Similar Documents at Zion |
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Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20217J4791999-10-18018 October 1999 SER Approving Exemption from Certain Requirements of 10CFR73 for Zion Nuclear Power Station,Units 1 & 2.NRC Concluded That Proposed Alternative Measures for Protection Against Radiological Sabotage Meets Requirements of 10CFR73.55 ML20211K0401999-08-31031 August 1999 SER Accepting Approval of Defueled Station Emergency Plan & Exemption from Certain Requirements of 10CFR50.47, Emergency Plans for Plants,Units 1 & 2 ML20236U6331998-07-24024 July 1998 Safety Evaluation Supporting Amends 179 & 166 to Licenses DPR-39 & DPR-48,respectively ML20236S3281998-07-20020 July 1998 Safety Evaluation Supporting Certified Fuel Handlers Training & Retraining Program ML20198P8361998-01-0909 January 1998 SER Accepting Determination of Zone of Influnce for Coatings in Containment of Plant,Units 1 & 2 ML20198P8721998-01-0909 January 1998 Safety Evaluation Accepting Request for Alternative Insp Requirements for Augmented Exam of Reactor Presure Vessels for Zion Nuclear Power Station,Units 1 & 2 ML20202F0761997-12-0202 December 1997 Safety Evaluation Denying Licensee Proposed Alternative Contained in Request for Relief CR-13,Rev 1,of Removing Only Insulation Classified as Removable.Staff Determined That Submittal Does Not Provide Acceptable Level of Quality ML20132F5111996-12-20020 December 1996 Safety Evaluation Supporting Amends 177 & 164 to Licenses DPR-39 & DPR-48,respectively ML20135D8971996-11-25025 November 1996 Corrected SE Supporting Amends 176 & 163 to Licenses DPR-39 & DPR-48,respectively ML20134P7941996-11-25025 November 1996 Safety Evaluation Supporting Amends 176 & 163 to Licenses DPR-39 & DPR-48,respectively ML20134H6781996-11-12012 November 1996 Safety Evaluation Supporting Amends 175 & 162 to Licenses DPR-39 & DPR-48,respectively ML20134F9851996-11-0606 November 1996 Safety Evaluation Supporting Amends 174 & 161 to Licenses DPR-39 & DPR-48,respectively ML20129H2901996-10-29029 October 1996 Safety Evaluation Supporting Amends 173 & 160 to Licenses DPR-39 & DPR-48,respectively ML20059E2871993-12-30030 December 1993 Safety Evaluation Supporting Amends 57,57,45,45,93,77,152 & 140 to Licenses NPF-37,NPF-66,NPF-72,NPF-77,NPF-11,NPF-18, DPR-39 & DPR-48 Respectively ML20058G2981993-11-29029 November 1993 Safety Evaluation Supporting Amends 151 & 139 to Licenses DPR-39 & DPR-48 ML20059M7851993-11-15015 November 1993 Safety Evaluation Supporting Amends 150 & 138 to Licenses DPR-39 & DPR-48,respectively ML20059L7511993-11-10010 November 1993 Safety Evaluation Accepting Category 3 Qualification in Lieu of Category 2 for Pressure Monitoring Instrumentation ML20059L6801993-11-0909 November 1993 Safety Evaluation Re Update to Plant Reg Guide 1.97 Parameter Summary Table ML20058E6661993-10-22022 October 1993 Corrected SE Re Revised Fuel Handling Accident Inside Containment.Se Mistakenly Gives Decontamination Factor for Elemental Iodine Value of 100 Instead of 133 ML20059B1961993-10-22022 October 1993 Safety Evaluation Accepting Util 930913 Reanalysis of Fuel Handling Accident Inside Containment ML20059A7211993-10-14014 October 1993 Safety Evaluation Supporting Amends 149 & 137 to Licenses DPR-39 & DPR-48,respectively ML20059C5521993-10-13013 October 1993 Corrected Safety Evaluation Supporting Amends 148 & 136 to Licenses DPR-39 & DPR-48,respectively ML20057F8351993-10-13013 October 1993 Safety Evaluation Supporting Amends 148 & 136 to Licenses DPR-39 & DPR-48,respectively ML20057A2091993-08-31031 August 1993 Safety Evaluation Denying Addl Exemptions from Fire Protection Requirements of 10CFR50,app R.Conclusions Reached When Granting Exemptions in 830307 & 880607 SEs Still Valid