CNL-19-135, Tennessee Valley Authority Browns Ferry Nuclear Plant - Ninth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe

Tennessee Valley Authority Browns Ferry Nuclear Plant - Ninth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe .

ML18361A801
Person / Time
Site:	Browns Ferry
Issue date:	12/27/2018
From:	Henderson E Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-19-135, EA-13-109
Download: ML18361A801 (22)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-19-135 December 27, 2018 10 CFR 2.202 10 CFR 50.4 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296

Subject:

Tennessee Valley Authority Browns Ferry Nuclear Plants Ninth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)

References:

1. NRC Order Number EA-13-109, Issuance of Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, dated June 6, 2013 (ML13143A321)

2. NRC Interim Staff Guidance JLD-ISG-2013-02, Compliance with Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, Revision 0, dated November 14, 2013 (ML13304B836)

3. NEI 13-02, Industry Guidance for Compliance with Order EA-13-109, BWR Mark I & II Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, Revision 1, dated April 23, 2015 (ML15113B318)

4. Letter from TVA to NRC, Tennessee Valley Authoritys Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident (Order Number EA-13-109), dated June 30, 2014 (ML14181B169)

5. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant First Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 19, 2014 (ML14353A428)

U.S. Nuclear Regulatory Commission CNL-18-135 Page 2 December 27, 2018

6. Letter from NRC to TVA, Browns Ferry Nuclear Plant, Units 1, 2, and 3 -

Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109 (Severe Accident Capable Hardened Vents)

(TAC Nos. MF4540, MF4541 and MF4542), dated February 11, 2015 (ML14356A362)

7. NRC Interim Staff Guidance JLD-ISG-2015-01, Compliance with Phase 2 of Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions, Revision 0, dated April 29, 2015 (ML15104A118)

8. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant Second Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 29, 2015 (ML15181A338)

9. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant Third Six-Month Status Report and Phase 1 and Phase 2 Overall Integrated Plan in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 29, 2015 (ML15365A554)

10. Letter from TVA to NRC, Tennessee Valley Authoritys Browns Ferry Nuclear Plant Fourth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2016 (ML16182A517)

11. Letter from TVA to NRC, Tennessee Valley Authority Browns Ferry Nuclear Plants Fifth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 22, 2016 (ML16357A577)

12. Letter from TVA to NRC, Tennessee Valley Authority Browns Ferry Nuclear Plants Sixth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2017 (ML17181A333)

13. Letter from TVA to NRC, Tennessee Valley Authority Browns Ferry Nuclear Plants Seventh Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 20, 2017 (ML17354A250)

U.S. Nuclear Regulatory Commission CNL-18-135 Page 3 December 27, 2018

14. Letter from TVA to NRC, Tennessee Valley Authority Browns Ferry Nuclear Plants Eighth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 27, 2018 (ML18179A139)

15. Letter from TVA to NRC, Tennessee Valley Authority, Browns Ferry Nuclear Plant, Unit 3, Completion of Required Action for NRC Order EA-13-109, Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (CAC No. MF4542), dated May 31, 2018 (ML18169A178)

On June 6, 2013, the Nuclear Regulatory Commission (NRC) issued an Order (Reference 1) to Tennessee Valley Authority (TVA). Reference 1 was immediately effective and directed TVA to install a reliable hardened venting capability for instances of pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris. Specific requirements are outlined in Attachment 2 of Reference 1.

Reference 1 required submission of a Phase 1 and Phase 2 Overall Integrated Plan (OIP) pursuant to Section IV, Condition D for Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3.

References 2 and 7 endorsed industry guidance document Nuclear Energy Institute (NEI) 13-02, Revision 1 (Reference 3) with clarifications and exceptions identified in References 2 and 7. Reference 3 provides direction regarding the content of the Phase 1 and Phase 2 OIPs and includes guidance for combining the OIPs.

Reference 4 provided TVAs Phase 1 OIP. The NRC issued its Interim Staff Evaluation relating to the BFN Phase 1 OIP on February 11, 2015 (Reference 6).

Reference 1 also requires submission of status reports at six-month intervals following submittal of the OIP. Reference 3 provides direction regarding the content of the status reports. TVA submitted the first six-month status report on December 19, 2014 (Reference 5) and has provided subsequent six-month status reports in References 8 through 14. Reference 15 provided notification of Order EA-13-109 compliance for Unit 3.

