|
---|
Category:Annual Operating Report
MONTHYEARLIC-21-0004, Radiological Effluent Release Report and Radiological Environmental Operating Report2021-04-29029 April 2021 Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-18-0010, 2017 Annual Report2018-04-0202 April 2018 2017 Annual Report ML17122A2762017-05-0202 May 2017 Transmittal of 2016 Annual Report LIC-15-0060, Annual Report for 2014 Loss-of-Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.462015-04-30030 April 2015 Annual Report for 2014 Loss-of-Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 LIC-14-0130, Decommissioning External Trust Fund - Financial Statements as of and for the Years Ended June 30, 2014 and 2013, and Independent Auditors' Report2014-11-0707 November 2014 Decommissioning External Trust Fund - Financial Statements as of and for the Years Ended June 30, 2014 and 2013, and Independent Auditors' Report ML14108A0442013-12-31031 December 2013 Omaha Public Power District Fort Calhoun Station Unit Radiological Environmental Operating Report for Technical Specification Section 5.94.b January 1, 2013 to December 31, 2013 LIC-13-0056, Annual Report for 2012 Loss-of-Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.462013-04-30030 April 2013 Annual Report for 2012 Loss-of-Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 ML12121A0062012-04-27027 April 2012 Annual Report for 2011 Loss-of-Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 LIC-12-0045, 2011 Annual Report for Omaha Public District (OPPD)2012-04-0303 April 2012 2011 Annual Report for Omaha Public District (OPPD) LIC-12-0052, Annual Report for Technical Specification Section 5.9.4a2011-12-31031 December 2011 Annual Report for Technical Specification Section 5.9.4a LIC-11-0029, Annual Report for 2010 Loss of Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.462011-04-0606 April 2011 Annual Report for 2010 Loss of Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 LIC-11-0046, Annual Report for Technical Specification Section 5.9.4.a, January 1, 2010 to December 31, 20102010-12-31031 December 2010 Annual Report for Technical Specification Section 5.9.4.a, January 1, 2010 to December 31, 2010 ML11123A1952010-12-31031 December 2010 Fort Calhoun - 2010 Radiological Environmental Operating Report for January 1, 2010 Through December 31, 2010 LIC-10-0027, Ft. Calhoun Station Unit 1 Annual Report for 2009 Loss of Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.462010-04-26026 April 2010 Ft. Calhoun Station Unit 1 Annual Report for 2009 Loss of Coolant Accident (Loca)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 LIC-10-0021, Omaha Public Power District - 2009 Annual Report2010-04-0202 April 2010 Omaha Public Power District - 2009 Annual Report ML1011706622009-12-31031 December 2009 Annual Report for Technical Specification Section 5.9.4.a, January 1, 2009 to December 31, 2009 ML0912803712009-04-0808 April 2009 Annual Report for Technical Specification Section 5.9.4.a, January 1, 2008 to December 31, 2008 LIC-09-0032, Fort Calhoun, Unit 1, Annual Report for Technical Specification Section 5.9.4.a, January 1, 2008 to December 31, 20082009-04-0808 April 2009 Fort Calhoun, Unit 1, Annual Report for Technical Specification Section 5.9.4.a, January 1, 2008 to December 31, 2008 LIC-09-0026, Annual Report for 2008 Loss (Loca)/Emergency Core Cooling Pursuant to 10 CFR 50.46 of Coolant Accident System (ECCS) Models2009-04-0303 April 2009 Annual Report for 2008 Loss (Loca)/Emergency Core Cooling Pursuant to 10 CFR 50.46 of Coolant Accident System (ECCS) Models ML0712702922006-12-31031 December 2006 Annual Report for Technical Specification Section 5.9.4.a, for January 1, 2006 to December 31, 2006 LIC-06-0044, Annual Report for 2005 Loss of Coolant Accident Loca/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.462006-04-12012 April 2006 Annual Report for 2005 Loss of Coolant Accident Loca/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 ML0411901872003-12-31031 December 2003 Omaha Public Power District Fort Calhoun Station Unit 1, Annual Report for Technical Specification Section 5.9.4.a, January 1, 2003 to December 31, 2003. ML0411901862003-12-31031 December 2003 Omaha Public Power District, Fort Calhoun Station Unit No. 1, Radiological Environmental Operating Report Technical Specification 5.9.4.b, 01/01/2003 Through 12/31/2003. 2021-04-29
[Table view] Category:Letter type:LIC