ML20056H5001993-08-27027 August 1993 Safety Evaluation Re Fire Protection Open Items from Section 3.2.1 of 780310 Safety Evaluation ML20057B1711993-03-24024 March 1993 Safety Evaluation Granting Relief Requests to Licenses DPR-39 & DPR-48 Re Second 10-yr Interval Inservice Testing Plan for Pumps & Valves ML20056C0501992-06-0909 June 1992 Safety Evaluation Supporting Amends 138 & 127 to Licenses DPR-39 & DPR-48,respectively ML20058D8081990-10-31031 October 1990 Safety Evaluation Supporting Amends 120 & 109 to Licenses DPR-39 & DPR-48,respectively ML20247E7421989-09-0808 September 1989 Safety Evaluation Supporting Amends 118 & 107 to Licenses DPR-39 & DPR-48,respectively ML20245F1631989-08-0101 August 1989 Safety Evaluation Supporting Amends 117 & 106 to Licenses DPR-39 & DPR-48,respectively ML20247P9591989-05-30030 May 1989 Safety Evaluation Supporting Amends 116 & 105 to Licenses DPR-39 & DPR-48,respectively ML20247M7431989-05-22022 May 1989 Safety Evaluation Supporting Util Compliance W/Atws Rule 10CFR50.62 ML20245H8051989-04-27027 April 1989 Safety Evaluation Supporting Amends 115 & 104 to Licenses DPR-39 & DPR-48,respectively ML20244E4141989-04-14014 April 1989 Safety Evaluation Supporting Util post-accident Monitoring Instrumentation Per Reg Guide 1.97 & Generic Ltr 82-33 ML20196B8081988-12-0202 December 1988 Safety Evaluation Supporting Util Responses to Generic Ltr 83-28,Items 3.1.3 & 3.2.3 Re post-maint Testing Requirements ML20207K9971988-10-11011 October 1988 SER Supporting Amends 113 & 102 to Licenses DPR-39 & DPR-48, Respectively ML20155G5771988-06-0707 June 1988 Safety Evaluation Recommending That Util 840727 Exemption Request from Sections III.G.2 & III.G.3 of 10CFR50,App R Be Granted.One Exemption Request Determined as Unnecessary ML20154A7781988-04-15015 April 1988 Safety Evaluation Supporting Amends 112 & 110 to Licenses DPR-39 & DPR-48,respectively ML20151M1281988-04-0606 April 1988 Safety Evaluation Supporting Amends 111 & 100 to Licenses DPR-39 & DPR-48,respectively ML20148P4951988-04-0404 April 1988 Safety Evaluation Supporting Amends 110 & 99 to Licenses DPR-39 & DPR-48,respectively ML20150F0601988-03-28028 March 1988 Safety Evaluation Supporting Amends 109 & 98 to Licenses DPR-39 & DPR-48,respectively ML20147B8831988-02-26026 February 1988 SER Re Matl Properties for Fracture Toughness Requirements for Protection Against PTS Events.Nrc Concludes That Many of 30 Measurements Added to List in WCAP-10962 Not Credible ML20149H5541988-02-0505 February 1988 Safety Evaluation Supporting Amend 108 to License DPR-39 ML20237H5511987-08-17017 August 1987 Safety Evaluation Supporting Amends 107 & 97 to Licenses DPR-39 & DPR-48,respectively ML20236J3961987-07-20020 July 1987 Safety Evaluation Supporting Amends 106 & 96 to Licenses DPR-39 & DPR-48,respectively ML20235E9171987-06-23023 June 1987 Safety Evaluation Supporting Amends 105 & 95 to Licenses DPR-39 & DPR-48,respectively ML20213G6351987-05-0808 May 1987 Safety Evaluation Supporting Amends 104 & 94 to Licenses DPR-39 & DPR-48,respectively ML20215K3831987-05-0707 May 1987 Safety Evaluation Re Util 861229 Submittal Concerning Matl Properties for Fracture Toughness Requirements for Protection Against PTS Events,Per 10CFR50.61.Reported Values of Copper & Nickel Content Unacceptable ML20205Q9561987-03-26026 March 1987 Safety Evaluation Supporting Amends 103 & 93 to Licenses DPR-39 & DPR-48,respectively ML20205G7221987-03-19019 March 1987 Safety Evaluation Supporting Amends 102 & 92 to Licenses DPR-39 & DPR-48 1999-08-31
