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MONTHYEARML1114003652011-06-17017 June 2011 Letter: Davis-Besse Nuclear Power Station, Unit 1 - Steam Generator Tube Integrity During a Large Break Loss-of-Coolant Accident Project stage: Other 2011-06-17
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Category:Letter
MONTHYEARIR 05000346/20243012024-02-0202 February 2024 NRC Initial License Examination Report 05000346/2024301 IR 05000346/20230042024-01-31031 January 2024 Integrated Inspection Report 05000346/2023004 ML23313A1352024-01-17017 January 2024 Authorization and Safety Evaluation for Alternative Request RP 5 for the Fifth 10 Year Interval Inservice Testing Program ML23353A1192023-12-19019 December 2023 Operator Licensing Examination Approval Davis Besse Nuclear Power Station, January 2024 L-23-260, Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station2023-12-0707 December 2023 Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station L-23-243, Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-0606 December 2023 Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23338A3172023-12-0606 December 2023 Notification of NRC Baseline Inspection and Request for Information; Inspection Report 05000346/2024001 IR 05000346/20234032023-11-0202 November 2023 Security Baseline Inspection Report 05000346/2023403 ML23293A0612023-11-0101 November 2023 Letter to the Honorable Marcy Kaptur, from Chair Hanson Responds to Letter Regarding Follow Up on Concerns Raised by Union Representatives During the June Visit to the Davis-Besse Nuclear Power Plant L-23-215, Changes to Emergency Plan2023-10-19019 October 2023 Changes to Emergency Plan ML23237B4222023-09-28028 September 2023 Energy Harbor Nuclear Corp. - Vistra Operations Company LLC - Letter Regarding Order Approving Transfer of Licenses and Draft Conforming License Amendments ML23269A1242023-09-27027 September 2023 Request for Withholding Information from Public Disclosure IR 05000346/20234012023-09-13013 September 2023 Security Baseline Inspection Report 05000346/2023401 (Public) L-23-205, Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-09-12012 September 2023 Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments L-23-172, Quality Assurance Program Manual2023-08-31031 August 2023 Quality Assurance Program Manual IR 05000346/20230112023-08-30030 August 2023 Biennial Problem Identification and Resolution Inspection Report 05000346/2023011 ML23129A1722023-08-25025 August 2023 Request for Withholding Information from Public Disclosure for Beaver Valley Power Station, Units 1 and 2; Davis Besse Nuclear Power Station, Unit 1; and Perry Nuclear Power Plant, Unit 1 IR 05000346/20230052023-08-24024 August 2023 Updated Inspection Plan for Davis-Besse Nuclear Power Station (Report 05000346/2023005) L-23-188, Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-08-0707 August 2023 Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments IR 05000346/20230502023-08-0303 August 2023 Special Inspection Report 05000346/2023050 IR 05000346/20230902023-08-0101 August 2023 EA-23-002 Davis-Besse Nuclear Power Station - NRC Inspection Report No. 05000346/2023090 (Public) ML23178A2742023-08-0101 August 2023 Letter to the Honorable Marcy Kaptur from Chair Hanson Responds to Letter Regarding the License Transfer Application for the Davis-Besse Nuclear Power Station L-23-175, Submittal of Fifth Ten Year Inservice Testing Program2023-08-0101 August 2023 Submittal of Fifth Ten Year Inservice Testing Program IR 05000346/20230022023-07-27027 July 2023 Integrated Inspection Report 05000346/2023002 ML23193A7842023-07-13013 July 2023 Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection 05000346/2023402 ML23178A2422023-06-28028 June 2023 Reassignment of the U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch III ML23160A2342023-06-13013 June 2023 Confirmation of Initial License Examination L-23-034, 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2023-06-13013 June 2023 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models IR 05000346/20235012023-06-13013 June 2023 Emergency Preparedness Biennial Exercise Inspection Report 05000346/2023501 L-23-135, Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-05-31031 May 2023 Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations L-23-065, Annual Financial Report2023-05-22022 May 2023 Annual Financial Report ML23124A1742023-05-17017 May 2023 Energy Harbor Fleet Vistra License Transfer - Request for Withholding Information from Public Disclosure for Commance Peak Plant, Units 1 & 2, Beaver Valley Station, Units 1 & 2, Davis Besse Station, Unit 1 and Perry Plant, Unit 1 ML23129A0112023-05-16016 May 2023 Notice of Consideration of Approval of Indirect and Direct License Transfer for Comanche Peak Plant, Units 1 & 2, Beaver Valley Station, Units 1 & 2, Davis Besse Station, Unit 1 and Perry Plant, Unit 1 (EPID L-2023-LLM-0000) (Letter) ML23131A2732023-05-15015 May 2023 Notification of NRC Supplemental Inspection 95001 and Request for Information L-23-101, Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 20222023-05-12012 May 2023 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 2022 L-23-131, Readiness for Resumption of NRC Supplemental Inspection2023-05-12012 May 2023 Readiness for Resumption of NRC Supplemental Inspection IR 05000346/20230102023-05-0909 May 2023 Commercial Grade Dedication Inspection Report 05000346/2023010 ML23123A1272023-05-0303 May 2023 Information Request to Support Upcoming Problem Identification and Resolution Inspection at Davis-Besse Nuclear Power Station IR 05000346/20230012023-05-0101 May 2023 Integrated Inspection Report 05000346/2023001 and 07200014/2022001 L-23-092, Occupational Radiation Exposure Report for Year 20222023-04-27027 April 2023 Occupational Radiation Exposure Report for Year 2022 ML23111A1972023-04-26026 April 2023 Information Meeting with Question and Answer Session to Discuss NRC 2022 End-of-Cycle Plant Performance Assessment of Davis-Besse Nuclear Power Plant Station ML23114A1062023-04-25025 April 2023 Information Request to Support the NRC Annual Baseline Emergency Action Level and Emergency Plan Changes Inspection CP-202300181, ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, ISFSI, Corrected Affidavit for Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-04-20020 April 2023 ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, ISFSI, Corrected Affidavit for Application for Order Consenting to Transfer of Licenses and Conforming License Amendments CP-202300157, ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, and ISFSI, Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-04-14014 April 2023 ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, and ISFSI, Application for Order Consenting to Transfer of Licenses and Conforming License Amendments ML23096A1382023-04-11011 April 2023 Review of the Spring 2022 Steam Generator Tube Inspection Report L-23-061, Submittal of the Decommissioning Funding Status Reports2023-03-31031 March 2023 Submittal of the Decommissioning Funding Status Reports L-23-037, and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments2023-03-29029 March 2023 and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments L-23-066, Annual Notification of Property Insurance Coverage2023-03-21021 March 2023 Annual Notification of Property Insurance Coverage ML23066A2892023-03-14014 March 2023 Request for Threshold Determination Under 10 CFR 50.80 and 10 CFR 72.50 for an Amendment to the Voting Agreement ML23066A2592023-03-14014 March 2023 Request for Withholding Information from Public Disclosure for Beaver Valley Power Station, Units 1 and 2, Davis Besse Nuclear Power Station, Unit 1, and Perry Nuclear Power Plant, Unit 1 2024-02-02
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 17, 2011 Mr. Barry S. Allen Site Vice President FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Mail Stop A-DB-3080 550'1 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 - STEAM GENERATOR TUBE INTEGRITY DURING A LARGE-BREAK LOSS-OF-COOLANT ACCIDENT (TAC NO. ME6289)
Dear Mr. Allen:
On February 23,2010, the U.S. Nuclear Regulatory Commission (NRC) staff conducted an audit at the Davis-Besse Nuclear Power Station, Unit No.1 (DBNPS). The purpose of the audit was for the NRC staff to gain a better understanding of the approach taken by the FirstEnergy Nuclear Operating Company (FENOC, the licensee), for ensuring steam generator (SG) tube integrity following a large-break loss-of-coolant accident (LBLOCA) for DBNPS.
