CNL-17-138, Plant'S 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

Plant'S 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

ML17354A250
Person / Time
Site:	Browns Ferry
Issue date:	12/20/2017
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-17-138, EA-13-109
Download: ML17354A250 (21)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-17-138 December 20, 2017 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 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)

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)

U.S. Nuclear Regulatory Commission CNL-17-138 Page 2 December 20, 2017

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)

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)

U.S. Nuclear Regulatory Commission CNL-17-138 Page 3 December 20, 2017.

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 TVA's 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 12.

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 sixth 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.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 20th day of December 2017 .

. VV. s ice President, Nuclear Regulatory Affairs & Support Services Enclosure cc: See Page 4

U.S. Nuclear Regulatory Commission CNL-17-138 Page 4 December 20, 2017

Enclosure:

Tennessee Valley Authority Browns Ferry Nuclear Plants Seventh 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 Seventh 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 Browns Ferry Nuclear Plant (BFN) developed an Overall Integrated Plan (Reference 1 in Section 8) documenting the installation of a Hardened Containment Vent System (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 2. Updates of milestone accomplishments will be based on the combined Phase 1 and 2 Overall Integrated Plan dated December 29, 2015.

BFN developed an updated and combined Phase 1 and 2 Overall Integrated Plan (Reference 7 in Section 8) documenting:

1. The installation of a Hardened Containment Vent System (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 2.

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 2.

This enclosure provides an update of milestone accomplishments since submittal of the combined Phase 1 and 2 Overall Integrated Plan and previous update (Reference 12) 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 12).

The status is current as of December 1, 2017.

Phase 2 Unit 3 Design Engineering On-site/Complete 3 Milestone Schedule Status The following provides an update to Part 5 of the combined Phase 1 and 2 Overall Integrated Plan. 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-17-138 E-1

Comments Target Activity {Include date Milestone Completion Status changes in this Date column}

Phase 1 and 2 HCVS Milestone Table Submit Overall Integrated Plan June 2014 Complete Submit 6 Month Updates:

December Update 1 Complete 2014 Update 2 June 2015 Complete Update 3 [Simultaneous with Phase 2 December Complete OIP] 2015 Update 4 June 2016 Complete December Update 5 Complete 2016 Update 6 June 2017 Complete December Complete Update 7 2017 with this submittal Update 8 June 2018 Not Started December Update 9 Not Started 2018 CNL-17-138 E-2

Phase 1 Specific Milestones Phase 1 Modifications:

Hold preliminary/conceptual design November Complete meeting 2014 November Modifications Evaluation Complete 2015 Unit 1 Design Engineering On-April 2016 Complete June 2016 site/Complete November Unit 1 Implementation Outage Complete 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 Not Started Unit 3 Walk Through April 2018 Not Started Demonstration/Functional Test Phase 1 Procedure Changes Active Operations Procedure Changes July 2016 Complete Developed Site Specific Maintenance Procedure July 2016 Complete Developed November Procedure Changes Active Complete 2016 Phase 1 Training:

September Training Complete Complete 2016 CNL-17-138 E-3

Phase 1 Completion December Unit 1 HCVS Implementation Complete 2016 Unit 2 HCVS Implementation April 2017 Complete Unit 3 HCVS Implementation March 2018 In-Progress Full Site HCVS Implementation March 2018 Not Started 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 Not Started Unit 3 Walk Through March 2018 Not Started Demonstration/Functional Test December Unit 1 Design Engineering On-site/Complete In-Progress May 2018 2017 Unit 1 Implementation Outage October 2018 Not Started Unit 1 Walk Through October 2018 Not Started Demonstration/Functional Test Unit 2 Design Engineering On-site/Complete May 2018 In-Progress 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 Operations Procedure Changes Developed In Progress March 2018 2017 Site Specific Maintenance Procedures December In-Progress March 2018 Developed 2017 Procedure Changes Active March 2018 Not Started CNL-17-138 E-4

Phase 2 Training:

December Training Complete In-Progress March 2018 2017 Phase 2 Completion Unit 3 HCVS Implementation March 2018 Not Started Unit 1 HCVS Implementation October 2018 Not Started 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]

4 Changes to Compliance Method The following is a list of changes made to the information provided in the Combined Phase 1 and 2 Overall Integrated Plan (Reference 7). 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 compliance method.

