked by failed coatings. The total quantities of fibrous debris and failed coatings are conservatively assumed in these calculations. |
| | : 2. Identify the required NPSH and the available NPSH. |
| | The required EPICS and CSS pump NPSH is based on vendor specified requirements for the pumps at runout conditions. These requirements are conservatively imposed for all operating conditions and flow rates up to and including runout. The following represent the bounding conditions (i.e. minimum margin) for available NPSH and are compared to the vendor specified required NPSH. |
| | PUMP NPSH REQUIRED NPSH - AVAILABLE MARGIN (ff) (ft) (ft) |
| | CS 22 25.8 3.8 LPSI 20 26.1 6.1 HPSI 25 28.8 3.8 Note that the Combustion Engineering System 80 ECCS design includes termination of the LPSI pump injection upon switchover to recirculation and suction from the recirculation sump. However, the available NPSH for the LPSI pump has been evaluated to ensure that the adequate suction head is available to support operation should operators elect to override the ESF logic and realign the pump to provide additional core flow. This mode of operation, however, is not credited in the Palo Verde UFSAR Chapter 15 analyses. Note also that the available NPSH for the HPSI and CSS pumps conservatively assume concurrent operation of the LPSI pump during recirculation. |
| | : 3. Specify whether the current design-basis NPSH analysis differs from the most recent analysis reviewed and approved by the NRC for which a safety evaluation was issued. |
| | The most recent NPSH analysis reviewed and approved by the NRC is that documented in the Palo Verde SER (NUREG-0857), Section 6.2.2 and Section 6.3.1. The calculations which supported the original SER, however, have been revised. Revision to the calculations was made in order to incorporate recirculation sump screen blockage as required by Regulatory Guide 1.82, Supplement 1 and were revised using the methodology of NUREG-0897. None of the general |
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| STATE OF ARIZONA))ss.COUNTY OF MARICOPA)I, J.M.Levine, represent that I am Senior Vice President-Nuclear, 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 Bc9(A Day Of , 1997.Notary Public My Commission Expires orrcQL sQL MORA E.MEADOR Wotan Pobtio-State of Arizona MARrtCOPA COUNTY My Contnt.Bp'es Apnt 6, 1999 I H II'tt ATTACHMENT RESPONSE TO NRC GENERIC LETTER 97-04 ASSURANCE OF NET POSITIVE SUCTION HEAD FOR EMERGENCY CORE COOLING AND CONTAINMENT HEAT REMOVAL PUMPS The following is provided in response to NRC Generic Letter 97-04, Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps, dated October 7, 1997 for Palo Verde Nuclear Generating Station.SYSTEMS OVERVIEW Palo Verde is a three unit Combustion Engineering System 80 pressurized water reactor facility with an Emergency Core Cooling System (ECCS)and a Containment Spray System (CSS)which function to provide cooling flow to the core and to reduce containment pressure, respectively, following certain design basis accidents.
| | calculational methodology of the original calculation, which was reviewed and approved by the NRC, was affected. |
| The ECCS is comprised of two independent trains each with one high pressure safety injection (HPSI)system and one low pressure safety injection (LPSI)system.The train related HPSI, LPSI and CSS pump suctions are aligned in parallel to the respective train containment sump following depletion of the borated water inventory in the Refueling Water Tank.These are the only pumps which take suction from the recirculation sump during accident conditions.
| | : 4. Specify whether containment overpressure (i.e. containment pressure above the vapor pressure of the sump or suppression pool fluid) was credited in the calculation of available NPSH. Specify the amount of overpressure needed and the minimum overpressure available. |
| Figure 1 illustrates the Palo Verde configuration.
| | No containment overpressure is credited in the calculation of available NPSH for Palo Verde as described in the response to Question 1. |
| GENERIC LETTER 97-04 RESPONSES 1.Specify the general methodology used to calculate the head loss associated with the ECCS suction strainers (sump screens).The response to this question will conservatively encompass the total methodology used to quantify the available net positive suction head (NPSHA)to the ECCS pumps and the CSS Pumps, inclusive of the specific methodology for the calculation of the loss associated with the ECCS sump screens.The general methodology used at Palo Verde to calculate the NPSHA for the ECCS and CSS pumps is as follows: The basic equation for calculating NPSH is: NPSH h+hyp++h3)hi8 where: h,=absolute pressure on the surface of the liquid supply level.
| | : 5. When containment overpressure is credited in the calculation of available NPSH, confirm that an appropriate containment pressure analysis was done to establish the minimum containment pressure. |
| | Not applicable. |
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| h,=head corresponding to the vapor pressure of the liquid at the temperature being pumped.h=static height that the liquid supply level is above or below the pump centerline or impeller eye.h=suction line losses including entrance losses and friction losses.Additional detail on each of the terms is provided below.h,-absolute pressure on the surface of the liquid supply level This term is the containment pressure above atmospheric pressure that is taken credit for in the analysis.Palo Verde, however, does not credit containment overpressure and conservatively assumes that the sump fluid is saturated at the containment pressure at all times.Hence, h, is assumed equal to the vapor pressure of the sump fluid at the pump suction, h.h-head corresponding to the vapor pressure of the liquid at the temperature being pumped As noted for the absolute pressure term, hthe Palo Verde NPSHA analyses assume that the sump fluid is at saturated conditions.
| | t II Il II SDCHx 484 689 7 69 695 671 693 HPSI2 616 405 478 699 617 113 Cold Leg Loop 2A 44 44 307 615 114 217 LPSI 2 626 TRAIN B Containment Sump 627 Cold Leg 123 |
| Since containment overpressure is not credited and therefore h, is equal to h, the sump fluid temperature is irrelevant and the available head reduces to the difference between the static water head and the suction losses defined below.h-static height that the liquid supply level is above or below the pump centerline or impeller eye This term is the minimum static height of fluid above the ECCS and CSS pump datum.The minimum water height in containment following a LOCA, for conditions which will result in transfer of the ECCS and CSS pump suction to the recirculation sump, has been calculated assuming minimum transfer volume from the RWT and other water sources.h-all suction line losses including entrance losses and friction losses Palo Verde has calculated the total suction line losses for the ECCS and CSS pumps using standard industry methodology.