MONTHYEARLIC-24-0007, License Amendment Request (LAR) to Revise License Termination Plan (LTP)2024-06-18018 June 2024 License Amendment Request (LAR) to Revise License Termination Plan (LTP) LIC-24-0008, Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (Dqap), Unit No. 1 and ISFSI2024-05-16016 May 2024 Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (Dqap), Unit No. 1 and ISFSI LIC-24-0003, Independent Spent Fuel Storage Installation - Radiological Effluent Release Report and Radiological Environmental Operating Report2024-04-25025 April 2024 Independent Spent Fuel Storage Installation - Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-24-0006, (Fcs), Unit 1, Independent Spent Fuel Storage Installation, Phase 1 Final Status Survey Report to Support Approved License Termination Plan2024-04-17017 April 2024 (Fcs), Unit 1, Independent Spent Fuel Storage Installation, Phase 1 Final Status Survey Report to Support Approved License Termination Plan LIC-24-0005, Annual Decommissioning Funding / Irradiated Fuel Management Status Report2024-03-0101 March 2024 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-24-0002, Independent Spent Fuel Storage Installation - Submittal of Annual Radioactive Effluent Release Report2024-02-27027 February 2024 Independent Spent Fuel Storage Installation - Submittal of Annual Radioactive Effluent Release Report LIC-23-0007, Response to Fort Calhoun, Unit 1 & Independent Spent Fuel Storage Installation Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements Request for Additional Information2023-12-0606 December 2023 Response to Fort Calhoun, Unit 1 & Independent Spent Fuel Storage Installation Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements Request for Additional Information LIC-23-0005, Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - 2nd Request for Additional Information (EPID L-2021-LIT-0000) June 2, 20232023-08-24024 August 2023 Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - 2nd Request for Additional Information (EPID L-2021-LIT-0000) June 2, 2023 LIC-23-0004, (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report2023-04-20020 April 2023 (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-23-0003, Annual Decommissioning Funding / Irradiated Fuel Management Status Report2023-03-15015 March 2023 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-23-0001, Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - Request for Additional Information2023-02-27027 February 2023 Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - Request for Additional Information LIC-23-0002, Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report2023-02-20020 February 2023 Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report LIC-22-0010, Response to Fort Calhoun Station, Unit No. 1 - Review of License Termination Plan Requirements - Request for Additional Information2022-06-15015 June 2022 Response to Fort Calhoun Station, Unit No. 1 - Review of License Termination Plan Requirements - Request for Additional Information LIC-22-0005, (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report2022-04-20020 April 2022 (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-22-0009, Annual Decommissioning Funding / Irradiated Fuel Management Status Report2022-03-30030 March 2022 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-22-0006, Reactor Head Disposition Project Overview2022-03-17017 March 2022 Reactor Head Disposition Project Overview LIC-22-0004, Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report2022-02-17017 February 2022 Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report LIC-21-0008, Organizational and Management Change2021-10-28028 October 2021 Organizational and Management Change LIC-21-0007, ISFSI Only Emergency Plan Update2021-09-0808 September 2021 ISFSI Only Emergency Plan Update LIC-21-0004, Radiological Effluent Release Report and Radiological Environmental Operating Report2021-04-29029 April 2021 Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-21-0003, Independent Spent Fuel Storage Installation - 2021 Annual Decommissioning Funding / Irradiated Fuel Management Status Report2021-03-30030 March 2021 Independent Spent Fuel Storage Installation - 2021 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-21-0002, Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report2021-02-22022 February 2021 Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report LIC-20-0015, Correction to Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report 2019 (ML20121A092)2020-07-29029 July 2020 Correction to Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report 2019 (ML20121A092) LIC-20-0014, Submittal of Revision 8 to the Fort Calhoun Station (Fcs), Physical Security Plan (PSP)2020-07-15015 July 2020 Submittal of Revision 8 to