• Page 52-54 of 86. Updated Part 5 Milestone Schedule.

• Attachment 7. Updated Phase 1 ISE Open Items 8, 9, and 10 to include closure documentation.

• Attachment 7. Updated Phase 2 OIP Open Items 1 and 2 to include closure documentation.

• Attachment 7. Updated Phase 2 ISE Open Items 1 thru 6 to include closure documentation.

There are no changes to the compliance method as documented in the combined Phase 1 and 2 Overall Integrated Plan (Reference 7).

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 Overall Integrated Plan and Interim Staff Evaluations The following tables provide a summary of the open items documented in the combined Phase 1 and 2 Overall Integrated Plan or the Interim Staff Evaluation (ISE) and the status of each item.

CNL-17-138 E-5

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

1. Perform an assessment of Closed - An assessment was completed and temperature and radiological documented in the Design Change Technical conditions to ensure that operating Evaluation of DCN 71389 for Unit 1, DCN 71390 for personnel can safely access and Unit 2, DCN 71391 for Unit 3, calculation operate controls at the Remote MDQ0000642015000351 HCVS Operator (Mission)

Operating Station based on time Dose Calculation, and calculation constraints listed in Attachment 2. MDQ0009992014000291 Temperature Response of the Reactor Building Following an Extended Loss of AC Power. (This calculation also evaluates the temperature response in the Unit 1/2 and Unit 3 Diesel Building during an ELAP event.)

2. Perform an evaluation for HCVS Closed - An evaluation was performed and ability to operate from the MCR documented in calculation MDQ0000322015000347 and has the ability to be supplied R0, HCVS Nitrogen System Sizing Analysis, and adequate amounts of pneumatic DCN 71389.

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

3. Perform an evaluation for FLEX Closed - An evaluation was performed for FLEX portable generators and nitrogen portable generators and documented in a White cylinders use past 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions. Paper reviewed during 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 HCVS Nitrogen System Sizing Analysis. 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 was revised to include venting for loss of DC power.

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

Unit 3 - In Progress

5. Perform an evaluation for FLEX Closed - An evaluation for FLEX portable generator portable generators use for post 24 use for post 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions was performed and hour actions in Severe Accident documented in Engineering Information Record from conditions. AREVA (R06161114360), Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFN).

CNL-17-138 E-6

Combined Phase 1 and 2 OIP Open Status Item

6. Electrical load shedding will be Closed (Reference 6) - Calculation 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. EDQ0009992013000202 R3, 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 (Reference 6) - A conceptual meeting was DCNs will be staged so that there held in November 2014, and a staging plan was used is no effect on the operating units. to separate the existing HWWV from the HCVS.

8. The wetwell vent will be designed Closed (Reference 6) - The existing wetwell vent to remove 1% of rated thermal (CLTP) and the HCVS (EPU) have been designed for power at EPU conditions. 1 percent of rated thermal power at EPU conditions.

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

Phase 2 Open Items

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

for the sustained operating period.

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

• Suppression Pool Level 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

• 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, CNL-17-138 E-7

Combined Phase 1 and 2 OIP Open Status Item AREVA document 51-9262174-003, Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP), 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.

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

Phase 1 Interim Staff Evaluation Status Open Item

1. Make available for NRC staff audit Closed - An assessment was completed and an evaluation of temperature and documented in the Design Change Technical radiological conditions to ensure Evaluation of DCN 71389 for Unit 1, DCN 71390 for that operating personnel can safely Unit 2, and DCN 71391 for Unit 3, calculation access and operate controls and MDQ0000642015000351 HCVS Operator (Mission) support equipment. Dose Calculation , and calculation MDQ0009992014000291 Temperature Response of the Reactor Building Following an Extended Loss of AC Power. (This calculation also evaluates the temperature response in the Unit 1/2 and Unit 3 Diesel Building during an ELAP event.)