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217J4791999-10-18018 October 1999 SER Approving Exemption from Certain Requirements of 10CFR73 for Zion Nuclear Power Station,Units 1 & 2.NRC Concluded That Proposed Alternative Measures for Protection Against Radiological Sabotage Meets Requirements of 10CFR73.55 A99026, Monthly Operating Repts for Sept 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers A99023, Monthly Operating Repts for Aug 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20211K0401999-08-31031 August 1999 SER Accepting Approval of Defueled Station Emergency Plan & Exemption from Certain Requirements of 10CFR50.47, Emergency Plans for Plants,Units 1 & 2 A99022, Monthly Operating Repts for July 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Zion Nuclear Power Station,Units 1 & 2.With A99021, Monthly Operating Repts for June 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Zion Nuclear Power Station,Units 1 & 2.With A99019, Monthly Operating Repts for May 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20195B2591999-05-19019 May 1999 Rev 66a to CE-1-A,consisting of Proposed Changes to QAP for Dnps,Qcs,Znps,Lcs,Byron & Braidwood Stations A99016, Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20195H9521999-04-30030 April 1999 Revised Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2 A99013, Monthly Operating Repts for Mar 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results A990101, Monthly Operating Repts for Feb 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20205M7061998-12-31031 December 1998 Unicom Corp 1998 Summary Annual Rept. with A99002, Monthly Operating Repts for Dec 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98062, Monthly Operating Repts for Nov 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Zion Nuclear Power Station,Units 1 & 2.With ML20196J0061998-11-19019 November 1998 Rev 66 to Topical Rept CE-1-A, QA Program ML20196A4191998-11-19019 November 1998 Safety Evaluation Accepting QA TR CE-1-A,Rev 66 Re Changes in Independent & Onsite Review Organization by Creating NSRB A98057, Monthly Operating Repts for Oct 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98052, Monthly Operating Rept for Sept 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98049, Special Rept 304-123-98-001SR:on 980902,valid Failure Rept for 2A EDG Occurred.Cause Unknown.Util Submitted Written Certification of Permanent Cessation of Operations at Zion Station,Units 1 & 21998-09-25025 September 1998 Special Rept 304-123-98-001SR:on 980902,valid Failure Rept for 2A EDG Occurred.Cause Unknown.Util Submitted Written Certification of Permanent Cessation of Operations at Zion Station,Units 1 & 2 ML20195D1221998-08-31031 August 1998 DSAR, for Zion Station A98048, Monthly Operating Repts for Aug 1998 for Zion Station,Units 1 & 2.With1998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Zion Station,Units 1 & 2.With ML20237E2331998-08-21021 August 1998 Revised Pages of Section 20 of Rev 66 to CE-1-A, QA Topical Rept A98042, Monthly Operating Repts for July 1998 for Zion Station,Units 1 & 21998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Zion Station,Units 1 & 2 ML20236U6331998-07-24024 July 1998 Safety Evaluation Supporting Amends 179 & 166 to Licenses DPR-39 & DPR-48,respectively ML20236S3281998-07-20020 July 1998 Safety Evaluation Supporting Certified Fuel Handlers Training & Retraining Program A98041, Monthly Operating Repts for June 1998 for Zion Nuclear Station,Units 1 & 21998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Zion Nuclear Station,Units 1 & 2 ML20236J7911998-06-12012 June 1998 LER 98-S02-00:on 980517,first Shift Security Officer Reported Being Wounded by Unknown Subject Who Fled Area. Caused by accidental,self-inflicted Gunshot Wound.Removed Officer from Duty & Charged Officer W/Filing False Rept A98039, Monthly Operating Repts for May 1998 for Zion Generating Station,Units 1 & 21998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Zion Generating Station,Units 1 & 2 