The purpose of this letter is to provide the combined Phase 1 and Phase 2 OIP six-month status report pursuant to Section IV, Condition D of Reference 1, which delineates progress made in implementing the requirements of Reference 1. The Enclosure provides an update of milestone accomplishments since submittal of the eighth six-month status report, including any changes to the compliance method or schedule.

There are no new regulatory commitments resulting from this submittal. If you have any question regarding this submittal, please contact Mike Oliver at (256) 729-7874.

U.S. Nuclear Regulatory Commission CNL-18-135 Page 4 December 27, 2018 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 27 day of December 2018.

Respectfully, E. K. Henderson Director, Nuclear Regulatory Affairs

Enclosure:

Tennessee Valley Authority Browns Ferry Nuclear Plants Ninth Six-Month Status Report for the Implementation of Order EA-13-109, Issuance of Order to Modify Licenses With Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions cc (w/Enclosure):

NRR Director - NRC Headquarters NRO Director - NRC Headquarters NRC Regional Administrator - Region II NRR Project Manager - Browns Ferry Nuclear Plant NRC Senior Resident Inspector - Browns Ferry Nuclear Plant

ENCLOSURE Tennessee Valley Authority Browns Ferry Nuclear Plants Ninth Six-Month Status Report for the Implementation of Order EA-13-109, Issuance of Order to Modify Licenses With Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions 1 Introduction On June 6, 2013, the Nuclear Regulatory Commission (NRC) issued Order EA-13-109, Order Modifying Licenses with Regard to Requirements for Reliable Hardened Containment Vents (HCVS) Capable of Operation Under Severe Accident Conditions (Reference 1 in Section 8), to Tennessee Valley Authority (TVA). This Order was immediately effective and directs the Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, to install a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris in response to Order EA-13-109.

BFN developed an Overall Integrated Plan (OIP) to provide HCVS. (Phase 1 was provided in Reference 2.)

BFN developed an updated and combined Phase 1 and 2 OIP (Reference 5) documenting:

1. The installation of a HCVS that provides a reliable hardened venting capability for instances of pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, in response to Reference 1.

2. An alternative venting strategy that makes it unlikely that a drywell vent is needed to protect the containment from overpressure related failure under severe accident conditions, including those that involve a breach of the reactor vessel by molten core debris, in response to Reference 1.

This enclosure provides an update of milestone accomplishments since submittal of the combined Phase 1 and 2 OIP and previous update (Reference 14) including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestone(s) have been completed since the previous update (Reference 14).

The status is current as of December 1, 2018.

Unit 1 Implementation Outage Unit 1 Walk Through Demonstration/Functional Test Unit 1 HCVS Implementation 3 Milestone Schedule Status The following provides an update to Part 5 of the combined Phase 1 and 2 OIP. It provides the activity status of each item and whether the expected completion date has changed.

These dates are planning dates subject to change as design and implementation details are developed.

The revised milestone target completion dates do not impact the order implementation date.

CNL-18-135 E-1 of 18

Target Activity Milestone Completion Comments Status Date Phase 1 and 2 HCVS Milestone Table Submit Overall Integrated Plan June 2014 Complete Submit 6 Month Updates:

December Complete Update 1 2014 Update 2 June 2015 Complete Update 3 [Simultaneous with Phase 2 December Complete OIP] 2015 Update 4 June 2016 Complete December Complete Update 5 2016 Update 6 June 2017 Complete December Complete Update 7 2017 Update 8 June 2018 Complete December Complete Update 9 2018 with this submittal CNL-18-135 E-2 of 18

Phase 1 Specific Milestones Phase 1 Modifications:

Hold preliminary/conceptual design November Complete meeting 2014 November Complete Modifications Evaluation 2015 Unit 1 Design Engineering On- April 2016 Complete June 2016 site/Complete November Complete Unit 1 Implementation Outage 2016 Unit 1 Walk Through November Complete Demonstration/Functional Test 2016 Unit 2 Design Engineering On- June 2016 Complete December 2016 site/Complete Unit 2 Implementation Outage March 2017 Complete Unit 2 Walk Through April 2017 Complete Demonstration/Functional Test Unit 3 Design Engineering On- July 2017 Complete site/Complete Unit 3 Implementation Outage March 2018 Complete Unit 3 Walk Through April 2018 Complete Demonstration/Functional Test Phase 1 Procedure Changes Active Operations Procedure Changes July 2016 Complete Developed Site Specific Maintenance Procedure July 2016 Complete Developed November Complete Procedure Changes Active 2016 Phase 1 Training:

