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Category:Letter
MONTHYEARIR 05000317/20230042024-02-0101 February 2024 Integrated Inspection Report 05000317/2023004 and 05000318/2023004 ML24029A0102024-01-29029 January 2024 Request for Information and Notification of Conduct of IP 71111.21.N.04, Age-Related Degradation, Reference Inspection Report 05000317/2024010 and 05000318/2024010 ML24003A8872024-01-19019 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0033 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) 05000318/LER-2023-004, Submittal of LER 2023-004-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Submittal of Automatic Reactor Trip from Reactor Protection System Actuation Due to Loss of Unit Service Transformer2024-01-16016 January 2024 Submittal of LER 2023-004-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Submittal of Automatic Reactor Trip from Reactor Protection System Actuation Due to Loss of Unit Service Transformer ML24011A0732024-01-11011 January 2024 Proposed Alternative to the Requirements for Repair/Replacement of Saltwater (SW) System Buried Piping 05000318/LER-2023-002, Forward LER 2023-002-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Automatic Reactor Trip from Reactor Protection System Actuation Due to Loss of Unit Service Transformer2024-01-0808 January 2024 Forward LER 2023-002-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Automatic Reactor Trip from Reactor Protection System Actuation Due to Loss of Unit Service Transformer 05000318/LER-2023-003, Forward LER 2023-003-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Manual Actuation of Auxiliary Feedwater System Due to 22 Steam Generator Feedwater Pump Trip2024-01-0808 January 2024 Forward LER 2023-003-00 for Calvert Cliffs Nuclear Power Plant, Unit 2, Manual Actuation of Auxiliary Feedwater System Due to 22 Steam Generator Feedwater Pump Trip ML24005A0222024-01-0505 January 2024 Revised Steam Generator Tube Inspection Reports ML23304A0642024-01-0202 January 2024 Issuance of Amendment No. 349 to Modify the Long-Term Coupon Surveillance Program RS-23-125, Request for Exemption from 10 CFR 2.109(b)2023-12-0707 December 2023 Request for Exemption from 10 CFR 2.109(b) ML23331A2992023-11-27027 November 2023 Submittal of Condition Prohibited by Technical Specifications Due to Failure to Sample Diesel Generator Fuel Oil Storage Tank IR 05000317/20230102023-11-20020 November 2023 Biennial Problem Identification and Resolution Inspection Report 05000317/2023010 and 05000318/2023010 ML23318A4722023-11-14014 November 2023 Supplement to License Amendment Request to Adopt TSTF-59-A ML23317A1032023-11-10010 November 2023 Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information ML23317A1192023-11-10010 November 2023 Constellation Energy Generation, LLC - 2023 Annual Report - Guarantees of Payment of Deferred Premiums ML23310A0442023-11-0707 November 2023 Project Manager Assignment IR 05000317/20230402023-11-0202 November 2023 95001 Supplemental Inspection Report 05000317/2023040 and Follow-Up Assessment Letter IR 05000317/20230032023-11-0101 November 2023 Integrated Inspection Report 05000317/2023003 and 05000318/2023003 IR 05000317/20230902023-10-26026 October 2023 Final Significance Determination of a White Finding with Assessment Follow-Up and Notice of Violation; Inspection Report 05000317/2023090 ML23289A1202023-10-16016 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-23-108, Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator Pressure Retaining Welds and Full Penetration Welded Nozzles2023-10-11011 October 2023 Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator Pressure Retaining Welds and Full Penetration Welded Nozzles RS-23-105, Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds and Nozzle Inside Radius Sections2023-10-10010 October 2023 Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds and Nozzle Inside Radius Sections ML23279A1202023-10-0606 October 2023 Response to NRC Inspection Report and Preliminary White Finding IR 05000317/20230502023-09-29029 September 2023 Special Inspection Report 05000317/2023050 and Preliminary White Finding and Apparent Violation ML23272A1032023-09-29029 September 2023 Condition Prohibited by Technical Specifications Due to Inoperable Nuclear Instrumentation at Very Low Power IR 05000317/20234012023-09-18018 September 2023 Cyber Security Inspection Report 05000317/2023401 and 05000318/2023401 ML23254A0012023-09-0505 September 2023 Registration of Use of Casks to Store Spent Fuel IR 05000317/20230052023-08-31031 August 2023 Updated Inspection Plan for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 (Report 05000317/2023005 and 05000318/2023005) ML23158A1952023-08-30030 August 2023 R. E. Ginna - Issuance of Amendments to Adopt TSTF-273-A, Revision 2, Safety Function Determination Program Clarifications ML23241A8412023-08-29029 August 2023 Response to Request for Additional Information - Proposed Alternative to the Requirements for Repair/Replacement of Saltwater (SW) System Buried Piping ML23240A3872023-08-28028 August 2023 Senior Reactor and Reactor Operator Initial License Examinations ML23151A3472023-08-21021 August 2023 Issuance of Amendments to Adopt TSTF-295-A, Modify Note 2 to Actions of PAM Table to Allow Separate Condition Entry for Each Penetration ML23219A1662023-08-16016 August 2023 Request for Additional Information Regarding Proposed Alternative to the Requirements for Repair/Replacement of Saltwater (SW) System Buried Piping (EPID: L-2023-LLR-0006) - Non-proprietary