Documentation is available for audit.

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

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

of dc power.

Documentation is available for audit.

Unit 3 - In Progress CNL-17-138 E-8

Phase 1 Interim Staff Evaluation Status Open Item

3. Make available for NRC staff audit Closed - Calculation EDQ0009992013000202 R3, documentation demonstrating that 250V DC Unit Batteries, 1, 2, & 3 Evaluation for the all load sheds will be accomplished Beyond Design Basis External Event (BDBEE) within one hour of event initiation Extended Loss of AC Power (ELAP), has been and will occur in an area not issued to determine load shedding impact on the unit impacted by a possible radiological batteries, and is available for audit.

event.

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

implemented the order will be able Documentation is available for audit.

to vent through the existing vent system unaffected by the implementation of HCVS on other units.

5. Make available for NRC staff audit Closed - The existing wetwell vent (CLTP) and the analyses demonstrating that HCVS HCVS (EPU) have been designed for 1 percent of has the capacity to vent the rated thermal power at EPU conditions.

steam/energy equivalent of one Analyses are available for audit.

percent of licensed/rated thermal power (unless a lower 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.

6. Make available for NRC staff audit Closed - A communication system has been documentation that demonstrates implemented that uses hand held radios for adequate communication between communication between the main control room and the remote HCVS operation the remote operating station (DCN 70852).

locations and HCVS decision Documentation is available for audit.

makers during ELAP and severe accident conditions.

CNL-17-138 E-9

Phase 1 Interim Staff Evaluation Status Open Item

7. Make available for NRC staff audit Closed - An evaluation was performed and concluded documentation of an evaluation that the containment isolation valves will open under verifying the existing containment the maximum expected differential pressure and is isolation valves, relied upon for the documented in FLOWSERVE Report RAL-70181, HCVS, will open under the Design Review Report of Size 14 Class 150 Wafer maximum expected differential Butterfly Valve with Pneumatic Actuator R1.

pressure during BDBEE and Documentation is available for audit.

severe accident wetwell venting.

8. Make available for NRC staff audit Closed - All electrical and I&C components were documentation of a seismic procured as seismically qualified or as Seismic Class qualification evaluation of HCVS I to ensure their functionality following a seismic components. event. Seismic qualification reports of HCVS components are available for audit.

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

necessary to implement this order including qualification methods.

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

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

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

CNL-17-138 E-10

Phase 1 Interim Staff Evaluation Status Open Item

11. Make available for NRC staff audit Closed - HCVS batteries/battery charger final sizing the final sizing evaluation for evaluation was performed and documented in the HCVS batteries/battery charger Design Change Technical Evaluation of DCN 71389 including incorporation into FLEX for Unit 1, DCN 71390 for Unit 2 and DCN 71391 for DG loading calculation. Unit 3. There is no incorporation of the 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 R3 Electrical Evaluation for Portable Power Supply for Unit Battery Chargers and calculation EDQ0003602015000325 R1 Electrical Evaluation for 4KV Spare FLEX Turbine Generators.

Documentation is available for audit.

12. Make available for NRC staff audit Closed - Evaluation completed and documented in documentation of the HCVS calculation MDQ0000322015000347 R1, HCVS nitrogen pneumatic system design Nitrogen System Sizing Analysis, DCN 71389 for including sizing and location. Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3. Documentation is available for audit.

13. Make available for NRC staff audit Closed - Tornado and seismic missile criteria are the seismic and tornado missile located in System 64A Design Criteria Document final design criteria for the HCVS (DCD). As part of DCN 71389 for Unit 1, DCN 71390 stack. 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. Documentation is available for audit.

14. Provide a description of the final Closed - The final design of HCVS at BFN to address design of the HCVS to address hydrogen detonation and deflagration is the hydrogen detonation and installation of a check valve near the vent discharge deflagration. release point. 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.

Documentation is available for audit.

