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Category:Letter type:RS
MONTHYEARRS-23-121, Sixth Ten-Year Interval Inservice Testing Program2023-11-30030 November 2023 Sixth Ten-Year Interval Inservice Testing Program RS-23-119, Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information2023-11-10010 November 2023 Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information RS-23-107, Relief Request I5R-22, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval2023-11-0808 November 2023 Relief Request I5R-22, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval RS-23-102, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-10-16016 October 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation RS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023 Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans RS-23-071, Application to Adopt TSTF-564, Safety Limit MCPR2023-08-30030 August 2023 Application to Adopt TSTF-564, Safety Limit MCPR RS-23-080, Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs2023-08-30030 August 2023 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs RS-23-077, Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-06-16016 June 2023 Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations RS-23-078, Supplement to License Amendment Request to Revise Technical Specification 3.1.4, Control Rod Scram Times2023-06-16016 June 2023 Supplement to License Amendment Request to Revise Technical Specification 3.1.4, Control Rod Scram Times RS-23-042, Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling2023-05-25025 May 2023 Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling RS-23-070, Supplement to License Amendment Request Regarding Transition to GNF3 Fuel2023-05-16016 May 2023 Supplement to License Amendment Request Regarding Transition to GNF3 Fuel RS-23-057, Supplement to License Amendment Request Regarding Transition to GNF3 Fuel2023-04-17017 April 2023 Supplement to License Amendment Request Regarding Transition to GNF3 Fuel RS-23-049, Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations2023-03-23023 March 2023 Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations RS-23-041, Response to Request for Additional Information for Alternative Request RV-23H2023-03-14014 March 2023 Response to Request for Additional Information for Alternative Request RV-23H RS-23-045, Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.2032023-02-28028 February 2023 Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.203 RS-23-003, Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-102023-01-31031 January 2023 Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-10 RS-23-004, Response to Request for Additional Information Regarding Transition to GNF3 Fuel License Amendment Request2023-01-23023 January 2023 Response to Request for Additional Information Regarding Transition to GNF3 Fuel License Amendment Request RS-22-126, Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI2022-11-30030 November 2022 Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI RS-22-121, Notice of Intent to Pursue Subsequent License Renewal Applications2022-11-0909 November 2022 Notice of Intent to Pursue Subsequent License Renewal Applications RS-22-117, Response to Request for Additional Information License Amendment Request Regarding New Fuel Storage Vault and Spent Fuel Storage Pool Criticality Methodologies2022-11-0303 November 2022 Response to Request for Additional Information License Amendment Request Regarding New Fuel Storage Vault and Spent Fuel Storage Pool Criticality Methodologies RS-22-116, Submittal of Relief Requests Associated with the Sixth Inservice Testing Interval2022-11-0101 November 2022 Submittal of Relief Requests Associated with the Sixth Inservice Testing Interval RS-22-115, Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors2022-10-19019 October 2022 Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors RS-22-092, Nine and Quad Cities - Application to Revise Primary Containment Isolation Instrumentation Technical Specifications in Accordance with TSTF-306, Revision 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration2022-10-0303 October 2022 Nine and Quad