September Complete Training Complete 2016 Phase 1 Completion December Complete Unit 1 HCVS Implementation 2016 Unit 2 HCVS Implementation April 2017 Complete Unit 3 HCVS Implementation March 2018 Complete Full Site HCVS Implementation March 2018 Complete CNL-18-135 E-3 of 18

Phase 2 Specific Milestones Phase 2 Modifications:

Hold preliminary/conceptual design meeting January 2017 Complete Modifications Evaluation April 2017 Complete Unit 3 Design Engineering On-site/Complete May 2017 Complete September 2017 Unit 3 Implementation Outage March 2018 Complete Unit 3 Walk Through March 2018 Complete Demonstration/Functional Test December Complete May 2018 Unit 1 Design Engineering On-site/Complete 2017 Unit 1 Implementation Outage October 2018 Complete Unit 1 Walk Through October 2018 Complete Demonstration/Functional Test Unit 2 Design Engineering On-site/Complete May 2018 Complete Unit 2 Implementation Outage March 2019 Not Started Unit 2 Walk Through March 2019 Not Started Demonstration/Functional Test Phase 2 Procedure Changes Active September Complete March 2018 Operations Procedure Changes Developed 2017 Site Specific Maintenance Procedures December Complete March 2018 Developed 2017 Procedure Changes Active March 2018 Complete Phase 2 Training:

December Complete March 2018 Training Complete 2017 Phase 2 Completion Unit 3 HCVS Implementation March 2018 Complete Unit 1 HCVS Implementation October 2018 Complete Unit 2 HCVS Implementation March 2019 Not Started Full Site HCVS Implementation March 2019 Not Started Submit Completion Report [60 days after full May 2019 Not Started site compliance]

CNL-18-135 E-4 of 18

4 Changes to Compliance Method The following is a list of changes made to the information provided in the Combined Phase 1 and 2 OIP (Reference 5). These changes were made to clarify the OIP and provide more specific information because the design process is further along than previously anticipated.

These changes meet the NEI 13-02, Industry Guidance for Compliance with Order EA 109, BWR Mark I & II Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, Revision 1, compliance method.

• Updated Part 5: Implementation Schedule Milestones, Phase 2 Milestone Schedule.

There are no changes to the compliance method as documented in the combined Phase 1 and 2 OIP (Reference 5).

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation BFN expects to comply with the order implementation date, and no relief/relaxation is required at this time.

6 Open Items from Combined Phase 1 and 2 OIP and ISE The following tables provide a summary of the open items documented in the combined Phase 1 and 2 OIP or the ISE and the status of each item.

Combined Phase 1 and 2 OIP Status Open Item Phase 1 Open Items

1. Perform an assessment of Closed - An assessment was completed and documented in temperature and radiological the Design Change Technical Evaluation of Design Change conditions to ensure that Notice (DCN) 71389 for Unit 1, DCN 71390 for Unit 2, operating personnel can safely DCN 71391 for Unit 3, calculation MDQ0000642015000351, access and operate controls at HCVS Operator (Mission) Dose Calculation, and calculation the Remote Operating Station MDQ0009992014000291, Temperature Response of the based on time constraints listed Reactor Building Following an Extended Loss of AC Power.

in Attachment 2. calculation MDQ0009992014000291 also evaluates the temperature response in the Unit 1/2 and Unit 3 Diesel Building during an Extended Loss of AC Power (ELAP) event.

2. Perform an evaluation for HCVS Closed - An evaluation was performed and documented in ability to operate from the MCR calculation MDQ0000322015000347 Revision 0, HCVS and has the ability to be supplied Nitrogen System Sizing Analysis, and DCN 71389.

adequate amounts of pneumatic pressure for 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions.

CNL-18-135 E-5 of 18

Combined Phase 1 and 2 OIP Status Open Item

3. Perform an evaluation for FLEX Closed - An evaluation was performed for Mitigation portable generators and nitrogen Strategies for Beyond-Design-Basis External Events (FLEX) cylinders use past 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> portable generators and documented in a White Paper actions. reviewed during the FLEX audit and documented in Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Report for the Onsite Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Instrumentation Related to Orders EA-12-049 and EA-12-051 (ML15069A358).

A nitrogen cylinder use evaluation was performed and documented in DCN 71389 for Unit 1, DCN 71390 for Unit 2, DCN 71391 for Unit 3, and calculation MDQ0000322015000347. A combination of installed and dedicated nitrogen cylinder carts will be used to provide a seven-day supply of nitrogen.