| | ~7 206 676 62 124 Loop 2B Containment Sump TRAIN A 205 67 HPSI1 673 404 476 698 Cold Leg Loop 1A 306 134 542 LPSI 1 647 143 Cold Leg Loop 1B SDCHx 485 684 678 144 543 247 687 672 FIGURE 1 - ECCS AND CSS CONFIGURATION DURING RECIRCULATION MODE |
| In
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| ~~li general, the calculated line losses are the sum of the losses for the total piping runs and the losses for the valves, fittings and components. | |
| Additional loss is applied for entrance and exit effects due to the sump screen.Loss due to the accumulation of fibrous debris.is also included in accordance with NRC Regulatory Guide 1.82, Revision 1, Sumps for Emergency Core Cooling and Containment Spray Systems.Piping losses are based on friction factors for clean stainless steel piping.No consideration of aging or increased pipe roughness is included due to the relative cleanliness of the water and minimum system operation time.Maximum (conservative) head loss is predicated on bounding system operation which maximizes the suction flow rate for each of the pumps and for the common suction flow paths.For Palo Verde, the suction piping head loss is calculated assuming concurrent operation of the train related ECCS and CSS pumps at their respective vendor specified run-out flow rates during the limiting mode of operation.
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| No credit for variable ECCS or CSS flow rate, as a function of containment pressure, is assumed.The limiting mode of operation considered in the evaluation of NPSHA is recirculation following injection for a large break or certain small break LOCAs.No other design basis accidents, such as the Main Steam Line Break event, result in sufficient depletion of the Refueling Water Tank which would initiate the transfer of the ECCS and CSS pump suction to the recirculation sump.No other mode of operation requires a suction flow path from the recirculation sump for which NPSH must be evaluated.
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| The Palo Verde recirculation sump screen design is described in the PVNGS UFSAR, Section 6.2.2.2.The screen is composed of an outer trash rack, a medium coarse screen, and a fine inner screen.Head loss for the clean composite screen is calculated by summing the losses across the rack and each screen.The calculated losses are predicated on maximum flow conditions corresponding to concurrent operation of the train related ECCS and CSS pumps at design runout flow rate.The resultant head losses are based on published empirical correlations and have been determined to be negligible.
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| This conclusion is supported by initial sump design testing by the Architect-Engineer.The head loss across the sump screen associated with fibrous debris accumulation has been incorporated in accordance with r iII NRC Regulatory Guide 1.82, Revision 1.The head loss correlation published in NUREG-0897, Containment Emeergency Sump Performance, has been applied to quantify the loss conservatively assuming equal debris loading on the available flow area of the sump screen.The available flow area considers the fraction of screen area blocked by failed coatings.The total quantities of fibrous debris and failed coatings are conservatively assumed in these calculations.
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| 2.Identify the required NPSH and the available NPSH.The required EPICS and CSS pump NPSH is based on vendor specified requirements for the pumps at runout conditions.
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| These requirements are conservatively imposed for all operating conditions and flow rates up to and including runout.The following represent the bounding conditions (i.e.minimum margin)for available NPSH and are compared to the vendor specified required NPSH.PUMP CS LPSI HPSI NPSH-REQUIRED NPSH-AVAILABLE (ff)(ft)22 25.8 20 26.1 25 28.8 MARGIN (ft)3.8 6.1 3.8 Note that the Combustion Engineering System 80 ECCS design includes termination of the LPSI pump injection upon switchover to recirculation and suction from the recirculation sump.However, the available NPSH for the LPSI pump has been evaluated to ensure that the adequate suction head is available to support operation should operators elect to override the ESF logic and realign the pump to provide additional core flow.This mode of operation, however, is not credited in the Palo Verde UFSAR Chapter 15 analyses.Note also that the available NPSH for the HPSI and CSS pumps conservatively assume concurrent operation of the LPSI pump during recirculation.
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| 3.Specify whether the current design-basis NPSH analysis differs from the most recent analysis reviewed and approved by the NRC for which a safety evaluation was issued.The most recent NPSH analysis reviewed and approved by the NRC is that documented in the Palo Verde SER (NUREG-0857), Section 6.2.2 and Section 6.3.1.The calculations which supported the original SER, however, have been revised.Revision to the calculations was made in order to incorporate recirculation sump screen blockage as required by Regulatory Guide 1.82, Supplement 1 and were revised using the methodology of NUREG-0897.
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| None of the general
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| calculational methodology of the original calculation, which was reviewed and approved by the NRC, was affected.4.Specify whether containment overpressure (i.e.containment pressure above the vapor pressure of the sump or suppression pool fluid)was credited in the calculation of available NPSH.Specify the amount of overpressure needed and the minimum overpressure available.
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| No containment overpressure is credited in the calculation of available NPSH for Palo Verde as described in the response to Question 1.5.When containment overpressure is credited in the calculation of available NPSH, confirm that an appropriate containment pressure analysis was done to establish the minimum containment pressure.Not applicable.