Cities - Application to Revise Primary Containment Isolation Instrumentation Technical Specifications in Accordance with TSTF-306, Revision 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration RS-22-066, License Amendment Request to Revise Technical Specification 3.1.4, Control Rod Scram Times2022-08-25025 August 2022 License Amendment Request to Revise Technical Specification 3.1.4, Control Rod Scram Times RS-22-065, License Amendment Request Regarding Transition to GNF3 Fuel2022-08-18018 August 2022 License Amendment Request Regarding Transition to GNF3 Fuel RS-22-093, Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans2022-08-18018 August 2022 Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans RS-22-101, Response to Request for Additional Information Related to Relief Request I6R-01 Associated with the Sixth Inservice Inspection Interval2022-08-10010 August 2022 Response to Request for Additional Information Related to Relief Request I6R-01 Associated with the Sixth Inservice Inspection Interval RS-22-099, Submittal of Upcoming Sixth Inservice Inspection Interval Relief Requests I6R-09 and I6R-102022-07-19019 July 2022 Submittal of Upcoming Sixth Inservice Inspection Interval Relief Requests I6R-09 and I6R-10 RS-22-082, Defueled Safety Analysis Report Update, Revision 112022-06-22022 June 2022 Defueled Safety Analysis Report Update, Revision 11 RS-22-080, Withdrawal and Proposed Alternative I6R-08 Associated with Code Case N-921 for Sixth Inservice Inspection Intervals2022-06-0909 June 2022 Withdrawal and Proposed Alternative I6R-08 Associated with Code Case N-921 for Sixth Inservice Inspection Intervals RS-22-064, License Amendment Request Regarding New Fuel Storage Vault and Spent Fuel Storage Pool Criticality Methodologies with Proposed Change to Technical Specifications Section 4.3.12022-06-0808 June 2022 License Amendment Request Regarding New Fuel Storage Vault and Spent Fuel Storage Pool Criticality Methodologies with Proposed Change to Technical Specifications Section 4.3.1 RS-22-051, Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists2022-04-12012 April 2022 Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists RS-22-049, Constellation Energy Generation, LLC, Supplemental Information to Correct Typographical Errors in Constellation'S Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for2022-04-0404 April 2022 Constellation Energy Generation, LLC, Supplemental Information to Correct Typographical Errors in Constellation'S Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for V RS-22-046, Relief Requests Associated with the Sixth Inservice Inspection Interval2022-03-25025 March 2022 Relief Requests Associated with the Sixth Inservice Inspection Interval RS-22-045, Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2022-01, Preparation and Scheduling of Operator Licensing Examinations2022-03-25025 March 2022 Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2022-01, Preparation and Scheduling of Operator Licensing Examinations RS-22-042, Report on Status of Decommissioning Funding for Shutdown Reactors2022-03-23023 March 2022 Report on Status of Decommissioning Funding for Shutdown Reactors RS-22-027, Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated2022-02-23023 February 2022 Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated P RS-22-023, Constellation Energy Generation, LLC, Executed Trust Fund Agreement Amendment and Subordinate Trust Agreement2022-02-23023 February 2022 Constellation Energy Generation, LLC, Executed Trust Fund Agreement Amendment and Subordinate Trust Agreement RS-22-019, Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists2022-02-16016 February 2022 Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists RS-22-015, Notification of Completion of License Transfer and Request to Continue Processing Pending NRC Actions Previously Requested by Exelon Generation Company, LLC2022-02-0101 February 2022 Notification of Completion of License Transfer and Request to Continue Processing Pending NRC Actions Previously Requested by Exelon Generation Company, LLC RS-21-009, Proposed Relief Request Associated with Code Case N-9212022-01-18018 January 2022 Proposed