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MONTHYEARML16266A0862016-09-22022 September 2016 License Amendment Request - Control Room Emergency Ventilation System Project stage: Request ML16306A4712016-11-0202 November 2016 Acceptance Review License Amendment Request - Control Room Emergency Ventilation System Project stage: Acceptance Review ML16315A1122016-11-10010 November 2016 Supplement to License Amendment Request - Control Room Emergency Ventilation System Project stage: Supplement ML17075A0152017-03-16016 March 2017 E-mail from R. Guzman to E. Villar - Calvert Cliffs Unit Nos. 1 and 2 - Request for Additional Information License Amendment Request - Control Room Emergency Ventilation System Project stage: RAI ML17081A3032017-03-22022 March 2017 Response to Request for Additional Information to License Amendment Request - Control Room Emergency Ventilation System Project stage: Response to RAI ML17209A6202017-08-30030 August 2017 Issuance of Amendments Control Room Recirculation Signal and Control Room Emergency Ventilation System Technical Specifications Project stage: Approval 2016-09-22
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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
[Table view] Category:Response to Request for Additional Information (RAI)
MONTHYEARML23317A1032023-11-10010 November 2023 Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information ML23241A8432023-08-29029 August 2023 Enclosure 3 - Response to Request for Additional Information - Non-Proprietary Version 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 ML23166A1052023-06-15015 June 2023 Response to Request for Additional Information Related to the License Amendment Request to Modify the Long-Term Coupon Surveillance Program ML23155A0012023-06-0404 June 2023 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of an Emergency License Amendment Request - One-Time Extension of the Control Room Emergency Ventilation System (C RS-22-123, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator2022-12-0707 December 2022 Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator RS-22-084, Response to Request for Additional Information Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator .2022-06-17017 June 2022 Response to Request for Additional Information Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator . RS-22-074, Response to Request for Additional Information - Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds .2022-05-20020 May 2022 Response to Request for Additional Information - Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds . 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 ML21334A3422021-11-30030 November 2021 Supplement to Response to Request for Additional Information Regarding the Spent Fuel Pool Cooling - Shutdown Cooling Systems Licensing Design Basis License Amendment Request ML21320A2422021-11-16016 November 2021 Stations - Response to Request for Additional Information - Proposed Alternative for Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds ML21308A5072021-11-0404 November 2021 Supplement to Response to Request for Additional Information Regarding the Spent Fuel Pool Cooling - Shutdown Cooling Systems Licensing Design Basis License Amendment Request ML21298A0432021-10-25025 October 2021 Response to Request for Additional Information Regarding the Spent Fuel Pool Cooling - Shutdown Cooling Systems Licensing Design Basis License Amendment Request JAFP-21-0087, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-09-16016 September 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments ML21208A0072021-07-26026 July 2021 Response to Request for Additional Information for Application to Revise Technical Specifications to Adopt TSTF-567 Rev 1, Add Containment Sump TS to Address GSI-191 Issues NMP2L2773, Company - Response to Request for Additional Information2021-06-30030 June 2021 Company - Response to Request for Additional Information JAFP-21-0044, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-06-11011 June 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments JAFP-21-0032, Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting2021-04-20020 April 2021 Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting RS-20-017, Response to Request for Additional Information - Proposed Alternative to Utilize Code Case N-8852021-02-0101 February 2021 Response to Request for Additional Information - Proposed Alternative to Utilize Code Case N-885 ML20317A1122020-11-12012 November 2020 Final Response and Close-out to Generic Letter 2004-02 ML20280A5132020-10-0606 October 2020 Response to Request for Additional Information - End of Interval Relief Request Associated with the Fourth Ten-Year Inservice Inspection (ISI) Interval ML20188A2642020-07-0606 July 2020 Clinton Power Station, R.E. Ginna Station, Limerick Station, Nine Mile Point Station & Peach Bottom Station - Proposed Alternative to Utilize Code Case OMN-26 - Response to Request for Additional Information ML20182A1102020-06-30030 June 2020 Response to Request for Additional Information to License Amendment Request - Proposed Changes to Technical Specification (TS) 3.8.1 Emergency Diesel Generator Surveillance Requirements Voltage ML20107F7652020-04-16016 April 2020 Response to Request for Additional Information to License Amendment Request - Revision to Technical Specification 5.5.7, Reactor Coolant Pump Flywheel Inspection Program NMP2L2711, Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-8792019-10-16016 October 2019 Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-879 ML19282B7182019-10-0909 October 2019 Revised Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors ML19277D1032019-10-0303 October 2019 Response to Request for Additional Information Revised - Final Response to Generic Letter 2004-02 ML19217A3372019-08-0606 August 2019 Response to RAI #6 Regarding the Application to Adopt 10 CFR 50.69 ML19217A1432019-08-0505 