the Fort Calhoun Station (Fcs), Physical Security Plan (PSP) LIC-20-0012, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration and Certification of Permanent Removal of All Spent Fuel Assemblies from the Spent Fuel Pool2020-05-18018 May 2020 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration and Certification of Permanent Removal of All Spent Fuel Assemblies from the Spent Fuel Pool LIC-20-0011, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2020-05-0707 May 2020 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-20-0009, (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report2020-04-30030 April 2020 (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-20-0008, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2020-04-13013 April 2020 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-20-0006, (Fcs), Unit 1, Request for Exemption from 10 CFR 20, Appendix G, Section Iii.E2020-03-26026 March 2020 (Fcs), Unit 1, Request for Exemption from 10 CFR 20, Appendix G, Section Iii.E LIC-20-0004, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2020-03-10010 March 2020 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-20-0003, Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report2020-02-27027 February 2020 Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report LIC-20-0002, Independent Spent Fuel Storage Installation - Submittal of Revision 7 to Physical Security Plan2020-02-27027 February 2020 Independent Spent Fuel Storage Installation - Submittal of Revision 7 to Physical Security Plan LIC-20-0001, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2020-02-0606 February 2020 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-19-0025, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2019-12-19019 December 2019 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-19-0007, Post-Shutdown Decommissioning Activities Report2019-12-16016 December 2019 Post-Shutdown Decommissioning Activities Report LIC-19-0021, Independent Spent Fuel Storage Installation - Response to Request for Additional Information License Amendment for ISFSI-only EP and EAL Scheme2019-11-20020 November 2019 Independent Spent Fuel Storage Installation - Response to Request for Additional Information License Amendment for ISFSI-only EP and EAL Scheme LIC-19-0022, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2019-11-18018 November 2019 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration LIC-19-0018, Submittal of Revision 6 to the Fort Calhoun Station (Fcs), Physical Security Plan (PSP)2019-11-14014 November 2019 Submittal of Revision 6 to the Fort Calhoun Station (Fcs), Physical Security Plan (PSP) LIC-19-0020, Independent Spent Fuel Storage Installation - Updated Information Submittal and Revision 1 of the Blast Analysis2019-10-17017 October 2019 Independent Spent Fuel Storage Installation - Updated Information Submittal and Revision 1 of the Blast Analysis LIC-19-0017, Clarification to Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associated with Access Authorization for Fort Calhoun Station Dated 9 November, 20042019-08-0808 August 2019 Clarification to Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associated with Access Authorization for Fort Calhoun Station Dated 9 November, 2004 An LIC-19-0010, License Amendment Request (LAR) 19-03; Revised Fort Calhoun Station License in Support of the Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associa2019-05-20020 May 2019 License Amendment Request (LAR) 19-03; Revised Fort Calhoun Station License in Support of the Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associated LIC-19-0008, Submittal of 2018 Annual Report2019-04-0404 April 2019 Submittal of 2018 Annual Report LIC-19-0004, Independent Spent Fuel Storage Installation - Submittal of Revision 4 to Physical Security Plan (PSP)2019-03-28028 March 2019 Independent Spent Fuel Storage Installation - Submittal of Revision 4 to Physical Security Plan (PSP) LIC-19-0005, 2019 Annual Decommissioning Funding I Irradiated Fuel Management Status Report2019-03-28028 March 2019 2019 Annual Decommissioning Funding I Irradiated Fuel Management Status Report LIC-19-0001, License Amendment Request (LAR) 19-01: Independent Spent Fuel Storage Installation (ISFSI) Emergency Plan and Emergency Action Level Scheme2019-02-28028 February 2019 License Amendment Request (LAR) 19-01: Independent Spent Fuel Storage Installation (ISFSI) Emergency Plan and Emergency Action Level Scheme LIC-19-0003, Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associated with Access Authorization for Fort Calhoun Station Dated 