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| t II Il II SDCHx 484 689 7 69 695 671 693 HPSI2 LPSI 2 44 44 TRAIN B 405 478 699 307 615 616 617 113 114 626 217 Cold Leg Loop 2A Containment Sump~7 206 676 62 627 123 124 Cold Leg Loop 2B Containment Sump HPSI1 LPSI 1 205 67 673 404 476 698 306 TRAIN A 134 542 Cold Leg Loop 1A SDCHx 485 684 678 647 143 144 543 247 Cold Leg Loop 1B 687 672 FIGURE 1-ECCS AND CSS CONFIGURATION DURING RECIRCULATION MODE f'k.C-I D'll}}
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Category:CORRESPONDENCE-LETTERS
MONTHYEARML17313B0991999-10-14014 October 1999 Forwards LER 99-005-00 Reporting Findings & Corrective Actions Taken as Result of Out of Tolerance MSSV Condition in Unit 1 Which Was Discovered During pre-outage Testing ML17313B0881999-10-12012 October 1999 Forwards Response to NRC 990831 RAI Re Several Relief Requests That Accompanied Second ten-yr Interval ISI Program Submitted on 980317.Revised Relief Request 6 Is Provided in Encl 2 ML17300B3501999-09-29029 September 1999 Forwards Revised Bases Pages,Providing Addl Discussion of Options Available to Exit Required Action G of TS 3.8.1 & Revised Page for TS 3.3.7,in Response to NRC RAI Re Proposed Amend to TS 3.8.1 & 3.3.7 ML17300B3551999-09-28028 September 1999 Responds to Aministrative Ltr 99-03, Preparation & Scheduling of Operator Licensing Exams. Proposed Palo Verde Operator Licensing Exam Schedule & Estimated Number of Applicants Planning to Take Exams Encl ML17313B0851999-09-24024 September 1999 Requests Approval of Alternative to Repair Requirements of 10CFR50.55a,authorizing Alternative Use of Mechanical Nozzle Seal Assemblies,As Described in Encl,For RCS Hot Leg Instrumentation & Sampling Nozzles for Two Operating Cycles ML17313B0781999-09-20020 September 1999 Forwards Rev 22 to PVNGS Emergency Plan. Summary Description of Changes,Included ML17300B3331999-09-14014 September 1999 Forwards MOR for August 1999 & Revised MOR for Jul 1999 for Pvngs,Units 1,2 & 3 ML17300B3351999-09-0808 September 1999 Informs That Repairs to Plant EDG 2A Jacket Water Cooling sub-sys Were Completed & EDG Was Declared Operable on 990903 at Approx 21:45 Mst.Noed Was Not Necessary,Since 72 Hour Completion Time Was Met ML17313B0761999-09-0303 September 1999 Requests Enforcement Discretion to TS Section 3.8.1, AC Sources - Operating. Enforcement Discretion Would Allow,On One Time Basis,Extension of Completion Time in Required Action B.4 of TS 3.8.2 from 72 H to 108 H ML17313B0731999-08-31031 August 1999 Informs That RR Bean (License OP-50452-1) Has Been Permanently Reassigned to Position That Does Not Require License & Requests That Individuals License Be Expired Per 10CFR55.55 ML20211A9501999-08-12012 August 1999 Discusses 990720-21 Workshop Conducted in Region IV Ofc,Re Exchange of Info in Area of Use of Risk Insights in Regulatory Activities.List of Attendees,Summary of Topic & Issues,Agenda & Copies of Handouts Encl ML17313B0581999-08-0606 August 1999 Forwards Rev 1 of Changes to TS Bases Implemented Between Aug 1998 & Jul 1999.Insertion Instructions & List of Affected Pages Included ML17313B0311999-08-0303 August 1999 Submits Response to NRC AL 99-02, Operating Reactor Licensing Actions Estimates, for Fys 2000 & 2001 ML20210L1461999-08-0303 August 1999 Informs That NRC Plans to Administer Gfes of Written Operator Licensing Exam on 991006.Requests Submittal of Ltr Identifying Individuals Taking Exam,Personnel Allowed Access to Exams & Mailing Address for Exams ML17313B0431999-07-30030 July 1999 Advises of Listed Senior Mgt Changes That Have Taken Place at Plant ML17313B0441999-07-30030 July 1999 Forwards Comments on Draft NRC Repts Evaluation of AOVs at Us Light-Water Reactors (1999) & Idaho Natl Engineering & Environ Lab Rept (INEEL)EXT-98-00383,Study of AOVs in Npps. ML17313B0151999-07-20020 July 1999 Submits Request to Obtain All Data Previously Sent by PVNGS & Currently in REIRS for OLs NPF-41,NPF-51 & NPF-74.Data Is Requested in Electronic Form (Ascii Format) as It Currently Exists in REIRS Sys ML17313B0091999-07-20020 July 1999 Forwards Requested Calculations Performed to Verify That Increase in Max Radially Averaged Enrichment for Fuel Assemblies from 4.3 Weight Percent to 4.8 Weight Percent Did Not Affect Requirements for TSs 3.7.15,3.7.17 & 4.3.1 ML17313B0171999-07-16016 July 1999 Forwards LER 99-005-00,re Automatic Rt Which Occurred on 990618,following Sensor Failure in Core Protection Calculators.Corrective Actions Described in LER Are Not Necessary to Maintain Compliance with Regulations ML17300B3111999-07-15015 July 1999 Forwards PVNGS Unit 2 ISI Rept for Eighth Refueling Outage. No Commitments Made to NRC by Ltr ML17300B3141999-07-15015 July 1999 Forwards Corrected Electronic Files for Individual Monitoring Repts for 1998.Original Electronic Files Were Found to Have Two Administrative Errors,Which Has Been Corrected.Encl Withheld,Per 10CFR2.790 ML20209G6771999-07-0808 July 1999 Forwards Supplemental Info to Confirm That Decommissioning Funding Plans of Public Service Co of Nm for Interests in PVNGS Have Been Reviewed by Nm Public Regulation Commission. Final Order & Recommended Decisions in Case 2742,also Encl ML17300B2931999-07-0202 July 1999 Submits Withdrawal of Relief 5 for Second ISI Interval for Units 1,2 & 3.Proposed Alternative Is Related to Exam Requirements for Component Supports for