A98035, Monthly Operating Repts for Apr 1998 for Zion Station,Units 1 & 21998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Zion Station,Units 1 & 2 A98033, Monthly Operating Repts for Mar 1998 for Zion Station,Units 1 & 21998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Zion Station,Units 1 & 2 A98029, Monthly Operating Repts for Feb 1998 for Zion Station,Units 1 & 21998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for Zion Station,Units 1 & 2 A98015, Monthly Operating Repts for Jan 1998 for Zion Station,Units 1 & 21998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for Zion Station,Units 1 & 2 ML20199K1651998-01-23023 January 1998 Rev 65h to Topical Rept CE-1-A, Comm Ed QA Tr ML20198P8361998-01-0909 January 1998 SER Accepting Determination of Zone of Influnce for Coatings in Containment of Plant,Units 1 & 2 ML20198P8721998-01-0909 January 1998 Safety Evaluation Accepting Request for Alternative Insp Requirements for Augmented Exam of Reactor Presure Vessels for Zion Nuclear Power Station,Units 1 & 2 A98034, 1997 Annual 10CFR50.59 Summary Rept1997-12-31031 December 1997 1997 Annual 10CFR50.59 Summary Rept ML20216D3611997-12-31031 December 1997 Unicom Corp 1997 Summary Annual Rept A98004, Monthly Operating Repts for Dec 1997 for Zion Station,Units 1 & 21997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for Zion Station,Units 1 & 2 ML20202F1451997-12-0303 December 1997 Independent Investigation Team Rept on Safety Conscious Work Environment at Zion Station ML20202F0761997-12-0202 December 1997 Safety Evaluation Denying Licensee Proposed Alternative Contained in Request for Relief CR-13,Rev 1,of Removing Only Insulation Classified as Removable.Staff Determined That Submittal Does Not Provide Acceptable Level of Quality A97076, Monthly Operating Repts for Nov 1997 for Zion Station,Units 1 & 21997-11-30030 November 1997 Monthly Operating Repts for Nov 1997 for Zion Station,Units 1 & 2 ML20199J5931997-11-26026 November 1997 SG Insp Results,Fall 1996 Refueling Outage 14 (Z2R14) A97063, Special Rept 295-123-97-002SR:on 971014,failure of 1B EDG Occurred.Exam of Nipple Fractured Surface Revealed Failure Occurred Through Thread Root.Unit 1 Defueled & Unit 2 in Mode 5 Throughout Event1997-11-13013 November 1997 Special Rept 295-123-97-002SR:on 971014,failure of 1B EDG Occurred.Exam of Nipple Fractured Surface Revealed Failure Occurred Through Thread Root.Unit 1 Defueled & Unit 2 in Mode 5 Throughout Event A97069, Monthly Operating Repts for Oct 1997 for Zion Station,Units 1 & 21997-10-31031 October 1997 Monthly Operating Repts for Oct 1997 for Zion Station,Units 1 & 2 ML20211M0181997-10-0707 October 1997 Special Rept 295-123-97-001SR:on 970904,OA Motor Declared Inoperable Due to Pin Hole Leaks Identified on Pressure Regulating Relief valve,0FP0052.Procedure Was Rewritten to Ensure 0FP0052 Would Maintain Same Pressure When Fully Open A97058, Monthly Operating Repts for Sept 1997 for Zion Generating Station,Units 1 & 21997-09-30030 September 1997 Monthly Operating Repts for Sept 1997 for Zion Generating Station,Units 1 & 2 ML20210V2401997-09-19019 September 1997 Rev 65g to Topical Rept CE-1-A, Comm Ed QA Manual 1999-09-30
[Table view] |
Text
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0. 89 TO FACILITY OPERATING LICENSE NO. DPR-39 AND AMENDMENT NO. 79 TO FACILITY OPERATING LICENSE N0. DPR-48 COMMONWEALTH EDISON COMPANY ZION NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-295 AND 50-304
SUMMARY
A revised ECCS analysis was performed for Zion 1 and 2. Changes in the analysis assumptions included: 10% steam generator tube plugging (uniform distribution); 15x15 Optimized Fuel; a maximum accumulator water volume of 888 cubic feet; and a containment spray actuation time increase to 92.5 seconds.