August 2019 Revised Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors ML19200A2162019-07-19019 July 2019 Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors ML19183A0122019-07-0101 July 2019 Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power ... JAFP-19-0057, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-06-0404 June 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 NMP1L3279, Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants2019-05-0101 May 2019 Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants JAFP-19-0006, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-01-0808 January 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 ML18316A0342018-11-12012 November 2018 Response to Request for Additional Information: Proposed Changes to Technical Specification 3.8.1 Actions A.3 and D.3 to Extend the Offsite Circuit Inoperable Completion Times from 72 Hours to 14 ... ML18283A0342018-10-10010 October 2018 Supplement to Final Response to Generic Letter 2004-02, Dated August 13, 2018 ML18239A2602018-08-27027 August 2018 Supplement to Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 1, Provide Risk .. ML18201A4062018-06-21021 June 2018 Plants, Units 1 and 2 - Exelon'S Response to NRC Questions ML18172A1452018-06-21021 June 2018 Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 1, Provide Risk-Informed ... NMP1L3221, Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 & 2, R. E. Ginna - Response to Request for Additional Information License Amendment Request to Adopt Emergency Action Level Schemes.2018-05-10010 May 2018 Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 & 2, R. E. Ginna - Response to Request for Additional Information License Amendment Request to Adopt Emergency Action Level Schemes. RS-18-061, Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis)2018-05-0202 May 2018 Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis) ML18047A1242018-02-16016 February 2018 Relief Requests Associated with Fifth Ten-Year Lnservice Testing Interval: Supplement 1 - Response to Request for Additional Information ML18025A7992018-01-25025 January 2018 Response to Request for Additional Information Regarding Generic Letter 2016-01 ML18018B3402018-01-18018 January 2018 Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 1, Provide Risk-Informed Extended Completion Times. ML18011A6652018-01-11011 January 2018 Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 1, Provide Risk-Informed Extended Completion Times. RS-17-053, Response to Request for Additional Information Regarding Generic Letter 2016-012017-04-27027 April 2017 Response to Request for Additional Information Regarding Generic Letter 2016-01 ML17081A3032017-03-22022 March 2017 Response to Request for Additional Information to License Amendment Request - Control Room Emergency Ventilation System RS-17-044, Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography2017-03-13013 March 2017 Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography RS-17-003, Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal2017-01-0505 January 2017 Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal ML16246A2022016-09-0101 September 2016 Response to Request for Additional Information Regarding Relief Request for Dissimilar Metal Butt Weld Examinations 2023-08-29
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200 Exelon Way Exelon Generation Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.90 March 22, 2017 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-53 and DPR-69 Docket Nos. 50-317 and 50-318
Subject:
Response to Request for Additional Information to License Amendment Reque~t - Control Room Emergency Ventilation System.
References:
- 1. License Amendment Request - Control Room Emergency Ventilation System, dated September 22, 2016.
- 2. Supplement to License Amendment Request - Control Room Emergency Ventilation System, dated November 10, 2016.
By letter dated September 22, 2016 (Reference 1) (ADAMS Accession No. ML16266A086),
and supplemented by letter dated November 10, 2016 (Reference 2) (ADAMS Accession No. ML 1631SA112), Exelon Generation Company, LLC (Exelon) requested an amendment to the Calvert Cliffs Nuclear Power Plant (CCNPP), Units 1 and 2, Technical Specifications (TSs) 3.3.8 "Control Room Recirculation Signal (CARS)" and TS 3.7.8 "Control Room Emergency Ventilation System (CREVS)."
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and determined that additional information was needed in order to complete this review. A formal request for additional information (RAI) was transmitted to Mr. Enrique Villar (Exelon) was by Mr. Richard Guzman (NRG) on March 16, 2017, following a clarification call held on March 15, 2017.
Attachment 1 to this letter contains the requested information followed by Exelon's response.
There are no regulatory commitments contained in this letter.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 22nd day of March 2017.
U.S. Nuclear Regulatory Commission LAR - Control Room Emergency Ventilation System March 22, 2017 Page2 If you should have any questions regarding this submittal, please contact Enrique Villar at 610-765-5736.
Respectfully, David T. Gudger Manager
- Licensing & Regulatory Affairs Exelon Generation Company, LLC
Attachment:
- 1. Request for Supplemental Information cc: NRC Regional Administrator, Region I w/attachments NRC Senior Resident Inspector, CCNPP "
NRC Project Manager, NRR, CCNPP "
S. T. Gray, State of Maryland "
ATTACHMENT 1 Request for Additional Information License Amendment Request Control Room Emergency Ventilation System Calvert Cliffs Nuclear Power Plant, Units 1 and 2 CAC NOS. MF8406 and MF8407 DOCKET Nos. 50-317 and 50-318
Request for Additional Information License Amendment Request Control Room Emergency Ventilation System Attachment 1 Docket Nos. 50-317 and 50-318 Page 1of2 In a license amendment request (LAA) dated September 22, 2016 (ADAMS Accession No.