Second ISI Interval ML17313A9951999-06-26026 June 1999 Provides Response to NRC GL 98-01,Suppl 1, Y2K Readiness of Computer Sys at Nuclear Power Plants. ML17300B2831999-06-26026 June 1999 Requests NRC Approval of Proposed Alternative IAW Provisions of 10CFR50.55a(a)(3)(i) to 10CFR50.55a(g) & Requirements of ASME Boiler & Pressure Vessel Code Section XI for Repairs & Installation.Description of Proposed Alternative,Encl ML17313A9901999-06-15015 June 1999 Forwards Response to RAI Re GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Movs. No Commitments Being Made to NRC by Ltr ML17313A9521999-05-24024 May 1999 Notifies NRC That Ja Proctor,License SOP-50314,has Been Permanently Reassigned to Position That Does Not Require License.License Should Be Expired,Per 10CFR55.55 ML20206Q3111999-05-18018 May 1999 Final Response to FOIA Request for Documents.Forwards App a Records Being Released in Entirety ML17313A9311999-05-13013 May 1999 Notifies NRC That Rev 2 to COLR for Unit 2 Remains Applicable Following Recently Completed Unit 2 Reload ML17313A9481999-05-12012 May 1999 Informs of Change Needed in Order to Update Current Mailing List.Future Mailings for J Horne Should Be Forwarded to Listed Address ML17313A9261999-05-0707 May 1999 Forwards LER 99-004-00,per 10CFR50.73.LER Repts Findings & Corrective Actions Taken as Result of Unit 2 Out of Tolerance Pressurizer Safety Valve (Psv) Condition Which Was Discovered During Outage Testing ML20206H1931999-05-0303 May 1999 Forwards 1998 Annual Rept, for SONGS Units 2 & 3 & PVNGS Units 1,2 & 3.SCEs Form 10K Annual Rept to Securites & Exchange Commission for Fiscal Yr Ending 981231,encl ML17313A9091999-04-30030 April 1999 Forwards Proprietary Proposed Test Outlines for Initial License Exams to Be Administered at PVNGS in Aug/Sept 1999. No Commitments Are Contained in Ltr.Proprietary Info Withheld ML17313A9181999-04-30030 April 1999 Forwards Electronic File of Individual Monitoring Repts for 1998.Encl Withheld Per 10CFR2.790 ML17313A9191999-04-30030 April 1999 Forwards Special Rept 2-SR-99-001 Re SG Tube Plugging in PVNGS Unit 2,per TS Reporting Requirement 5.6.8.Complete Results of SG Tube Inservice Insp Will Be Submitted by 000422 ML17300B3751999-04-23023 April 1999 Forwards LER 99-003-00,reporting Condition Prohibited by TS 3.7.17 Where Spent Fuel Assembly Was Stored in Inappropriate Region in Spent Fuel Pool ML17313A9081999-04-23023 April 1999 Documents 990421 Telcon with E Emeigh,Which Requested Extension for Submitting Next Matl Balance Rept for Pvngs,As Required by 10CFR70.53 & 74.13.Required Info Will Be Submitted by 990531 ML20205T7421999-04-21021 April 1999 Forwards Partially Withheld Insp Repts 50-528/99-05, 50-529/99-05 & 50-530/99-05 on 990322-26.Determined That Security Program Properly Implemented.Insp Repts Details Withheld (Ref 10CFR73.21) ML17313B0271999-04-21021 April 1999 Forwards Proprietary Epec Pro Forma Cashflow Statement for 1999.Proprietary Info Withheld,Per 10CFR2.790.Affidavit Encl ML17313A9031999-04-21021 April 1999 Forwards Rev to Relief Request 12 Submitted 990420 to Second 10-yr ISI Interval.Revised Relief Request Discusses in More Detail Actions APS Will Take When There Is Identified Leakage from Bolted Connection ML17313A8971999-04-20020 April 1999 Requests Use of Alternatives to 10CFR50.55a(g) Inservice Insp Requirements.Proposed Alternatives Are Related to Visual Exam of Bolted Connections 05000529/LER-1999-002, Forwards LER 99-002-00 Re Findings & Corrective Actions Taken as Result of Plant Out of Tolerance MSSV Condition Which Was Discovered During pre-outage Testing1999-04-19019 April 1999 Forwards LER 99-002-00 Re Findings & Corrective Actions Taken as Result of Plant Out of Tolerance MSSV Condition Which Was Discovered During pre-outage Testing ML17313A8931999-04-14014 April 1999 Forwards LER 99-003,reporting Condition Prohibited by TSs That Existed When Surveillance Requirement to Verify Essential Chilled Water Sys Valve Positions Was Not Met ML20205Q0821999-04-13013 April 1999 Forwards Second ISI Interval Relief Request 10 from ASME Section XI & Applicable Addenda Re Visual Exams Performed Subsequent to Repair or Replacement of Component or Alteration of Item ML17313A8901999-04-13013 April 1999 Forwards LER 98-003-01 Re MSSV as-found Lift Pressures out- Side of TS Limits.Ler Suppl Provides Evaluation Findings from Unit 3 out-of-tolerance MSSVs Conditions Which Were Discovered During pre-outage Testing ML17313A8831999-04-0808 April 1999 Forwards 1998 Annual Radioactive Effluent Release Rept for Pvngs,Units 1,2 & 3 & Rev 13 to ODCM, for Pvngs,Units 1,2 & 3 IAW TS 5.6.3 ML20205F3491999-03-30030 March 1999 Forwards Proprietary & non-proprietary Info Re Status of Decommissioning Funding for Pvngs,Units 1,2 & 3,per 10CFR50.75(f)(1).Proprietary Info Withheld,Per Requirements of 10CFR2.790(b)(1) ML17313A8671999-03-24024 March 1999 Submits Info Re Present Levels & Sources of Property Insurance Maintained for Pvngs,Per 10CFR50.54(w)(3) ML17313A8601999-03-16016 March 1999 Forwards Revised Relief Requests PRR-05,PRR-06 & PRR-11 to Clarify That Proposed Design Flow Testing for Lpsi,Hpsi & Containment Spray Pumps Will Be Performed Using Instruments That Comply with Code Requirements,Per 990226 Telcon ML17313A8551999-03-0505 March 1999 Requests Proposed Code Alternative IAW 10CFR50.55a(e)(3),as Acceptable Alternative to Requirements of 10CFR50.55a(e)(1), for Installation of in-line safety-related Flow Measurement Instrument in ASME Class 3 Pipe 1999-09-08