The analysis also assumed a 102% power level, and an increase in the total peaking factor (Fq) from 2.13 to 2.32 (Reference 1).
The analysis was performed with the revised 1981 Westinghouse ECCS Evaluation Model (Refer'ence 2). This version includes the BART computer program, a
.mecha'nistic core heat transfer model (References 3 and 4). This constitutes an approved ECCS model.
The large-break LOCA cases analyzed were for a double ended, pump discharge, cold leg break with discharge multipliers of 0.4, 0.6 and 0.8. The small-break LOCA analyzed was a 6-inch diameter cold leg break. These cases have been shown, in previous analyses, to be the limiting breaks with respect to peak cladding temperatures.
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Supplemental information regarding the containment spray actuation time, the new containment fan cooler heat removal curves, and non-L,0CA transients and-accidents was also provided (Reference 5). The spray actuation time was set to 45 seconds, the original FSAR value. Also provided was an assessment of the impact of these changes on non-LOCA transients and accidents.
In addition to the revised analyses, the report (Reference 1) included changes to the Technical Specifications for Zion 1 and 2 to reflect the changes in accumulator water inventory and the peaking factor of 2.32 (F ).
q Additional information cr>ncerning asymmetric steam generator tube plugging, maximum permissible plugging, the non-LOCA design base calculation basis, and accumulator water volume for the small-break LOCA was requested from the licensee. The licensee has provided the requested infonnation (Reference 6).
Subsequent to these submittals, Westinghouse notified the NRC of an error in the Evaluation Model methodology used to transfer WREFLOOD generated data into the BART. computer program (Reference 7). The licensee has submitted a revised large break ECCS aralysis for which the BART input more accurately reflects the time integrated volume of water delivered to the core based on the WREFLOOD output curve.(data) for the core inlet flooding rate (Reference 8).
'The revised ECCS analysis, based on the supplemental analysis (Reference 8),
results in a peak cladding temperature of 2159 degrees Fahrenheit, total core hydrogen generation of less than 0.3%, and local cladding oxidation of 6.94%
for the limiting break (0.6 discharge coefficient). The peak cladding I
temperature for the small-break LOCA is 1747 degrees Fahrenheit, with core wide and local oxidation values of less than 0.3% and 1.45% respectively (Reference 1). These values are within the required limits as specified in 10 CFR 50.46.
STAFF EVALUATION This revised ECCS performance analysis has been made using an NRC-approved evaluation model which satisfies the requirements of 10.CFR 50.46 and.Appen-dix K to Part 50. Both large-break LO,CAs and small break LOCAs have been ,
considered. The methods for accounting for steam generator tube plagging are anintegralpartoftheWestinkhouseevaluationmodelandhavebeenpreviously approved by the NRC. The difference in steam generator tube plugging levels, between the worst case steam generator and the best case steam generator, is currently less than 3%. Westinghouse has considered the effects of asymmetric tube plugging and has determined that asymmetric plugging levels which do not exceed the analyzed uniform plugging levels (e.g., 10% uniform plugging, maximum 10% difference between any steam generators) will have no adverse impact upon transients. Commonwealth Edison will not plug greater than 10% of the tubes in any steam generator or exceed more than 10% asymmetric plugging without further analysis and prior notification to the NRC (Reference 6).
-The staff has reviewed the calculation of the containment backpressure in the revised ECCS analysis and determined that the analysis was performed using a previously approved model for containment parameters. The original (Reference
- 1) analysis was performed using a containment spray flow initiation time of 92.5 seconds. During the review process, the licensee, Commonwealth Edison, determined that a spray initiation time of 50 to 57 seconds, depending on the
4_
-offsite power availability assumptions, was more appropriate. The licensee has conducted a revised analysis in support of the Reactor Containment Fan Cooler requirements and provided a re-analysis for the ECCS evaluation (Reference 5).
Changes in the revised analysis include: (1) a containment spray actuation time of 45 seconds (the original Zion FSAR value); (2) the new reactor containment fan cooler heat removal curves (an increased capacity); and (3) minor enhancements in the treatment of fuel pellet density and volumetric heat generation calculations in the LOCTA-IV initialization scheme (Reference 9).