Relief Request Associated with Code Case N-921 RS-22-004, Supplement to Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2022-01-0404 January 2022 Supplement to Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RS-21-121, Proposed Changes to Decommissioning Trust Agreements and Master Terms2021-12-15015 December 2021 Proposed Changes to Decommissioning Trust Agreements and Master Terms RS-21-114, Request for Exemption from 10 CFR 2.109(b)2021-10-28028 October 2021 Request for Exemption from 10 CFR 2.109(b) RS-21-110, Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors2021-10-19019 October 2021 Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors RS-21-103, Updated Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations for Byron Station and Dresden Nuclear Power Station2021-09-28028 September 2021 Updated Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations for Byron Station and Dresden Nuclear Power Station RS-21-097, Withdrawal of Certification of Permanent Cessation of Power Operations for Dresden Nuclear Power Station, Units 2 and 3, and Previously Submitted Licensing Actions in Support of Decommissioning2021-09-15015 September 2021 Withdrawal of Certification of Permanent Cessation of Power Operations for Dresden Nuclear Power Station, Units 2 and 3, and Previously Submitted Licensing Actions in Support of Decommissioning RS-21-091, Implementation of Insider Threat Program Requirements Associated with the Voluntary Security Clearance Program and Advisement of Leadership Changes2021-09-13013 September 2021 Implementation of Insider Threat Program Requirements Associated with the Voluntary Security Clearance Program and Advisement of Leadership Changes RS-21-086, Supplement to Request for Exemptions from Portions of 10 CFR 50.47 and 10 CFR 50, Appendix E2021-08-23023 August 2021 Supplement to Request for Exemptions from Portions of 10 CFR 50.47 and 10 CFR 50, Appendix E RS-21-078, Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel2021-08-19019 August 2021 Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel 2023-08-30
[Table view] Category:Licensee 30-Day Written Event Report
MONTHYEARRS-11-124, Plant Specific ECCS Evaluation Changes - 10 CFR 50.46 30-Day Report for Fuel Type GE142011-07-28028 July 2011 Plant Specific ECCS Evaluation Changes - 10 CFR 50.46 30-Day Report for Fuel Type GE14 SVPLTR 09-0044, Day Response on Inadvertent Control Rod Withdrawal2009-09-21021 September 2009 Day Response on Inadvertent Control Rod Withdrawal SVPLTR 09-0027, Written Follow Up Report on Release of Radionuclide2009-07-0606 July 2009 Written Follow Up Report on Release of Radionuclide RS-08-073, Plant Specific ECCS Evaluation Changes - 10 CFR 50.46 30-Day Report for Fuel Type SVEA-96 Optima22008-05-23023 May 2008 Plant Specific ECCS Evaluation Changes - 10 CFR 50.46 30-Day Report for Fuel Type SVEA-96 Optima2 ML0216407762002-06-0707 June 2002 Offsite Dose Calculation Manual (OCDM) Required Action Not Met During Units 2/3 Main Chimney Particulate, Iodine, and Noble Gas Sampling System Inoperability ML17252A3201977-11-23023 November 1977 LER 77-047/03L-0 for Dresden Unit 3 Regarding During Normal Unit 3 Operation, Surveillance Program Review Revealed Violation of T.S.1.0.CC.b Maximum Combined Interval Time by 3.5 Days for HPCI Monthly Valve and Pump Operability ML17252A2881977-05-0303 May 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-8 ML17252A2911977-04-22022 April 1977 License Event Report - Rod Withdrawal at Approx. 44% Power, Discovered Rod Block Monitor Channels 7 and 8 Automatically Bypassed ML17252A2901977-04-21021 April 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-10 ML17252A2711977-04-21021 April 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-9 ML17252A2721977-04-20020 April 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-7 ML17252A2751977-03-23023 March 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-4 ML17252A2821977-03-0202 March 1977 Transmittal of Reportable Occurrence Report No. 50-249/1977-4 ML17252A2581977-01-20020 January 1977 Transmittal of Reportable Occurrence Report No. 50-249/1976-36 ML17252A2701976-12-0202 December 1976 Transmittal of Reportable Occurrence