9 November, 2004 and Relaxation R2019-02-28028 February 2019 Revised Response to Orders for Interim Safeguards and Security Compensatory Measures and Implementation of Additional Security Measures Associated with Access Authorization for Fort Calhoun Station Dated 9 November, 2004 and Relaxation Requ LIC-19-0002, Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report2019-01-0303 January 2019 Independent Spent Fuel Storage Installation Annual Radioactive Effluent Release Report LIC-18-0031, Independent Spent Fuel Storage Installation - Transmittal of Emergency Plan Update2018-12-17017 December 2018 Independent Spent Fuel Storage Installation - Transmittal of Emergency Plan Update LIC-18-0030, Request for Partial Site Release Phase 22018-11-12012 November 2018 Request for Partial Site Release Phase 2 LIC-18-0028, Letter of Intent to Submit Request for Additional Partial Site Release2018-10-18018 October 2018 Letter of Intent to Submit Request for Additional Partial Site Release 2024-06-18
[Table view] |
Text
HYMN Omaha Public PowerDistrict 444 South 16th Street Mall Omaha NE 68102-2247 April 3, 2009 LIC-09-0026 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
References:
- 1. Docket No. 50-285
- 2. EMF-2328(P)(A), Revision 0, "PWR Small Break LOCA Evaluation Model, S-RELAP5 Based," Framatome ANP, Inc.,
March 2001
- 3. EMF-2103(P)(A), Revision 0, "Realistic Large Break LOCA Methodology for Pressurized Water Reactors," Framatome ANP, Inc., April 2003
Subject:
Annual Report for 2008 Loss of Coolant Accident (LOCA)/Emergency Core Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 In accordance with 10 CFR 50(46)(a)(3)(ii), the Omaha Public Power District (OPPD) is submitting the annual 10 CFR 50.46 summary report for 2008. This summary report updates all identified changes or errors in the LOCA/ECCS codes, methods, and applications used by AREVA (formerly Framatome ANP) to model Fort Calhoun Station (FCS), Unit No. 1. The Small Break (SB) and Large Break (LB) LOCA analysis methodology used by AREVA for the FCS Analysis of Record is described in References 2 and 3 respectively.
OPPD has received the 2008 AREVA 10 CFR 50.46 Annual Notification Report for the SB and LB LOCA Analyses that are subject to the reporting requirements of 10 CFR 50.46.
For 2008, there were two SB LOCA Analysis Peak Clad Temperature (PCT) 10 CFR 50.46 Model Assessment errors of 0°F and -80 F. These errors are described in Attachment 1. Attachment 2 provides the 2008 SB LOCA Margin Summary Sheet for FCS. As a result of the -8 0F total errors, the SB LOCA PCT changed from the baseline value (reported in the FCS Updated Final Safety Analysis Report) of 1537°F to 1529°F. The sum of the absolute values of the errors/changes in the SB LOCA analysis of record is 8°F.
-Aec IoIK Employment with Equal Opportunity 4171
U.S. Nuclear Regulatory Commission LIC-09-0026 Page 2 For 2008, there were three LB LOCA Analysis PCT 10 CFR 50.46 Model Assessment errors of +7°F, -20'F, and 0°F. These errors are described in . Attachment 4 provides the 2008 LB LOCA Margin Summary Sheet for FCS. Because of the -130 F total errors, the LB LOCA PCT changed from the baseline value (reported in the FCS Updated Final Safety Analysis Report) of 1636°F to 1623°F. The sum of the absolute value of the errors/changes in the LB LOCA analysis of record is 27°F.
In summary, the FCS PCT values for SB and LB LOCA remain less than the 10 CFR 50.46(b)(1) acceptance criteria of 2200'F.
If you should have any questions, please contact Mr. Bill R. Hansher at (402) 533-6894.
No commitments to the NRC are made in this letter.
Division Manager Nuclear Engineering Attachments:
- 1. 10 CFR 50.46 Small Break LOCA Model Assessments
- 2. Fort Calhoun Station Small Break LOCA Margin Summary Sheet
- 3. 10 CFR 50.46 Large Break LOCA Model Assessments
- 4. Fort Calhoun Station Large Break LOCA Margin Summary Sheet c: E. E. Collins, NRC Regional Administrator, Region IV A. B. Wang, NRC Project Manager J. D. Hanna, NRC Senior Resident Inspector K7
LIC-09-0026 Page 1 10 CFR 50.46 Small Break LOCA Model Assessments Inconsistencies in Application of the S-RELAP5 Mixture Level Model It was discovered that there is a limitation in the S-RELAP5 mixture level model.
The S-RELAP5 mixture level model detection logic determines the locations of mixture level by primarily looking at the void distributions in stacks of consecutive vertical volumes.
Under certain circumstances, the removal of extra mixture levels according to heat structure conditions may not be performed properly, resulting in random removal of mixture levels.