4. Revise 1/2/3-EOI Appendix-13 to Closed for Unit 1 EOI Appendix-13 Revision 3, include venting for loss of DC Emergency Venting Primary Containment, was revised to power. include venting for loss of direct current (DC) power.

Closed for Unit 2 EOI Appendix-13 Revision 9 was revised to include venting for loss of DC power.

Closed for Unit 3 EOI Appendix-13 Revision 6 was revised to include venting for loss of DC power.

5. Perform an evaluation for FLEX Closed - An evaluation for FLEX portable generator use for portable generators use for post post 24-hour actions was performed and documented in 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions in Severe Engineering Information Record from AREVA document Accident conditions. 51-9262174-003, Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFN).

6. Electrical load shedding will be Closed - Calculation EDQ0009992013000202 Revision 3, performed in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of the event. 250V DC Unit Batteries, 1, 2, & 3 Evaluation for the Beyond Design Basis External Event (BDBEE) ELAP, has been issued to determine load shedding impact on the unit batteries.

7. The implementation of the HCVS Closed - A conceptual meeting was held in November 2014, DCNs will be staged so that there and a staging plan was used to separate the existing is no effect on the operating Hardened Wet Well Vent (HWWV) from the HCVS.

units.

8. The wetwell vent will be designed Closed - The existing wetwell vent and the HCVS have been to remove 1% of rated thermal designed for 1 percent of rated thermal power at Extended power at EPU conditions. Power Uprate (EPU) conditions.

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Combined Phase 1 and 2 OIP Status Open Item

9. Implement the Harris Radio Closed - A communication system has been implemented System for communication that uses hand held radios for communication between the between the MCR and the ROS. main control room and the ROS (DCN 70852).

Combined Phase 1 and 2 OIP Status Open Item Phase 2 Open Items

1. Perform an evaluation for the Closed - Equipment and Controls locations of the SAWA equipment Plant instrumentation for Severe Accident Water and controls, as well as ingress Management (SAWM) that is qualified to NRC Regulatory and egress paths for the Guide (RG) 1.97 or equivalent is considered qualified for the expected Severe Accident sustained operating period without further evaluation.

conditions (temperature, The following plant instruments are qualified to RG 1.97:

humidity, radiation) for the sustained operating period.

• Drywell (DW) Pressure Indicators, 1,2,3-PI-64-67B

• Suppression Pool Level Indicators, 1,2,3-LI-64-159A.

Passive components that do not need to change state after initially establishing Severe Accident Water Addition (SAWA) flow do not require evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered:

• SAWA/SAWM flow instrument,

• SAWA/SAWM pump,

• FLEX generator, and

• SAWA throttle valve.

These components will be used at a remote location (outside Reactor Building) and have been evaluated for the environmental conditions applicable at those locations.

Ingress and Egress A quantitative evaluation of expected dose rates, AREVA document 51-9262174-003, has been performed per NEI HCVS-WP-02, Sequences for HCVS Design and Method for Determining Radiological Dose from HCVS Piping, and found the dose rates at deployment locations including ingress/egress paths are acceptable.

CNL-18-135 E-7 of 18

Combined Phase 1 and 2 OIP Status Open Item

2. Perform a hydraulic evaluation to Closed - Hydraulic Analysis calculation ensure flow adequacy can be met MDN0003602014000233, Hydraulic Analysis for Fukushima for all 3 units using 1 FLEX pump FLEX Connection Modifications, was revised to include a to support SAWA flow bounding case that concluded that a single FLEX pump (with requirement booster pump) can provide 500 gallons per minute (gpm) to the Unit 1 Reactor Pressure Vessel (RPV), 500 gpm to the Unit 2 RPV, and 500 gpm to Unit 3 RPV at an RPV pressure of 106 pounds per square inch gage (psig) in response to a SAWA event.

Phase 1 Interim Staff Evaluation Status Open Item

1. Make available for NRC staff An evaluation of temperature and radiological conditions was audit an evaluation of performed to ensure that Operating personnel can safely temperature and radiological access and operate controls at the ROS located in the Diesel conditions to ensure that Buildings and in the Reactor Building. This evaluation is operating personnel can safely documented in Unit 1 DCN 71389 Design Change Technical access and operate controls and Evaluation (Pages 70-73 of 81), Unit 2 DCN 71390 Design support equipment. Change Technical Evaluation (Pages 65-68 of 75), and Unit 3 DCN 71391 Design Change Technical Evaluation (Pages 60-63 of 69). Calculations MDQ0000642015000351 and MDQ0009992014000291 were used to validate the evaluation.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

2. Make available for NRC audit 1-EOI Appendix-13 Revision 3 was revised to include venting documentation that procedure for loss of DC power.