Report No. 50-249/1976-34 IR 05000249/20190761976-12-0202 December 1976 Transmittal of Reportable Occurrence Report No. 50-249/1976-34 ML17252A2461976-11-0404 November 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-23 in Accordance with Technical Specifications, Section 6.6.B ML17252A2451976-11-0404 November 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-25 in Accordance with Technical Specifications, Section 6.6.B ML17252A2391976-10-22022 October 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-20 in Accordance with Technical Specifications, Section 6.6.B ML17252A2411976-10-21021 October 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-18 in Accordance with Technical Specifications, Section 6.6.B ML17252A2401976-10-21021 October 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-19 in Accordance with Technical Specifications, Section 6.6.B ML17252A2231976-10-12012 October 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-15 in Accordance with Technical Specifications, Section 6.6.B ML17252A2261976-09-30030 September 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-17 in Accordance with Technical Specifications, Section 6.6.B ML17252A2361976-07-0101 July 1976 Transmittal of Reportable Occurrence Report No. 50-249/1976-1 ML17252A2101976-02-0505 February 1976 Letter Submitting Reportable Occurrence Number 050-249/1976-3 in Accordance with Technical Specifications, Section 6.6.B IR 05000249/19750361975-09-0202 September 1975 Report of Abnormal Occurrence 50-249/75-36 Per Section 6.6.A of the Technical Specifications Re Reactor High Pressure Sensor Setpoint Drift ML17252A1761975-09-0202 September 1975 Report of Abnormal Occurrence 50-249/75-36 Per Section 6.6.A of the Technical Specifications Re Reactor High Pressure Sensor Setpoint Drift ML17252A1711975-08-15015 August 1975 Report of A.O. Per Section 6.6.A of the Technical Specifications Isolation Condenser High Flow Sensor Setpoint Drift IR 05000249/19750321975-07-31031 July 1975 Report of Abnormal Occurrence 50-249/75-32 Per Section 6.6.A of the Technical Specifications Failure of Restrainer Clamp Bolt Keeper on Jet Pumps ML17252A1741975-07-31031 July 1975 Report of Abnormal Occurrence 50-249/75-32 Per Section 6.6.A of the Technical Specifications Failure of Restrainer Clamp Bolt Keeper on Jet Pumps ML17252A4471975-07-0303 July 1975 Report of Abnormal Occurrence 50-249/75-31 for Dresden, Unit 3, Regarding Cracks in Control Rod Drive Collet Housings IR 05000249/19750311975-07-0303 July 1975 Report of Abnormal Occurrence 50-249/75-31 for Dresden, Unit 3, Regarding Cracks in Control Rod Drive Collet Housings ML17252A7861975-03-27027 March 1975 Report of Abnormal Occurrence Per Section 6.6.a of the Technical Specification - Exceeding Set-point on Main Stream Line Hi Hi Rad ML17252A8271975-02-14014 February 1975 Report of Abnormal Occurrence Per Section 6.6.A of the Technical Specification - Reactor Feed Pump 3C Pump Casting Vent Line Weld Leak ML17252A8361975-01-14014 January 1975 Report of 4 Inch Recirculation Bypass Line Inspection 2011-07-28
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Text
Exelon.
Exelon Nuclear 4300 Winfield Road www.exeloncoTp.com Nuclear Warrenville, I L 60555 10 CFR 50.46(a)(3)(ii)
RS-08-073 May 23, 2008 U .S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 Renewed Facility Operating License No. DPR-19 NRC Docket No. 50-237
Subject:
Plant Specific ECCS Evaluation Changes -10 CFR 50.46 30-Day Report for Fuel Type SVEA-96 Optima2
Reference:
Letter from D. Bost (Exelon Generation Company, LLC) to U.S . NRC, "Plant Specific ECCS Evaluation Changes - 10 CFR 50.46 Report," dated October 31, 2007 In accordance with 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors," paragraph (a)(3)(ii), Exelon Generation Company, LLC (EGC),
is submitting this letter and its attachment to notify the NRC of changes or errors discovered in the Dresden Nuclear Power Station (DNPS) Unit 2 plant specific emergency core cooling (ECCS) evaluation for Westinghouse fuel type SVEA-96 Optima2 that have been determined to be significant. This submittal meets the requirements of 10 CFR 50.46(a)(3)(ii) for submittal of a report within 30 days .