On May 19, 2010 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML101170196), the NRC staff issued a report summarizing the results of the audit. In that report, the NRC staff identified two potential inconsistencies between various licensee documents. FENOC's response to the audit report was provided in a letter dated July 16, 2010 (ADAMS Accession No. ML102020232).
One of the potential inconsistencies involves the need to perform full-length SG tube inspections to ensure compliance with License Condition 2.C(7)c, despite DBNPS Technical Specifications (TSs) not requiring full-length tube inspections. In the July 16, 2010, letter, FENOC committed to update the Davis-Besse Steam Generator Management Program Manual to explicitly state that portions of the tube excluded from inspection by DBNPS TS 5.5.8 were to be inspected to meet License Condition 2.C(7)c.
The NRC staff finds this action is acceptable given your plans to replace your SGs, at which time the NRC staff expects your TSs would be modified to once again explicitly require full length tube inspections.
B. Allen -2 The other potential inconsistency identified in the NRC staff audit report involves the source term used in the DBNPS final safety analysis report (FSAR) for the maximum hypothetical accident and the source term used to satisfy License Condition 2.C(7)c. In particular, the NRC staff noted that the dose consequence analysis supporting License Condition 2.C(7)c is based on a gap release source term, which is not consistent with Title 10 of the Code of Federal Regulations (10 CFR) Section 100.11.
The NRC staff notes that the dose criteria in 10 CFR 100.11 are based on a postulated major accident scenario resulting in a source term that is representative of a substantial core melt.
This source term description is provided in the footnote to the regulation. As such, it is the expectation of the NRC staff that the licensee's LBLOCA dose consequence analysis performed to show compliance with License Condition 2.C(7)c should be based on a source term that is consistent with that for which the regulatory acceptance criteria was established.
Alternatively, if a licensee's calculations use a best estimate source term, based on a small percentage of the fuel melt source term, the dose criteria of 10 CFR 100.11 must be proportionally reduced to show compliance with the regulation.
The NRC staff notes that application of the criteria in 10 CFR 100.11 or 10 CFR 50.67, based on a source term that is representative of a substantial core melt, is consistent with the NRC staff expectations which were provided in a letter dated July 8,2008 (ADAMS Accession No. ML081070092), from the NRC to the Pressurized Water Reactor Owner's Group concerning Topical Report BAW-2374, Revision 2, "A Risk-Informed Assessment of Once-Through Steam Generator Tube Thermal Loads Due To Breaks In Reactor Coolant System Upper Hot Leg Large*Bore Piping." This NRC staff position was also reiterated in the May 19, 2010, audit report.
The NRC staff concluded in the audit report that the total maximum hypothetical accident dose is below the limits of 10 CFR 100.11. In addition, the NRC staff noted that plant procedures are in place and operator training has been performed to limit the potential for a release of radioactive material following a LBLOCA event. Specifically, the DBNPS SG tube rupture procedure includes actions to control and track secondary side isolation if SG tubes rupture is suspected.
Given the low likelihood of the LBLOCA event, the compensatory measures implemented to reduce the potential for release of radioactive materials following a LBLOCA event, and the planned replacement of the existing DBNPS once-through SGs, the NRC staff determined that the inconsistency does not create any safety issues in the short term (i.e., until the time the SGs are replaced, or approximately 5 years).
B. Allen -3 However, following the replacement of the SGs at DBNPS, the NRC staff expects that the dose analysis for the LBLOCA event will be consistent with the regulations and the NRC staff expectations discussed above.
If you have any questions, please contact me at 301-415-3867 or bye-mail at Michael. Mahoney@nrc.gov.
~
Michael Mahoney, Project M Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346 cc: Distribution via Listserv
ML111400365 OFFICE DORULPL3-2/PM DORULPL3-21LA DRAlAADB/BC NAME MMahoney SRohrer nate DATE 6/16/11 6/16/11 5/26/11 OFFICE DCI/CSGB/BC OGC DORULPL3-21BC NAME RTaylor/MYoder IfI BHarris JZimmerman DATE 5/26/11 6/6111 6/17/11