[Table view] Category:INCOMING CORRESPONDENCE
MONTHYEARML17313B0991999-10-14014 October 1999 Forwards LER 99-005-00 Reporting Findings & Corrective Actions Taken as Result of Out of Tolerance MSSV Condition in Unit 1 Which Was Discovered During pre-outage Testing ML17313B0881999-10-12012 October 1999 Forwards Response to NRC 990831 RAI Re Several Relief Requests That Accompanied Second ten-yr Interval ISI Program Submitted on 980317.Revised Relief Request 6 Is Provided in Encl 2 ML17300B3501999-09-29029 September 1999 Forwards Revised Bases Pages,Providing Addl Discussion of Options Available to Exit Required Action G of TS 3.8.1 & Revised Page for TS 3.3.7,in Response to NRC RAI Re Proposed Amend to TS 3.8.1 & 3.3.7 ML17300B3551999-09-28028 September 1999 Responds to Aministrative Ltr 99-03, Preparation & Scheduling of Operator Licensing Exams. Proposed Palo Verde Operator Licensing Exam Schedule & Estimated Number of Applicants Planning to Take Exams Encl ML17313B0851999-09-24024 September 1999 Requests Approval of Alternative to Repair Requirements of 10CFR50.55a,authorizing Alternative Use of Mechanical Nozzle Seal Assemblies,As Described in Encl,For RCS Hot Leg Instrumentation & Sampling Nozzles for Two Operating Cycles ML17313B0781999-09-20020 September 1999 Forwards Rev 22 to PVNGS Emergency Plan. Summary Description of Changes,Included ML17300B3331999-09-14014 September 1999 Forwards MOR for August 1999 & Revised MOR for Jul 1999 for Pvngs,Units 1,2 & 3 ML17300B3351999-09-0808 September 1999 Informs That Repairs to Plant EDG 2A Jacket Water Cooling sub-sys Were Completed & EDG Was Declared Operable on 990903 at Approx 21:45 Mst.Noed Was Not Necessary,Since 72 Hour Completion Time Was Met ML17313B0761999-09-0303 September 1999 Requests Enforcement Discretion to TS Section 3.8.1, AC Sources - Operating. Enforcement Discretion Would Allow,On One Time Basis,Extension of Completion Time in Required Action B.4 of TS 3.8.2 from 72 H to 108 H ML17313B0731999-08-31031 August 1999 Informs That RR Bean (License OP-50452-1) Has Been Permanently Reassigned to Position That Does Not Require License & Requests That Individuals License Be Expired Per 10CFR55.55 ML17313B0581999-08-0606 August 1999 Forwards Rev 1 of Changes to TS Bases Implemented Between Aug 1998 & Jul 1999.Insertion Instructions & List of Affected Pages Included ML17313B0311999-08-0303 August 1999 Submits Response to NRC AL 99-02, Operating Reactor Licensing Actions Estimates, for Fys 2000 & 2001 ML17313B0441999-07-30030 July 1999 Forwards Comments on Draft NRC Repts Evaluation of AOVs at Us Light-Water Reactors (1999) & Idaho Natl Engineering & Environ Lab Rept (INEEL)EXT-98-00383,Study of AOVs in Npps. ML17313B0431999-07-30030 July 1999 Advises of Listed Senior Mgt Changes That Have Taken Place at Plant ML17313B0151999-07-20020 July 1999 Submits Request to Obtain All Data Previously Sent by PVNGS & Currently in REIRS for OLs NPF-41,NPF-51 & NPF-74.Data Is Requested in Electronic Form (Ascii Format) as It Currently Exists in REIRS Sys ML17313B0091999-07-20020 July 1999 Forwards Requested Calculations Performed to Verify That Increase in Max Radially Averaged Enrichment for Fuel Assemblies from 4.3 Weight Percent to 4.8 Weight Percent Did Not Affect Requirements for TSs 3.7.15,3.7.17 & 4.3.1 ML17313B0171999-07-16016 July 1999 Forwards LER 99-005-00,re Automatic Rt Which Occurred on 990618,following Sensor Failure in Core Protection Calculators.Corrective Actions Described in LER Are Not Necessary to Maintain Compliance with Regulations ML17300B3111999-07-15015 July 1999 Forwards PVNGS Unit 2 ISI Rept for Eighth Refueling Outage. No Commitments Made to NRC by Ltr ML17300B3141999-07-15015 July 1999 Forwards Corrected Electronic Files for Individual Monitoring Repts for 1998.Original Electronic Files Were Found to Have Two Administrative Errors,Which Has Been Corrected.Encl Withheld,Per 10CFR2.790 ML20209G6771999-07-0808 July 1999 Forwards Supplemental Info to Confirm That Decommissioning Funding Plans of Public Service Co of Nm for Interests in PVNGS Have Been Reviewed by Nm Public Regulation Commission. Final Order & Recommended Decisions in Case 2742,also Encl ML17300B2931999-07-0202 July 1999 Submits Withdrawal of Relief 5 for Second ISI Interval for Units 1,2 & 3.Proposed Alternative Is Related to Exam Requirements for Component Supports for Second ISI Interval ML17313A9951999-06-26026 June 1999 Provides Response to NRC GL 98-01,Suppl 1, Y2K Readiness of Computer Sys at Nuclear Power Plants. ML17300B2831999-06-26026 June 1999 Requests NRC Approval of Proposed Alternative IAW Provisions of 10CFR50.55a(a)(3)(i) to 10CFR50.55a(g) & Requirements of ASME Boiler & Pressure Vessel Code Section XI for Repairs & Installation.Description of Proposed Alternative,Encl ML17313A9901999-06-15015 June 1999 Forwards Response to RAI Re GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Movs. No Commitments Being Made to NRC by Ltr ML17313A9521999-05-24024 May 1999 Notifies NRC That Ja Proctor,License SOP-50314,has Been Permanently Reassigned to Position That Does Not Require License.License Should Be Expired,Per 10CFR55.55 ML17313A9311999-05-13013 May 1999 Notifies NRC That Rev 2 to COLR for Unit 2 Remains