1/2/3-EOI Appendix-13 has been 2-EOI Appendix-13 Revision 9 was revised to include venting revised to include venting for loss for loss of DC power.

of dc power.

3-EOI Appendix-13 Revision 6 was revised to include venting for loss of DC power.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 1 Interim Staff Evaluation Status Open Item

3. Make available for NRC staff Calculation EDQ0009992013000202, 250V DC Unit audit documentation Batteries, 1, 2, & 3 Evaluation for the Beyond Design Basis demonstrating that all load sheds External Event (BDBEE) Extended Loss of AC Power will be accomplished within one (ELAP), has been issued to determine load shedding impact hour of event initiation and will on the unit batteries. The performance of the load shed is occur in an area not impacted by directed by 0-FSI-1, FLEX Support Instruction, and a possible radiological event. performed in accordance with 0-FSI-3F, Load Shed of 250V Main Bank Battery 1, 2, 3. The load shed is performed in the Control Bay and Electrical Board rooms only and will not require entry into areas that are impacted by a possible radiological event.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

4. Make available for NRC staff A conceptual meeting was held in November 2014, and a audit documentation that staging plan was used to separate the existing HWWV from demonstrates that operating units the HCVS. The HCVS has been implemented on all three that have not implemented the units.

order will be able to vent through This ISE Open Item was closed during NRC audit and the existing vent system documented in ML18038B606 (Reference 12).

unaffected by the implementation of HCVS on other units.

5. Make available for NRC staff The existing wetwell vent and the HCVS have been designed audit analyses demonstrating that for 1 percent of rated thermal power at EPU (3952 MWt)

HCVS has the capacity to vent conditions. This analysis is available and documented in the steam/energy equivalent of Calculation NDQ0000642015000341, HCVS MAAP Analysis.

one percent of licensed/rated This ISE Open Item was closed during NRC audit and thermal power (unless a lower documented in ML18038B606 (Reference 12).

value is justified), and that the suppression pool and the HCVS together are able to absorb and reject decay heat, such that following a reactor shutdown from full power containment pressure is restored and then maintained below the primary containment design pressure and the primary containment pressure limit.

CNL-18-135 E-9 of 18

Phase 1 Interim Staff Evaluation Status Open Item

6. Make available for NRC staff A communication system has been implemented audit documentation that (DCN 70852) that uses hand held radios for communication demonstrates adequate between the main control room (MCR) and the remote communication between the operating station. This Radio System consists of a Ultra High remote HCVS operation locations Frequency (UHF)/Very High Frequency (VHF) trunked and HCVS decision makers system and an independent VHF channel (F4). The In-plant during ELAP and severe accident Radio System is accessed by handheld radios and has conditions. normal and emergency diesel generator-backed power supply. The radio system is powered from two Class 1E redundant power sources, the 480V DG Auxiliary Boards A and B. Primary power source will be from the 480V DG Auxiliary Board A via a second 480-208V/120V transformer/distribution center. In the event of loss of primary power source, power to radio equipment will be automatically transferred to backup source via transfer switches located in each cabinet, with exception of cabinet 4, which receives power via cabinet 1 transfer switch.

Backup power source includes Uninterrupted Power Supply (UPS) with battery capacity to supply four UHF channels for three hours. Therefore, in this configuration, capacity is reduced from five simultaneous conversations to three.

The loads supplied via UPS can be alternatively supplied from a portable generator via a transfer switch (0-FSI-4B).

UPS conservation can be accomplished by switching off one of the two UPSs until such time the active UPS reaches low level. Then, the UPS previously switched off can be returned to service extending the overall time the radio system can remain operable without portable generator power to approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

BFN maintains a large number of handheld radios, batteries, and charging units. The FLEX program does not maintain dedicated handheld radios. These units, spare batteries, and chargers will be gathered if not readily available in the control rooms.