ML23228A1002023-08-15015 August 2023 Notification of Readiness for NRC 95001 Inspection ML23188A0402023-08-0808 August 2023 Issuance of Amendment Nos. 346 and 324 Adoption of TSTF-577, Revised Frequencies for Steam Generator Tube Inspections, Revision 1 ML23214A1572023-08-0707 August 2023 Correction to the Renewed Facility Operating License Page 3 in Amendment No 345 IR 05000317/20230022023-08-0303 August 2023 Integrated Inspection Report 05000317/2023002 ML23188A0512023-07-13013 July 2023 Correction to the Renewed Facility Operating License Pages in Amendment Nos. 336 and 314 ML23186A0372023-07-13013 July 2023 Correction to the Renewed Facility Operating License Pages in Amendment Nos. 340 and 318 IR 05000317/20233012023-07-12012 July 2023 Initial Operator Licensing Examination Report 05000317/2023301 and 05000318/2023301 IR 05000317/20230122023-07-10010 July 2023 Commercial Grade Dedication Report 05000317/2023012 and 05000318/2023012 ML23180A2362023-06-29029 June 2023 Correction of Errors on Technical Specification Pages RS-23-083, Withdrawal - Proposed Alternatives Related to the Steam Generators2023-06-27027 June 2023 Withdrawal - Proposed Alternatives Related to the Steam Generators ML23156A6752023-06-20020 June 2023 Request for Withholding Information from Public Disclosure for Proposed Alternative to the Requirements for Repair/Replacement of Saltwater System Buried Piping 2024-02-01
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Exelon Generation~ Larry D. Smith Regulatory Assurance Manager Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, MD 20657 410 495 5219 Office 410 610 9729 Mobile www.exeloncorp.com larry.smith2@exeloncorp .com TS 3.3.10 and 5.6.7 January 21, 2021 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Unit No. 2 Renewed Facility Operating License No. DPR-53 NRC Docket No. 50-317
Subject:
Reactor Coolant Subcooled Margin Monitor System Special Report This special report is submitted in accordance with Calvert Cliffs Nuclear Power Plant Technical Specification 3.3.10. The report is required due to the Unit 1 Reactor Coolant Subcooled Margin Monitor System_having less than the required minimum number of operable channels .
ACTION TAKEN On December 6, 2020 at 1030, Post Accident Monitoring System (PAMS) Channel B Temperature Transmitter 1TT112CB became erratic causing faulty readings. This caused PAMS Channel B Reactor Coolant System (RCS) Subcooled Margin Monitor (SMM) to be declared inoperable. At that time PAMS Channel A RCS SMM was OPERABLE and provided the one Technical Specification required RCS SMM channel.
On December 10, 2020 at 1517, Unit 1 Control Room received an unexpected alarm at window E-10 on 1C06, "RVLMS [Reactor Vessel Level Monitoring System] CH A 1C144A" and Operations responded in accordance with the applicable alarm respons~ procedure. The Channel A Post-Accident Monitoring Display at 1C06 System Health screen indicated a fan malfunction, and showed a Fan Fail Red light illuminated at the same time. In accordance with site procedure the associated cabinet (1C144A) should be considered inoperable. This rendered PAMS Channel A RCS SMM inoperable. With both PAMS RCS SMM channels inoperable at the same time, Calvert Cliffs entered Technical Specification 3.3.10, Condition A for Unit 1. When the Completion Time of Condition A expired, Calvert Cliffs entered Technical Specification 3.3.10, Condition B for Unit 1, which requires submission of this report in accordance with Technical Specification 5.6. 7.
PREPLANNED ALTERNATE METHOD OF MONITORING Subcooled margin indication is designated for post-accident monitoring use . It provides the plant operator with information to determine if inadequate core cooling is occurring. Core Exit
Document Control Desk January 21, 2021 Page 2 Thermocouples, Primary System Resistive Temperature Detectors and Primary System pressure measures are used to calculate the degrees of subcooling or superheating that exist in the Reactor Coolant System.
The removal of Channel A from operable status, combined with the previous inoperability of Channel B eliminates the single required operating subcooling indication: however, alternate methods of monitoring determining subcooled margin, using pressurizer level, Reactor Coolant System pressure, hot and cold leg temperature, and core exit thermocouple instrumentation, were initiated as required by plant procedures.
CAUSES OF INOPERABILITY The cause of inoperability of the Channel A subcooled margin indication is the failure of Channel A RVLMS cabinet cooling fan. The most probable cause of this failure is age-related degradation.
The cause of inoperability of the Channel B subcooled margin indication is the failure of a Reactor Inlet (Tco1d) temperature instrument loop. The repair of the Tcold indication will require an outage to repair.
PLANS AND SCHEDULES FOR RESTORING THE SYSTEM TO OPERABLE STATUS Currently, Maintenance is waiting on the replacement fan assembly to arrive onsite. The expected return to service date for Channel A RVLMS is mid-April 2021.
The expected return to service date of the Channel B RVLMS is following the 2022 Unit 1 Refueling Outage.
There are no regulatory commitments contained in this correspondence.
Should you have questions regarding this matter, please contact me at (410) 495-5219.
Respectfully, Larry D. Smith Regulatory Assurance Manager LDS/KLG/lmd cc: NRC Project Manager, Calvert Cliffs S. Seaman, MD-DNR NRC Regional Administrator, Region I NRC Resident Inspector, Calvert Cliffs