A review of the input assumptions and parameter values used for the small-break LOCA analysis resulted in the identification of an inconsistency in the accumu-lator water volume used. The input and assumptions used for the small-break LOCA analysis, with the exception of the core linear power distribution, are consistent with the September 1974 10 CFR 50, Appendix K submittal, and the analysis was performed using the currently approved ECCS small-break models.
The analysis is reported to use a 900 cubic foot volume, whereas the revised value as specified in the Technical Specifications requires a maximum volume not in excess of 888 cubic feet.
Since this appeared to be inconsistent with 10 CFR 50.36, which requires that Technical Specifications be derived from the safety analysis, the licensee was requested to justify how compliance was met. In response (Reference 6), the l licensee has provided additional information for the limiting small-break LOCA.
In May 1981, a new large-break LOCA was approved which featured a reduced water inventory in the accumulators from 900 cubic feet to 868 cubic feet. The small-break LOCA did not have to be reanalyzed on the basis of the accumulator
.s.
water inventory change. -Unlike the large-break LOCA, the accumulator water volume change from 900 to 868 cubic feet is unimportant in mitigating Zion's small-break LOCA transient. Westinghouse determined that an accumulator water volume of 800 cubic feet was more than adequate to cover Zion's small-break LOCA. The core recovers very quickly in the Zion limiting case small-break LOCA analysis once the accumulators have actuated. Less than 300 cubic feet of water injected from each of the available accumulators recovers the core in the limiting break transient. The remaining water in the accumulator tanks pro-vides the inventory to maintair{ the downcomer and core full until the system depressurizes to approximately 200 psia, at which time pump safety injection flow matches break flow. Continued flow from the accumulators is not needed to prevent another core uncovery with less than 600 cubic feet of water per accumulator tank having delivered. Therefore, both the current accumulator volume Technical Specification limit of 868 cubic feet and the proposed value of 888 cubic feet protect the core during small-break LOCA scenarios. The proposed Technical Specification increase to 888 cubic feet will provide consistency with the new analysis for the limiting large-break LOCA. The effects of these changes on all other transients or classes of accidents in addition to the LOCA have been evaluated by Westinghouse and the licensee (Reference 5). It was determined by Westinghouse and Commonwealth Edison Company that the Thermal Design Flow (TOF) and the maximum primary coolant average temperature (Tave) of the Zion Units bound the 10% steam generator tube plugging situation in the non-LOCA transient analyses. The non-LOCA transients are analyzed with a nuclear heat flux hot channel factor (FqN) of 2.32. The concerns regarding flow reduction due to 10% uniform tube plugging have been addressed by Westinghouse. The Thermal Design Flow (TDF) has been shown by analysis to be unaffected by 10% uniform tube plugging. The impact of the
reduced heat transfer area in the steam generators has also been analyzed and demonstrated to be negligible. No change in the Tave program is necessary nor
, 'will any change be affected. Therefore, since both the Thermal Design Flow and
, 'Tave program are unchanged, the margin of safety a's calculated in the existing
' transient and accident analyses is unaffected for a 10% tube plugging level.
Compliance with 10 CFR 50.46 was demonstrated using previously approved LOCA
- valuation Models. 'For non-LOCA events, it w'as demonstrated that the current transient and accident analyses are unaffected by the 10% steam generator tube plugging level.
O We note,. howeve~r, that item 1A of the 1980 order requires that the PCT not exceed 2050 F using the October 22, 1979 model. Therefore the licensee should use the more limiting of either the peaking factor from the current analysis or the peaking factor from the analysis on which the 1980 Order is based.
STAFF FINDINGS The staff has reviewed the calculation of the containment backpressure in the revised ECCS analysis and determined that the analysis was performed with a previously approved model and containment parameters. We find the revised analysis acceptable.
This revised ECCS performance evaluation has been made using an NRC approved evaluation model which satisfies the requirements of 10 CFR 50.46 and Appendix K to Part 50. A 10% uniform steam generator tube plugging is incorporated into the model. A maximum total peaking factor of 2.32 (F q
) was used resulting in a peak cladding temperature of 2159 degrees Fahrenheit for the limiting break.