Handheld Radios can additionally be operated in Radio-to-Radio mode enabling communications not affected by shielding or distance.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 1 Interim Staff Evaluation Status Open Item

7. Make available for NRC staff An evaluation was performed and concluded that the audit documentation of an containment isolation valves will open under the maximum evaluation verifying the existing expected differential pressure and is documented in containment isolation valves, Flowserve Report RAL-70181, Design Review Report of relied upon for the HCVS, will Size 14 Class 150 Wafer Butterfly Valve with Pneumatic open under the maximum Actuator, Revision 1.

expected differential pressure This ISE Open Item was closed as documented in during BDBEE and severe ML18038B606 (Reference 12).

accident wetwell venting.

8. Make available for NRC staff Electrical and instrument and control components were audit documentation of a seismic procured as seismically qualified or as Seismic Class I to qualification evaluation of HCVS ensure their functionality following a seismic event. Seismic components. qualification reports of HCVS components are available for audit.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

9. Make available for NRC staff Instrumentation and controls necessary to implement this audit descriptions of all order including equipment description, location, and instrumentation and controls qualifications are available for audit.

(existing and planned) necessary This ISE Open Item was closed during NRC audit and to implement this order including documented in ML18038B606 (Reference 12).

qualification methods.

10. Make available for NRC staff Descriptions of local conditions (temperature, radiation audit the descriptions of local and humidity) anticipated during ELAP and severe accident conditions (temperature, radiation for the components (valves, instrumentation, sensors, and humidity) anticipated during transmitters, indicators, electronics, control devices, and etc.)

ELAP and severe accident for the required for HCVS venting including confirmation that the components (valves, components are capable of performing their functions during instrumentation, sensors, ELAP and severe accident conditions are available for audit.

transmitters, indicators, This ISE Open Item was closed during NRC audit and electronics, control devices, and documented in ML18038B606 (Reference 12).

etc.) required for HCVS venting including confirmation that the components are capable of performing their functions during ELAP and severe accident conditions.

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Phase 1 Interim Staff Evaluation Status Open Item

11. Make available for NRC staff HCVS batteries/battery charger final sizing evaluation was audit the final sizing evaluation performed and documented in the Design Change Technical for HCVS batteries/battery Evaluation of DCN 71389 for Unit 1, DCN 71390 for Unit 2, charger including incorporation and DCN 71391 for Unit 3. There is no incorporation of the into FLEX DG loading calculation. HCVS battery/battery charger required into the FLEX DG loading calculation due to no plans or requirements to recharge the HCVS battery after depletion. The HCVS electrical loads will be aligned back to their normal power supply which is the Unit Battery. The recharging of the Unit Battery is incorporated into the FLEX DG loading calculations. Calculation EDQ0003602014000281 Revision 3, Electrical Evaluation for Portable Power Supply for Unit Battery Chargers, and calculation EDQ0003602015000325 Revision 1, Electrical Evaluation for 4KV Spare FLEX Turbine Generators, were used to validate the evaluation.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

12. Make available for NRC staff The HCVS evaluation has been completed and documented audit documentation of the HCVS in DCN 71389 for Unit 1, DCN 71390 for Unit 2, DCN 71391 nitrogen pneumatic system for Unit 3, and calculation MDQ0000322015000347, HCVS design including sizing and Nitrogen System Sizing Analysis. As documented in location. DCN 71389 Design Change Technical Evaluation (Page 29 of 81), there are 9 Nitrogen Cylinders required for Unit 1 for 7 days of Hardened Vent operation. There are 5 Nitrogen Cylinders installed to support Hardened Vent operation for Unit 1. As documented in DCN 71390 Design Change Technical Evaluation (Page 28 of 75), there are 10 Nitrogen Cylinders required for Unit 2 for 7 days of Hardened Vent operation. As documented in DCN 71391 Design Change Technical Evaluation (Page 26 of 69), there are 9 Nitrogen Cylinders required for Unit 3 for 7 days of Hardened Vent operation. 24 Nitrogen Cylinders are required for Units 2 and 3 for 7 days simultaneous operation. There are 5 Nitrogen Cylinders installed to support Hardened Vent operation for Units 2 and 3. There are 6 Nitrogen Cylinder carts with 6 Nitrogen Cylinders on each cart available in the FLEX Storage building with no other committed use of them.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 1 Interim Staff Evaluation Status Open Item

13. Make available for NRC staff Tornado and seismic missile criteria are located in the audit the seismic and tornado Primary Containment System (64A) Design Criteria missile final design criteria for the Document (DCD). As part of DCN 71389 for Unit 1, HCVS stack. DCN 71390 for Unit 2, and DCN 71391 for Unit 3, a markup reflecting these changes has been generated and will be incorporated in the next revision of the DCD per TVA process.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