As a result, AREVA has performed code modifications to deal with this logic limitation in S-RELAP5 in order to eliminate potential level tracking problems.
After an evaluation, it was found that no safety impact results from this error.
Scoping calculations were used to support the engineering judgment for the determination of the PCT impact. For the Fort Calhoun SB LOCA analysis, the PCT impact was estimated to be 0°F.
Legacy Fortran Programming Issue with Point Kinetics in RELAP5 Based Computer Codes A legacy FORTRAN programming issue with point kinetics solution of the RELAP5 based computer code was discovered. The limitation consists of incorrect indexing in the four summations that compute terms for the delayed neutron fractions from each group that contributes to the total power.
After an evaluation, it was found that no safety impact resulted from this condition. For the Fort Calhoun SB LOCA analysis, the PCT impact was estimated to be -8°F.
LIC-09-0026 Page 1 Small Break LOCA Margin Summary Sheet - Annual Report Plant Name: Fort Calhoun Station Utility Name: Omaha Public Power District EvaluationModel: Small Break LOCA Net PCT Effect Absolute PCT Effect A. Prior 10 CFR 50.46 Changes or Error Corrections- APCT = 0°F O0F Previous Years B. Prior 10 CFR 50.46 Changes or Error Corrections- APCT = - 8"F 8°F This year Absolute Sum of 10 CFR 50.46 Changes APCT = 8"F The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates of the PCT impact for changes and errors identified since this analysis is less than 2200'F.
LIC-09-0026 Page 1 10 CFR 50.46 Large.Break LOCA Model Assessments Inconsistencies in Application of the S-RELAP5 Mixture Level Model It was discovered that there is a limitation in the S-RELAP5 mixture level model.
The S-RELAP5 mixture level model detection logic determines the locations of mixture level by primarily looking at the void distributions in stacks of consecutive vertical volumes. Under certain circumstances, the removal of extra mixture levels according to heat structure conditions may not be performed properly, resulting in random removal of mixture levels.
As a result, AREVA has performed code modifications to deal with this logic limitation in S-RELAP5 in order to eliminate potential level tracking problems.
After an evaluation, it was found that no safety impact results from this error.
Scoping calculations were used to support the engineering judgment for the determination of the PCT impact. For the Fort Calhoun LB LOCA analysis, the PCT impact was estimated to be +7°F.
Legacy Fortran Programming Issue with Point Kinetics in RELAP5 Based Computer Codes A legacy FORTRAN programming issue with point kinetics solution of the RELAP5 based computer code was discovered. The limitation consists of incorrect indexing in the four summations that compute terms for the delayed neutron fractions from each group that contributes to the total power.
After an evaluation, it was found that no safety impact resulted from this condition. For the Fort Calhoun LB LOCA analysis, the PCT impact was estimated to be -20 0 F.
Cold Leg Condensation in RLBLOCA Methodology An issue with Realistic Large Break LOCA (RLBLOCA) was discovered. AREVA determined that, for analyses assuming a single train of pumped injection due to a single failure assumption, the S-RELAP5 modeling significantly underpredicts the condensation in the cold legs and the downcomer during the reflood phase after the accumulators empty. Because of this, the ECCS water entering the downcomer is suffiently subcooled to absorb the downcomer wall heat release without significant boiling. If the condensation were properly modeled, it is expected that the ECCS water would enter the downcomer in a saturated or only slightly subcooled state and that heat release from the downcomer would lead to boiling and reduction of reflood driving head.
An evaluation was performed for Fort Calhoun and there is a 0°F impact to PCT.
LIC-09-0026 Page 1 Large Break LOCA Margin Summary Sheet - Annual Report Plant Name: Fort Calhoun Station Utility Name: Omaha Public Power District Evaluation Model: Large Break LOCA Net PCT Effect Absolute PCT Effect A. Prior 10 CFR 50.46 Changes or Error Corrections- APCT = 0°F 0°F Previous Years B. Prior 10 CFR 50.46 Changes or Error Corrections- APCT = -13°F 27°F This year I I Absolute Sum of 10CFR 50.46 Changes APCT = 27 0 F The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates of the PCT impact for changes and errors identified since this analysis is less than 2200 0 F.