In the referenced letter, EGC provided the NRC with the annual 10 CFR 50.46 Report for DNPS Units 2 and 3. The attachment to that letter identified the use of ATRIUM-9B and GE 14 fuel in the DNPS Unit 2 reactor core . Subsequent to the submittal of this evaluation, EGC partially loaded the reactor core of DNPS Unit 2 with Westinghouse SVEA-96 Optima2 fuel . In order to support the introduction of this new fuel type, EGC implemented the Westinghouse Loss of Coolant Accident (LOCA) model . At that time, the calculated peak cladding temperature (PCT) in the Westinghouse LOCA model was the same value as that provided in the referenced letter .
On April 24, 2008, Westinghouse initially notified EGC of a potential non-conservative assumption in the Westinghouse 10 CFR 50, Appendix K LOCA analysis for SVEA-96 Optima2 fuel in DNPS Unit 2 that resulted in an increase of calculated net PCT of 80 degrees Fahrenheit (°F) to a value of 2230 °F. Based on further discussions with Westinghouse, EGC confirmed the non-conservative assumption on April 25, 2008, at which point EGC notified the NRC in accordance with 10 CFR 50.72, "Immediate notification requirements for operating nuclear power reactors,"
(i .e., Event Number 44168).
In 2007, Westinghouse performed a LOCA analysis for DNPS Units 2 and 3. This analysis assumed that the DNPS Unit 3 low pressure core spray (LPCS) flow would bound the DNPS Unit 2 flow, and thus was used as the assumed flow value for both Unit 2 and Unit 3.
May 23, 2008 U. S . Nuclear Regulatory Commission Page 2 In April 2008, while performing a scoping study to support a potential DNPS Unit 2 LPCS modification, Westinghouse discovered that the DNPS Unit 2 LPCS flow was not bounded by the Unit 3 flow, as previously assumed . Utilizing the DNPS Unit 2 LPCS flow value in the LOCA analysis resulted in the PCT increase of 80 °F . Since the Unit 3 LPCS flow value input for the LOCA analysis was correct, this error did not affect the DNPS Unit 3 LOCA analysis of record .
Subsequent to identification of the incorrect DNPS Unit 2 LPCS flow assumption, EGC determined that a 2.4 percent reduction in the maximum average planar heat generation rate (MAPLHGR) limit would offset the 80 °F increase in the limiting PCT. DNPS Unit 2 has been operating with more than 3 percent margin in MAPLHGR since the start of the current operating cycle (i.e ., November 2007) . EGC has implemented administrative limits for DNPS Unit 2 to maintain these margins.
The attachment to this letter provides the PCT value and the associated "rack-up" sheets for SVEA-96 Optima2 fuel in DNPS Unit 2, assuming a 2.4 percent reduction in the administrative MAPLHGR limit. There are no analytical changes required for fuel types ATRIUM-9B and GE 14 that were previously submitted in the referenced letter . Additionally, EGC will submit a Licensee Event Report on or before June 24, 2008, in accordance with the requirements of 10 CFR 50.73, "Licensee event report system," and 10 CFR 50.46 If there are any questions concerning this letter, please contact Mr. John L. Schrage at (630) 657-2821 .
Jeffre Manager - Licensing
Attachment:
Dresden Nuclear Power Station Unit 2 - 10 CFR 50.46 Report 30-Day Report for Fuel Type SVEA-96 Optima2 cc: Regional Administrator - NRC Region III NRC Senior Resident Inspector - Dresden Nuclear Power Station
Attachment Dresden Nuclear Power Station Unit 2 10 CFR 50.46 30-Day Report for Fuel Type SVEA-96 Optima2 PLANT NAME : Dresden Nuclear Power Station, Unit 2 ECCS EVALUATION MODEL: USA5 REPORT REVISION DATE : 05/06/2008 CURRENT OPERATING CYCLE: 21 ANALYSIS OF RECORD Evaluation Model : "Westinghouse BWR ECCS Evaluation Model : Supplement 3 to Code Description, Qualification and Application to SVEA-96 Optima2 Fuel,"
WCAP-16078-P-A, November 2004.