14. Provide a description of the final The final design of HCVS at BFN to address hydrogen design of the HCVS to address detonation and deflagration is the installation of a check hydrogen detonation and valve near the vent discharge release point. A description of deflagration. this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

15. Provide a description of the The HCVS provides a direct vent path from the wetwell to an strategies for hydrogen control exhaust point above the Reactor Building roof in accordance that minimizes the potential for with NEI 13-02, Section 4.1.5. This is a leak tight system hydrogen gas migration and with no boundary valves outside the primary containment ingress into the reactor building isolation valves (PCIVs) that would allow hydrogen gas or other buildings. migration and ingress into the Reactor Building or other buildings. Per NEI 13-02 Frequently Asked Question FAQ-04, an effluent release velocity of 8000 feet per minute will assure that the effluent plume will not be entrained into the roof recirculation zone of a given building. A description of this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

16. Provide design details that The BFN design includes a separate HCVS stack for each minimize unintended cross flow unit as well as meeting the testing criteria and valve of vented fluids within a unit and requirements for PCIVs and control and boundary valves.

between units on the site. A description of this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 2 Interim Staff Evaluation Status Open Item

1. Licensee to perform a hydraulic Calculation MDN0003602014000233 was revised to include evaluation to ensure flow a bounding case that concluded that a single FLEX pump adequacy can be met for all 3 (with booster pump) can provide 500 gpm) to the Unit 1 RPV, units using 1 FLEX pump to 500 gpm to the Unit 2 RPV, and 500 gpm to the Unit 3 RPV, support SAWA flow requirement. each at RPV pressure of 106 psig in response to a SAWA event.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

2. Licensee to evaluate the SAWA Equipment and Controls equipment and controls, as well Plant instrumentation for SAWM is qualified to NRC as the ingress and egress paths Regulatory Guide (RG) 1.97 or equivalent and is considered for the expected severe accident qualified for the sustained operating period without further conditions (temperature, evaluation. The following plant instruments are qualified to humidity, radiation) for the RG 1.97:

sustained operating period.

• DW Pressure Indicators, 1,2,3-PI-64-67B, and

• Suppression Pool Level Indicators, 1,2,3-LI-64-159A.

Passive components that do not need to change state after initially establishing SAWA flow do not require evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered:

• SAWA/SAWM flow instrument,

• SAWA/SAWM pump,

• FLEX generator, and

• SAWA throttle valve.

These components will be used at a remote location (outside Reactor Building) and have been evaluated for the environmental conditions applicable at those locations.

Ingress and Egress For locations outside the Reactor Building between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 days when SAWA is being utilized, BFN performed a qualitative evaluation of equipment and deployment locations and confirmed they are protected by distance and/or buildings with substantial shielding to minimize dose rates. A quantitative evaluation of expected dose rates, AREVA document 51-9262174-003, has been performed per NEI HCVS-WP-02 and found the dose rates at deployment locations including ingress/egress paths are acceptable.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 2 Interim Staff Evaluation Status Open Item

3. Licensee to demonstrate how Equipment and Controls SAWA flow is capable to perform Plant instrumentation for SAWA that is qualified to RG 1.97 its intended function for the or equivalent is considered qualified for the sustained sustained operating period under operating period without further evaluation. The following the expected temperature and plant instruments are qualified to RG 1.97:

radiological conditions.

• DW Pressure Indicators, 1,2,3-PI-64-67B, and

• Suppression Pool Level Indicators, 1,2,3-LI-64-159A.

Passive components that do not need to change state after initially establishing SAWA flow do not require evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered for temperature and radiation effects:

• SAWA/SAWM flow instrument,

• FLEX/SAWA pump,

• FLEX generator, and

• SAWA throttle valve.

Temperature The location of SAWA equipment and controls that are the same or similar as FLEX will be bounded by the FLEX evaluations for temperature.