Applicable Following Recently Completed Unit 2 Reload ML17313A9481999-05-12012 May 1999 Informs of Change Needed in Order to Update Current Mailing List.Future Mailings for J Horne Should Be Forwarded to Listed Address ML17313A9261999-05-0707 May 1999 Forwards LER 99-004-00,per 10CFR50.73.LER Repts Findings & Corrective Actions Taken as Result of Unit 2 Out of Tolerance Pressurizer Safety Valve (Psv) Condition Which Was Discovered During Outage Testing ML20206H1931999-05-0303 May 1999 Forwards 1998 Annual Rept, for SONGS Units 2 & 3 & PVNGS Units 1,2 & 3.SCEs Form 10K Annual Rept to Securites & Exchange Commission for Fiscal Yr Ending 981231,encl ML17313A9191999-04-30030 April 1999 Forwards Special Rept 2-SR-99-001 Re SG Tube Plugging in PVNGS Unit 2,per TS Reporting Requirement 5.6.8.Complete Results of SG Tube Inservice Insp Will Be Submitted by 000422 ML17313A9181999-04-30030 April 1999 Forwards Electronic File of Individual Monitoring Repts for 1998.Encl Withheld Per 10CFR2.790 ML17313A9091999-04-30030 April 1999 Forwards Proprietary Proposed Test Outlines for Initial License Exams to Be Administered at PVNGS in Aug/Sept 1999. No Commitments Are Contained in Ltr.Proprietary Info Withheld ML17313A9081999-04-23023 April 1999 Documents 990421 Telcon with E Emeigh,Which Requested Extension for Submitting Next Matl Balance Rept for Pvngs,As Required by 10CFR70.53 & 74.13.Required Info Will Be Submitted by 990531 ML17300B3751999-04-23023 April 1999 Forwards LER 99-003-00,reporting Condition Prohibited by TS 3.7.17 Where Spent Fuel Assembly Was Stored in Inappropriate Region in Spent Fuel Pool ML17313B0271999-04-21021 April 1999 Forwards Proprietary Epec Pro Forma Cashflow Statement for 1999.Proprietary Info Withheld,Per 10CFR2.790.Affidavit Encl ML17313A9031999-04-21021 April 1999 Forwards Rev to Relief Request 12 Submitted 990420 to Second 10-yr ISI Interval.Revised Relief Request Discusses in More Detail Actions APS Will Take When There Is Identified Leakage from Bolted Connection ML17313A8971999-04-20020 April 1999 Requests Use of Alternatives to 10CFR50.55a(g) Inservice Insp Requirements.Proposed Alternatives Are Related to Visual Exam of Bolted Connections 05000529/LER-1999-002, Forwards LER 99-002-00 Re Findings & Corrective Actions Taken as Result of Plant Out of Tolerance MSSV Condition Which Was Discovered During pre-outage Testing1999-04-19019 April 1999 Forwards LER 99-002-00 Re Findings & Corrective Actions Taken as Result of Plant Out of Tolerance MSSV Condition Which Was Discovered During pre-outage Testing ML17313A8931999-04-14014 April 1999 Forwards LER 99-003,reporting Condition Prohibited by TSs That Existed When Surveillance Requirement to Verify Essential Chilled Water Sys Valve Positions Was Not Met ML20205Q0821999-04-13013 April 1999 Forwards Second ISI Interval Relief Request 10 from ASME Section XI & Applicable Addenda Re Visual Exams Performed Subsequent to Repair or Replacement of Component or Alteration of Item ML17313A8901999-04-13013 April 1999 Forwards LER 98-003-01 Re MSSV as-found Lift Pressures out- Side of TS Limits.Ler Suppl Provides Evaluation Findings from Unit 3 out-of-tolerance MSSVs Conditions Which Were Discovered During pre-outage Testing ML17313A8831999-04-0808 April 1999 Forwards 1998 Annual Radioactive Effluent Release Rept for Pvngs,Units 1,2 & 3 & Rev 13 to ODCM, for Pvngs,Units 1,2 & 3 IAW TS 5.6.3 ML20205F3491999-03-30030 March 1999 Forwards Proprietary & non-proprietary Info Re Status of Decommissioning Funding for Pvngs,Units 1,2 & 3,per 10CFR50.75(f)(1).Proprietary Info Withheld,Per Requirements of 10CFR2.790(b)(1) ML17313A8671999-03-24024 March 1999 Submits Info Re Present Levels & Sources of Property Insurance Maintained for Pvngs,Per 10CFR50.54(w)(3) ML17313A8601999-03-16016 March 1999 Forwards Revised Relief Requests PRR-05,PRR-06 & PRR-11 to Clarify That Proposed Design Flow Testing for Lpsi,Hpsi & Containment Spray Pumps Will Be Performed Using Instruments That Comply with Code Requirements,Per 990226 Telcon ML17313A8551999-03-0505 March 1999 Requests Proposed Code Alternative IAW 10CFR50.55a(e)(3),as Acceptable Alternative to Requirements of 10CFR50.55a(e)(1), for Installation of in-line safety-related Flow Measurement Instrument in ASME Class 3 Pipe ML17313A8241999-02-23023 February 1999 Advises That Kp Jarvis,License OP-50287-1,no Longer Needs to Maintain License as Permanently Assigned to Position Requiring No License ML17313A8111999-02-18018 February 1999 Forwards PVNGS Unit 3 7th Refueling Outage, Which Provides Complete Results of SG Tube Inservice Insp Performed,Per TS 5.6.8 ML17313A8721999-02-16016 February 1999 Discusses Resolution of Generic Safety Issue 171, ESF Failures from Loss-of-Offsite Power Subsequent to Loca. Util Has Low Vulnerability to Loca/Grid Collapse/Loop Scenario ML17313A7611999-01-22022 January 1999 Forwards PVNGS Unit 3 Inservice Insp Rept Seventh Refueling Outage, Per 10CFR50.55a.Ltr Contains No New Commitments 1999-09-08
[Table view] |
Text
CATEGORY y
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) l~
ACCEbSION NBR:9801070174 DOC.DATE: 97/12/30 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 LEVINE,J.M. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Provides APS 90 day response to NRC GL 97-04, "Assurance of Sufficient Net Positive Suction Head for ECC &. Containment Heat Removal Pumps."
DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal: Gen'eral Distribution NOTES:STANDARDIZED PLANT 05000528@
Standardized plant. '05000529 Standardized plant. 05000530()
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 LA 1 1 PD4-2 PD 1 1 CLIFFORD,J 1 1 INTERNAL: ACRS 1 1 CENTER 1 1 NRR/DE/ECGB/A 1 1 NRR/DE M B 1 1 NRR/DRCH/HICB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 D OGC/HDS2 1 0 EXTERNAL: NOAC 1 1 NRC PDR U
E N
NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL 13
Cammltment. InnovattNL Energy.
James M. Levine TEL (602)393-5300 Mall Station 7602 Pa'lo Verde Nuclear Senior Vice President FAX (602)3934077 P.O. Box 52034 Generating Station Nuclear Phoenix, AZ 65072-2034 102-04057 JMUAKK/JRP December 30, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1,2, and 3 Docket Nos. STN 60 - 628/629/630 Response to NRC Generic Letter 97-04 This letter provides Arizona Public Service Company's (APS), 90 day response to NRC Generic Letter 97-04, "Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps ".
The attached response addresses items 1-5 of the Requested Information Section of the Generic Letter. In addition to the response, APS is working with the Combustion Engineering Owners Group (GEOG) and other industry groups in addressing the issues associated with the referenced Generic Letter.
Should you have any questions or concerns plea'se contact Scott A. Bauer at (602) 393-5978.
Sincerely, JMUAKK/JRP/rlh Attachment cc: E. W. Merschoff K. E. Perkins J. W. Clifford J. H. Moorman 9801070i74 971230 PDR ADGCK 05000528 P PDR
STATE OF ARIZONA )
) ss.
COUNTY OF MARICOPA )
I, J. M. Levine, represent that I am Senior Vice President - Nuclear, 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 Bc9(A Day Of , 1997.
Notary Public orrcQL sQL My Commission Expires MORA E. MEADOR Wotan Pobtio - State of Arizona MARrtCOPA COUNTY My Contnt. Bp'es Apnt 6, 1999
I H
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ATTACHMENT RESPONSE TO NRC GENERIC LETTER 97-04 ASSURANCE OF NET POSITIVE SUCTION HEAD FOR EMERGENCY CORE COOLING AND CONTAINMENTHEAT REMOVAL PUMPS The following is provided in response to NRC Generic Letter 97-04, Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps, dated October 7, 1997 for Palo Verde Nuclear Generating Station.
SYSTEMS OVERVIEW Palo Verde is a three unit Combustion Engineering System 80 pressurized water reactor facility with an Emergency Core Cooling System (ECCS) and a Containment Spray System (CSS) which function to provide cooling flow to the core and to reduce containment pressure, respectively, following certain design basis accidents. The ECCS is comprised of two independent trains each with one high pressure safety injection (HPSI) system and one low pressure safety injection (LPSI) system. The train related HPSI, LPSI and CSS pump suctions are aligned in parallel to the respective train containment sump following depletion of the borated water inventory in the Refueling Water Tank. These are the only pumps which take suction from the recirculation sump during accident conditions. Figure 1 illustrates the Palo Verde configuration.
GENERIC LETTER 97-04 RESPONSES
- 1. Specify the general methodology used to calculate the head loss associated with the ECCS suction strainers (sump screens).
The response to this question will conservatively encompass the total methodology used to quantify the available net positive suction head (NPSHA) to the ECCS pumps and the CSS Pumps, inclusive of the specific methodology for the calculation of the loss associated with the ECCS sump screens. The general methodology used at Palo Verde to calculate the NPSHA for the ECCS and CSS pumps is as follows:
The basic equation for calculating NPSH is:
NPSH h+ hyp+ + h3) hi8 where:
h, = absolute pressure on the surface of the liquid supply level.
h, = head corresponding to the vapor pressure of the liquid at the temperature being pumped.
h= static height that the liquid supply level is above or below the pump centerline or impeller eye.
h= suction line losses including entrance losses and friction losses.