CNL-17-138 E-11

Phase 1 Interim Staff Evaluation Status Open Item

15. Provide a description of the Closed -The HCVS provides a direct vent path from strategies for hydrogen control that the wetwell to an exhaust point above the Reactor minimizes the potential for Building Roof in accordance with NEI 13-02 section hydrogen gas migration and 4.1.5. This is a leak tight system with no boundary ingress into the reactor building or valves outside the PCIVs that would allow hydrogen other buildings. gas migration and ingress into the Reactor Building or other buildings. Per NEI 13-02 FAQ-04 an effluent release velocity of 8000 fpm 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. Documentation is available for audit.

16. Provide design details that Closed -The BFN design includes a separate HCVS minimize unintended cross flow of stack for each unit as well as meeting the testing vented fluids within a unit and criteria and valve requirements for PCIVs, control and between units on the site. boundary valves. 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. Documentation is available for audit.

Phase 2 Interim Staff Evaluation Status Open Item

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

CNL-17-138 E-12

Phase 2 Interim Staff Evaluation Status Open Item

2. Licensee to evaluate the SAWA Closed - Equipment and Controls equipment and controls, as well as Plant instrumentation for SAWM that is qualified to the ingress and egress paths for the RG 1.97 or equivalent is considered qualified for the expected severe accident conditions sustained operating period without further evaluation.

(temperature, humidity, radiation) for The following plant instruments are qualified to the sustained operating period. RG 1.97:

• DW Pressure 1,2,3-PI-64-67B

• Suppression Pool Level 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

• 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, Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP), 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-17-138 E-13

Phase 2 Interim Staff Evaluation Status Open Item

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

temperature and radiological The following plant instruments are qualified to conditions. RG 1.97:

• DW Pressure 1,2,3-PI-64-67B

• Suppression Pool Level 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

• 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 A quantitative evaluation of expected dose rates (AREVA document 51-9262174-003 Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP)) 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 are acceptable.

CNL-17-138 E-14

Phase 2 Interim Staff Evaluation Status Open Item

4. Licensee to demonstrate that The wetwell vent has been designed and installed containment failure as a result of (Units 1 and 2 only) to meet NEI 13-02 Rev 1 overpressure can be prevented guidance which will ensure that it is adequately sized without a drywell vent during severe to prevent containment overpressure under severe accident conditions. accident conditions.

The SAWM strategy will ensure that the wetwell vent remains functional for the period of sustained operation. Browns Ferry Nuclear Plant will follow the guidance (flow rate and timing) for SAWA/SAWM described in BWROG-TP-15-008 and BWROG-TP-15-011. 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.

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

strategy is successful in making it unlikely that a drywell vent is Reference Browns Ferry needed. Plant Nuclear Plant Torus freeboard Torus freeboard volume is volume is 525,000 gallons 757,544 gallons SAWA flow is 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 /> 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 followed by 100 GPM 100 GPM from from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 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 hours The above parameters for Browns Ferry Nuclear Plant 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 Browns Ferry Nuclear Plant makes it unlikely that a DW vent is needed to prevent containment overpressure related failure.

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Phase 2 Interim Staff Evaluation Status Open Item

6. Licensee to demonstrate that there Closed - Browns Ferry Nuclear Plant utilizes the is adequate communication Harris Radio System to communicate between the between the MCR and the operator MCR and the operator at the FLEX pump. This at the FLEX pump during severe communication method is the same as described for accident conditions. Order EA-12-049. These items will be powered and remain powered using the same methods as evaluated under EA-12-049 and continued for the period of sustained operation.

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. 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)

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

3. NEI 13-02, Industry Guidance for Compliance with NRC Order EA-13-109, To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 1, dated April 2015 (ML15113B318)

4. 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 2013 (ML13304B836).

5. NRC Endorsement of industry Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109) Rev 0, dated May 14, 2014 (ML14128A219).

6. JLD-ISG-2012-01, Compliance with Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated August 29, 2012 (ML12229A174)

7. 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)

8. 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 2015 (ML15104A118).

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9. 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)

10. 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)

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 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)

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