Calculations :
"Dresden 2 & 3 LOCA Analysis for SVEA-96 Optima2 Fuel," OPTIMA2-TR021 DR-LOCH, Revision 2, Westinghouse Electric Company LLC, June 2007.
Fuel Analyzed in Calculation: SVEA-96 Optima2 Limiting Fuel Type : SVEA-96 Optima2 Limiting Single Failure: LPCI injection valve Limiting Break Size and Location: 1 .0 double-ended guillotine break in the recirculation pump suction line Reference Peak Cladding Temperature (PCT) PCT = 2150°F MARGIN ALLOCATION A. PRIOR LOCA MODEL ASSESSMENTS None - new LOCA analysis APCT = 0°F PCT 2150°F B. CURRENT LOCA MODEL ASSESSMENTS New analysis (See Note 1) APCT = 0°F Non-Conservative LPCS performance parameters (See Note 2) OPCT = +80 °F MAPLHGR limit reduction implemented for Dresden unit 2 cycle 21 (See APCT = -80 °F Note 2 Total PCT change from current assessments JAPCT = 0°F Cumulative PCT change from current assessments E APCT = 160°F PCT 2150°F
Attachment Dresden Nuclear Power Station Unit 2 10 CFR 50.46 30-Day Report for Fuel Type SVEA-96 Optima2 Assessment Notes 1 . Current LOCA Model Assessment With Dresden Nuclear Power Station (DNPS) Unit 2 Cycle 21 startup in November 2007, Unit 2 implemented a plant-specific LOCA Analysis for DNPS . This analysis applies to operation of the Westinghouse Optima2 fuel in the DNPS reactors . This analysis applies specific inputs and assumptions in the LOCA calculation approved in the licensed Westinghouse methodology. Included are:
- a. Containment back pressure - the amount of containment overpressure credited in accordance with acceptance letter issued by the NRC,
- b. Proportional ECCS leakage,
- c. ECCS temperature reduction, d . Plant-specific ECCS parameters including the ECCS flow and leakages specific to Dresden,
- e. Emergency Diesel Generator load sequencing time delays specific to Dresden,
- f. Two channel model, and
- g. Improved definition of end of lower plenum flashing used to terminate non-zero heat transfer coefficient.
Reference:
"Dresden 2 & 3 LOCA Analysis for SVEA-96 Optima2 Fuel," OPTIMA2-TR021 DR-LOCA, Revision 2, Westinghouse Electric Company LLC, June 2007.
2 . Current LOCA Model Assessment Westinghouse performed the LOCA analysis for DNPS Unit 2 (D2) and Unit 3 (D3) as documented in Reference 1 . This analysis used a value for low pressure core spray (LPCS) performance based on an assumption that the flow rates from the D3 LPCS system bounded D2. In April 2008, Westinghouse discovered the use of the D3 LPCS performance for D2 is non-conservative . There is no impact on D3. This error resulted in an increased PCT of 80 °F . With a starting PCT value of 2150 °F, as documented in Reference 1, D2 exceeded the 10 CFR 50.46 acceptance criterion of 2200 °F for PCT. In Reference 2, Westinghouse determined the Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) limit reduction necessary for D2 to meet all 10 CFR 50.46 criteria while maintaining a PCT at or below the licensing basis value of 2150 °F for the entire Cycle 21 operation. DNPS has implemented the MAPLHGR limit reduction for unit 2. Therefore, the net PCT remains at 2150 °F .
References :
(1) "Dresden 2 & 3 LOCA Analysis for SVEA-96 Optima2 Fuel," OPTIMA2-TR021 DR-LOCA, Revision 2, Westinghouse Electric Company LLC, June 2007.
(2) "Impact Assessment of Dresden 2 Non-Conservative LPCS Performance Parameters,"
Westinghouse Letter LTR-LIS-08-325, April 2008.