. , -7 The licensee also evaluated the potential effects of these changes on non-LOCA cccidents and transients. It was concluded that the Themm1 Design Flow will be met and that the maximum primary coolant average temperature assmed in l previously approved analyses will not be exceeded. These changes will there-fore not involve a reduction in the margin of safety with respect to DOW and other criteria for non-LOCA events.
The changes to the Technical Specifications are supported by the safety cnalyses provided by the licensee. - C' -
We find this evaluation acceptable, subject to the licensee's commitaast not to cxceed 10% steam generator tube plugging in any one steam generator or exceed core than 10% asymmetric plugging without further analysis and prior notification to the NRC. This commitment was docketed March 8,1985.
We note that until the order item A.1 is lifted or amended, an F q limit of 2.2 is necessary in order for the PCT to remain below 2050 using the October 22, 1979 model. -
4 e
The licensee's submittal of March 8, 1985, made as a result of NRC .,
staff request to clarify the original sub~ittal, m corrected a calculational error in the original submittal dated October 19, 1984.
Environmental Consideration These amendments involve a change in the installation or use of the facilities components located within the restricted areas as defined in 10 CFR 20. The staff has determined that these amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public connent on such finding. Accordingly,' these amendments meets i
the eligibility criteria for categorical exclusion set forth in 10 CFR Sec 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement l or environmental assessment need be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner,
- .. E and (2) such activities will be conducted in compliance with the Comission's regulations and the issuance of these amendments will not be' inimical to the common defense and security or to the health and safety _of the public.
Dated: Mai24,1985 Principal Contributor: -
- E. Throm
W $'
- g. f.'
. REFERENCES
- 1. Letter from R. N. Cascarano, Nuclear Licensing Administrator, Commonwealth Edison, to H. R. Denton, Director,, Nuclear Regulatory Commission,
Subject:
Zion Generating Station Units 1 and 2 Revised ECCS Analysis and Proposed Amendment to Facility Ope (ating License Nos. DPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304, dated October 19, 1984.
- 2. Rahe, E.P., " Westinghouse ECCS Evaluation Model, 1981 Version,"
WCAP-9920-P-A Rev.1 (Proprietary), WCAP-9221-P-1 Rev.1
. (Non-Proprietary),1981.
- 3. Letter from D. G. Mcdonald (NRC) to R. E. Uhrig (FP&L) transmitting NRC's SER concerning WCAP-9561, "BART A-1, A Computer Code for Best Estimate Analysis of Reflood Transients," December 21, 1983.
- 4. Letter from D. G. Mcdonald (NRC) to R. E. Uhrig (FP&L) transmitting Turkey Point SER based on 8 ART.
- 5. Letter from R. N. Cascarano, Nuclear Licensing Administrator, Commonwealth Edison, to' H. R. Denton, Director, Nuclear Regulatory Commission,
Subject:
Zion Generating Station Units 1 and 2 Revised ECCS Analysis and Proposed Amendment to Facility Operating License Nos. OPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304, dated February 14, 1985.
- 6. . Letter from R. N. Cascarano, Nuclear Licensing Administrator, Commonwealth Edison,- to H. R. Denton, Director, Nuclear Regulatory Commissiom,
Subject:
. Zion Generating Station Units 1 and 2 Revised ECCS Analysis and Proposed Amendment to Facility Operating License Nos. DPR-39 and DPR-48 NRC Docket -
Nos. 50-295 and 50-304, dated March 8, 1985. Response to NRC requested for additional informatio{ dated February 19, 1985.
- 7. Letter from E. P. Rahe, Westinghouse, to D. G. Eisenhut, NRC, Westinghouse Letter NS-NRC-85-3025, dated March 22, 1985.
- 8. Letter from P. C. LeBlond, Nuclear Licensing Administrator, Commonwealth Edison,- to H. R. Denton, Director, Nuclear Regulatory Commission,
Subject:
Zion Nuclear Power Station Un.its 1 and 2/ Addendum to the Revised ECCS Analysis and Proposed Amendment to Facility Operating License Nos. DPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304, dated April 19, 1985.
- 9. Letter from E. P. Rahe, Westinghouse, to C. Thomas, NRC, Westinghouse Letter NS-EPR-2952, dated August 14, 1984.
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