ML16266A086), as supplemented by letter dated November 10, 2016 (ADAMS Accession No.
ML16315A112), Exelon Generation Company, LLC (Exelon or the licensee) requested an amendment to the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Technical Specifications (TSs) 3.3.8 "Control Room Recirculation Signal (CARS)" and TS 3.7.8 "Control Room Emergency Ventilation System (CREVS)." In order to complete its review, the NRC staff requests the following additional information:
The LAR stated that the CREV system was modified by adding leak tight hatches that cover the outside intake and exhaust openings and that the installation of the hatches altered the Control Room envelope (CRE) which resulted in the CREV system operating in full recirculation mode during normal and accident conditions. The licensee is proposing to remove TS 3.7.8 Conditions "A" and "C" in its entirety and to retain TS 3.7.8 Condition "B" and renumber it as Condition "A". Current TS Conditions A and C address the inoperability of the outside air intake and exhaust dampers of the CREV. Current TS Action "B" relates to the inoperability of the Toilet area exhaust isolation valve. The retention of Condition "B" indicates that the operating toilet exhaust fan will result in a continuous drawn-in leakage into the CRE during normal conditions. Please explain this apparent inconsistency between the statements in the LAR and the TSs.
Exelon Response The statement of the CREV system operating in full recirculation mode did not include the toilet exhaust isolation valve.
In the current mode of CREV system operation, the toilet exhaust isolation valve is normally open with the toilet exhaust fan running to remove stale air from the toilet area. The toilet exhaust isolation valve is a gravity damper and closes on loss of the exhaust fan flow. The toilet exhaust fan is tripped as a result of a Safety Injection Actuation Signal and/or a Control Room Recirculation Signal actuation. This isolation valve (i.e., damper) is in a separate duct routed in a different area from the dampers in the existing TS 3. 7 .8 Conditions "A" and "C". The toilet exhaust fan and isolation valve (damper) is not associated with the dampers in the existing TS 3.7.8 Conditions "A" and "C".
The supplemental letter dated November 10, 2016, states that with the hatches installed and the system in permanent recirculation mode, the outside air intake and exhaust dampers no longer perform a safety function. Calvert Cliffs Updated Final Safety Analysis Report (UFSAR) Section 9.8.2.3, "Auxiliary Building Ventilating Systems," subsection "Control Room," contains the following statements:
In the event that both the non-safety related chiller and the safety-related condensers are rendered inoperable by a tornado, a post-tornado mode of cooling the Control Room and cable spreading rooms is available. In this mode
Request for Additional Information License Amendment Request Control Room Emergency Ventilation System Attachment 1 Docket Nos. 50-317 and 50-318 Page 2 of 2 of cooling, the fresh air dampers are fully opened, the recirculation dampers are fully closed, and the exhaust damper is fully opened to allow Control Room and cable spreading room cooling using outside air only.
[... ]
With the isolation dampers closed, smoke can be evacuated from the isolated zone by means of an auxiliary fan. This fan is selectively connected to the return duct of any zone by operating motorized dampers in the auxiliary duct system. Air from the outside is allowed to enter the supply duct of the isolated zone by operating motorized dampers and manually opening the roof mounted hatch and damper. The operating panel for the motorized dampers and smoke removal fan is located just outside the Control Room entrance in the heater bay area.
Are any of the dampers and hatches discussed in the UFSAR the same dampers and the associated hatches discussed in the LAA? If they are, please explain how the removal of the dampers from the TSs will impact the functional capability of the dampers as described in the UFSAR.
Exelon Response Calvert Cliffs licensing basis does not postulate the occurrence of a tornado concurrent with a design basis accident or event in order to achieve safe shutdown. Therefore, design basis radioactive releases requiring CREV system operation in the full recirculation mode are not necessary to be considered. This allows for a post-tornado mode of cooling the Control Room to involve use of fresh air from outside the Control Room ventilation boundary.
The post-tornado mode of cooling is established using the dampers described in the LAA. They are addressed in the UFSAR as the fresh air dampers. In the event of a tornado that renders the cooling components of the CREV system inoperable, the hatches covering the roof openings over the fresh air dampers that are locked close can be opened. Operation of these hatches (unlocking and opening them) is a simple operation that requires no special tools and is controlled by procedure. Once the hatches are open, the operations staff would then use a keyswitch to operate the fresh air dampers and place them in the fresh air mode. The opening of these hatches can be completed prior to a heatup of the Control Room that would impact the ability of the plant to safely shutdown. Post tornado system operation would not change based on the removal of the dampers from the TS.
The dampers described in the LAA are not associated with the smoke removal function described in the UFSAR. The smoke removal system has separate ductwork, dampers and fans. Therefore, the smoke removal function will not be affected by the changes requested in the LAA.