Radiation For equipment locations outside the Reactor Building between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 days when SAWA is being utilized, BFN performed a qualitative evaluation of equipment and deployment locations and confirmed they are protected by distance and/or buildings with substantial shielding to minimize dose rates. A quantitative evaluation of expected dose rates, AREVA document 51-9262174-003, has been performed per NEI HCVS-WP-02 and found the dose rates at deployment locations including ingress/egress paths are acceptable.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 2 Interim Staff Evaluation Status Open Item

4. Licensee to demonstrate that The wetwell vent has been designed and installed to meet containment failure as a result of NEI 13-02 Revision 1 guidance which will ensure that it is overpressure can be prevented adequately sized to prevent containment overpressure under without a drywell vent during severe accident conditions.

severe accident conditions. The SAWM strategy will ensure that the wetwell vent remains functional for the period of sustained operation. BFN will follow the guidance (flow rate and timing) for SAWA/SAWM described in BWROG-TP-15-008, SAWA Timing, and BWROG-TP-15-011, SAWM Supporting Evaluations. The wetwell vent will be opened prior to exceeding the Primary Containment Pressure Limit value of 62 psig. Therefore, containment over pressurization is prevented without the need for a drywell vent.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

5. Licensee to demonstrate how the Using Figure 2.1.C from the combined Phase 1 and 2 OIP, plant is bounded by the reference compare the reference plant parameters to the plant specific plant analysis that shows the parameters.

SAWM strategy is successful in Reference Plant Browns Ferry making it unlikely that a drywell Nuclear Plant vent is needed.

Torus freeboard volume is Torus freeboard volume is 525,000 gallons 757,544 gallons SAWA flow is 500 gpm at SAWA flow is 500 gpm at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by 100 gpm from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 100 gpm from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> The above parameters for BFN compared to the reference plant that determine success of the SAWM strategy demonstrate that the reference plant values are bounding. Therefore, the SAWM strategy implemented at BFN makes it unlikely that a DW vent is needed to prevent containment overpressure related failure.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

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Phase 2 Interim Staff Evaluation Status Open Item

6. Licensee to demonstrate that BFN utilizes the Harris Radio System to communicate there is adequate communication between the MCR and the operator at the FLEX pump.

between the MCR and the This communication method is the same as accepted in operator at the FLEX pump Order EA-12-049. These items will be powered and during severe accident remained powered using the same methods as evaluated conditions. under EA-12-049 and continued for the period of sustained operation.

This ISE Open Item was closed during NRC audit and documented in ML18038B606 (Reference 12).

7 Interim Staff Evaluation Impacts There are no potential impacts to the Interim Staff Evaluation(s) identified at this time.

8 References The following references support the updates to the combined Phase 1 and 2 Overall Integrated Plan described in this enclosure.

1. NRC Order Number EA-13-109, Issuance of Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, dated June 6, 2013 (ML13143A321)

2. Letter from TVA to NRC, Tennessee Valley Authoritys Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident (Order Number EA-13-109), dated June 30, 2014 (ML14181B169)

3. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant First Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 19, 2014 (ML14353A428)

4. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant Second Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 29, 2015 (ML15181A338)

5. Letter from TVA to NRC, Tennessee Valley Authority's Browns Ferry Nuclear Plant Third Six-Month Status Report and Phase 1 and Phase 2 Overall Integrated Plan in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 29, 2015 (ML15365A554)

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6. Letter from TVA to NRC Tennessee Valley Authoritys Browns Ferry Nuclear Plant Fourth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2016 (ML16182A517)

7. Letter from TVA to NRC Tennessee Valley Authority Browns Ferry Nuclear Plants Fifth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109),dated December 22, 2016 (ML16357A577)

8. Letter from TVA to NRC Tennessee Valley Authority Browns Ferry Nuclear Plants Sixth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2017 (ML17181A333).

9. Letter from TVA to NRC Tennessee Valley Authority Browns Ferry Nuclear Plants Seventh Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 20, 2017 (ML17354A250)

10. Letter from NRC to TVA, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4540, MF4541, and MF4542), dated February 11, 2015 (ML14356A362)

11. Letter from NRC to TVA, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 2 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (CAC Nos. MF4540, MF4541, and MF4542), dated September 6, 2016 (ML16244A762)

12. Letter from NRC to TVA, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Report for the Audit of Licensee Responses to Interim Staff Evaluations Open Items Related to NRC Order EA-13-109 To Modify Licenses With Regard To Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (CAC Nos. MF4540, MF4541, and MF4542; EPID L-2014-JLD-0044), dated February 21, 2018 (ML18038B606)

13. Letter from TVA to NRC, Tennessee Valley Authority, Browns Ferry Nuclear Plant, Unit 3, Completion of Required Action for NRC Order EA-13-109, Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (CAC No. MF4542), dated May 31, 2018 (ML18169A178)

14. Letter from TVA to NRC, Tennessee Valley Authority Browns Ferry Nuclear Plants Eighth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 27, 2018 (ML18179A139)

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