Additional detail on each of the terms is provided below.
h, - absolute pressure on the surface of the liquid supply level This term is the containment pressure above atmospheric pressure that is taken credit for in the analysis. Palo Verde, however, does not credit containment overpressure and conservatively assumes that the sump fluid is saturated at the containment pressure at all times. Hence, h, is assumed equal to the vapor pressure of the sump fluid at the pump suction, h.
h- head corresponding to the vapor pressure of the liquid at the temperature being pumped As noted for the absolute pressure term, h the Palo Verde NPSHA analyses assume that the sump fluid is at saturated conditions. Since containment overpressure is not credited and therefore h, is equal to h, the sump fluid temperature is irrelevant and the available head reduces to the difference between the static water head and the suction losses defined below.
h- static height that the liquid supply level is above or below the pump centerline or impeller eye This term is the minimum static height of fluid above the ECCS and CSS pump datum. The minimum water height in containment following a LOCA, for conditions which will result in transfer of the ECCS and CSS pump suction to the recirculation sump, has been calculated assuming minimum transfer volume from the RWT and other water sources.
h- all suction line losses including entrance losses and friction losses Palo Verde has calculated the total suction line losses for the ECCS and CSS pumps using standard industry methodology. In
~ ~
li
general, the calculated line losses are the sum of the losses for the total piping runs and the losses for the valves, fittings and components. Additional loss is applied for entrance and exit effects due to the sump screen. Loss due to the accumulation of fibrous debris. is also included in accordance with NRC Regulatory Guide 1.82, Revision 1, Sumps for Emergency Core Cooling and Containment Spray Systems.
Piping losses are based on friction factors for clean stainless steel piping. No consideration of aging or increased pipe roughness is included due to the relative cleanliness of the water and minimum system operation time.
Maximum (conservative) head loss is predicated on bounding system operation which maximizes the suction flow rate for each of the pumps and for the common suction flow paths. For Palo Verde, the suction piping head loss is calculated assuming concurrent operation of the train related ECCS and CSS pumps at their respective vendor specified run-out flow rates during the limiting mode of operation. No credit for variable ECCS or CSS flow rate, as a function of containment pressure, is assumed.
The limiting mode of operation considered in the evaluation of NPSHA is recirculation following injection for a large break or certain small break LOCAs. No other design basis accidents, such as the Main Steam Line Break event, result in sufficient depletion of the Refueling Water Tank which would initiate the transfer of the ECCS and CSS pump suction to the recirculation sump. No other mode of operation requires a suction flow path from the recirculation sump for which NPSH must be evaluated.
The Palo Verde recirculation sump screen design is described in the PVNGS UFSAR, Section 6.2.2.2. The screen is composed of an outer trash rack, a medium coarse screen, and a fine inner screen. Head loss for the clean composite screen is calculated by summing the losses across the rack and each screen. The calculated losses are predicated on maximum flow conditions corresponding to concurrent operation of the train related ECCS and CSS pumps at design runout flow rate. The resultant head losses are based on published empirical correlations and have been determined to be negligible. This conclusion is supported by initial sump design testing by the Architect - Engineer.
The head loss across the sump screen associated with fibrous debris accumulation has been incorporated in accordance with
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NRC Regulatory Guide 1.82, Revision 1. The head loss correlation published in NUREG-0897, Containment Emeergency Sump Performance, has been applied to quantify the loss conservatively assuming equal debris loading on the available flow area of the sump screen. The available flow area considers the fraction of screen area blocked by failed coatings. The total quantities of fibrous debris and failed coatings are conservatively assumed in these calculations.
- 2. Identify the required NPSH and the available NPSH.
The required EPICS and CSS pump NPSH is based on vendor specified requirements for the pumps at runout conditions. These requirements are conservatively imposed for all operating conditions and flow rates up to and including runout. The following represent the bounding conditions (i.e. minimum margin) for available NPSH and are compared to the vendor specified required NPSH.
PUMP NPSH REQUIRED NPSH - AVAILABLE MARGIN (ff) (ft) (ft)
CS 22 25.8 3.8 LPSI 20 26.1 6.1 HPSI 25 28.8 3.8 Note that the Combustion Engineering System 80 ECCS design includes termination of the LPSI pump injection upon switchover to recirculation and suction from the recirculation sump. However, the available NPSH for the LPSI pump has been evaluated to ensure that the adequate suction head is available to support operation should operators elect to override the ESF logic and realign the pump to provide additional core flow. This mode of operation, however, is not credited in the Palo Verde UFSAR Chapter 15 analyses. Note also that the available NPSH for the HPSI and CSS pumps conservatively assume concurrent operation of the LPSI pump during recirculation.
- 3. Specify whether the current design-basis NPSH analysis differs from the most recent analysis reviewed and approved by the NRC for which a safety evaluation was issued.
The most recent NPSH analysis reviewed and approved by the NRC is that documented in the Palo Verde SER (NUREG-0857), Section 6.2.2 and Section 6.3.1. The calculations which supported the original SER, however, have been revised. Revision to the calculations was made in order to incorporate recirculation sump screen blockage as required by Regulatory Guide 1.82, Supplement 1 and were revised using the methodology of NUREG-0897. None of the general
calculational methodology of the original calculation, which was reviewed and approved by the NRC, was affected.
- 4. Specify whether containment overpressure (i.e. containment pressure above the vapor pressure of the sump or suppression pool fluid) was credited in the calculation of available NPSH. Specify the amount of overpressure needed and the minimum overpressure available.
No containment overpressure is credited in the calculation of available NPSH for Palo Verde as described in the response to Question 1.
- 5. When containment overpressure is credited in the calculation of available NPSH, confirm that an appropriate containment pressure analysis was done to establish the minimum containment pressure.
Not applicable.
t II Il II SDCHx 484 689 7 69 695 671 693 HPSI2 616 405 478 699 617 113 Cold Leg Loop 2A 44 44 307 615 114 217 LPSI 2 626 TRAIN B Containment Sump 627 Cold Leg 123
~7 206 676 62 124 Loop 2B Containment Sump TRAIN A 205 67 HPSI1 673 404 476 698 Cold Leg Loop 1A 306 134 542 LPSI 1 647 143 Cold Leg Loop 1B SDCHx 485 684 678 144 543 247 687 672 FIGURE 1 - ECCS AND CSS CONFIGURATION DURING RECIRCULATION MODE
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